毕业设计智能电网相关文献翻译中文英文
智能电网构架毕业论文中英文翻译文献
中英文资料外文翻译文献场域网络的标准化和灵活的IPv6架构最后一英里的智能电网构架本文旨在为智能电网的最后一英里的基于开放标准IPv6的基础设施提供一个综合和全面的视角，用于支持一系列先进的应用程序（如读表，需求响应，遥测，遥信和电网监控和自动化），同时作为多服务平台也从中受益。
在本文中，我们将展示IPv6网络基础设施的各种模块如何提供一个高效，灵活，安全和多业务的基于开放标准的网络。
为了讨论电业在转型过程中需要处理的一些问题例如遗留的老设备，网络和应用程序集成，在过渡期推出的混合网络结构的操作，随后的文件会有更进一步的阐述。
1.介绍在过去几年，由于在智能电网基础设施的突出作用，最后一英里网络已经获得了相当大的发展势头。
这些网络在本文件称为邻区网络（NAN），他们支持一系列应用不仅包括用电计量和管理，而且包括需求响应（DR）和配电自动化（DA）应用高级应用；需求响应应用为用户提供机会可以基于实时电价信息而优化其能源使用；配电自动化（DA）应用它允许分布的监测和控制，自动故障检测，1隔离和管理，并作为未来的虚拟电厂，其中包括分布式发电，住宅能源存储（例如，电动汽车（EV）充电），以及小规模的社区电力交易。
场区网络（FAN）（(NAN和具有回程广域网接口的通讯设备的组合)已经成为一个智能电网的网络基础设施的核心组成部分。
事实上，他们作为回程网络可以为各种其他电网控制设备提供服务;例如多租户服务（煤气表和水表），家庭局域网（HAN）设备的数据交换服务，这些都通过各种无线连接或有线线路连接的技术。
这就形成了对部署的IP协议套件的需求，并使的公开标准的使用提供了可靠性，可扩展性，安全性，跨网络和灵活性，从而能为应付数量快速增长的电网配电网络的关键应用提供支持。
IP也使得领区网络（NAN）容易整合到到端到端的网络架构。
通过场区网络正在运行的应用程序之一是抄表，每个电表定期把使用数据发向一个事业单位端点的应用服务器。
电气供配电系统大学毕业论文英文文献翻译及原文
毕业设计（论文）外文文献翻译文献、资料中文题目：供配电系统文献、资料英文题目：POWER SUPPLY AND DISTRIBUTIONSYSTEM文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：班级：姓名：学号：指导教师：翻译日期： 2017.02.14POWER SUPPLY AND DISTRIBUTION SYSTEMABSTRACTThe basic function of the electric power system is to transport the electric power towards customers. The l0kV electric distribution net is a key point that connects the power supply with the electricity using on the industry, business and daily-life. For the electric power, allcostumers expect to pay the lowest price for the highest reliability, but don't consider that it's self-contradictory in the co-existence of economy and reliable.To improve the reliability of the power supply network, we must increase the investment cost of the network construction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic,between the investment and the loss by calculating the investment on power net and the loss brought from power-off.KEYWARDS：power supply and distribution,power distribution reliability，reactive compensation,load distributionTEXTThe revolution of electric power system has brought a new big round construction,which is pushing the greater revolution of electric power technique along with the application of new technique and advanced equipment. Especially, the combination of the information technique and electric power technique, to great ex- tent, has improved reliability on electric quality and electric supply. The technical development decreases the cost on electric construction and drives innovation of electric network. On the basis of national and internatio- nal advanced electric knowledge, the dissertation introduces the research hotspot for present electric power sy- etem as following.Firstly, This dissertation introduces the building condition of distribution automation(DA), and brings forward two typical construction modes on DA construction, integrative mode and fission mode .It emphasize the DA structure under the condition of the fission mode and presents the system configuration, the main station scheme, the feeder scheme, the optimized communication scheme etc., which is for DA research reference.Secondly, as for the (DA) trouble measurement, position, isolation and resume, This dissertation analyzes the changes of pressure and current for line problem, gets math equation by educing phase short circuit and problem position under the condition of single-phase and works out equation and several parameter s U& , s I& and e I& table on problem . It brings out optimized isolation and resume plan, realizes auto isolation and network reconstruction, reduces the power off range and time and improves the reliability of electric power supply through problem self- diagnoses and self-analysis. It also introduces software flow and use for problem judgement and sets a model on network reconstruction and computer flow.Thirdly, electricity system state is estimated to be one of the key techniques in DA realization. The dissertation recommends the resolvent of bad measurement data and structure mistake on the ground of describing state estimate way. It also advances a practical test and judging way on topology mistake in state estimate about bad data test and abnormity in state estimate as well as the problem and effect on bad data from state measure to state estimate .As for real time monitor and control problem, the dissertation introduces a new way to solve them by electricity break and exceptional analysis, and theway has been tested in Weifang DA.Fourthly, about the difficulty for building the model of load forecasting, big parameter scatter limit and something concerned, the dissertation introduces some parameters, eg. weather factor, date type and social environment effect based on analysis of routine load forecasting and means. It presents the way for electricity load forecasting founded on neural network(ANN),which has been tested it’s validity by example and made to be good practical effect.Fifthly, concerning the lack of concordant wave on preve nting concordant wave and non-power compensation and non-continuity on compensation, there is a topology structure of PWM main circuit and nonpower theory on active filter the waves technique and builds flat proof on the ground of Saber Designer and proves to be practical. Meanwhile, it analyzes and designs the way of non-power need of electric network tre- nds and decreasing line loss combined with DA, which have been tested its objective economic benefit throu- gh counting example.Sixthly, not only do the dissertation design a way founded on the magrginal electric price fitted to our present national electric power market with regards to future trends of electric power market in China and fair trade under the government surveillance, that is group competitio n in short-term trade under the way of grouped price and quantity harmony, but also puts forward combination arithmetic, math model of trading plan and safty economical restriction. It can solve the original contradiction between medium and long term contract price and short term competitive price with improvement on competitive percentage and cut down the unfair income difference of electric factory, at the same time, it can optimize the electric limit for all electric factories and reduce the total purchase charge of electric power from burthen curve of whole electric market network.The distribution network is an important link among the power system. Its neutral grounding mode and operation connects security and stability of the power system directly. At the same time, the problem about neutral grounding is associated with national conditions, natural environment, device fabrication and operation. For example, the activity situation of the thunder and lightning, insulating structure and the peripheral interference will influence the choice of neutral grounding mode Conversely, neutral grounding mode affects design, operation, debugs and developing. Generally in the system higher in grade in the voltage, the insulating expenses account for more sizable proportion at the total price of the equipment. It is very remarkable to bring the economic benefits by reducing the insulating level. Usually such system adopt the neutral directly grounding andadopt the autoreclosing to guarantee power supply reliability. On the contrary, the system which is lower in the voltage adopts neutral none grounding to raise power supply reliability. So it is an important subject to make use of new- type earth device to apply to the distribution network under considering the situation in such factors of various fields as power supply reliability, safety factor, over-voltage factor, the choice of relay protection, investment cost, etc.The main work of this paper is to research and choice the neutral grounding mode of the l0kV distribution network. The neutral grounding mode of the l0kV network mainly adopts none grounding, grounding by arc suppressing coil, grounding by reactance grounding and directly grounding. The best grounding mode is confirmed through the technology comparison. It can help the network run in safety and limit the earth electric arc by using auto-tracking compensate device and using the line protection with the detection of the sensitive small ground current. The paper introduces and analyzes the characteristic of all kind of grounding modes about l0kV network at first. With the comparison with technological and economy, the conclusion is drawn that the improved arc suppressing coil grounding mode shows a very big development potential.Then, this paper researches and introduces some operation characteristics of the arc suppressing coil grounding mode of the l0kV distribution network. And then the paper put emphasis on how to extinguish the earth electric arc effectively by utilizing the resonance principle. This paper combines the development of domestic and international technology and innovative achievement, and introduces the computer earth protection and autotracking compensate device. It proves that the improved arc suppressing coil grounding mode have better operation characteristics in power supply reliability, personal security, security of equipment and interference of communication. The application of the arc suppressing coil grounding mode is also researched in this paper.Finally, the paper summarizes this topic research. As a result of the domination of the arc suppressing coil grounding mode, it should be more popularized and applied in the distribution network in the future.The way of thinking, project and conclusions in this thesis have effect on the research to choose the neutral grounding mode not only in I0kV distribution network but also in other power system..The basic function of the electric power system is to transport the electric power towards customers. The l0kV electric distribution net is a key point that connects the power supply with the electricity using on the industry, business and daily-life. For the electric power, all costumers expect to pay the lowest price for the highest reliability, butdon't consider that it's self-contradictory in the co-existence of economy and reliable. To improve the reliability of the power supply network, we must increase the investment cost of the network con- struction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic, between the investment and the loss by calculating the investment on power net and the loss brought from power-off. The thesis analyses on the economic and the reliable of the various line modes, according to the characteristics various line modes existed in the electric distribution net in foshan..First, the thesis introduces as the different line modes in the l0kV electric distribution net and in some foreign countries. Making it clear tow to conduct analyzing on the line mode of the electric distribution net, and telling us how important and necessary that analyses are.Second, it turns to the necessity of calculating the number of optimization subsection, elaborating how it influences on the economy and reliability. Then by building up the calculation mode of the number of optimization subsection it introduces different power supply projects on the different line modes in brief. Third, it carries on the calculation and analyses towards the reliability and economy of the different line modes of electric distribution net, describing drafts according by the calculation. Then it makes analysis and discussion on the number of optimization subsection.At last, the article make conclusion on the economy and reliability of different line modes, as well as, its application situation. Accordion to the actual circumstance, the thesis puts forward the beneficial suggestion on the programming and construction of the l0kV electric distribution net in all areas in foshan. Providing the basic theories and beneficial guideline for the programming design of the lOkV electric distribution net and building up a solid net, reasonable layout, qualified safe and efficiently-worked electric distribution net.。
智能电网发展现状英文作文
智能电网发展现状英文作文很多人都在关心智能电网的发展现状，我也是其中之一。
智能电网是指利用先进的通信、计算和控制技术，实现对电力系统的智能化管理和运行。
它能够实现电力的高效利用、提高供电可靠性、降低能源消耗等多种优势。
目前，智能电网发展已经取得了一定的成就，但也面临着一些挑战和问题。
英文：The development of smart grid is a topic of great concern for many people, myself included. A smart grid refers to the use of advanced communication, computing, and control technologies to achieve intelligent management and operation of the power system. It can achieve efficient use of electricity, improve power supply reliability, and reduce energy consumption. At present, the development of smart grid has made some achievements, but it also faces some challenges and problems.中文：智能电网的发展是许多人关注的话题，我也是其中之一。
智能电网是指利用先进的通信、计算和控制技术，实现对电力系统的智能化管理和运行。
它能够实现电力的高效利用、提高供电可靠性、降低能源消耗等多种优势。
目前，智能电网发展已经取得了一定的成就，但也面临着一些挑战和问题。
英文：One of the achievements of the development of smartgrid is the integration of renewable energy sources intothe power grid. For example, in my city, we have a large-scale solar power plant that is connected to the smart grid. This allows the power generated from the solar panels to be efficiently distributed and used, reducing the reliance on traditional fossil fuels and decreasing greenhouse gas emissions. This is a great example of how smart grid technology can promote the use of clean and sustainable energy.中文：智能电网发展的成就之一是将可再生能源整合到电力网中。
毕业设计外文原文+翻译(电力系统)
河南理工大学HENAN POLYTECHNIC UNIVERSITY英文文献翻译En glish literature tran slati on学院：电气工程与自动化学院专业班级：___________ 电气11-4班_______ 姓名： __________________ 宋家鹏_______ 学号：311008001120 __________ 扌旨导老师：____________ 汪旭东_______2014年6月5日河南理工大学HENAN POLYTECHNIC UNIVERSITY2.5 对称三相电路在这一部分，我们介绍三相对称电路的一下几个话题：丫连接,相电压，线电压，线电流，△形连接负荷，△ - Y变换，以及等效的相图。
c Ca Ab B图2-10三相Y连接电源带Y连接对称负荷电路图对称Y连接图2-10显示的是一个三相Y连接电源带Y连接对称负荷电路图。
对于Y连接电路，每个相的中性点是连接起来的。
在图2-10中电源中性点标记的是n,而负载中性点标记的是N。
把三相电源假设为理想电源，即阻抗忽略不计。
同时，电源和负载之间线路阻抗，中性点n与N之间的线路阻抗也可忽略不计。
三相负荷是对称的，意味着三相之中任意两相间的阻抗是相同的。
对称相电压在图2-10中,三相电源的终端呗标记为a、b、c,电源相电压标记为E an ,E bn，E cn，当电源的三相电压有相同的幅度，任意两相之间互差120度角时，电源是对称的。
当以E an 作为参考相量时，相电压的幅值是10V，对称三相相电压如下所示：E an=10 0E bn10 120 10 240 (2.5.1 )E cn10 120 10 240河南理工大学HENAN POLYTECHNIC UNIVERSITY图2-11以E an 作为参考的对称正序相电压向量图当E an 超前E bn 120度，E bn 超前E cn 以120度角时，此时的相序称为正相序或 者abc 相序。
智能电网的优势英语作文
智能电网的优势英语作文English:Smart grids offer numerous advantages in the modern energy landscape. Firstly, they enhance reliability and efficiency by allowing real-time monitoring and control of energy distribution, minimizing disruptions and optimizing resource allocation. Secondly, smart grids facilitate the integration of renewable energy sources, such as solar and wind power, by managing their variability and intermittency through advanced forecasting and demand response mechanisms. Additionally, they empower consumers with greater awareness and control over their energy usage through smart meters and home automation technologies, enabling them to make informed decisions and potentially reduce their electricity bills. Moreover, smart grids enable grid operators to detect and respond to faults and outages more swiftly, enhancing overall system resilience. Furthermore, they promote the adoption of electric vehicles by offering convenient charging infrastructure and grid-friendly charging schedules, thereby reducing greenhouse gas emissions and reliance on fossil fuels in the transportation sector. Overall, smart grids represent a pivotal advancement in the modernization of energy infrastructure, offeringa pathway towards a more sustainable, resilient, and efficient energy system.中文翻译:智能电网在现代能源格局中具有许多优势。
电气毕业设计用外文翻译(中英文对照)
The Transformer on load ﹠Introduction to DC Machine sThe Transformer on loadIt has been shown that a primary input voltage 1V can be transformed to any desired open-circuit secondary voltage 2E by a suitable choice of turns ratio. 2E is available for circulating a load current impedance. For the moment, a lagging power factor will be considered. The secondary current and the resulting ampere-turns 22N I will change the flux, tending to demagnetize the core, reduce m Φ and with it 1E . Because the primary leakage impedance drop is so low, a small alteration to 1E will cause an appreciable increase of primary current from 0I to a new value of 1I equal to ()()i jX R E V ++111/. The extra primary current and ampere-turns nearly cancel the whole of the secondary ampere-turns. This being so , the mutual flux suffers only a slight modification and requires practically the same net ampere-turns 10N I as on no load. The total primary ampere-turns are increased by an amount 22N I necessary to neutralize the same amount of secondary ampere-turns. In the vector equation , 102211N I N I N I =+; alternatively, 221011N I N I N I -=. At full load, the current 0I is only about 5% of the full-load current and so 1I is nearly equal to 122/N N I . Because in mind that 2121/N N E E =, the input kV A which is approximately 11I E is also approximately equal to the output kV A, 22I E .The physical current has increased, and with in the primary leakage flux to which it is proportional. The total flux linking the primary ,111Φ=Φ+Φ=Φm p , is shown unchanged because the total back e.m.f.,（dt d N E /111Φ-）is still equal and opposite to 1V . However, there has been a redistribution of flux and the mutual component has fallen due to the increase of 1Φ with 1I . Although the change is small, the secondary demand could not be met without a mutual flux and e.m.f. alteration to permit primary current to change. The net flux s Φlinking the secondary winding has been further reduced by the establishment of secondary leakage flux due to 2I , and this opposes m Φ. Although m Φ and2Φ are indicated separately , they combine to one resultant in the core which will be downwards at the instant shown. Thus the secondary terminal voltage is reduced to dt d N V S /22Φ-= which can be considered in two components, i.e. dt d N dt d N V m //2222Φ-Φ-=or vectorially 2222I jX E V -=. As for the primary, 2Φ is responsible for a substantially constant secondaryleakage inductance 222222/Λ=ΦN i N . It will be noticed that the primary leakage flux is responsiblefor part of the change in the secondary terminal voltage due to its effects on the mutual flux. The two leakage fluxes are closely related; 2Φ, for example, by its demagnetizing action on m Φ has caused the changes on the primary side which led to the establishment of primary leakage flux.If a low enough leading power factor is considered, the total secondary flux and the mutual flux are increased causing the secondary terminal voltage to rise with load. p Φ is unchanged in magnitude from the no load condition since, neglecting resistance, it still has to provide a total back e.m.f. equal to 1V . It is virtually the same as 11Φ, though now produced by the combined effect of primary and secondary ampere-turns. The mutual flux must still change with load to give a change of 1E and permit more primary current to flow. 1E has increased this time but due to the vector combination with 1V there is still an increase of primary current.Two more points should be made about the figures. Firstly, a unity turns ratio has been assumed for convenience so that '21E E =. Secondly, the physical picture is drawn for a different instant of time from the vector diagrams which show 0=Φm , if the horizontal axis is taken as usual, to be the zero time reference. There are instants in the cycle when primary leakage flux is zero, when the secondary leakage flux is zero, and when primary and secondary leakage flux is zero, and when primary and secondary leakage fluxes are in the same sense.The equivalent circuit already derived for the transformer with the secondary terminals open, can easily be extended to cover the loaded secondary by the addition of the secondary resistance and leakage reactance.Practically all transformers have a turns ratio different from unity although such an arrangement issometimes employed for the purposes of electrically isolating one circuit from another operating at the same voltage. To explain the case where 21N N ≠ the reaction of the secondary will be viewed from the primary winding. The reaction is experienced only in terms of the magnetizing force due to the secondary ampere-turns. There is no way of detecting from the primary side whether 2I is large and 2N small or vice versa, it is the product of current and turns which causes the reaction. Consequently, a secondary winding can be replaced by any number of different equivalent windings and load circuits which will give rise to an identical reaction on the primary .It is clearly convenient to change the secondary winding to an equivalent winding having the same number of turns 1N as the primary.With 2N changes to 1N , since the e.m.f.s are proportional to turns, 2212)/('E N N E = which is the same as 1E .For current, since the reaction ampere turns must be unchanged 1222'''N I N I = must be equal to 22N I .i.e. 2122)/(I N N I =.For impedance , since any secondary voltage V becomes V N N )/(21, and secondary current I becomes I N N )/(12, then any secondary impedance, including load impedance, must become I V N N I V /)/('/'221=. Consequently, 22212)/('R N N R = and 22212)/('X N N X = .If the primary turns are taken as reference turns, the process is called referring to the primary side. There are a few checks which can be made to see if the procedure outlined is valid.For example, the copper loss in the referred secondary winding must be the same as in the original secondary otherwise the primary would have to supply a different loss power. ''222R I must be equal to 222R I . ）222122122/()/(N N R N N I ∙∙ does in fact reduce to 222R I .Similarly the stored magnetic energy in the leakage field )2/1(2LI which is proportional to 22'X I will be found to check as ''22X I . The referred secondary 2212221222)/()/(''I E N N I N N E I E kVA =∙==.The argument is sound, though at first it may have seemed suspect. In fact, if the actual secondarywinding was removed physically from the core and replaced by the equivalent winding and load circuit designed to give the parameters 1N ,'2R ,'2X and '2I , measurements from the primary terminals would be unable to detect any difference in secondary ampere-turns, kVA demand or copper loss, under normal power frequency operation.There is no point in choosing any basis other than equal turns on primary and referred secondary, but it is sometimes convenient to refer the primary to the secondary winding. In this case, if all the subscript 1’s are interchanged for the subscript 2’s, the necessary referring constants are easily found; e.g. 2'1R R ≈,21'X X ≈; similarly 1'2R R ≈ and 12'X X ≈.The equivalent circuit for the general case where 21N N ≠ except that m r has been added to allow for iron loss and an ideal lossless transformation has been included before the secondary terminals to return '2V to 2V .All calculations of internal voltage and power losses are made before this ideal transformation is applied. The behaviour of a transformer as detected at both sets of terminals is the same as the behaviour detected at the corresponding terminals of this circuit when the appropriate parameters are inserted. The slightly different representation showing the coils 1N and 2N side by side with a core in between is only used for convenience. On the transformer itself, the coils are , of course , wound round the same core.Very little error is introduced if the magnetising branch is transferred to the primary terminals, but a few anomalies will arise. For example ,the current shown flowing through the primary impedance is no longer the whole of the primary current. The error is quite small since 0I is usually such a small fraction of 1I . Slightly different answers may be obtained to a particular problem depending on whether or not allowance is made for this error. With this simplified circuit, the primary and referred secondary impedances can be added to give: 221211)/(Re N N R R += and 221211)/(N N X X Xe +=It should be pointed out that the equivalent circuit as derived here is only valid for normal operation at power frequencies; capacitance effects must be taken into account whenever the rate of change of voltage would give rise to appreciable capacitance currents, dt CdV I c /=. They are important at high voltages and at frequencies much beyond 100 cycles/sec. A further point is not theonly possible equivalent circuit even for power frequencies .An alternative , treating the transformer as a three-or four-terminal network, gives rise to a representation which is just as accurate and has some advantages for the circuit engineer who treats all devices as circuit elements with certain transfer properties. The circuit on this basis would have a turns ratio having a phase shift as well as a magnitude change, and the impedances would not be the same as those of the windings. The circuit would not explain the phenomena within the device like the effects of saturation, so for an understanding of internal behaviour .There are two ways of looking at the equivalent circuit:(a) viewed from the primary as a sink but the referred load impedance connected across '2V ,or (b) viewed from the secondary as a source of constant voltage 1V with internal drops due to 1Re and 1Xe . The magnetizing branch is sometimes omitted in this representation and so the circuit reduces to a generator producing a constant voltage 1E (actually equal to 1V ) and having an internal impedance jX R + (actually equal to 11Re jXe +).In either case, the parameters could be referred to the secondary winding and this may save calculation time .The resistances and reactances can be obtained from two simple light load tests.Introduction to DC MachinesDC machines are characterized by their versatility. By means of various combination of shunt, series, and separately excited field windings