(参考资料)供配电系统英文文献
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.。
电力系统毕业论文中英文外文文献翻译精选全文完整版
可编辑修改精选全文完整版电力系统电力系统介绍随着电力工业的增加，与用于生成和处置现今大规模电能消费的电力生产、传输、分派系统相关的经济、工程问题也随之增多。
这些系统组成了一个完整的电力系统。
应该着重提到的是生成电能的工业，它不同凡响的地方在于其产品应按顾客要求即需即用。
生成电的能源以煤、石油，或水库和湖泊中水的形式贮存起来，以备以后所有需。
但这并非会降低用户对发电机容量的需求。
显然，对电力系统而言服务的持续性相当重要。
没有哪一种服务能完全幸免可能显现的失误，而系统的本钱明显依托于其稳固性。
因此，必需在稳固性与本钱之间找到平稳点，而最终的选择应是负载大小、特点、可能显现中断的缘故、用户要求等的综合表现。
但是，网络靠得住性的增加是通过应用必然数量的生成单元和在发电站港湾各分区间和在国内、国际电网传输线路中利用自动断路器得以实现的。
事实上大型系统包括众多的发电站和由高容量传输线路连接的负载。
如此，在不中断整体服务的前提下能够停止单个发电单元或一套输电线路的运作。
现此生成和传输电力最普遍的系统是三相系统。
相关于其他交流系统而言，它具有简便、节能的优势。
尤其是在特定导体间电压、传输功率、传输距离和线耗的情形下，三相系统所需铜或铝仅为单相系统的75%。
三相系统另一个重要优势是三相电机比单相电机效率更高。
大规模电力生产的能源有：1.从常规燃料（煤、石油或天然气）、城市废料燃烧或核燃料应用中取得的蒸汽；2.水；3.石油中的柴油动力。
其他可能的能源有太阳能、风能、潮汐能等，但没有一种超越了试点发电站时期。
在大型蒸汽发电站中，蒸汽中的热能通