they can be designed to display a wide variety of volt-ampere or speed-torque characteristics for both dynamic and steadystate operation. Because of the ease with which they can be controlled , systems of DC machines are often used in applications requiring a wide range of motor speeds or precise control of motor output.The essential features of a DC machine are shown schematically. The stator has salient poles and is excited by one or more field coils. The air-gap flux distribution created by the field winding is symmetrical about the centerline of the field poles. This axis is called the field axis or direct axis.As we know , the AC voltage generated in each rotating armature coil is converted to DC in the external armature terminals by means of a rotating commutator and stationary brushes to which the armature leads are connected. The commutator-brush combination forms a mechanical rectifier,resulting in a DC armature voltage as well as an armature m.m.f. wave which is fixed in space. The brushes are located so that commutation occurs when the coil sides are in the neutral zone , midway between the field poles. The axis of the armature m.m.f. wave then in 90 electrical degrees from the axis of the field poles, i.e., in the quadrature axis. In the schematic representation the brushes are shown in quarature axis because this is the position of the coils to which they are connected. The armature m.m.f. wave then is along the brush axis as shown.. (The geometrical position of the brushes in an actual machine is approximately 90 electrical degrees from their position in the schematic diagram because of the shape of the end connections to the commutator.)The magnetic torque and the speed voltage appearing at the brushes are independent of the spatial waveform of the flux distribution; for convenience we shall continue to assume a sinusoidal flux-density wave in the air gap. The torque can then be found from the magnetic field viewpoint.The torque can be expressed in terms of the interaction of the direct-axis air-gap flux per pole d Φ and the space-fundamental component 1a F of the armature m.m.f. wave . With the brushes in the quadrature axis, the angle between these fields is 90 electrical degrees, and its sine equals unity. For a P pole machine 12)2(2a d F P T ϕπ= In which the minus sign has been dropped because the positive direction of the torque can be determined from physical reasoning. The space fundamental 1a F of the sawtooth armature m.m.f. wave is 8/2π times its peak. Substitution in above equation then gives a d a a d a i K i mPC T ϕϕπ==2 Where a i =current in external armature circuit;a C =total number of conductors in armature winding;m =number of parallel paths through winding;And mPC K a a π2=Is a constant fixed by the design of the winding.The rectified voltage generated in the armature has already been discussed before for an elementary single-coil armature. The effect of distributing the winding in several slots is shown in figure ,in which each of the rectified sine waves is the voltage generated in one of the coils, commutation taking place at the moment when the coil sides are in the neutral zone. The generated voltage as observed from the brushes is the sum of the rectified voltages of all the coils in series between brushes and is shown by the rippling line labeled a e in figure. With a dozen or so commutator segments per pole, the ripple becomes very small and the average generated voltage observed from the brushes equals the sum of the average values of the rectified coil voltages. The rectified voltage a e between brushes, known also as the speed voltage, is m d a m d a a W K W mPC e ϕϕπ==2 Where a K is the design constant. The rectified voltage of a distributed winding has the same average value as that of a concentrated coil. The difference is that the ripple is greatly reduced.From the above equations, with all variable expressed in SI units:m a a Tw i e =This equation simply says that the instantaneous electric power associated with the speed voltage equals the instantaneous mechanical power associated with the magnetic torque , the direction of power flow being determined by whether the machine is acting as a motor or generator.The direct-axis air-gap flux is produced by the combined m.m.f. f f i N ∑ of the field windings, the flux-m.m.f. characteristic being the magnetization curve for the particular iron geometry of the machine. In the magnetization curve, it is assumed that the armature m.m.f. wave is perpendicular to the field axis. It will be necessary to reexamine this assumption later in this chapter, where the effects of saturation are investigated more thoroughly. Because the armature e.m.f. is proportional to flux timesspeed, it is usually more convenient to express the magnetization curve in terms of the armature e.m.f. 0a e at a constant speed 0m w . The voltage a e for a given flux at any other speed m w is proportional to the speed,i.e. 00a m m a e w w e Figure shows the magnetization curve with only one field winding excited. This curve can easily be obtained by test methods, no knowledge of any design details being required.Over a fairly wide range of excitation the reluctance of the iron is negligible compared with that of the air gap. In this region the flux is linearly proportional to the total m.m.f. of the field windings, the constant of proportionality being the direct-axis air-gap permeance.The outstanding advantages of DC machines arise from the wide variety of operating characteristics which can be obtained by selection of the method of excitation of the field windings. The field windings may be separately excited from an external DC source, or they may be self-excited; i.e., the machine may supply its own excitation. The method of excitation profoundly influences not only the steady-state characteristics, but also the dynamic behavior of the machine in control systems.The connection diagram of a separately excited generator is given. The required field current is a very small fraction of the rated armature current. A small amount of power in the field circuit may control a relatively large amount of power in the armature circuit; i.e., the generator is a power amplifier. Separately excited generators are often used in feedback control systems when control of the armature voltage over a wide range is required. The field windings of self-excited generators may be supplied in three different ways. The field may be connected in series with the armature, resulting in a shunt generator, or the field may be in two sections, one of which is connected in series and the other in shunt with the armature, resulting in a compound generator. With self-excited generators residual magnetism must be present in the machine iron to get the self-excitation process started.In the typical steady-state volt-ampere characteristics, constant-speed primemovers being assumed. The relation between the steady-state generated e.m.f. a E and the terminal voltage t V isa a a t R I E V -=Where a I is the armature current output and a R is the armature circuit resistance. In a generator, a E is large than t V ; and the electromagnetic torque T is a countertorque opposing rotation.The terminal voltage of a separately excited generator decreases slightly with increase in the load current, principally because of the voltage drop in the armature resistance. The field current of a series generator is the same as the load current, so that the air-gap flux and hence the voltage vary widely with load. As a consequence, series generators are not often used. The voltage of shunt generators drops off somewhat with load. Compound generators are normally connected so that the m.m.f. of the series winding aids that of the shunt winding. The advantage is that through the action of the series winding the flux per pole can increase with load, resulting in a voltage output which is nearly constant. Usually, shunt winding contains many turns of comparatively heavy conductor because it must carry the full armature current of the machine. The voltage of both shunt and compound generators can be controlled over reasonable limits by means of rheostats in the shunt field. Any of the methods of excitation used for generators can also be used for motors. In the typical steady-state speed-torque characteristics, it is assumed that the motor terminals are supplied from a constant-voltage source. In a motor the relation between the e.m.f. a E generated in the armature and the terminal voltage t V isa a a t R I E V +=Where a I is now the armature current input. The generated e.m.f. a E is now smaller than the terminal voltage t V , the armature current is in the opposite direction to that in a motor, and the electromagnetic torque is in the direction to sustain rotation ofthe armature.In shunt and separately excited motors the field flux is nearly constant. Consequently, increased torque must be accompanied by a very nearly proportional increase in armature current and hence by a small decrease in counter e.m.f. to allow this increased current through the small armature resistance. Since counter e.m.f. is determined by flux and speed, the speed must drop slightly. Like the squirrel-cage induction motor ,the shunt motor is substantially a constant-speed motor having about 5 percent drop in speed from no load to full load. Starting torque and maximum torque are limited by the armature current that can be commutated successfully.An outstanding advantage of the shunt motor is ease of speed control. With a rheostat in the shunt-field circuit, the field current and flux per pole can be varied at will, and variation of flux causes the inverse variation of speed to maintain counter e.m.f. approximately equal to the impressed terminal voltage. A maximum speed range of about 4 or 5 to 1 can be obtained by this method, the limitation again being commutating conditions. By variation of the impressed armature voltage, very wide speed ranges can be obtained.In the series motor, increase in load is accompanied by increase in the armature current and m.m.f. and the stator field flux (provided the iron is not completely saturated). Because flux increases with load, speed must drop in order to maintain the balance between impressed voltage and counter e.m.f.; moreover, the increase in armature current caused by increased torque is smaller than in the shunt motor because of the increased flux. The series motor is therefore a varying-speed motor with a markedly drooping speed-load characteristic. For applications requiring heavy torque overloads, this characteristic is particularly advantageous because the corresponding power overloads are held to more reasonable values by the associated speed drops. Very favorable starting characteristics also result from the increase in flux with increased armature current.In the compound motor the series field may be connected either cumulatively, so that its.m.m.f.adds to that of the shunt field, or differentially, so that it opposes. The differential connection is very rarely used. A cumulatively compounded motor hasspeed-load characteristic intermediate between those of a shunt and a series motor, the drop of speed with load depending on the relative number of ampere-turns in the shunt and series fields. It does not have the disadvantage of very high light-load speed associated with a series motor, but it retains to a considerable degree the advantages of series excitation.The application advantages of DC machines lie in the variety of performance characteristics offered by the possibilities of shunt, series, and compound excitation. Some of these characteristics have been touched upon briefly in this article. Still greater possibilities exist if additional sets of brushes are added so that other voltages can be obtained from the commutator. Thus the versatility of DC machine systems and their adaptability to control, both manual and automatic, are their outstanding features.负载运行的变压器及直流电机导论负载运行的变压器通过选择合适的匝数比，一次侧输入电压1V 可任意转换成所希望的二次侧开路电压2E 。
毕业设计论文外文文献翻译中英文对照电气对中国智能电网的研究
1Research on Smart Grid in ChinaJingjing Lu, Da Xie, Member, IEEE and Qian Ai, Member, IEEEAbstract--The Smart Grid is the latest direction for the futurepower system development. In this paper, firstly the backgroundof Smart Grid, its meaning, as well as the concept and structurewere presented. Typical diagram of Smart Grid was illustrated.Then, the current development of Smart Grid in United States and Europe were described, development ideas and the future trends in these countries were summarized and compared as well.Besides, the driving force of Smart Grid in China was analyzed,with detailed introduction of current related projects in China.The relation between the UHV Power Grid and the Smart Grid was discussed. Finally, the potential role of Smart Grid in future power grids in China was prospected and a new direction for China’s Smart Grid development was charted.Index Terms—Smart Grid, UHV power grid, planning,operation, managementI. INTRODUCTIONWith the promotion of world economy modernization, theprice of oil has been kept on a upward trend. What is also noticeable is the shortage of energy supply around the world, the increasing pressures on resources and environment pressure, and the enormous power losses in energy delivery due to the low eff iciency of the current power grid. What’s more, owing to the growing electricity demands and the users’increasing requirements for reliability and quality, the power industry is now facing unprecedented challenges and opportunities. Therefore, a new sort of power system of environment friendly, economic, high performance, low investment, safety, reliability and flexibility has been a goal of engineers in power industry.Still, the emergence of advanced meter infrastructure and more extensive usage of the Internet accelerate the process [1]. Since 1990's, with the increasing use of distributed generation power, more demands and requirements have been proposed for power grid intensity [2], [3]. To find out a optimal solution for these problems, power companies should accept the idea of new technology adoption, potential mining of the existing power system and improvement of its application and utilization. Consensus has been reached by experts and scholars from different countries that future power gird must be able to meet various requirements of energy generating and the demands of highly market-oriented power transaction so that the needs of the self-selection from customers can be satisfied individually. All of these will become the future development direction of Smart Grid.This paper focuses on the status of the development of the Smart Grid, analyzing the driving force of the Smart Grid and introducing the current demonstration projects in China. It also discusses the relation between UHV power grid and Smart Grid, and then prospect the significance of Smart Grid in the future. A new direction for Chinese Smart Grid development is charted as well, which might be the reference for the development of Smart Grid in China.II. CONCEPT OF SMART GRIDSmart Grid is a gradual development process accompanied with the technology innovation, demands of energy saving and managements needs. People will have their own understandingfor Smart Grid, no matter if they are facility suppliers, IT companies, consulting firms, public power companies or power generation companies. From the earlier smart intelligence meteringto electrical intelligence, from transmission and distribution automation to a whole intelligent process, the concept of smart power grid has been enriched substantially [4]. In 2006, US IBM presented a "Smart Grid" solution. This is a relatively complete concept for current Smart Grid which indicates its official birth [5].As shown in Fig.1, a Smart Grid is basically overlaying the physical power system with an information system which links a variety of equipments and assets together with sensors to form a customer service platform. It allows the utility and consumers to constantly monitor and adjust electricity use. The management of operation will be more intelligent and scientific based on the dynamic analysis of needs both from user-side and demand side which can increase capital investment efficiency due to tighter design limits and optimized use of grid assets.In comparison with traditional grid, Smart Grid includes integrated communication systems, advanced Sensing,metering, measurement infrastructure, complete decision support and human interfaces.III. CURRENT RESEARCH ACTIVITIESA. Comparison of researches in Smart Grid area between European and the United statesIn the United States, there were several large power outages in recent years. Because of which, electric power industry pays closer attention to power quality and reliability;customers draw out more requests for electricity supply. The ever-increasing demands of national security and environmental protection policy of the United States leads to the establishment of a higher standard for power grid construction and management [6]. At the same time, in recent years’ researches of basic materials, power and information technologies, breakthroughs have been achieved for implementation target which shows the significant improvement of reliability, efficiency in power network. Such as the emergence of superconducting cables, it assures Obama’s new gove rnment of United States has seen the daylights of the Smart Grid.Similarly, the European power users also raise higher requirements for electricity supply & power quality [7].Because of the extreme attention for environmental protection,compared with the construction of power grid in US,Europeans have more concerns about the construction of renewable energy access, the impact on wildlife, as well as the actively research on real-time monitoring and remotecontrolling.All is about to realize the "Plug & Play use" idea,ensuring a more friendly, flexible access and interaction with the user. In both Europe and United States, the most common direction for grid development is to seek new and renewable sources for energy generation. However, Smart Grid is not a fixed, static project, according to their particular status and main problems, all countries need to simplify the Smart Grid and make it adjusted to fit their own features.B. Driving force of the Smart Grid in ChinaThe drivers for Smart Grid construction can be concluded into market, circumstances, safety and power quality. Chinese power industry is also facing the similar situation as in Europe and the United States.At Market-oriented reforms level, the national network and unified national electricity market has not completely formed.In national wide, power exchanges are not effective; neither does the true meaning of the online bidding. From a long term view,China's transaction approaches of power markets and pricing structure is developing, market demand and supply sides will have more frequent interactions. In order to attract more users to join the market competition, power companies must improve their service, strengthen the interaction with users and provide more products for selection, so as to meet the demands of different types of users.At the macro policy level, the power industry needs to meet the requirements ofresource-saving and environment-friendly society’s construction, adapt to climate change and suitable for sustainable development.Regarding the Chinese power grid itself, a strong backbone network has not been built yet, and it is still not strong enough to withstand multiple faults circumstances. The regional power grid backbone is also in a lower stability level, which results in a limited flexibility for system operation, etc. The snow storm weather in early 2008 which led to a blackout in major area of China vividly exposed the weakness of the current Chinese grid in safeguard of electricity supply aspect.Moreover, the lack of intelligent power distribution leads to a regional, seasonal shortage of electricity and coexistent in some areas with both surplus & shortages of electricity.There still remain challenges that how to improve the efficiency of power investment and construction, how to ensure the security and reliability of power grid’s operation, to ensure power quality; how to improve the maintenance of power system; how to enhance the service quality to users, as well as how to improve the power grid management in China.For these issues, Smart Grid would be an ideal solution.C. Current research activities in ChinaIn the year of 2006, IBM published the guideline named ‘Establishing Smart Power Grid and Innovating Management Methods – A New Thought of the Development of Electric in China’. Directed at the current opportunities and challenges of the power grid companies in China, the guideline suggests improving the efficiency of electrical investments and construction, the stability of power grid, and the companies’service and ma nagement level through the construction of smart power grid and the innovation of management methods.Meanwhile, IBM proposed that it can provide a whole scheme - Solution Architecture for Energy (SAFT) for the power companies in China to use the smart power grid effectively. SAFT contains several parts: first is to improvethe digital level by connecting the equipments with sensors;Second is to establish the data collecting and integrating system; Third is to analyze: SAFT optimize the operating progress and management based on the analyzing of the data[5]. This is the bud of smart power grid in Chin.In October 2007, East China Power Grid Company embarked on the research area of the feasibility of smart power grid. The research project was not only correlated with the progress of those advanced companies and research facilities abroad, but also take the current situation and future needs of east china power grid into consideration. The result came out as, based on the high equipment level and strong technological innovation ability, the construction of smart power grid is feasible in east china power grid. East China Power Grid Company would follow the belief that‘Concerning the future and change fast with needs, and providing high quality service’, when bui lding smart power grid. There is a three step strategy with an advanced power grid distributing center built by 2010, the construction of digital power grid with primary intelligence completed by 2020, and a smart power grid with the ability of self-healing built by 2030 [8]. The construction plan is still under consideration.On Feb. 28, 2009, as a part of the smart power grid of East China Power Grid Company, the three-state security defense and power generation monitoring system passed the acceptance check in Beijing, which stands for stable-state,transient-state and dynamic-state. The system integrated three single systems altogether for the first time, which includes power management system, power grid dynamic wan monitor system and online stability analysis and warning system. The operator has full access to the whole view of the power grid operating situation andthe decision-making assistance without switching in systems or platforms. Besides, the system can effectively improve the management standardization and the level of flow of the related power plants through establishing the management checking platform and the assistance marketservice quality analyzing platform.The development of smart power grid research in China is slow and far behind the west. So far, only East China Power Grid Company and North China Power Grid Company have carried out researches about the developing and implementation plan. It is a tradition for China to emphasize technology development, and in fact, the equipments in China are more advanced than those in developed countries. Thus,smart power grid has a bright prospect in China.IV. PROSPECTS OF SMART GRID IN CHINAIn order to solve the problems of imbalance distribution for generation resources and power loads, the transmission capacity should be enhanced by building long-distance and large-capacity power transmission systems. And unity or united UHV power grids should be constructed under coordinated plan. The transmission of power on a large scale from west and north China to middle and east China can reduce the pressure of energy in the east China and the pressure of transmission and environmental protection.Furthermore, this can expedite the conversion from resource advantage to economy advantage and realize the coordinated development of nation economy. Chinese politics system,economic environment and management system also promotes UHV power grids in its development. At present, China is studying the future large power grids technology and has the ability to construct the national united power grids. On Jan, 16,2009, the first UHV power line in China was finished and put into operation.Unity or united UHV power grid, distributed power generating or scattered interactive power supplying grid are the trends of development. China, as the delegate in unity or united UHV power grid development trend, is different from any western countries. In China, is it in contradiction to develop both UHV power grid and Smart Grid? Though the large power grid with linkage effect has the advantage of optimizing the resources, it has the potential risk of power outage in large area. The ability to control the large power grid and maintain its stability is required by the fast development of power grid. And the smart power gird with self-healing and high reliability matches such requirements.Thus, smart power grid is the direction of China power grid development while building UHV power grid and the grid of different level, as well as improving the operating and management level of the grid.According to the precondition and the background of UHVpower grid development in current China, the aspects which should be paid more attention on are as follows:Smart Planning: The power grid should become selfhealing and smart. The ability of power grid planning optimization should be enhanced. So should be the ability of receive-side power grid planning, on the premise of the UHV AC/ DC feed-in and differentvoltage level coordinated development. The most important thing is to change the concepts and methods of power planning, and to make the traditional power development concept such like regarding building new power stations as a wide-ranging concept of resourcesdistribution.Smart Operation: The dispatching pattern is developing towards a coordinated control direction, aiming at the enhancement of control and mastering of large power grid. The future Smart Grid should be coordinated with a matching control center equipped with more advanced power system management ability, for the purpose of improving the functions and performanceof existing EMS, MOS, WAMMAP system in an integral manner, at the same time to track down the correlations between different power grid monitoring and controlling indexes,and to construct a logic structure based power system monitoring and controlling index system. Through thegradual process of implementation of dynamic security monitoring, power system pre-alarm processing and precontrol,much more accurate and comprehensive knowledge of the operation state of the power systemcan be obtained, based on which, the most effective and timely measures and actions can be taken to fulfill the power system control and dispatching strategy, finally to improve the safeguard of the whole power system’sstability and security.Smart Management: The management pattern of power system is undergoing an evolution from vertical mode to distributed mode, from function management to process management, from grid construction to both construction and operation modes.V. CONCLUSIONSmart Grid is a hot spot in today's electric power system,also regarded as one of the vanes in 21st century for the major scientific and technological innovation and development in power system. Many countries in the world are involved in this big trend, and have set up a lot of Smart Grid demonstration projects and test platforms. Also, the theoretical and experimental research in Smart Grid has made some achievements. The international exchanges have greatly promoted the development of Smart Grid. Because of China's electricity distribution and extremely uneven distribution of electricity load, it is the right time to develop special highvoltage power grid. As the development of Smart Grid is still at the very beginning stage of our country, how to combine the special high-voltage power grids with intelligent power grid is the main problem confronted. The direction to development and the characteristics of smart power grids in China are still open for our experts and scholars for further study.VI. REFERENCES[1] David G. Hart, " Using AMI to Realize the Smart Grid," in Proc. 2008IEEE Power and Energy Society General Meeting - Conversion andDelivery of Electrical Energy in the 21st Century, pp. 1-2.[2] S. Massoud Amin and B.F. Wollenberg, “Toward a Smart Grid: powerdeli very for the 21st century,” IEEE Power and Energy Magazine, Vol.3, No. 5 Sept.-Oct. 2005, pp. 34-41.[3] D. Divan and H. Johal, “A Smarter Grid for Improving SystemReliability and Asset Utilization,” Power Electronics and MotionControl Conference, August, 2006.[4] Tai, H. and Hogain, E.O., “Behind the buzz [In My View]," IEEE Trans.Power and Energy Magazine, vol. 7, pp. 96 - 92, Mar.-Apr. 2009.[5] Fujie Sun, Ming Lei and Chengbin Yang, “Establishing Smart PowerGrid and Innovating Management Methods– A New Thought of theDevelopment of Electric in China," IBM Corp, [Online]. Available:[6] Richard E. Brown, " Impact of Smart Grid on distribution systemdesign," in Proc. 2008 IEEE Power and Energy Society General Meeting- Conversion and Delivery of Electrical Energy in the 21st Century, pp.1-4.[7] European Commission, Directorate-General for Research, “Draft -Strategic Deployment Document for Europe’s Electricity Networks ofthe future”, 2008[8] Junqing Shuai, Aiming at the forefront and Establishing SmartGrid, State Grid, issue 2, pp.54-57, 2008.VII. BIOGRAPHIESJingjing Lu was born in Hunan, China in 1985. Shereceived her B.Sc. degree in electrical engineeringfrom Shanghai Jiao Tong University, Shanghai,China in 200 . Now she is a gradate student ofDepartment of Electrical Engineering, Shanghai Jiaoong University in Shanghai, China. She mainlyfocuses her research on power system simulation,FACTS and Smart Grid.Da Xie (M’03) was born in Heilongjiang, China in1969. He received his B.Sc. degree in electricalengineering from Shanghai Jiao Tong University,Shanghai, China in 1991, the M.Sc. degree inelectrical engineering from Harbin Institute ofTechnology, Harbin, China in 1996,and the Ph.D.degree in electrical engineering from Shanghai JiaoTong University, Shanghai, China in 1999. Now heis associate professor in Shanghai Jiao TongUniversity, EE department. He mainly focuses hisresearch on FACTS and power system simulation.Qian Ai (M’03) was born in Hubei, China in1969.He received the B.Sc. degree in electricalengineering from Shanghai Jiao Tong University,Shanghai, China, the M.Sc. degree in electricalengineering from Wuhan University, Wuhan, China,and the Ph.D. degree in electrical engineering fromTsinghua University, Beijing, China. He worked asa Research Fellow from 1999 to 2002 in NanyangTechnological University, Singapore, and theUniversity of Bath, Bath, U.K. He is currently anAssociate Professor at Shanghai Jiao Tong University. His interests includepower system modeling, power quality, FACTS and Micro grid.对中国智能电网的研究摘要 -智能电网是电力系统的未来发展的新方向。
电气专业毕业设计英文文献
电气专业毕业设计英文文献电气专业毕业设计英文文献外文资料与中文翻译外文资料:Relay protection present situation anddevelopment一、Relay protection development present situationElectrical power system's swift development to the relay protection proposed unceasingly the new request, the electronic technology, the computer technology and communication's swift development unceasingly has infused the new vigor for the relay protection technology's development, therefore, the relay protection technology is advantageous, has completed the development 4 historical stage in 40 remaining years of time.After the founding of the nation, our country relay protection discipline, the relay protection design, the relay factory industry and the relay protection technical team grows out of nothing, has passed through the path which in about 10 year the advanced countries half century pass through. In the 50s, our country engineers and technicians creatively absorption, the digestion, have grasped the overseas advanced relay protection equipment performance and the movement technology [1], completed one to have the deep relay protection theory attainments and the rich service experience's relay protection technical team, and grew the instruction function to the national relay protection technical team's establishment. The Achengrelay factory introduction has digested at that time the overseas advanced relay technique of manufacture, has established our country own relay manufacturing industry.Therefore our country has completed the relay protection research, the design, the manufacture, the movement and the teaching complete system in the 60s. This is the mechanical and electrical -like relay protection prosperous time, was our country relay protection technology development has laid the solid foundation.From the late 50s, the transistor relay protection was starting to study. In the 60s to the 80s in is the time which the transistor relay protection vigorous development and widely uses. And the Tianjin University and the Nanjing Electric power Automation Plant cooperation research's 500kv transistor direction high frequency protection develops with the Nanjing Electric power Automation Research institute the transistor high frequency block system is away from the protection, moves on the Gezhou Dam 500 kv lines [2], finished the 500kv line protection to depend upon completely from the overseas import time.From the 70s, started based on the integration operational amplifier's integrated circuit protection to study. Has formed the complete series to the late 80s integrated circuit protection, substitutes for the transistor protection gradually. The development which, the production, the application protected to the early 90s integrated circuit were still in the dominant position, this was theintegrated circuit protection time. The integrated circuit power frequency change quantity direction which develops in this aspect Nanjing Electric power Automation Research institute high frequency protected the influential role [3], the Tianjin University and the Nanjing Electric power Automation Plant cooperation development's integrated circuit phase voltage compensation type direction high frequency protection alsomoved in many 220kv and on the 500kv line.Our country namely started the computer relay protection research from the late 70s [4], the institutions of higher learning and the scientific research courtyard institute forerunner's function. Huazhong University of Science and Technology, the Southeast University, the North China electric power institute, Xi'an Jiaotong University, the Tianjin University, Shanghai Jiaotong University, the Chongqing University and the Nanjing Electric power Automation Research institute one after another has developed the different principle, the different pattern microcomputer protective device. in 1984 the original North China electric power institute developed the transmission line microcomputer protective device first through the appraisal, and obtained the application in the system [5], has opened in our country relay protection history the new page, protected the promotion for the microcomputer to pave the way. In the main equipment protection aspect, the generator which the Southeast University and Huazhong University of Science and Technology develops loses magnetism protection, the generator protection and the generator? Bank of transformers protectionalso one after another in 1989, in 1994 through appraisal, investment movement. The Nanjing Electric power Automation Research institute develops microcomputer line protective device alsoin 1991 through appraisal. Tianjin University and Nanjing Electric power Automation Plant cooperation development microcomputer phase voltage compensation type direction high frequency protection, Xi'an Jiaotong University and Xuchang relay factory cooperation development positive sequence breakdown component direction high frequencyprotection also one after another in 1993, in 1996 through appraisal. Hence, the different principle, the different type's microcomputer line and the main equipment protect unique, provided one group of new generation performance for the electrical power system to be fine, the function was complete, operation reliable relay protection installment. Along with the microcomputer protective device's research, in microcomputer aspects and so on protection software, algorithm has also made many theory progresses. May say that started our country relay protection technology from the 90s to enter the time which the microcomputer protected.二、future development of Relay protectionThe future trend of relay protection technology is to computerization, networking is intelligent, protect, control, measure and data communication developing by integration. The principles of protection of electric power circuits are quite independent of the relay designs which may be applied. For example, if the current to an electriccircuit or a machine is greater than that which can be tolerated, it is necessary to take remedial action. The device for recognizing the condition and initiating corrective measures would be termed as an over-current relay regardless of the mechanists by whichthe function would be accomplished. Because the functions of electromechanical devices are easily described, their performance wills ever as a basis for presenting a description of relays and relay systemsin general.Relays must have the following characteristics: Reliability---The nature of the problem is that the relay may be idle for periods extending into years and then be required tooperatewith fast responds, as intended, the first time. The penalty for failure to operate properly may run into millions of dollars.Selectivity---The relay must not respond to abnormal, but harmless, system conditions such as switching transients or sudden changes in load.Sensitivity---The relay must not fail to operate, even in borderline situations, when operation was planned.Speed---The relay should make the decision to act as close to instantaneously as possible. If intentional time delay is available, it should be predictable and precisely adjustable.Instantaneous---The term means no intentional time delay.There are several possible ways to classify relays: by function, by construction, by application. Relays are one of two basic types of construction: electromagnetic or solid-state. The electromagnetic type relies on the development of electromagnetic forces on movable members,which provide switching action by physically opening or closing sets of contacts. The solid state variety provides switching action with no physical motion by changing the state of serially connected solid state component from no conducting to conducting(or vice versa). Electromagnetic relays are older and more widely used; solid state relays are more versatile, potentially more reliable, and fast.1)ComputerizationWith swift and violent development of computer hardware, computer protect hardware develop constantly even. The power system is improving to the demand that the computer protects constantly, besides basic function protected, should with trouble information of the large capacity and data the long-term parkingspace also, fast data processing function, strong communication capacity, network in order to share the whole system data , information , ability , network of resource with other protection , control device , dispatcher, high-level language programming ,etc.. This requires computer protector to have function which is equivalent to a pc machine. In computer is it develop initial stage to protect, is it make with one minicom relay protection install to imagine. Because the small-scale organism was accumulated greatly, with high costs at that time, dependability was bad, this imagined it was unrealistic . Now, exceed the minicomputer of those years greatly with computer protector size similar worker function , speed , memory capacity of accusing of machine, so make with complete sets of worker person who accuse of opportunity of relay protection already ripe, this will be one of the developing direction that a computer is protected . Tianjin university is it spend whom transformation act as continue the electric protector with computer protector structure self-same one worker person whoaccuse of to develop into already. The advantage of this kind of device is as follows, (1)it have functions of 486pc,it can meet to at present and it is various kinds of function demand where computerprotect future. (2)The size and structure are similar to present computer protector , the craft is superior, takes precautions against earthquakes , defends overheatedly and defending the electromagnetic ability of interfering strongly, can operate it in very abominable working environment , the cost is acceptable.(3)Adopting std bus or pc bus, hardware module , can select different module for use to different protection wantonly , it is flexible , easy to expand to dispose.It is an irreversible development trend to continue the computer , computerization of the electric protector. But to how better meet power system demand, how about raise the dependability of relay protection further, how make heavy economic benefits and social benefit, need carry on concrete deep research.2) NetworkedComputer network become the technological pillar of information age as message and data communication tool, made the mankind producing , basic change has taken place in the appearance with social life. It isinfluencing each industrial field deeply, has offered the powerful communication means for each industrial field too. Up till now, except that protect differentially and unite protecting vertically, all continue electric protector can only react that protect the electric quantity of installing office. The function of relay protection is only limited to excising the trouble component too , narrow the accident coverage. This mainly lack the powerful data communication means. Having already put forward the concept protected systematically abroad, this meant the safe automatics mainly at that time. Because the function of relay protection is not only limited to excising the trouble component and restriction accident coverage (this is primary task), the peace and steadiness that will be guaranteed the whole system run . This require each protect unit can share the whole operation and data , trouble of information of system, each protect unit and coincident floodgate device coordination on the basis of analysing the information and data, guarantee systematic peace and steadiness run . Obviously , realize the primary condition that system protect the whole system every protector of capitalequipment link with the computer network, namely the one that realized the computer protector is networked. This is totally possible under present technological condition .To general protecting systematically , realize the computer networking of the protector has a very great advantage too. It continue electric trouble not the less many in information not systematic can receiving protector ,for trouble nature , judgement and the trouble,trouble of position from measuring the less accurate. Protect to self-adaptation research of principle pass long time very already , make certain achievement too, but should really realize protecting the self-adaptation to the operation way of the system and trouble state, must obtain more system operating and trouble information , the computer that only realizes protecting is networked, could accomplish this . As to the thing that some protectors realize computer networking , can improve the dependability protected . Tianjin Sanxia vltrahigh voltage many return circuit bus bar , 500kv of power station , put forward one distributed principle that bus bar protected to future 1993 such as university, succeed in developing this kind of device tentatively. Principle its bus bar is it disperse several (with protect into bus bar back to way the same ) bus bar protect Entrance to protect traditional concentration type, disperse and install it in every return circuit is protected and rejected , each protect the unit to link with the computer network, each one protects the electric current amount that the unit only inputs a return circuit , after changing it into figure amount, convey to the protection units of other return circuits through the computer network, each protect the unit according to the electric current amount of this return circuit and electric current amount of other return circuits gotfrom computer network, carry on bus bar differential calculation that protect, if result of calculation prove bus bar trouble jump format return circuit circuit breaker only, isolate the bus bar of the trouble. At the time of the trouble outside the bus bar district , each protect the unit and calculate for movements of the external trouble. This kind protect principle by distributed bus barthat network realize with computer, bus bar protect principle have higher dependability than traditional concentration type. Because if one protect unit interfere or mistake in computation and when working up by mistake, can only jump format return circuit , can is it make bus bar to be whole of malignant accident that excise to cause wrong, this is very important to systematic pivot with supervoltage bus bar of hydropower station like SanxiaCan know computer protector networked to can raise and protect the performance and dependability greatly while being above-mentioned, this is an inexorable trend that a computer protects development 3) Protect , control , measure , data communication integratesOn terms that realize computerization of relay protection and networked, the protector is a high performance , multi-functional computer in fact, it is a intelligent terminal on the computer network of whole power system. It can obtain any information and data of operating and trouble of the power system from network , can convey network control centre or any terminal function , and can also finish the measurement , control , data communication function in there is no normal running of trouble cases, namely realize protecting ,controlling , measuring , data communication integrates.At present, for measurement, need that protects and controlling, all equipment of the outdoor transformer substation, two voltage, electric current of voltage transformer, circuit,etc. must with control cable guide to the top management room for instance. Lay control cable take a large amount of investment, make the very much complicated returncircuit 2 times in a large amount. But if above-mentioned protection, control, measure, data communication integrated computer device, install in to is it by the equipment , protect into voltage , electric current amount of equipment in device this after changing into the figure amount to protect outdoor transformer substation on the spot, send to the top management room through the computer network, can avoid a large number of controlcables . If use optic fibre as the transmission medium of the network , can avoid and interfere electromagnetically. The photocurrent mutual inductor of now (ota ) and photovoltage mutual inductor (otv ) have been already during the course of studying and testing, must get application in the power system in the future. In case of adopting ota and otv, namely should be putting and is being protected near the equipment.After the optical signals of ota and otv are input in the integrated device here and changes into an electric signal, what is on one hand uses as being protected calculation is judged ; As measurement amount on the other hand, send to the top management room through the network. Can to protect operation of equipment control order send this integrated device to through network from top management room, therefore the integrated device carries out the operation of the circuit breaker. The university of Tianjin put forward protecting,controlled , measured , communication integration in 1992, develop based on tms320c25 digital signal processor (dsp ) first protecting , control , measure , the integrated device of data communication.4)IntelligentIn recent years, if artificial intelligence technology neural network, hereditary algorithm, evolve plan , fuzzy logic ,etc. get application in power system all field, the research that is used in the field of relay protection has already begun too. Neural network one non-linear method that shine upon, a lot of difficult to list equation or difficult in order to the complicated non-linear question that is solved, use the method of the neural network to be very easily solved .For example the short circuit of crossing the resistance of courseof emergence is a non-linear problem in transmit electricity in the systematic electric potential angle of both sides of line and lay cases, it is very difficult to make discrimination , trouble of position while being correct for distance to protect, is it work up or is it work up to refuse by mistake to lead to the fact; If use neural network method, through a large number of trouble training of sample, so long as sample centralized to fully consider various kinds of situations, can differentiate correctly while any trouble takes place. Other if hereditary algorithm , is it is it have is it solve complicated abilityof problem to asking unique their too to plan to evolve. Artificial intelligence the being method proper to is it can make it solve speed to be fast not to ask to combine. Can predict , the artificial intelligence technology must get application in the field of relay protection, in order to solve the problem difficult to solvewith the routine method.中文翻译:继电保护的现状与发展一、继电保护发展现状电力系统的飞速发展对继电保护不断提出新的要求，电子技术、计算机技术与通信技术的飞速发展又为继电保护技术的发展不断地注入了新的活力，因此，继电保护技术得天独厚，在40余年的时间里完成了发展的4个历史阶段。
电力系统与智能电网专业英语
电流变送器
32
voltage regulation
电压调整
13
Network interface card
网络接口卡
33
on load tap changing transformer（OLTC）
有载调压变
压器
14
Pulse Code Modulation
脉冲编码调制
fault calculations
短路计算
18
packet switching
包交换技术
38
load forecasting
负荷预测
19
fuel cells
燃料电池
39
leakage reactances,
漏电抗
20
twisted pair
双绞线
40
Human–Machine Interface
人机界面
姓名：班级：学号：
二、段落翻译
Original text:
Book1: Smart Grid-Technology and Applications(2012) : 269.
Large quantities of electrical energy can be stored using pumped hydro or underground compressed air facilities. Such schemes can have a power rating of up to 1-2 GW with an energy capacity of 10-20 GWh. Smaller quantities of energy can be stored in batteries, flywheels and Superconducting Magnetic Energy Storage (SMES) devices [1-3]. Fuel cells convert a continuous source of chemical energy into electricity but have a similar impact on the power network as some energy storage systems (for example, flow batteries).
智能电网英语作文
智能电网英语作文In the modern era, the concept of the smart grid has emerged as a transformative technology that promises to revolutionize the energy industry. The smart grid refers to an intelligent network of electricity generation, transmission, distribution, and consumption that utilizes advanced technologies such as sensors, meters, analytics, and automation to improve efficiency, reliability, and sustainability.The need for a smart grid arises from the growing demand for electricity coupled with the challenges posed by aging infrastructure and the integration of renewable energy sources. The traditional grid, with its limited capabilities and inflexible structure, is unable to meet these demands effectively. The smart grid, on the other hand, offers a dynamic and adaptive solution that can handle the complexities of modern energy systems.One of the key features of the smart grid is itsability to collect and analyze data in real-time. This is achieved through the deployment of smart meters and sensors throughout the grid. These devices monitor and transmitinformation about energy usage, demand, and supply,enabling utilities to make informed decisions aboutresource allocation and management. This data-driven approach not only improves operational efficiency but also enhances customer engagement and satisfaction.Another crucial aspect of the smart grid is its interoperability and integration capabilities. Itseamlessly integrates various energy sources, including renewables like solar and wind, with traditional power plants. This integration ensures a more balanced andreliable energy supply, reduces dependence on fossil fuels, and lowers greenhouse gas emissions. Furthermore, the smart grid's ability to connect and communicate with devices and appliances in homes and businesses enables demand response programs that encourage conservation and reduce peak demand. The benefits of the smart grid are numerous. Itimproves the overall efficiency of the energy system, reduces waste and losses, and enhances the reliability of power supply. It also promotes the integration of renewable energy, which is crucial for achieving sustainability and mitigating the impacts of climate change. Additionally, thesmart grid creates new business opportunities and economic growth by enabling innovative services and products in the energy sector.Despite its many advantages, the transition to a smart grid faces some challenges. These include technological complexities, high initial investments, and the need for widespread infrastructure upgrades. However, with continued research and development, as well as government policies and incentives, the smart grid has the potential to become a reality in the near future.In conclusion, the smart grid represents a significant leap forward in the energy industry. It offers a comprehensive solution to address the challenges of aging infrastructure, increasing demand, and the integration of renewable energy sources. By leveraging advanced technologies and data analytics, the smart grid can transform the way we generate, transmit, distribute, and consume electricity, making it more efficient, reliable, and sustainable.**智能电网：能源行业的革命**在现代社会，智能电网作为一项变革性技术，已经崭露头角，有望彻底改变能源行业。
智能电网供配电系统中英文对照外文翻译文献
中英文对照资料外文翻译外文资料翻译Power supply system of high-rise building designAbstract: with the continuous development of city size, more and more high-rise buildings, therefore high-rise building electrical design to the designers had to face. In this paper, an engineering example, describes the electrical design of high-rise buildings and some of the more typical issues of universal significance, combined with the actual practice of an engineering solution to the problem described.Key words: high-rise building; electrical design; distribution; load calculation1 Project OverviewThe commercial complex project,with a total construction area of 405570m2,on the ground floor area of 272330m2, underground construction area of 133240m2, the main height of 99m. Project components are: two office buildings, construction area is 70800m2, 28 layers, the standard story is 3.2m.2 Load Calculation1) Load characteristics: electric load, much larger than the "national civil engineering technical measures" Large 120W/m2 indicators, especially in the electricity load more food, and different types of food and beverage catering different cultural backgrounds also high.2) the uncertainty of a large load, because the commercial real estate rents are often based on market demand, and constantly adjust the nature of the shops, making the load in the dynamic changes.3) There is no specification and technical measures in the different types of commercial projects refer to the detailed parameters of the shops, engineering design load calculation in the lack of data, in most cases to rely on staff with previous experience in engineering design calculations.Load the selection of parameters: for the above problems, the load calculation, the first developer of sales and good communication, to determine the form of layers of the forms and nature of floor area, which is calculated on the basis of electrical load basis; followed to determine parameter index within the unit area of shops is also very important and complex because there is no clear indicator of the specification can refer to; and different levels of economic development between cities is not balanced, power indices are also different; will be in the same city, different regions have different consumer groups .3) the need to factor in the choice: parameters determined, the need for load calculation. Need to factor commonly used method, the calculation will not repeat them. Need to explore is the need for coefficient selection, which in the current specifications, manuals and the "unified technical measures" is also not clear requirements, based on years of design experience that most end shops in the distribution or level within the household distribution box with case Kx generally take a while, in the calculation of the loop route to take 0.7 to 0.8, the distribution transformers in the substation calculations take 0.4 to 0.6.3 substations setLoad calculation based on the results of this project the total installed capacity of transformer 43400Kv.A, after repeated consultations with the power company, respectively, in the project in northern, central and southern three sections set the three buildings into three power substations, 1 # set 6 sets 2500Kv.A transformer substation, take the northern section of power supply; 2 # 4 1600Kv.A transformer substations located, plus 6 sets 2000Kv.A transformers, take the middle of the power supply, in addition to 5 Taiwan 10Kv.A high-pressure water chillers (total 4000Kv.A); 3 # substation located 2 units plus 2 units 1000Kv.A 2000Kv.A transformers, take the southern section of A, B twooffice supply. 10Kv power configuration of this project into two points, each at the two 10Kv lines, the power company under the provisions of 10Kv power capacity: maximum load per channel is about to 11000Kv.A, two is the 22000Kv.A, design # 1 , 3 # combination of a substation 10Kv, power line, with a total capacity of 21000Kv.A; 2 # substation transformers and 10Kv, 10Kv chillers sharing a power line, with a total capacity of 22400Kv.A. The design of the substation layout, in addition to meeting regulatory requirements, it also need to consider the high-pressure cabinets, transformers and low voltage power supply cabinet by order of arrangement, especially in low voltage distribution cabinet to feed the cable smooth and easy inspection duty problems are not seriously consider the construction of the cable crossing will cause more long detour, a waste of floor space, and convenient inspections and other issues【8】.4 small fire load power supplyIn the design of large commercial projects often encounter small fire load of electrical equipment and more dispersed distribution, if fed by a substation, a substation will be fed a lot of low-voltage low-current counter circuit breaking capacity circuit breaker and conductor of the dynamic and thermal stability in a certain extent. According to GB50045-1995 "fire protection design of tall buildings," rule "should be used in Fire Equipment dedicated power supply circuit, the power distribution equipment shall be provided with clear signs." Interpretation of the provisions of the power supply circuit means "from the low-voltage main distribution room (including the distribution of electrical room) to last a distribution box, and the general distribution lines should be strictly separated." In this design, the use of methods to increase the level of distribution, that is different from the substation bus segments, respectively, a fire fed a special circuit, set in place two distribution cabinets, distribution cabinets and then the resulting radial allocated to the end of the dual power to vote each box, so that not only meets the specification requirements for dedicated power supply circuit, but also to avoid feeding the substation level of many small current loop.5, the choice of circuit breaker and conductorCommercial real estate projects use the room as the uncertainty in the choice of circuit breakers and conductors must be considered in a certain margin to meet the needs caused by adjustment of the load changes. According to this characteristic, increased use in the design of the plug bus-powered, not only meet the requirements of large carrying capacity, and also allows the flexibility to increase supply and distribution, are reserved in each shaft in the plug-box backup in order to change, according to changes in upper and lower load, to adjust. For example: a bus is responsible for a shaft 1 to 3 layers of power, when a layer due to the change in capacity increases, while the 3-layer capacity is reduced, you can use a spare plug box layer off the 3-layer 1 layer capacity rationing . This level distribution in the substation, select the circuit breaker to choose the setting value when the circuit breaker to adjust to changes at the end to adjust the load setting value; in the bus and the transformer circuit breaker according to the choice of the general framework of values to select . For example: Route certain equipment capacity 530Kv, Kx take 0.7 to calculate current of 704A, select the frame circuit breaker is 1000A, tuning is 800A; current transformer for the 1000/50; bus carrying capacity for the 1000A, this road can meet the maximum 1000A current load requirements, even if there is adjustment, power distribution switches and circuit can not make big changes.6 layer distribution box setAccording to the division of layers of fire protection district, respectively numbered as A ~ K layers within the set level shaft for the retail lighting power distribution box, with one on one power supply shops in radial power. Should be noted that the forms of the complex layers of layers of fire partition, does not correspond to the lower, making some of shaft power in charge of the fire district at the same time, also responsible for the power supply adjacent to the fire district. At design time, using the principle of proximity, while also taking into account the burden of the whole trunk load conditions, so that each shaft as far as possible a more balanced load. PrerequisitesThe loop that you want to auto-tune must be in automatic mode. The loopoutput must be controlled by the execution of the PID instruction. Auto-tune will fail if the loop is in manual mode.Before initiating an auto-tune operation your process must be brought to a stable state which means that the PV has reached setpoint (or for a P type loop, a constant difference between PV and setpoint) and the output is not changing erratically.Ideally, the loop output value needs to be near the center of the control range when auto-tuning is started. The auto-tune procedure sets up an oscillation in the process by making small step changes in the loop output. If the loop output is close to either extreme of its control range, the step changes introduced in the auto-tune procedure may cause the output value to attempt to exceed the minimum or the maximum range limit.If this were to happen, it may result in the generation of an auto-tune error condition, and it will certainly result in the determination of less than near optimal suggested values.Auto-Hysteresis and Auto-DeviationThe hysteresis parameter specifies the excursion (plus or minus) from setpoint that the PV (process variable) is allowed to make without causing the relay controller to change the output. This value is used to minimize the effect of noise in the PV signal to more accurately determine the natural oscillation frequency of the process.If you select to automatically determine the hysteresis value, the PID Auto-Tuner will enter a hysteresis determination sequence. This sequence involves sampling the process variable for a period of time and then performing a standard deviation calculation on the sample results.In order to have a statistically meaningful sample, a set of at least 100 samples must be acquired. For a loop with a sample time of 200 msec, acquiring 100 samples takes 20 seconds. For loops with a longer sample time it will take longer. Even though 100 samples can be acquired in less than 20 seconds for loops with sample times less than 200 msec, the hysteresis determinationsequence always acquires samples for at least 20 seconds.Once all the samples have been acquired, the standard deviation for the sample set is calculated. The hysteresis value is defined to be two times the standard deviation. The calculated hysteresis value is written into the actual hysteresis field (AHYS) of the loop table.TipWhile the auto-hysteresis sequence is in progress, the normal PID calculation is not performed. Therefore, it is imperative that the process be in a stable state prior to initiating an auto-tune sequence. This will yield a better result for the hysteresis value and it will ensure that the process does not go out of control during the auto-hysteresis determination sequence.The deviation parameter specifies the desired peak-to-peak swing of the PV around the set point. If you select to automatically determine this value, the desired deviation of the PV is computed by multiplying the hysteresis value by 4.5. The output will be driven proportionally to induce this magnitude of oscillation in the process during auto-tuning.Auto-Tune SequenceThe auto-tuning sequence begins after the hysteresis and deviation values have been determined. The tuning process begins when the initial output step is applied to the loop output.This change in output value should cause a corresponding change in the value of the process variable. When the output change drives the PV away from setpoint far enough to exceed the hysteresis boundary a zero-crossing event is detected by the auto-tuner. Upon each zero crossing event the auto-tuner drives the output in the opposite direction.The tuner continues to sample the PV and waits for the next zero crossing event.A total of twelve zero-crossings are required to complete the sequence. The magnitude of the observed peak-to-peak PV values (peak error) and the rate at which zero-crossings occur are directly related to the dynamics of the process. Early in the auto-tuning process, the output step value is proportionally adjustedonce to induce subsequent peak-to-peak swings of the PV to more closely match the desired deviation amount. Once the adjustment is made, the new output step amount is written into the Actual Step Size field (ASTEP) of the loop table.The auto-tuning sequence will be terminated with an error, if the time between zero crossings exceeds the zero crossing watchdog interval time. The default value for the zero crossing watchdog interval time is two hours.Figure 1 shows the output and process variable behaviors during an auto-tuning sequence on a direct acting loop. The PID Tuning Control Panel was used to initiate and monitor the tuning sequence.Notice how the auto-tuner switches the output to cause the process (as evidenced by the PV value) to undergo small oscillations. The frequency and the amplitude of the PV oscillations are indicative of the process gain and natural frequency.7 public area distribution box setTaking into account the future needs of the business re-decoration of public areas must be reserved for power. Here the design needs to consider the following points:①question of how much reserve power, lighting and electricity, which according to GB50034-2004 "Architectural Lighting Design Standards" table of Article 6.1.3 and 6.1.8, commercial building lighting power density value, high-end supermarkets, business offices as 20W/m2, under the "decorative lighting included 50% of the total lighting power density calculation" requirements, using the reserved standard 40W/m2.②In order to facilitate the decoration in each partition set fire lighting in public areas and emergency lighting distribution box distribution box, in order to identify the electrical power distribution decoration cut-off point.③the staircase, storage rooms and other parts of the decoration does not need to do, set the power distribution circuit or a separate distribution box, try not to be reserved from the public area of electricity distribution board fed hardcover out.④control of lighting in public areas, the majority in two ways, namely,C-BUS control system or the BA system, the use of C-BUS has the advantage of more flexible control, each road can be fed out of control, adjustable light control; shortcomings is a higher cost. BA system control advantages of using low cost, simple control; disadvantage is that the exchanges and contacts for the three-phase, three-way control may be related both to open, or both, in the decoration of the contacts required to feed the power supply circuit diverge to avoid failure blackouts.Design of distribution box 8In the commercial real estate design, shop design is often only a meter box, and outlet route back to the needs of the user according to their second design, but the shops are difficult to resolve within the power supply fan coil units, air-conditioning system as a whole can not debug. The project approach is to add a circuit breaker in the meter box for the coil power supply, another way for users to use the second design, as shown below.User distribution box design9 distribution cabinet / box number and distribution circuitsLarge-scale projects are often low voltage distribution cabinet / box number, low-voltage circuits to feed the more often there will be cabinet / box number and line number duplication, resulting in the design and the future looks difficult maintenance and overhaul. The project has three 10Kv substations, 20 transformer, hundreds of low-voltage fed out of the closet, fed the circuit more. Accordance with the International Electrotechnical Commission (IEC) and the Chinese national standard requirements:①All the distribution number to be simple and clear, not too box and line numbers are not repeated.②number to simple and clear, not too long.③distinction between nature and type of load.④law was easy to find, make viewer at a glance. Based on the above requirements and on the ground, fire district and the underground construction industry form the different conditions, using two slightly different ways.Essential for the underground garage, uses a single comparison, also relatively fire district neat, according to fire district number, such as AL-BL-1 / 1, AP and APE, the meaning of the letters and numbers: AL on behalf of lighting distribution (AP on behalf of Power distribution box, APE on behalf of the emergency power distribution box); BI on behalf of the basement; 1 / 1 for partition 1, I fire box. Above ground is more complex, more fire district, and on the fire district does not correspond to the lower, according to shaft number is better, such as AL-1-A1, AP, and APE, letters and numbers mean: 1 represents a layer; A1 on behalf of A, No. 1 shaft fed a distribution box. Fed a low-voltage circuits, such as the number of uses: W3-6-AL-1-A1, W3-6) indicates that the route back to power supply transformer 3, 6, feed the power distribution cabinet, AL-1-A1, said the then the first loop of the distribution box for the AL-1-A1 and so on, and so on.10 ConclusionWith more and more complex commercial design projects, designers need to continually improve the design level, designed to make fine. These are only bits of the design in the business lessons learned, and the majority of designers want to communicate译文：浅谈高层建筑供配电系统设计摘要：随着城市规模的不断发展，高层建筑越来越多，因此，高层建筑电气设计就成为设计者不得不面对的问题。
智能电网供配电系统中英文对照外文翻译文献
中英文对照资料外文翻译外文资料翻译Power supply system of high-rise building designAbstract: with the continuous development of city size, more and more high-rise buildings, therefore high-rise building electrical design to the designers had to face. In this paper, an engineering example, describes the electrical design of high-rise buildings and some of the more typical issues of universal significance, combined with the actual practice of an engineering solution to the problem described.Key words: high-rise building; electrical design; distribution; load calculation1 Project OverviewThe commercial complex project,with a total construction area of 405570m2,on the ground floor area of 272330m2, underground construction area of 133240m2, the main height of 99m. Project components are: two office buildings, construction area is 70800m2, 28 layers, the standard story is 3.2m.2 Load Calculation1) Load characteristics: electric load, much larger than the "national civil engineering technical measures" Large 120W/m2 indicators, especially in the electricity load more food, and different types of food and beverage catering different cultural backgrounds also high.2) the uncertainty of a large load, because the commercial real estate rents are often based on market demand, and constantly adjust the nature of the shops, making the load in the dynamic changes.3) There is no specification and technical measures in the different types of commercial projects refer to the detailed parameters of the shops, engineering design load calculation in the lack of data, in most cases to rely on staff with previous experience in engineering design calculations.Load the selection of parameters: for the above problems, the load calculation, the first developer of sales and good communication, to determine the form of layers of the forms and nature of floor area, which is calculated on the basis of electrical load basis; followed to determine parameter index within the unit area of shops is also very important and complex because there is no clear indicator of the specification can refer to; and different levels of economic development between cities is not balanced, power indices are also different; will be in the same city, different regions have different consumer groups .3) the need to factor in the choice: parameters determined, the need for load calculation. Need to factor commonly used method, the calculation will not repeat them. Need to explore is the need for coefficient selection, which in the current specifications, manuals and the "unified technical measures" is also not clear requirements, based on years of design experience that most end shops in the distribution or level within the household distribution box with case Kx generally take a while, in the calculation of the loop route to take 0.7 to 0.8, the distribution transformers in the substation calculations take 0.4 to 0.6.3 substations setLoad calculation based on the results of this project the total installed capacity of transformer 43400Kv.A, after repeated consultations with the power company, respectively, in the project in northern, central and southern three sections set the three buildings into three power substations, 1 # set 6 sets 2500Kv.A transformer substation, take the northern section of power supply; 2 # 4 1600Kv.A transformer substations located, plus 6 sets 2000Kv.A transformers, take the middle of the power supply, in addition to 5 Taiwan 10Kv.A high-pressure water chillers (total 4000Kv.A); 3 # substation located 2 units plus 2 units 1000Kv.A 2000Kv.A transformers, take the southern section of A, B twooffice supply. 10Kv power configuration of this project into two points, each at the two 10Kv lines, the power company under the provisions of 10Kv power capacity: maximum load per channel is about to 11000Kv.A, two is the 22000Kv.A, design # 1 , 3 # combination of a substation 10Kv, power line, with a total capacity of 21000Kv.A; 2 # substation transformers and 10Kv, 10Kv chillers sharing a power line, with a total capacity of 22400Kv.A. The design of the substation layout, in addition to meeting regulatory requirements, it also need to consider the high-pressure cabinets, transformers and low voltage power supply cabinet by order of arrangement, especially in low voltage distribution cabinet to feed the cable smooth and easy inspection duty problems are not seriously consider the construction of the cable crossing will cause more long detour, a waste of floor space, and convenient inspections and other issues【8】.4 small fire load power supplyIn the design of large commercial projects often encounter small fire load of electrical equipment and more dispersed distribution, if fed by a substation, a substation will be fed a lot of low-voltage low-current counter circuit breaking capacity circuit breaker and conductor of the dynamic and thermal stability in a certain extent. According to GB50045-1995 "fire protection design of tall buildings," rule "should be used in Fire Equipment dedicated power supply circuit, the power distribution equipment shall be provided with clear signs." Interpretation of the provisions of the power supply circuit means "from the low-voltage main distribution room (including the distribution of electrical room) to last a distribution box, and the general distribution lines should be strictly separated." In this design, the use of methods to increase the level of distribution, that is different from the substation bus segments, respectively, a fire fed a special circuit, set in place two distribution cabinets, distribution cabinets and then the resulting radial allocated to the end of the dual power to vote each box, so that not only meets the specification requirements for dedicated power supply circuit, but also to avoid feeding the substation level of many small current loop.5, the choice of circuit breaker and conductorCommercial real estate projects use the room as the uncertainty in the choice of circuit breakers and conductors must be considered in a certain margin to meet the needs caused by adjustment of the load changes. According to this characteristic, increased use in the design of the plug bus-powered, not only meet the requirements of large carrying capacity, and also allows the flexibility to increase supply and distribution, are reserved in each shaft in the plug-box backup in order to change, according to changes in upper and lower load, to adjust. For example: a bus is responsible for a shaft 1 to 3 layers of power, when a layer due to the change in capacity increases, while the 3-layer capacity is reduced, you can use a spare plug box layer off the 3-layer 1 layer capacity rationing . This level distribution in the substation, select the circuit breaker to choose the setting value when the circuit breaker to adjust to changes at the end to adjust the load setting value; in the bus and the transformer circuit breaker according to the choice of the general framework of values to select . For example: Route certain equipment capacity 530Kv, Kx take 0.7 to calculate current of 704A, select the frame circuit breaker is 1000A, tuning is 800A; current transformer for the 1000/50; bus carrying capacity for the 1000A, this road can meet the maximum 1000A current load requirements, even if there is adjustment, power distribution switches and circuit can not make big changes.6 layer distribution box setAccording to the division of layers of fire protection district, respectively numbered as A ~ K layers within the set level shaft for the retail lighting power distribution box, with one on one power supply shops in radial power. Should be noted that the forms of the complex layers of layers of fire partition, does not correspond to the lower, making some of shaft power in charge of the fire district at the same time, also responsible for the power supply adjacent to the fire district. At design time, using the principle of proximity, while also taking into account the burden of the whole trunk load conditions, so that each shaft as far as possible a more balanced load. PrerequisitesThe loop that you want to auto-tune must be in automatic mode. The loopoutput must be controlled by the execution of the PID instruction. Auto-tune will fail if the loop is in manual mode.Before initiating an auto-tune operation your process must be brought to a stable state which means that the PV has reached setpoint (or for a P type loop, a constant difference between PV and setpoint) and the output is not changing erratically.Ideally, the loop output value needs to be near the center of the control range when auto-tuning is started. The auto-tune procedure sets up an oscillation in the process by making small step changes in the loop output. If the loop output is close to either extreme of its control range, the step changes introduced in the auto-tune procedure may cause the output value to attempt to exceed the minimum or the maximum range limit.If this were to happen, it may result in the generation of an auto-tune error condition, and it will certainly result in the determination of less than near optimal suggested values.Auto-Hysteresis and Auto-DeviationThe hysteresis parameter specifies the excursion (plus or minus) from setpoint that the PV (process variable) is allowed to make without causing the relay controller to change the output. This value is used to minimize the effect of noise in the PV signal to more accurately determine the natural oscillation frequency of the process.If you select to automatically determine the hysteresis value, the PID Auto-Tuner will enter a hysteresis determination sequence. This sequence involves sampling the process variable for a period of time and then performing a standard deviation calculation on the sample results.In order to have a statistically meaningful sample, a set of at least 100 samples must be acquired. For a loop with a sample time of 200 msec, acquiring 100 samples takes 20 seconds. For loops with a longer sample time it will take longer. Even though 100 samples can be acquired in less than 20 seconds for loops with sample times less than 200 msec, the hysteresis determinationsequence always acquires samples for at least 20 seconds.Once all the samples have been acquired, the standard deviation for the sample set is calculated. The hysteresis value is defined to be two times the standard deviation. The calculated hysteresis value is written into the actual hysteresis field (AHYS) of the loop table.TipWhile the auto-hysteresis sequence is in progress, the normal PID calculation is not performed. Therefore, it is imperative that the process be in a stable state prior to initiating an auto-tune sequence. This will yield a better result for the hysteresis value and it will ensure that the process does not go out of control during the auto-hysteresis determination sequence.The deviation parameter specifies the desired peak-to-peak swing of the PV around the set point. If you select to automatically determine this value, the desired deviation of the PV is computed by multiplying the hysteresis value by 4.5. The output will be driven proportionally to induce this magnitude of oscillation in the process during auto-tuning.Auto-Tune SequenceThe auto-tuning sequence begins after the hysteresis and deviation values have been determined. The tuning process begins when the initial output step is applied to the loop output.This change in output value should cause a corresponding change in the value of the process variable. When the output change drives the PV away from setpoint far enough to exceed the hysteresis boundary a zero-crossing event is detected by the auto-tuner. Upon each zero crossing event the auto-tuner drives the output in the opposite direction.The tuner continues to sample the PV and waits for the next zero crossing event.A total of twelve zero-crossings are required to complete the sequence. The magnitude of the observed peak-to-peak PV values (peak error) and the rate at which zero-crossings occur are directly related to the dynamics of the process. Early in the auto-tuning process, the output step value is proportionally adjustedonce to induce subsequent peak-to-peak swings of the PV to more closely match the desired deviation amount. Once the adjustment is made, the new output step amount is written into the Actual Step Size field (ASTEP) of the loop table.The auto-tuning sequence will be terminated with an error, if the time between zero crossings exceeds the zero crossing watchdog interval time. The default value for the zero crossing watchdog interval time is two hours.Figure 1 shows the output and process variable behaviors during an auto-tuning sequence on a direct acting loop. The PID Tuning Control Panel was used to initiate and monitor the tuning sequence.Notice how the auto-tuner switches the output to cause the process (as evidenced by the PV value) to undergo small oscillations. The frequency and the amplitude of the PV oscillations are indicative of the process gain and natural frequency.7 public area distribution box setTaking into account the future needs of the business re-decoration of public areas must be reserved for power. Here the design needs to consider the following points:①question of how much reserve power, lighting and electricity, which according to GB50034-2004 "Architectural Lighting Design Standards" table of Article 6.1.3 and 6.1.8, commercial building lighting power density value, high-end supermarkets, business offices as 20W/m2, under the "decorative lighting included 50% of the total lighting power density calculation" requirements, using the reserved standard 40W/m2.②In order to facilitate the decoration in each partition set fire lighting in public areas and emergency lighting distribution box distribution box, in order to identify the electrical power distribution decoration cut-off point.③the staircase, storage rooms and other parts of the decoration does not need to do, set the power distribution circuit or a separate distribution box, try not to be reserved from the public area of electricity distribution board fed hardcover out.④control of lighting in public areas, the majority in two ways, namely,C-BUS control system or the BA system, the use of C-BUS has the advantage of more flexible control, each road can be fed out of control, adjustable light control; shortcomings is a higher cost. BA system control advantages of using low cost, simple control; disadvantage is that the exchanges and contacts for the three-phase, three-way control may be related both to open, or both, in the decoration of the contacts required to feed the power supply circuit diverge to avoid failure blackouts.Design of distribution box 8In the commercial real estate design, shop design is often only a meter box, and outlet route back to the needs of the user according to their second design, but the shops are difficult to resolve within the power supply fan coil units, air-conditioning system as a whole can not debug. The project approach is to add a circuit breaker in the meter box for the coil power supply, another way for users to use the second design, as shown below.User distribution box design9 distribution cabinet / box number and distribution circuitsLarge-scale projects are often low voltage distribution cabinet / box number, low-voltage circuits to feed the more often there will be cabinet / box number and line number duplication, resulting in the design and the future looks difficult maintenance and overhaul. The project has three 10Kv substations, 20 transformer, hundreds of low-voltage fed out of the closet, fed the circuit more. Accordance with the International Electrotechnical Commission (IEC) and the Chinese national standard requirements:①All the distribution number to be simple and clear, not too box and line numbers are not repeated.②number to simple and clear, not too long.③distinction between nature and type of load.④law was easy to find, make viewer at a glance. Based on the above requirements and on the ground, fire district and the underground construction industry form the different conditions, using two slightly different ways.Essential for the underground garage, uses a single comparison, also relatively fire district neat, according to fire district number, such as AL-BL-1 / 1, AP and APE, the meaning of the letters and numbers: AL on behalf of lighting distribution (AP on behalf of Power distribution box, APE on behalf of the emergency power distribution box); BI on behalf of the basement; 1 / 1 for partition 1, I fire box. Above ground is more complex, more fire district, and on the fire district does not correspond to the lower, according to shaft number is better, such as AL-1-A1, AP, and APE, letters and numbers mean: 1 represents a layer; A1 on behalf of A, No. 1 shaft fed a distribution box. Fed a low-voltage circuits, such as the number of uses: W3-6-AL-1-A1, W3-6) indicates that the route back to power supply transformer 3, 6, feed the power distribution cabinet, AL-1-A1, said the then the first loop of the distribution box for the AL-1-A1 and so on, and so on.10 ConclusionWith more and more complex commercial design projects, designers need to continually improve the design level, designed to make fine. These are only bits of the design in the business lessons learned, and the majority of designers want to communicate译文：浅谈高层建筑供配电系统设计摘要：随着城市规模的不断发展，高层建筑越来越多，因此，高层建筑电气设计就成为设计者不得不面对的问题。
智能电网外文翻译
2010 International Conference on Power System TechnologyNew Challenges to Power System Planning and Operation of Smart Grid Development in ChinaZhang Ruihua, Du Yumei, Liu YuhongAbstract--The future development trend of electric power gridis smart grid, which includes such features as secure and reliable, efficientandeconomical,cleanandgreen,flexibleandcompatible, open and interactive, integrated and so on. The concept and characteristics of smart grid are introduced in this paper.On the basis of practical national situation, thedevelopment plans of smart grid in china with Chinese characteristics are proposed. Smart grid development in china is bases on information technology, communication technology, computertechnologywiththehighintegrationwithinfrastructure of generating, transmission and distribution power system. Besides, smart grid development in china brings forward many new challenge and requirements for power system planning and operation in 9 key technologies as below:1. Planning and construction of strong ultra high voltage (UHV) power grid2. Large-scale thermal power, hydropower and nuclear power bases integration of power grid3. Large-scale renewable energy sources integration of power grid4. Distributed generation and coordinated development of the grids of various voltage ratings5. Study on smart grid planning and developing strategy6. Improve the controllability of the power grid based on power electronics technology.7. Superconductivity, energystorageand othernewtechnologies widely used in power system8.Powersystemsecuritymonitoring,fastsimulation,intelligent decision-making and comprehensive defense technology9. The application of emergency and restoration control technology in power systemIn response to the challenge, this paper presents the mainresearch contents, detailed implementation plan and anticipated goals ofabove 9 key technologies.Some measures andsuggestions for power system planning and operation of smart grid development in China are given in this paper.Index Terms--smart grid, power system planning, powersystem operation, key technologies, large-scale power bases, information andcommunicationtechnology,computertechnology.Zhang Ruihua is with the Institute of Electrical Engineering, Chinese Academy of Sciences(CAS), Beijing 100190, China (E-mail: ruihuazh @mail .iee ).DU Yumei is with the Institute of Electrical Engineering, Chinese Academy of S ciences(CAS), Beij ing 100190, ChinaLiu Yuhong is with the Institute of Electrical Engineering, Chinese Academy ofSciences(CAS), Beijing 100190, China978-1-4244-5940-7/10/$26.00©20 1 0 IEEEI. INTRODUCTIONWITH the increasing pressure on environmental protection, energy conserving and persistence develops improves gradually required for society. At the same time, power market-oriented development consistently and provide higher electric energy reliability and quality are required for consumer_ It require that the future smart grid must can to provide secure, reliable, clean, high quality power supply, is able to adapt to various of electric power generation, need being able to adapt to highly become market-oriented electric power exchange especially, acting on selfs own being able to adapt to customer especially chooses need, further, improve the ample power grid assets utilization efficiency and beneficial result, provide higher quality service. For this purpose, many countries without exception look upon smart grid as future development direction of power grid [1-4].On the basis of present situation and practical condition, the development plans of smart grid in china with Chinese characteristics are proposed. The imbalance in the distribution of energy resources and the development of regional economic requires the high efficient development of energy resource in western region to satisfy the electricity demand of whole country. Besides, the limitation of environmental capacity confines conventional coal-fired thermal power in East China, which requires a new model of power supply, which will carry out large-scale power flows and balance between regions [5].The power system condition in different areas of China is very different. The condition of China's energy and electricity load distribution to determine the long-distance large scale power transmission will be the direction of the development of China's power system_ So, this determined the smart grid of China with the common characters of smart grid, it with the unique characters of large sending ends, large receiving ends, large power transmission grid [6-9].Smart grid development in china is bases on information technology, communication technology, computer technology with the high integration with infrastructure of generating, transmission and distribution power system [10-13]. Smart grid development in china addresses many new challenge and requirements for power system planning and operation in 9 key technical aspects. To response the challenge, the paper presents main research contents and key technologies in the area of power system planning and operation, and proposed detailed implementation procedure and anticipated goals.Finally, some measures and suggestions for power system planning and operation about China smart grid development are given in the paper.II. DEFINITION AND CHARACTERISTICS OF SMART GRIDA. The Definition of Smart GridBased on physical power grid, smart grid is a new type power grid which highly integrates modern advanced information techniques, communication techniques, computer science and techniques with physical grids. It has many advantages, such as improving energy efficiency, reducing the impact to environment, enhancing the security and reliability of power supply and reducing the power loss of the electricity transmission network and so on.The objectives of smart grid are: fully satisfy customer requirements for electrical power, optimize resources allocation, ensure the security, reliability and economic of power supply, satisfy environment protection constraints, guarantee power quality and adapt to power market development. Smart grid can provide customer with reliable, economical, clean and interactive power supply and valueadded services.B. The Characteristics of Smart GridSmart grid holds the promise that the power sector can go "green" by not simply reducing the use of dirty power generation methods but instead become a system that can take more aggressive measures to lower greenhouse gas emissions through efficient integration of renewable energy sources. Smart grid that focus on improving demand-side management for energy and promoting renewable energy could be a transformational force that redefines the way people view energy generation, transmission and consumption, in that such grids would encourage active engagement by the broader society, not just power sector specialists.Smart grid mainly has features as secure and reliable, efficient and economical, clean and green, flexible and compatible, open and interactive, integrated and so on [14-15].( 1) Secure and Reliable: The power grid is still to maintain the power supply capacity to the users, rather than a large area power outage when big disturbances on the power grid, faults, natural disasters and extreme weather conditions, or man-made damage happen.( 2) Efficient and Economical: The power grid can improve the economic benefits through technological innovation, energy efficient management, orderly market competition and related policies. The power grid is in support of the electricity market and power transactions effectively to achieve the rational allocation of resources and reduce power losses and finally to improve the efficiency of energy.(3) Clean and Green: a large-scale of renewable energy sources can be fed into the grid which will reduce the potential impact on the environment.(4) Optimization: The power grid can improve power supply reliability and security to meet electricity demand in digital age. The optimal cost to provide qualified electricity to the community. Smart grid can optimize utilization of assets, reduce investment costs and operation and maintenance costs. Quality of power meets industry standards and consumer needs. Provide various level of power quality for the range of needs.(5) Interactive: interaction and real-time response to the power market and consumers, which improves service. Mature wholesale market operations in place, well integrated nationwide and integrated with reliability coordinators. Retail markets flourishing where appropriate. Minimize transmission congestion and constraints.(6) Self-healing: The power grid has capabilities such as real-time & on-line security assessment and analysis, powerful control system for early warning and prevention control, automatic fault diagnosis, automatic fault isolation and system self-recovery capability. Self-Healing and adaptive to correct problems before they become emergencies. Predictive rather than reactive, to prevent emergencies ahead rather than solve after. Resilient to attack and natural disasters with rapid restoration capabilities.(7) Flexible and Compatible: The power grid can support correct, reasonable integration of renewable energy sources and it is suitable for integration of distributed generation and micro power grid. Besides, it can improve and enhance the function of demand side management to achieve the efficient interaction capability with users. Accommodate all generation and storage options. Very large numbers of diverse distributed generation and storage devices deployed to complement the large generating plants.(8)Integrated: Unified platform and models are used on the power grid. It can achieve a high degree of integration and information sharing of power grid, and to achieve standard, normative and refined management, which integrates the infrastructure, processes, devices, information and market structure so that energy can be generated, distributed, and consumed more efficiently and cost effectively. Thereby achieving a more resilient, secure and reliable energy system. Integrated to merge all critical information.III. SMART GRID DEVELOPMENT IN CHINAA. Necessities of Constructing China's Smart grid(1) Rapid growth of economy and society require to construct strong and reliable, efficient and economical power gridPower grid is the important infrastructure of energy. Chinese economy will remain high-growth in the future, China's energy and electricity demand over a longer period of time to maintain a rapid growth in the basic pattern, as well as the distribution of primary energy resources, uneven distribution and productivity of the basic national conditions, objectively determine the need to implement long-distance,large-scale transmission, walking across the country optimization resource allocation path. Therefore, there is need to construct strong and reliable, efficient and economical power grid.(2) Global resource environment pressure require to construct resource-saving and environmentally-friendly power gridA smart grid is an inevitable choice for China to address issues in its power industry and develop a lower-carbon economy. Much of China's power is generated by dirty coal plants. The government has stated that it wants to clean up its act by boosting renewable power generation to 15 percent of the total power supply by 2020. Chinese smart grid proposals call for the integration of renewable power sources, including wind and solar. The current power grid isn't able to efficiently integrate intermittent power generation from wind turbines or solar panels.In order to optimize the energy structure, improve energy efficiency and improve the climate adaptability, the state has intensified the development on wind, solar and other renewable energy. Especially for the large-scale renewable energy base in the "Three North" area, the local demand is not large enough to consume all local electricity, it's necessary to transmit the electricity through long-distance grid to load center. Generally, due to the intermittence and fluctuation of renewable energy, formulation and implementation of accurate power generation plan is impossible, which challenge the request the present ability on power acceptance and optimizing resource allocation.(3) Various generation options require to construct open and transparent, friendly and interactive power grid With the improving of future Chinese electrification level, power generation enterprises and customers will have higher requirements for service quality and principles. In order to guarantee the power production and transmission, power generation enterprises require power grid to provide reliable, efficient and flexible power integration. Electrical power customers will be able to flexibly choose power supply modes, need interaction between power grid to realize high efficient economical power utilization, and be capable to send distributed energy power to power grid in the right time to realize clean and efficient energy utilization.(4) The development of power and relative industry require to construct power grid with leading technology and equipmentDepending on technology innovation, constructing unified strong smart grid is the development direction of power grid of china. Many advanced technologies and advanced equipment will be applied in constructing smart grid, a substantial platform can be established for the stable and secure operation of grids and improve the strength of the grids' primary systems. It can upgrade the manufacture technology of power equipment and control technology of power grid. The development of smart grid involved technology and products in many fields of information, communication, power equipment manufacture, intelligent home electricity machine and so on. It will promote not only the development of relative industry but also the technology innovation and equipment creation for intelligent building, intelligent home and intelligent transportation.B. Basis oj C onstructing China's Smart gridThe basic development goal of power grid is to form a security and economical power grid. Constructing smart grid firstly depend on strong physical power grid. China speeding up the construction the power grid with UHV grid as backbone and subordinate grids coordinated development at all levels. In the technical and institutional, equipment manufacturing and project put into practice aspects has laid down solid basis for the development of smart grid [16].China pays more attention to research and project implementation, many achievements in smart grid have been accomplished in China. To be specific, China has already research and implementation in following technical aspects: Generation link: In the power generation link includes distributed generation, renewable energy generation, generator and power system coordinate operation, and energy-saving oriented dispatching technology and auto-generation control.Transformation link: In the power transformation link includes UHV AC and U HV DC transmission, FACTS, digital substation technology, PMU-based W A MS, DMS, stateoriented maintenance and so on.Distribution and supply link: In the power distribution and supply link includes distribution automation system and feeder automation system, custom power, auto-metering, Automation measurement technology and electric automobile charge power station construction and so on.Dispatching link: In the Dispatching link, much research and application have been carried out, such as next generation dispatch technology supporting system, four main dispatch application platforms, dispatch technology of energy-saving generation, online early warning and coordinated security and defense technology, integrated model management, massive information process technology, intelligent visualization, dispatch defense technology for extreme disaster.Information building link: In the information building link includes construction of system information collection, load management system, automatic meter reading system and other related systems. After promoting of marketing information work for many years, the coverage of users with electricity collected automatically improves every year, scope and effect of the system is in gradual expansion, it has played an active role in the company's marketing, production and safety management. Many electricity companies are making themselves more digital and information-wise, which also contributes to smart grid construction.C. Development Goals oJ China's Smart gridThe general development goals of China smart grid is speed up construction of a strong power grid with U HV power grid as backbone, coordinated development of power grid at all voltage levels, with information technology, digitization, automation, interactive features into independent innovation,the world's leading strong smart grid.To achieve this goal, the State Grid Corporation of China in accordance with unified planning, unified standard, pilot first, as a whole to promote the principle of speeding up the construction by the UHV AC transmission lines and ±800kV, ±1000kV DC transmission lines constitute a UHV backbone power grid to achieve coordinated development of the power grid at all voltage levels around the power generation, transmission, substations, power distribution, supply, dispatching and other major links and information building, in phases to promote the development of strong smart grid.D. Characteristics of China's Smart GridChinese smart grid framework could be different from the rest of the world. This is due to the relatively primitive structure at the distribution ends, the extensive development ofUHV transmission in recent years, and also the unique asset ownership and management structure in China.China's specific national conditions determined the smart grid of China with the common characters of smart grid, besides, it has own unique characters. These characteristics as below:(1) Large sending ends. Based on intensive exploitation of large-scale thermal power, hydro power, nuclear power and renewable energy base, build a strong and smart guide constructed of UHV power networks as the backbone according to the general requirements of a reliable efficient self-adjustable grid. The strong and smart grid will greatly optimize the allocation of resources, improve the service quality and achieve flexible integration of different sources and loads.(2) Large power transmission grid. The Smart Grid initially proposed in the world is to promote intelligence and automation for distribution system. The shortage of electric power supply in China is still a challenge, so construction for a strong national transmission networks to realize the electric power transmission from the west to the east and the mutual supply between the south and the north is still the main task. In China, to develop a smart transmission grid should be ranked in a priority. Smart transmission grid includes both the construction of a strong U HV grid and the development of the smart dispatch and control technologies.(3) Large receiving ends. In China, the electricity price was not opened to follow the electricity market, so the room for demand side management and costumer participation is limited. Therefore Smart Grid in China has a much different connotation compared with that used in west countries.The smart grid with Chinese characteristics are the means and modes to realize grid asset efficient management, enlarge grids' capability to serve both electricity producers and electricity users, make rational developing planning strategies and optimize system operation under the conditions of continuously lowering costs, improving efficiency and benefits and bettering the reliability and availability of the whole power systems, with U HV power grid as backbone and the coordinated development of the power grid of various voltage levels and in combination of advanced information, communication and control technologies and the advanced managerial philosophy [17-18].IV. NEW CHALLENGES TO POWER SYSTEM PLANNING OFSMART GRID DEVELOPMENT IN CHI NA The development of smart grid in china bring forward many new challenges and requirements for power system planning in 5 key technical aspects, which are analyzed in this section, detailed implementation plan and anticipated goals are proposed. 5 key technical aspects are as follows:A. Planning and Construction of Strong UHV Power GridResearch content: Construct the UHV power grid structure to meet the requirements of smart grid development. The structure must have strong adaptive ability, high reliability and security, strong ability to resist failure for the integration of the multifarious large-scale power generation, and can provides a flexible and easy network infrastructure conditions for the stability control system. Study of the smart power grid structure with the flexible energy exchange ability and the operating conditions adjust ability that can achieve the effective management and efficient use of resources by adjusting power network, and can continuously improve the economic benefits of the power grid.Study the HVDC planning for the receiving-end of the power system, propose the configuration principles for the intelligent dynamic reactive power compensation devices and the planning indices of the HVDC that can improve the voltage stability in the multi-infeed HVDC power system. Forecasting the load, the installed capacity and the power flow scale on the base of the analysis to economic and social development and the energy resources distribution in our country. Demonstrate the major technical problems that should be considered during the construction process of the strong and reasonable UHV network structure. Study the various factors which will affect the development of UHV network with the current technology and the current development status of the power network.Implementation Plan: The first stage will focus mainly on the UHV power development strategy, and the rational structure of UHV power network. The second stage will fully research the way of the large power base integration to UHV power network, the main factors which will affect the multiinfeed HVDC power system, the planning for the receivingend of multi-infeed HVDC power transmission system, and other pivotal technologies. The third stage will fully build the strong UHV network that can meet the demand of the smart grid.Targets: Present the particular configuration of the UHV network that can meet the special needs of the future smart grid. Guide the coordinated and sustainable development to the power grid in our country.B. Large-Scale Ordinary Power Bases Integration of Power SystemResearch content: Smart grid development in china require to study on security and stability, control measures and integration patterns of large-scale hydropower or thermal power bases connecting to power systems. Study the security stability and control technology of the HVDC islanded sending mode. Study coordinated control strategy of AC/DC system to improve system stability and the interactions between the integrated huge wind farms and the power grid. The factors which impact on large power supplies integration of power system are analyzed.Implementation Plan: The first stage will focus mainly on compare the various integration patterns of large power supplies to power grid. The second stage will fully research coordinated control strategy of AC/DC system to improve system stability. The third stage will propose integration patterns and control measures of large power supplies to power grid satisfied to the requirement of smart grid.Targets: Propose the principles optimized integration patterns of large power supply integration to power grid. Enhance generators and power grid coordinate operation, to ensure power system safely and economical operation.C. Large-Scale Renewable Energy Sources Integration of Power SystemResearch content: Study and summarize the electricity production features of various renewable energy sources (such as wind power, photovoltaic power generation). Analyze the influence, the interaction and the technologies that must be considered when the large-scale renewable energy production with different characteristics integration to the power grid.Implementation Plan: The first stage will focus mainly on the influence when the large-scale renewable energy production with different characteristics integration to the power grid. The second stage will fully study the interaction and the technologies that must be considered when the largescale renewable energy production integration to the power grid. The third stage will study the reasonable delivery scale of the renewable energy base and the reasonable delivery proportion of the renewable energy and the conventional energy and other storage systems such as pumped storage device and flywheel energy storage device.Targets: propose the system planning methods and the technologies that can meet the demands when the large renewable energy integration to the power grid.D. Distributed Generation and Coordinated Development of Transmission and Distribution NetworkResearch content: Study the operating characteristics of different distributed power generation and power supply system, study the interaction mechanism between the distributed power supply system and the power grid. Study the coordinated development at all levels of power transmission and distribution under the smart grid goals, and propose the design principles about the coordinated development of the power transmission and distribution planning at all levels; Study the planning method for the coordinated development of UHV I EHV power grid; study the planning principles for regional power grid that are adapt to the development ofUHV power grid; study the influence of HVDC power in-feed and the development of regional EHV power grid; study the principles and the time of looping-off for UHV I EHV electromagnetic loop; study the coordinated planning for UHV I EHV power grid that can improve grid stability and inhibit the short circuit current.Implementation Plan: The first stage will focus mainly on the analysis methods for the distributed power supply system performance, and the coordinated development of the power transmission and distribution at all levels. The second stage will fully research the interaction mechanism between the distributed power supply system and the power grid, and the planning method for the coordinated development of UHV / EHV power grid. The third stage will propose the standards and test specifications for the distributed power gridconnection running.Targets: Propose the planning methods for the coordinated development of the transmission and distribution network, optimize the network resources and improve the safety and reliability of the power supply, and promote the orderly development of distributed power supply, and promote the coordinated development of the power grid at all levels.E. Study on Smart Grid Planning and Developing StrategyResearch content: After fully knowing the characteristics of smart grid development at home and abroad, and the development needs and supporting capacity for intelligence, development direction and problems of our smart grid will be analyzed, investigated and researched further, in order to identify development goals and recognize obstacles in the development process of smart grid. At the same time, we should pay more attention to the study of developing strategy for smart grid in combination with China's specific national conditions. In the strategic planning, the positions, developing frameworks and measures will be clarified. The development roadmap and goals of China's smart grid adaptable to the marketization, especially in the scenario of power market, should be studied. Study on Power System Planning based on Reliability. The procedure of power system planning based on reliability .Implementation Plan: The first stage will mainly focus on the developing strategy for china future power grid, theory and method of strong smart grid planning, Power System Planning based on reliability evaluation method and principle. The second stage will fully research the procedure of power system planning based on reliability. The third stage will develop theory and method structure of the smart grid planning that can meet the requirement of smart grid.Targets: Propose the concept and physical configuration of advanced power grid, propose the planning methods for the coordinated development of the power grid, and promote the coordinated development of the power grid at all levels.。
智能电网英文文献
Research on Dependable Distributed Systems forSmart GridQilin LiProduction and Technology Department, Sichuan Electric Power Science and Research Institute, Chengdu, P.R.ChinaEmail: li_qi_lin@Mingtian ZhouSchool of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu,P.R.ChinaEmail: mtzhou@Abstract—Within the last few years, smart grid has been one of major trends in the electric power industry and has gained popularity in electric utilities, research institutes and communication companies. As applications for smart grid become more distributed and complex, the probability of faults undoubtedly increases. This fact has motivated to construct dependable distributed systems for smart grid. However, dependable distributed systems are difficult to build. They present challenging problems to system designers. In this paper, we first examine the question of dependability and identify major challenges during the construction of dependable systems. Next, we attempt to present a view on the fault tolerance techniques for dependable distributed systems. As part of this view, we present the distributed tolerance techniques for the construction of dependable distributed applications in smart grid. Subsequently, we propose a systematic solution based on the middleware that supports dependable distributed systems for smart grid and study the combination of reflection and dependable middleware. Finally, we draw our conclusions and points out the future directions of research. Index Terms—smart grid, dependability, dependable middleware, fault-tolerance, fault, error, failure, error processing, fault treatment, replication, distributed recovery, partitioning, open implementation, reflection, inspection, adaptationI.I NTRODUCTIONWithin the last few years, smart grid has been one of major trends in the electric power industry and has gained popularity in electric utilities, research institutes and communication companies. The main purpose of smart grid is to meet the future power demands and to provide higher supply reliability, excellent power quality and satisfactory services. Although smart grid brings great benefits to electric power industry, such a new grid introduces new technical challenges to researchers and engineering practioners.As applications for smart grid become more distributed and complex, the probability of faults undoubtedly increases. Distributed systems are defined as a set of geographically distributed components that must cooperate correctly to carry out some common work. Each component runs on a computer. The operation of one component generally depends on the operation of other components that run on different computers[1] [2]. Although the reliability of computer hardware has improved during the last few decades, the probability of component failure still exists. Furthermore, as the number of interdependent components in a distributed system increases, the probability that a distributed service can easily be disrupted if any of the components involved should fail also increases[2]. This fact has motivated to construct dependable distributed systems for smart grid.Fault tolerance is needed in many different dependable distributed applications for smart grid. However, dependable distributed systems are difficult to build. They present challenging problems to system designers. System designers must face the daunting requirement of having to provide dependability at the application level, as well as to deal with the complexities of the distributed application itself, such as heterogeneity, scalability, performance, resource sharing, and the like. Few system designers have these skills. As a result, a systematic approach to achieving the desired dependability for distributed applications in smart grid is needed to simplify the difficult task.Recently, middleware has emerged as an important architectural component in supporting the construction of dependable distributed systems. Dependable middleware can render building blocks to be exploited by applications for enforcing non-functional properties, such as scalability, heterogeneity, fault-tolerance, performance, security, and so on[3]. These attractive features have made middleware a powerful tool in the construction of dependable distributed systems for smart grid [3].This paper makes three contributions to the construction of dependable distributed systems for smart grid. First of all, we examine the question of dependability and identify major challenges during the construction of dependable systems. Subsequently, we attempt to present a view on the fault tolerance techniques for dependable distributed systems. As part of© 2012 ACADEMY PUBLISHER doi:10.4304/jsw.7.6.1250-1257this view, we present the distributed tolerance techniques for building dependable distributed applications in smart grid. Finally, we propose a systematic solution based on the middleware that supports dependable distributed systems for smart grid and study the combination of reflection and dependable middleware.The remainder of this paper is organized as follows: SectionⅡstudies dependability matters for distributed systems in smart grid and identifies the major challenges for the construction of dependable systems. Section Ⅲintroduces basic concepts and key approaches related to fault-tolerance. In SectionⅣ, we discusses distributed fault-tolerant techniques for building dependable systems in smart grid. SectionⅤintroduces dependable middleware to address the ever increasing complexity of distributed systems for smart grid in a reusable way. Finally, SectionⅥdraws our conclusions and points out the future directions of research.Ⅱ.D EPENDABLILITY M ATTERSDistributed systems are intended to form the backbone of emerging applications for smart grid, including supervisory control, data acquisition system and distribution management system, and so on. An obvious benefit of distributed systems is that they reflect the global business and social environments in which electric utilities operate. Another benefit is that they can improve the quality of service in terms of scalability, reliability, availability, and performance for complex power systems.Dependability is an important quality in power distributed applications. In general terms, a system's dependability is defined as the degree to which reliance can justifiably be placed on the service it delivers [4]. The service delivered by a system is its behavior as it is perceived by its user(s); a user is another system (physical, human) which interacts with the former[4]. More specifically, dependability is a global concept that encapsulates the attributes of reliability (continuity of service), availability (readiness for usage), safety (avoidance of catastrophes), and security (prevention of unauthorized handling of information)[2] [4]. In power distributed environments, even small amounts of downtime can annoy customers, hurt sales, or endanger human lives. This fact has made it necessary to build dependable distributed systems for electric utilities.Fault tolerance is an important aspect of dependability. It is referred to as the ability for a system to provide its specified service in spite of component failure[2] [4]. Fault-tolerant system‘s behavior is predictable despite of partial failures, asynchrony, and run-time reconfiguration of the system. Moreover, fault-tolerant applications are highly available. The application can provide its essential services despite the failure of computing nodes, software object crash, communication network partition, value fault for applications [5]. However, building dependable distributed systems is complex and challenging. On the one hand, system designers have to deal explicitly with problems related to distribution, such as heterogeneity, scalability, resource sharing, partial failures, latency, concurrency control, and the like. On the other hand, system developers must have a deep knowledge of fault tolerance and must write fault-tolerant application software from scratch[2]. As consequence, they have to face a daunting and error-prone task of providing fault tolerance at the application level [2].Certain aspects of distributed systems make dependability more difficult to achieve. Distribution presents system developers with a number of inherent problems. For instance, partial failures are an inherent problem in distributed systems. A distributed service can easily be disrupted if any of the nodes involved should fail. As the number of computing nodes and communication links that constitute the system increases, the reliability of components in a distributed system rapidly decreases.Another inherent problem is concurrency control. System developers must address complex execution states of concurrent programs. Distributed systems consist of a collection of components, distributed over various computers connected via a computer network. These components run in parallel on heterogeneous operating systems and hardware platforms and are therefore prone to race conditions, the failure of communication links, node crashes, and deadlocks. Thus, dependable distributed systems are often more difficult to develop, applications developers must cope explicitly with the complexities introduced by distribution.In theory, the fault tolerance mechanisms of a dependable distributed system can be achieved with either software or hardware solution. However, the cost of custom hardware solution is prohibitive. In the meantime, software can provide more flexibility than its counterpart[2]. As a result, software is a better choice for implementing the fault tolerance‘s mechanisms and policies of dependable distributed systems[2]. However, the software solution for the construction of dependable is also difficult. This is particularly true if distributed systems‘ dependability requirements dynamically change during the execution of an application. Further complicating matters are accidental problems such as the lack of widely reused higher level application frameworks, primitive debugging tools, and non-scalable, unreliable software infrastructures. In that case, fault tolerance can be achieved using middleware [2]. Middleware can be devised to address these problems and to hide heterogeneity and the details of the underlying system software, communication protocols, and hardware. Built-in mechanisms and policies for fault-tolerant can be achieved by middleware and provide solutions to the problem of detecting and reacting to partial failures and to network partitioning. Middleware can render a reusable software layer that supports standard interfaces and protocols to construct a fault-tolerance distributed systems. Dependable middleware shields the underlying distributed environment‘s complexity by separating applications from explicit© 2012 ACADEMY PUBLISHERprotocol handling, disjoint memories, data replication, and facilitates the construction of dependable application [6].Ⅲ.F AULT T OLERANCEA. Failure, Error and FaultIn order to construct a dependable distributed system, it is important to understand the concepts of failure, error, and fault. In a distributed system, a failure occurs when the delivered service of a system or a component deviates from its specification[4]. An error is that part of the system state that is liable to lead to subsequent failure. An error affecting the service is an indication that a failure occurs or has occurred[4]. A fault is the adjudged or hypothesized cause of an error [4].In general terms, we think that an error is the manifestation of a fault in the distributed system, while a failure is the effect of an error on the service. As a result, faults are potential sources of system failures.Whether or not an error will actually lead to a failure depends on three major factors. One factor is the system composition, and especially the nature of the existing redundancy [4]. Another factor is the system activity. An error may be overwritten before creating damage[4]. A third factor is t he definition of a failure from the user‗s viewpoint. What is a failure for a given user may be a bearable nuisance for another one [4].Faults and their sources are extremely diversified. They can be categorized according to five main perspectives that are their phenomenological cause, their nature, their phase of creation or of occurrence, their situation with respect to the system boundaries, and their persistence [4].B. Fault modelsWhen designing a distributed fault-tolerant system, we can not to tolerate all faults. As consequence, we must define what types of faults the system is intended to tolerate. The definition of the types of faults to tolerate is referred to as the fault model, which describes abstractly the possible behaviors of faulty components[2] [4]. A system may not, and generally does not, always fail in the same way. The ways a system can fail are its fault modes. As a result, the fault model is an assumption about how components can fail [2] [4].In distributed systems, a fault model is characterized by component and communication failures[2] [4]. It is common to acknowledge that communication failures can only result in lost or delayed messages, since checksums can be used to detect and discard garbled messages[2] [4]. However, duplicated or disordered messages are also included in some models [2] [4].For a component, the most commonly assumed fault models are (in increasing order of generality): stopping failures or crashes, timing fault model, value fault model and arbitrary fault model[2] [4]. Stopping failures or crashes is the simplest and most common assumption about faulty components[2] [4]. This model always assumes that the only way a component can fail is by stopping the delivery of messages and that its internal state is lost [2] [4].The timing fault model assumes that a component will respond with the correct value, but not within a given time specification [2] [4]. A timing fault model can result in events arriving too soon or too late. A timing fault model includes delay and omission faults[2] [4]. A delay fault occurs when the message has the right content but arrives late[2] [4]. An omission fault occurs when no message is received. Sometimes, delay faults are called performance faults[2] [4]. In the value fault model, the value of delivered service does not comply with the specification [2] [4].Arbitrary fault model is the most general fault model, in which components can fail in an arbitrary way [2] [4]. As a result, if arbitrary faults are considered, no restrictive assumption will be made[2] [4]. An arbitrarily faulty component might even send contradictory messages to different destinations (a so-called byzantine fault)[2] [4]. This model can include all possible causes of fault, such as messages arriving too early or too late, messages with incorrect values, messages never sent at all, or malicious faults [2] [4].C. Error Processing and Fault TreatmentFault tolerance is system‘s ability to continue to provide service in spite of faults [2] [4]. It can be achieved by two main forms: error processing and fault treatment [2] [4]. The purpose of error processing is to remove errors from the computational state before a failure occurs, if possible before failure occurrence, whereas the purpose of fault treatment is to prevent faults from being activated again [2] [4].In error processing, error detection, error diagnosis, and error recovery are commonly used approaches[2] [4]. Error detection and diagnosis is an approach that first identifies an erroneous state in the system, and then assesses the damages caused by the detected error or by errors propagated before detection[2] [4]. After error detection and diagnosis, error recovery substitutes an error-free state for the erroneous state [2] [4].Error recovery may take on three forms: backward recovery, forward recovery, and compensation[2] [4]. In backward recovery, the erroneous state transformation consists of bringing the system back to a state already occupied prior to error occurrence[2] [4]. This entails the establishment of recovery points, which are points in time during the execution of a process for which the then current state may subsequently need to be restored [2] [4].In forward recovery, the erroneous state transformation consists of finding a new state, from which the system can operate[2] [4]. Error compensation renders enough redundancy so that a system is able to deliver an error-free service from the erroneous state [2] [4].The goal of fault treatment determines the cause of observed errors and prevents faults from being activated again[2] [4]. The first step in fault treatment is fault diagnosis, which consists of determining the cause(s) of error(s), in terms of both location and nature [2] [4]. Then it© 2012 ACADEMY PUBLISHERtakes actions aimed at making it (them) passive[2] [4]. This is achieved by preventing the component(s)identified as being faulty from being invoked in further executions[2] [4]. Fault treatment can be used to reconfigure a system to restore the level of redundancy so that the system is able to tolerate further faults [2] [4].Ⅳ.D ISTRIBUTED T OLERANCE T ECHNIQUESA. ReplicationIn order to mask the effects of faults, distributed fault tolerance always requires some form of redundancy. Replication is a classic example of space redundancy. Itexploits additional resources beyond what is needed for normal system operation to implement a distributed fault-tolerant service[2] [4]. The metaphor of replication is to manage the group of processes or replicas so as to maskfailures of some members of the group[2] [4]. By coordinating a group of components replicated on different computing nodes, distributed systems can provide continuity of service in the presence of failednodes [2] [4].There are three well-known replication schemes: active replication, passive replication, and semi-active replication. In active replication scheme, every replicaexecutes the same operations[2] [4]. Input messages are atomically multicasted to all replicas, who all process them and update their internal states. All replicas generate output messages [2] [4].Passive replication is a technique in which only one of the replicas (the primary) actively executes the operation, updates its internal state and sends output messages [2] [4]. The other replicas (the standby replicas) do not processinput messages; however, their internal state must be updated periodically by information sent by the primary [2] [4]. If the primary should fail, one of the standby replicas is elected to take its place [2] [4].Semi-active replication is a technique which is similar to active replication[2] [4]. In semi-active replication, all replicas will receive and process input messages. However, unlike active replication, the processing of messages is asymmetric in that one replica (the leader) takes responsibility for certain decisions (e.g., concerning message acceptance) [2] [4]. The leader replica can enforce its choice on the other replicas (the followers) without resorting to a consensus protocol [2] [4]. One alternative for semi-active replication is that the leader replica may take sole responsibility for sending output messages[2] [4]. Semi-active replication primarily targeted at crash failures. However, under certain conditions, this strategy can also be extended to deal with arbitrary or byzantine failures [2] [4].Continuity of service in the presence of failed nodesrequires replication of processes or objects on multiple nodes[2] [4]. Replication can provide high-available service for a dependable distributed system. By replicating their constituent objects and distributing their replicas across different computers connected by the network, distributed applications can be made dependable [5]. The major challenge of replication technique is to maintain replica consistency [7] [8] [9]. Replication will fail in its purpose if the replicas are not true copies of each other, both in state and in behavior [5] [10] [11] [12].B. Distributed RecoveryIn a dependable distributed system, some form of recovery is required to minimize the negative impact of a failed process or replica on the availability of a distributed service [4]. In its simplest form, this can be just a local recovery of the failed process or replica. However, distributed recovery will occurs if the recovery of one process or replica requires remote processes or replicas also to undergo recovery[4]. In this case, processes or replica must rollback to a set of checkpoints that together constitute a consistent global state [4].In order to create checkpoints, there are several major approaches. One way is asynchronous checkpointing[4]. In asynchronous checkpointing, checkpoints are created independently by each process or replica, and then when a failure occurs, a set of checkpoints must be found that represents a consistent global state [4]. This approach aims to minimize timing overheads during normal operation at the expense of a potentially large overhead when a global state is sought dynamically to perform the recovery[4]. The price to be paid for asynchronous checkpointing is domino effect. If no other global consistent state can be found, it might be necessary to roll all processes back to the initial state[4]. As a result, in order to avoid the domino effect, checkpoints can be taken in some coordinated fashion.Another way is to structure process or replica interactions in conversations[4]. In a conversation, processes or replicas can communicate freely between themselves but not with other processes external to a conversation[4]. If processes or replicas all take a checkpoint when entering or leaving a conversation, recovery of one process or replica will only propagate to other processes or replica in the same conversation [4].A third alternative is synchronous checkpointing [4] [13]. In this approach, dynamic checkpoint coordination is allowed so that a set of checkpoints can represent global consistent states [4] [13]. As consequence, the domino effect problem can be transparently avoided for the software developers even if the processes or replicas are not deterministic[4]. At each instant, each process or replica possesses one or two checkpoints: a permanent checkpoint (constituting a global consistent state) and another temporary checkpoint[4]. The temporary checkpoints may be undone or transformed into a permanent checkpoint. The creation of temporary checkpoints, and their transformation into permanent ones, is coordinated by a two-phase commit protocol to ensure that all permanent checkpoints effectively constitute a global consistent state [4].C. Partitioning ToleranceA distributed system may partition into a finite number of components. The processes or replicas in different© 2012 ACADEMY PUBLISHERcomponents can not communicate each other[11]. Partitioning may occur due to normal operations, such as in mobile computing, or due to failures of processes or inter-process communication. Performance failures due to overload situations can cause ephemeral partitions that are difficult to distinguish from physical partitioning [4]. Partitioning is a very real concern and a common event in wide area networks[4]. If the network partitions, different operations may be performed on the processes or replicas in different components, leading to inconsistencies that must be resolved when communication is re-established and the components remerge[5]. One strategy for achieving this is to allow components of a partition to continue some form of operation until the components can re-merge [4] [11]. Once the components of a partitioned remerge, the processes or replicas in the merged components must communicate their states, perform state transfer and reach a global consistent state [5].As another example, certain distributed fault-tolerance techniques are aimed at adopting dynamic linear voting protocol to ensure replica consistency in partitioned networks[5]. Voting protocols are based on quorums. In voting protocols, each node is assigned a number of votes. When a network is partitioned or remerged, if a majority of the last installed quorum is connected, a new quorum is established and updates can be performed within this partition [5].Ⅴ. DEPENDABLE M IDDLEWAREIn the past decade, middleware has emerged as a major building block in supporting the construction of distributed applications[14]. The development of distributed applications has been greatly enhanced by middleware. Middleware provides application developers with a reusable software layer that relieve them from dealing with frequently encountered problems related to distribution, such as heterogeneity, interoperability, security, scalability, and so on[14][15][16][17]. Implementation details are encapsulated inside the middleware itself and are shielded from both users and application develop ers‘, so that the infrastructure‘s diversities are homogenized by middleware [18] [19] [20] [21]. These attractive features have made middleware an important architectural component in the distributed system development practice. Further, with applications becoming increasingly distributed and complex, middleware appears as a powerful tool for the development of software systems [14].Recently, a strong incentive has been given to research community to develop middleware to provide fault tolerance to distributed applications[2]. Middleware support for the construction of dependable distributed systems has the potential to relieve application developers from the burden by making development process faster and easier and significantly enhancing software reuse. Hence, such middleware can render building blocks to be exploited by applications for enforcing dependability property [2].However, building such software infrastructure that achieves dependable goal is not an easy task. Neither the standard nor conventional implementations of middleware directly address complex problems related to dependable computing, such as partial failures, detection of and recovery from faults, network partitioning, real-time quality of service or high-speed performance, group communication, and causal ordering of events[9]. In order to cope with these limitations, many research efforts have been focused on designing new middleware systems capable of supporting the requirements imposed by dependability [5].A first issue that needs to be addressed by dependable middleware is interoperability[2]. Interoperability allows different software systems to exchange data via a common set of exchange formats, to read and write the same file formats, and to use the same protocols. As a result, in order to be useful, dependable middleware should be interoperable[2]. Through interoperability, dependable middleware can provide a platform-independent way for applications to interact with each other[2]. In other words, two systems running on the different middleware platforms can interoperate with each other even when implemented in different programming languages, operating systems, or hardware facilities [2].Another important problem concerns transparency. Dependable middleware should provide some form of transparency to applications[2]. It allows dynamically to add to an existing distributed application and to interfere as little as possible with applications at runtime. Therefore, many existing applications can benefit from the dependable middleware [2]. Traditional middleware is built adhering to the metaphor of the black box. Application developers do not have to deal explicitly with problems introduced by distribution. Middleware developed upon network operating systems provides application developers with a higher level of abstraction. The infrastructure‘s diversities are hidden from both users and application developers, so that the system appears as a single integrated computing facility [16].Although transparency philosophy has been proved successful in supporting the construction of traditional distributed systems, it cannot be used as the guiding principle to develop the new abstractions and mechanisms needed by dependable middleware to foster the development of dependable distributed systems when applied to the today‘s computing settings[15][18][19]. As a result, it is important to adopt an open implementation approach to the engineering of dependable middleware platforms in terms of allowing inspection and adaptation of underlying components at runtime[22][23][24][25].With networks becoming increasingly pervasive, major system requirements posed by today‘s networking infrastructure relate to openness and context-awareness [14]. This leads to investigate new approaches formiddleware with support for dependability and context-aware adaptability. However, in order to provide transparency, traditional middleware must make decisions on behalf of the application. This is inevitably© 2012 ACADEMY PUBLISHER。
智能电网英语作文
智能电网英语作文English:The smart grid is a modern electricity distribution system that integrates advanced technologies such as artificial intelligence, sensors, and communication networks. It enables two-way communication between the utility provider and the consumers, allowing for real-time monitoring and control of energy flow. Smart grids have the ability to optimize energy utilization, reduce wastage, and enhance grid reliability and resilience. By leveraging data analytics and machine learning, these intelligent systems can predict demand patterns, detect abnormalities, and respond proactively to potential issues. Additionally, smart grids support the integration of renewable energy sources like solar and wind power, facilitating a more sustainable and environmentally-friendly energy ecosystem. Overall, the smart grid represents a significant step towards a more efficient, secure, and sustainable energy infrastructure for the future.中文翻译:智能电网是一种现代电力分配系统，集成了人工智能、传感器和通讯网络等先进技术。
毕业设计英文文献翻译(电力方向附带中文)
毕业设计英文文献翻译(电力方向附带中文)大学毕业设计英文文献翻译,关于电力系统方向,电力谐波!绝对原创!HarmonicsService reliability and quality of power have become growing concerns for many facility managers, especially with the increasing sensitivity of electronic equipment and automated controls. There are several types of voltage fluctuations that can cause problems, including surges and spikes, sags, harmonic distortion, and momentary disruptions. Harmonics can cause sensitive equipment to malfunction and other problems, including overheating of transformers and wiring, nuisance breaker trips, and reduced power factor.What Are Harmonics?Harmonics are voltage and current frequencies riding on top of the normal sinusoidal voltage and current waveforms. Usually these harmonic frequencies are in multiples of the fundamental frequency, which is 60 hertz (Hz) in the US and Canada. The mostcommon source of harmonic distortion is electronic equipment using switch-mode power supplies, such as computers, adjustable-speed drives, and high-efficiency electronic light ballasts.Harmonics are created by these Dswitching loads‖ (also called “nonlinear loads,‖ because current does not vary smoothly with voltage as it does with simple resistive and reactive loads): Each time the current is switched on and off, a current pulse is created. The resulting pulsed waveform is made up of a spectrum of harmonic frequencies, including the 60 Hz fundamental and multiples of it. This voltage distortion typically results from distortion in the current reacting with system impedance. (Impedance is a measure of the total opposi tion―resistance, capacitance, and inductance―to the flow of an alternating current.) The higher-frequency waveforms, collectively referred to as total harmonic distortion (THD), perform no useful work and can be asignificant nuisance.Harmonic waveforms are characterized by their amplitude and harmonic number. In the U.S. and Canada, the third harmonic is 180 Hz―or 3 x 60 Hz―and the fifth harmonic is 300 Hz (5 x 60Hz). The third harmonic (and multiples of it) is the largest problem in circuits with single-phase loads such as computers and fax machines. Figure 1 shows how the 60-Hz alternating current (AC) voltage waveform changes when harmonics are added.大学毕业设计英文文献翻译,关于电力系统方向,电力谐波!绝对原创!The Problem with HarmonicsAny distribution circuit serving modern electronic devices will contain some degree of harmonic frequencies. The harmonics do not always cause problems, but the greater the power drawn by these modern devices or other nonlinear loads, the greater the level of voltage distortion. Potential problems (or symptoms of problems) attributed to harmonics include:■ Malfunction of sensitive equipment■ Random tripping of circuit breakers■ Flickering lights■ Very high neutral currents■ Overheated phase conductors, panels, and transformers ■ Premature failure of transformers and uninterruptible power supplies (UPSs)■ Reduced power factor■ Reduced system capacity (because harmonics create additional heat, transformers and otherdistribution equipment cannot carry full rated load)Identifying the ProblemWithout obvious symptoms such as nuisance breaker trips or overheated transformers, how do you determine whether harmonic current or voltages are a cause for concern? Here are several suggestions for simple, inexpensive measurements that a facility manager or staff electrician could take, starting at the outlet and moving upstream:■ Measure the peak and root mean square (RMS) voltage at a sample of receptacles. The Dcrest factor‖ is the ra tio of peak to RMS voltage. For a perfectly sinusoidal voltage, the crest factor will be 1.4. Low crest factor is a clear indicator of the presence of harmonics. Note that these measurements must be performed with a Dtrue RMS‖ meter―one that doesn‘t assume a perfectly sinusoidal waveform.■ Inspect distribution panels. Remove panel covers and visually inspect components for signs of overheating, including discolored or receded insulation or discoloration of terminal screws. If you see any of these symptoms, check that connectionsare tight (since loose connections could also cause overheating), and compare currents in all conductors to their ratings.■ Measure phase and neutral currents at the transformer secondary with clamp-on current probes. If no harmonics are being generated, the neutral current of a three-phase distribution system carries only the imbalance of the phase currents. In a well-balanced three-phase distribution system, phase currents will be very similar, and current in the neutral conductor should be much lower than phase current and far below its rated current capacity. If phase currents are similar and neutral current exceeds their imbalance by a wide margin, harmonics are present. If neutral current is above 70 percent of the cond uctor‘s rated capacity, you need to mitigate the problem.■Compare transformer temperature and loading with nameplate temperature rise and capacity ratings. Even lightly loaded transformers can overheat if harmonic current is high. A transformer that is near or over its rated temperature rise but is loaded well below its rated capacity is a clear sign that harmonics are at work. (Many transformers have built-in temperature gauges. If yours does not, infrared thermography can be used to detect overheating.)大学毕业设计英文文献翻译,关于电力系统方向,电力谐波!绝对原创!In addition to these simple measurements, many power-monitoring devices are now commercially available from a variety of manufacturers to measure and record harmonic levels. These instruments provide detailed information on THD, as well as on the intensity of individual harmonic frequencies. After taking the appropriate measurements to determine whether you have high levels of harmonics and, if so, to find the source, you will be well-positioned to choose the best solution.Solutions to Harmonics ProblemsThe best way to deal with harmonics problems is through prevention: choosing equipment and installation practices that minimize the level of harmonics in any one circuit or portion of a facility. Many power quality problems, including those resulting from harmonics, occur when new equipment is haphazardly added to older systems. However, even within existing facilities, the problems can often be solved with simple solutions such as fixing poor or nonexistent grounding on individual equipment or the facility as a whole, moving a few loads between branch circuits, or adding additional circuits to help isolate the sensitiveequipment from what is causing the harmonic distortion. If the problems cannot be solved by these simple measures, there are two basic choices: to reinforce the distribution system to withstand the harmonics or to install devices to attenuate or remove the harmonics. Reinforcing the distribution system means installing double-size neutral wires or installing separate neutral wires for each phase, and/or installing oversized or Krated transformers, which allow for more heat dissipation. There are also harmonic-rated circuit breakers and panels, which are designed to prevent overheating due to harmonics. This option is generally more suited to new facilities, because the costs of retrofitting an existing facility in this way could be significant. Strategies for attenuating harmonics, from cheap to more expensive, include passive harmonic filters, isolation transformers, harmonic mitigating transformers (HMTs), the Harmonic Suppression System (HSS) from Harmonics Ltd., and active filters(Table 1).Passive filters (also called traps) include devices that provide low-impedance paths to divert harmonics to ground and devices that create a higher-impedance path to discourage the flow of harmonics. Both of these devices, by necessity, change theimpedance characteristics of the circuits into which they are inserted. Another weakness of passive harmonic technologies is that, as their name implies, they cannot adapt to changes in the electrical systems in which they operate. This means that changes to the electrical system (for example, the addition or removal of power factorCcorrection capacitors or the addition of more nonlinear loads) could cause them to be overloaded or to create Dresonances‖ that could actually amplify, rather than diminish, harmonics.Active harmonic filters, in contrast, continuously adjust their behavior in response to the harmonic current content of the monitored circuit, and they will not cause resonance. Like an automatic transmission in a car, active filters are designed to accommodate a full range of expected operating conditions upon installation, without requiring further adjustments by the operator.Isolation transformers are filtering devices that segregate harmonics in the circuit in which they are created, protecting upstream equipment from the effects of harmonics. These transformers do not remove the problem in the circuit generating the harmonics, but they can prevent the harmonics from affecting more sensitive equipment elsewhere within the facility.大学毕业设计英文文献翻译,关于电力系统方向,电力谐波!绝对原创!Harmonic mitigating transformers actually do relieve problematic harmonics. HMTs can be quite cost-effective in the right application, because they can both improve reliability and reduce energy costs. The right application includes transformers that are heavily or moderately loaded and where high levels of harmonic currents are present. In addition, HMTs are very effective in supporting critical loads that are backed up by a UPS. UPSs and backup generators tend to have high impedance, which results in high voltage distortion under nonlinear loading. Because of this, equipment that operates flawlessly when supplied by utility power may malfunction when the backup system engages during a utility outage. Note that some of these power systems have output filters (either passive or active) to control harmonic levels. The presence or absence of such filters should be determined before adding an HMT.The Harmonics Ltd. Harmonic Suppression System is a unique solution for single-phase loads that is designed to suppress the third harmonic. An HSS is generally more expensive than an HMT, but it is designed to attenuate the harmonicsproblems throughout the entire distribution system, not just upstream of the transformer. The types of facilities that present the best opportunities for HSS installation are those that place a very high premium on power quality and reliability, such as server farms, radio and television broadcast studios, and hospitals. (See .) Economic EvaluationEvaluating the life-cycle costs and effectiveness of harmonics mitigation technologies can be ve ry challenging―beyond the expertise of most industrial facility managers. After performing the proper measurement and analysis of the harmonics problem, this type of evaluation requires an analysis of the costs of the harmonics problem (downtime of sensitive equipment, reduced power factor, energy losses or potential energy savings) and the costs of the solutions. A good place to start in performing this type of analysis is to ask your local utility or electricity provider for assistance. Many utilities offer their own power quality mitigation services or can refer you to outside power quality service providers.Additional ResourcesInstitute of Electrical and Electronics Engineers (IEEE),Standard 519-1992, DIEEE大学毕业设计英文文献翻译,关于电力系统方向,电力谐波!绝对原创!Recommended Practices and Requirements for Harmonic Control in Electric Power Systems‖ (1992), available at .Relationship between harmonics and symmetrical componentsAbstract New terminology is introduced to make clear the relationship between harmonics and symmetrical components. Three-phase sets are classified in terms of symmetrical sets and asymmetrical sets. Subclasses are introduced with the names symmetrical balanced sets, symmetrical unbalanced sets, asymmetrical balanced sets and asymmetrical unbalanced sets to show that a threephase set can resolve to either one, two or three symmetrical component sets. The results from four case studies show that these subclasses and their resolution to symmetrical component sets improve understanding of harmonic analysis of systems having balanced and unbalanced harmonic sources and loads.Keywords asymmetrical sets; harmonic flows; harmonic sources; symmetrical component sets; symmetrical sets Any periodic wave shape can be broken down into oranalysed as a fundamentalwave and a series of harmonics.Three-phase harmonic analysis requires a clear understanding of the relationship between symmetrical component injections from harmonic sources (e.g. adjustable speed drives, ASDs) and their relationship to harmonic flows (symmetrical components) arising from the application of a harmonic source to a linear system.Alimited number of references contain brief information concerning harmonics and symmetrical components. Reference 1, provides a paragraph on this topic and uses the heading Relationship between Harmonics and Symmetrical Components‘.It includes a table that is supported by a brief explanatory paragraph. The table expresses harmonics in terms of positive, negative and zero sequences. It states that these sequences are for harmonics in balanced three-phase systems. The heading refers to symmetrical components while the content refers to balanced three-phase systems. Herein lies the anomaly. Classically, symmetrical components (especially ero sequence) are only applied in unbalanced systems. The following questions rose after reading the Ref. 1 paragraph.(a)Do symmetrical components (especially zero sequence), in the classical sense,apply in balanced as well as unbalanced non-sinusoidal systems and is this abreak from tradition?(b)What do the terms, symmetrical, asymmetrical, balanced, unbalanced andsymmetrical components mean?(c)What are the conditions under which a system must operate so that harmonicsresolve to positive, negative and zero sequences and is the table given inRef. 1 correct?The terminology used is found inadequate for describing non-sinusoidal systems.There is thus a need to introduce a three-phase terminology that will show the relationship and make the comparison between injections (currents) and harmonic flows (voltages and currents) meaningful.References 3 provides the basis for the solution by providing definitions for threephase sets‘, symmetrical sets‘an d symmetricalcomponent sets‘.The purpose of this paper is to introduce an approach to harmonic analysis大学毕业设计英文文献翻译,关于电力系统方向,电力谐波!绝对原创!based on the classification of three-phase sets and to make to comparison between injections from harmonic sources and corresponding harmonic flows quantifiable by expressing the results in terms of the number of symmetrical component sets found.Harmonic flows and their resolution to symmetrical components depends upon the magnitudes and phase sequences of the injections from a harmonic source, on the system‘s sequence impedances, on three- and four-wire connections and on whether the customer‘s linear load on the system is balanced or unbalanced. Therefore, what is injected in terms of symmetrical component sets by a harmonic source is not necessarily received by the system, i.e. the harmonic flows may resolve to one, two or three symmetrical component sets and this depends upon the type of three-phase set found. Therefore, any three-phase harmonic may be partially made up of any of thesymmetrical component sets.Four case studies are reported and they show a novel method for teaching the flow of power system harmonics. It is important to use case studies as part of one‘s teaching as they link learning to concepts and improve understanding. They show how the method of symmetrical components can be extended to a system‘s response to harmonic flows. When taught as a group, the four case studies improve cognitive skills by showing that the symmetrical component responses under unbalanced situations are different to the balanced state.IEEE __TIONS ON POWER __NICS VOL.19,NO.3,__年大学毕业设计英文文献翻译,关于电力系统方向,电力谐波!绝对原创!谐波服务的可靠性和电能质量已成为越来越多设施经理的关注，尤其是随着电子设备和自动化控制灵敏度提高了很多。
电气专业毕业设计外文翻译--基于人工智能的长期电力负荷预测
附录A: 外文文献及译文第一部分：原文Artificial intelligence in long term electric load forecastingK. Metaxiotis, A. Kagiannas, D. Askounis, J. PsarrasAbstract: Intelligent solutions, based on artificial intelligence (AI) technologies, to solve complicated practicalproblems in various sectors are becoming more and more widespread nowadays. AI-based systems arebeing developed and deployedworldwide in myriad applications, mainly because of their symbolic reasoning,flexibility and explanation capabilities.This paper provides an overview for the researcher of AI technologies, as well as their current use in thefield of long term electric load forecasting (LTELF). The history of AI in LTELF is outlined, leading to adiscussion of the various approaches as well as the current research directions. The paper concludes bysharing thoughts and estimations on AI future prospects in this area. This review reveals that although stillregarded as a novel methodology, AI technologies are shown to have matured to the point of offering realpractical benefits in many of their applications.Keywords: Artificial intelligence; Electric load forecasting; Energy1. IntroductionIn the past two decades. AI has been defined as the study of how to make computers do thingsthat, at the moment, people do better. AI provides powerful and flexible means for obtaining solutions to a variety ofproblems that often cannot be solved by other, more traditional and orthodox methods.This review bears witness to the application of AI technologies in the field of long term electric loadforecasting (LTELF). Certainly, this is not the first paper to review the application of AI basedsystems in energy related problems with varying success. In general, AI developments in the fieldof energy have been reviewed by several authors from various points of view.Taylor and Lubkemanreviewed the applications of knowledge based programming to powerengineering problems, describing prototype projectsdeveloped at North Carolina State University,while the survey of Zhang et al. concerned the use of ES technology in electric powersystems. Ypsilantis and Yee presented a review of ESs for SCADA based power applicationsand Lubarskii et al. discussed the use of ESs for power networks. Since that time, several othersurvey papers have been written invariousenergy related areas.However, this paper has a different focus. Writing a fully comprehensive survey of AI applicationsin energy systems is objectively impracticable. For this reason, our paper aims to create a large knowledgebase for the researcher, introducing him/her to the specific area of AI applications in LTELF andindicating other fields fertile for research.2. AI applications in long term electric load forecasting2.1Expert systemsESsare one of the most commercially successful branches of AI. Welbankdefines an ES asfollows:An expert system is a program, which has a wide base of knowledge in a restricted domain,and uses complex inferential reasoning to perform tasks, which ahuman expert could do.In other words, an ES is a computer system containing a well organised body of knowledge,which emulates expert problem solving skills in a bounded domain ofexpertise. The systemis able to achieve expert levels of problem solving performance, which would normally beachieved by a skilled human, when confronted with significant problems in the domain.The first works in ES application in LTELF were implemented by Rahman and Bhatnagarand Jabbour et al. The objective of these approaches was to use the knowledge, experienceand analytical thinking of experimental system operators. Park et al. made a further step by usingfuzzy logic in an ES for a LTELF problem. In 1990, Ho et al. presented the use of aknowledge based ES in long term load forecasting of a Taiwan power system, while in 1993,Rahman and Hazim tried to generalize his first work. Markovic and Fraissler proposedan ES approach (based on Prolog) for long term load forecasting by plausibility checking ofannounced demand.In 1995, Kim et al. implemented a long term load forecaster by using ANNs and afuzzy ES, while later, Mori and Kobayashi presented an optimal fuzzy inference approach forthe LTELF problem. Ranaweera et al. proposed a fuzzy logic ES model for the LTELFproblem, which used fuzzy rules to incorporate historical weather and load data. These fuzzy ruleswere obtained from historical data using a learning type algorithm.A back propagation neural network with the output provided by a rule based ESwas designedby Chiu et al. for the LTELF problem. To demonstrate that the inclusion of the predictionfrom a rule based ES of a power system would improve the predictive capability of the network,load forecasting was performed on the Taiwan power system. The evaluation of the systemshowed that the inclusion of the rule based ES prediction significantly improved the neural network’s prediction of power load.2.2Artificial neural networksANNs are an information processing technique based on the way biological nervous systems,such as the brain, process information. The fundamental concept of ANNs is the structure of theinformation processing system. Composed of a large number of highly interconnected processingunits (“neurons”) connected into networks, a neural network system uses the human-like techniqueof learning by example to resolve problems. Every neuron applies an input, activationand an output function to its net input to calculate itsoutput. The neural network is configured for a specific application, such as data classification orpattern recognition, through a learning process called “training”.The first researchers who introduced the ANN application in LTELF were Lee et al., whoproposed an innovative ANN methodology for the LTELF problem. Park et al. proposed theuse of a multilayer network with three layers, i.e. one input, one hidden and one output. Thetraining of the network was performed through a simpleback-propagation algorithm. Using loadand weather information, the system produced three different forecast variables. Lee et al. treated electric load demands as a non-stationary timeseries, and they modeled the load profile by a recurrent neural network.In 1992,Peng et al. presented a search procedure for selecting the training cases for ANNsto recognize the relationship between weather changes and load shape, while Ho et al. implementeda multilayer neural network with an adaptive learningalgorithm.Chen et al. proposed an ANN for weather sensitive long term load forecasting, while analternative technique using a recurrent high order neural network was considered by Kariniotakiset al. Papalexopoulos et al. proposed the inclusion of additional input variables, suchas a seasonal factor and a cooling/heating degree into a single neural network.Czernichow et al. used a fully connected recurrent network for load forecasting in whichthe learning database consisted of 70,000 patterns with a high degree of diversity. Mandal et al.applied neural networks for LTELF in which the inputs consisted of the past load data only,and no weather variables were used, while Sforna and Proverbio investigated the application of ANNs in LTELF, through a research project at ENEL, and confirmed their positivecontribution.In1997, Kiartzis et al. presented the Bayesian combined predictor, aprobabilisticallymotivated predictor for LTELF based on the combination of an ANN predictor and two linearregression predictors. The method was applied to LTELF for the Greek Public Power Corporationdispatching center of the island of Crete. Ramanathan et al. made several comparisonsof statistical, time series and ANN methods for the LTELF.In 1998, Sforna reported the implementation of a software tool, called NEUFOR, based onANN technology and specifically designed to meet the operational needs of utility power systemdispatchers regarding online operation, while Papadakis et al. continued to improve theirprevious work. The same goes for Drezga and Rahman. The development of improved neuralnetwork based LTELF models for the power system of the Greek island of Crete, as well as radialbasis function networks and fuzzy neural type networks, were proposed and discussed by Kodogiannisand Anagnostakis in 1999. In the years 2000 and 2001, several researchers dealt withthe application of ANN to the LTELF problem, with varying success.3. ConclusionsElectricity long term load forecasting is important for the power industry, especially in thederegulated electricity market. Proper demand forecasts help the market participants to maximizetheir profits and/or reduce their possible losses by preparing an appropriate bidding strategy.Traditional statistics based linear regression methods need modification to capture the more andmore non-linearities in demand signals under the market conditions.What emerges from this discussion is that AI based systems are becoming more and morecommon decision making tools in LTELF. AI methods for forecasting have shown an ability togive better performance in dealing with the non-linearities andother difficulties in modeling thetime series. The ESs as well as the ANNs have been found to be the most popular for this field.The advantage of these technologies over statistical models lies in their ability to model a multivariate problem without making complex dependency assumptions among input variables.Furthermore, the ANN extracts the implicit non-linear relationship among input variables bylearning from training data.Concluding, we can say that AI techniques, like all other approximation techniques, haverelative advantages and disadvantages. There are no rules as to when a particular technique ismore or less suitable for LTELF. Based on the survey presented here, it is believed that AI offersan alternative “philosophy" which should not be underestimated at all.第二部分：译文基于人工智能的长期电力负荷预测K. Metaxiotis, A. Kagiannas, D. Askounis, J. Psarras摘要：基于人工智能( AI )技术的智能解决方案，由于是为了解决复杂的实际问题，所以在社会各界得到越来越广泛的重视。
外文文献翻译原文及译文
华北电力大学毕业设计（论文）附件外文文献翻译学号： 200701000324 姓名:杨曦所在院系：电力工程系专业班级：电气化0707指导教师：安勃原文标题： Research on Smart Grid in China2011年06月20日对中国智能电网的研究1摘要——智能电网是电力系统的未来发展的新方向。
在本文中，首先是智能电网的背景，意义，以及概念和结构。
典型的智能电网图如下所示.然后,在美国和欧洲智能电网的发展现状进行了描述，并对这些国家未来发展思路的趋势进行了总结和比较及分析。
此外，分析了中国智能电网发展的必要性，详细介绍了在目前与中国与有关项目，并对特高压电网和智能电网之间的的关系进行了讨论。
最后，对智能电网在未来在中国电网的潜在作用进行了展望和并为中国的智能电网发展指明新方向.索引词,智能电网，特高压电网，规划,经营，管理一导言随着世界经济全球化的推广,石油价格一直维持在一个上升的趋势。
还值得注意的是世界范围内的的能源供应短缺，对资源和环境的压力越来越大,同时，由于目前电网的低效率，在能源输送过程中损失了巨大的电力。
此外,由于不断增长的电力需求和用户对电力可靠性和质量日益增长的要求，电力工业正面临着前所未有的挑战和机遇。
因此，一个有环境友好,经济，高性能，低投资，安全性，可靠性和灵活性特点的的电力系统一直是电力工程师的目标。
尽管如此，基础设施和先进的仪表出现互联网更广泛地的使用加速了这个过程[1］。
自1990年以来随着分布式发电越来越多地使用，已经对对电网的强度提出更多的需求和要求［2][3]。
对于这些问题，为了找出最佳的解决方案，电力公司应接受新的思路，采用新技术，对现有的能源系统进行潜力挖掘，对技术和应用加以改进。
来自不同国家的学者和专家已经达成共识：未来电网的必须能够满足不同的需求及能源发电，高度市场化的电力交易的需求，由此可以满足客户的自我选择。
所有这些都将成为未来智能电网的发展方向。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
智能电网智能电网就是电网的智能化（智电电力），也被称为“电网2.0”，它是建立在集成的、高速双向通信网络的基础上，通过先进的传感和测量技术、先进的设备技术、先进的控制方法以及先进的决策支持系统技术的应用，实现电网的可靠、安全、经济、高效、环境友好和使用安全的目标，其主要特征包括自愈、激励和包括用户、抵御攻击、提供满足21世纪用户需求的电能质量、容许各种不同发电形式的接入、启动电力市场以及资产的优化高效运行。
美国能源部《Grid 2030》：一个完全自动化的电力传输网络，能够监视和控制每个用户和电网节点，保证从电厂到终端用户整个输配电过程中所有节点之间的信息和电能的双向流动。
中国物联网校企联盟：智能电网由很多部分组成，可分为：智能变电站，智能配电网，智能电能表，智能交互终端，智能调度，智能家电，智能用电楼宇，智能城市用电网，智能发电系统，新型储能系统。
现在对其中的一部分做简单介绍。
欧洲技术论坛：一个可整合所有连接到电网用户所有行为的电力传输网络，以有效提供持续、经济和安全的电力。
中国科学院电工研究所：智能电网是以包括各种发电设备、输配电网络、用电设备和储能设备的物理电网为基础，将现代先进的传感测量技术、网络技术、通讯技术、计算技术、自动化与智能控制技术等与物理电网高度集成而形成的新型电网，它能够实现可观测（能够监测电网所有设备的状态）、可控制（能够控制电网所有设备的状态）、完全自动化（可自适应并实现自愈）和系统综合优化平衡（发电、输配电和用电之间的优化平衡），从而使电力系统更加清洁、高效、安全、可靠。
美国电力科学研究院：IntelliGrid是一个由众多自动化的输电和配电系统构成的电力系统，以协调、有效和可靠的方式实现所有的电网运作：具有自愈功能；快速响应电力市场和企业业务需求；具有智能化的通信架构，实现实时、安全和灵活的信息流，为用户提供可靠、经济的电力服务。
国家电网中国电力科学研究院：以物理电网为基础(中国的智能电网是以特高压电网为骨干网架、各电压等级电网协调发展的坚强电网为基础)，将现代先进的传感测量技术、通讯技术、信息技术、计算机技术和控制技术与物理电网高度集成而形成的新型电网。
它以充分满足用户对电力的需求和优化资源配置、确保电力供应的安全性、可靠性和经济性、满足环保约束、保证电能质量、适应电力市场化发展等为目的，实现对用户可靠、经济、清洁、互动的电力供应和增值服务。
背景坚强智能电网的发展在全世界还处于起步阶段，没有一个共同的精确定义，其技术大致可分为四个领域：高级量测体系、高级配电运行、高级输电运行和高级资产管理。
高级量测体系主要作用是授权给用户，使系统同负荷建立起联系，使用户能够支持电网的运行；高级配电运行核心是在线实时决策指挥，目标是灾变防治，实现大面积连锁故障的预防；高级输电运行主要作用是强调阻塞管理和降低大规模停运的风险；高级资产管理是在系统中安装大量可以提供系统参数和设备（资产）“健康”状况的高级传感器，并把所收集到的实时信息与资源管理、模拟与仿真等过程集成，改进电网的运行和效率。
智能电网是物联网的重要应用，《计算机学报》刊登的《智能电网信息系统体系结构研究》一文对此进行了详细论述，并分析了智能电网信息系统的体系结构。
市场份额智能电网的建立是一个巨大的历史性工程。
目前很多复杂的智能电网项目正在进行中，但缺口仍是巨大的。
对于智能电网技术的提供者来说，所面临的推动发展的挑战是配电网络系统升级、配电站自动化和电力运输、智能电网网络和智能仪表。
根据派克调查机构的最新报告，智能电网技术市场将从2012年的330亿美元增长到2020年的730亿美元，8年间，市场累积达到4940亿美元。
《中国智能电网行业市场前瞻与投资战略规划分析前瞻》中指出，我国在“十二五”期间将建成“三纵三横一环网”的特高压交流线，并建设11回特高压直流输电工程，投资高达3000亿元;“十三五”期间投资虽略有放缓，投资额度也达到2500亿元。
到2015年，国家电网大范围、远距离的输电能力将达到2.5亿千瓦，每年输送电量1.15万亿千瓦时，可支撑新增1.45亿千瓦的清洁能源发电消纳和送出，能够满足超过100万辆电动汽车的使用要求，电网的资源优化配置能力、经济运行效率、安全水平和智能化水平将得到全面提升。
国外应用情况分析在电网发展基础方面，各国电力需求趋于饱和，电网经过多年的快速发展，架构趋于稳定、成熟，具备较为充裕的输配电供应能力。
德国制定了“E—Energy”计划，总投资1亿4千万欧元，2009年至2012年4年时间内，在全国6个地点进行智能电网实证实验。
同时还进行风力发电和电动汽车实证实验，并对互联网管理电力消费进行检测。
德国西门子、SAP及瑞士ABB等大企业均参与了这一计划。
预计西门子公司2014年智能电网年度市场规模将达300亿欧元，并计划抢占20%市场份额，每年确保60亿欧元订单。
先进性与现有电网相比，智能电网体现出电力流、信息流和业务流高度融合的显著特点，其先进性和优势主要表现在：（1）具有坚强的电网基础体系和技术支撑体系，能够抵御各类外部干扰和攻击，能够适应大规模清洁能源和可再生能源的接入，电网的坚强性得到巩固和提升。
（2）信息技术、传感器技术、自动控制技术与电网基础设施有机融合，可获取电网的全景信息，及时发现、预见可能发生的故障。
故障发生时，电网可以快速隔离故障，实现自我恢复，从而避免大面积停电的发生。
（3）柔性交/直流输电、网厂协调、智能调度、电力储能、配电自动化等技术的广泛应用，使电网运行控制更加灵活、经济，并能适应大量分布式电源、微电网及电动汽车充放电设施的接入。
（4）通信、信息和现代管理技术的综合运用，将大大提高电力设备使用效率，降低电能损耗，使电网运行更加经济和高效。
（5）实现实时和非实时信息的高度集成、共享与利用，为运行管理展示全面、完整和精细的电网运营状态图，同时能够提供相应的辅助决策支持、控制实施方案和应对预案。
（6）建立双向互动的服务模式，用户可以实时了解供电能力、电能质量、电价状况和停电信息，合理安排电器使用；电力企业可以获取用户的详细用电信息，为其提供更多的增值服务。
发展性趋势“十二五”期间，国家电网将投资5000亿元，建成连接大型能源基地与主要负荷中心的“三横三纵”的特高压骨干网架和13回长距离支流输电工程，初步建成核心的世界一流的坚强智能电网。
国家电网制定的《坚强智能电网技术标准体系规划》，明确了坚强智能电网技术标准路线图，是世界上首个用于引导智能电网技术发展的纲领性标准。
国网公司的规划是，到2015年基本建成具有信息化、自动化、互动化特征的坚强智能电网，形成以华北、华中、华东为受端，以西北、东北电网为送端的三大同步电网，使电网的资源配置能力、经济运行效率、安全水平、科技水平和智能化水平得到全面提升。
（1）智能电网是电网技术发展的必然趋势。
通讯、计算机、自动化等技术在电网中得到广泛深入的应用，并与传统电力技术有机融合，极大地提升了电网的智能化水平。
传感器技术与信息技术在电网中的应用，为系统状态分析和辅助决策提供了技术支持，使电网自愈成为可能。
调度技术、自动化技术和柔性输电技术的成熟发展，为可再生能源和分布式电源的开发利用提供了基本保障。
通信网络的完善和用户信息采集技术的推广应用，促进了电网与用户的双向互动。
随着各种新技术的进一步发展、应用并与物理电网高度集成，智能电网应运而生。
（2）发展智能电网是社会经济发展的必然选择。
为实现清洁能源的开发、输送和消纳，电网必须提高其灵活性和兼容性。
为抵御日益频繁的自然灾害和外界干扰，电网必须依靠智能化手段不断提高其安全防御能力和自愈能力。
为降低运营成本，促进节能减排，电网运行必须更为经济高效，同时须对用电设备进行智能控制，尽可能减少用电消耗。
分布式发电、储能技术和电动汽车的快速发展，改变了传统的供用电模式，促使电力流、信息流、业务流不断融合，以满足日益多样化的用户需求。
计划日本计划在2030年全部普及智能电网，同时官民一体全力推动在海外建设智能电网。
在蓄电池领域，日本企业的全球市场占有率目标是力争达到50%，获得约10万亿日元的市场。
日本经济产业省已经成立“关于下一代能源系统国际标准化研究会”，日美已确立在冲绳和夏威夷进行智能电网共同实验的项目[6]。
在中电联获悉，2020年中国将建成以华北、华东、华中特高压同步电网为中心，东北特高压电网、西北750千伏电网为送端，联结各大煤电基地、大水电基地、大核电基地、大可再生能源基地，各级电网协调发展的坚强智能电网。
华北、华东、华中特高压同步电网形成“五纵六横”主网架。
方向在绿色节能意识的驱动下，智能电网成为世界各国竞相发展的一个重点领域。
智能电网是电力网络，是一个自我修复，让消费者积极参与，能及时从袭击和自然灾害复原，容纳所有发电和能量储存，能接纳新产品，服务和市场，优化资产利用和经营效率，为数字经济提供电源质量。
智能电网建立在集成的、高速双向通信网络基础之上，旨在利用先进传感和测量技术、先进设备技术、先进控制方法，以及先进决策支持系统技术，实现电网可靠、安全、经济、高效、环境友好和使用安全的高效运行。
它的发展是一个渐进的逐步演变,是一场彻底的变革,是现有技术和新技术协同发展的产物，除了网络和智能电表外还饱含了更广泛的范围。
建设以特高压电网为骨干网架，各级电网协调发展，以信息化、自动化、互动化为特征的坚强智能电网，全面提高电网的安全性、经济性、适应性和互动性，坚强是基础, 智能是关键。
意义其重要意义体现在以下几个方面：（1）具备强大的资源优化配置能力。
我国智能电网建成后，将实现大水电、大煤电、大核电、大规模可再生能源的跨区域、远距离、大容量、低损耗、高效率输送，区域间电力交换能力明显提升。
（2）具备更高的安全稳定运行水平。
电网的安全稳定性和供电可靠性将大幅提升，电网各级防线之间紧密协调，具备抵御突发性事件和严重故障的能力，能够有效避免大范围连锁故障的发生，显著提高供电可靠性，减少停电损失。
（3）适应并促进清洁能源发展。
电网将具备风电机组功率预测和动态建模、低电压穿越和有功无功控制以及常规机组快速调节等控制机制，结合大容量储能技术的推广应用，对清洁能源并网的运行控制能力将显著提升，使清洁能源成为更加经济、高效、可靠的能源供给方式。
（4）实现高度智能化的电网调度。
全面建成横向集成、纵向贯通的智能电网调度技术支持系统，实现电网在线智能分析、预警和决策，以及各类新型发输电技术设备的高效调控和交直流混合电网的精益化控制。
（5）满足电动汽车等新型电力用户的服务要求。
将形成完善的电动汽车充放电配套基础设施网，满足电动汽车行业的发展需要，适应用户需求，实现电动汽车与电网的高效互动。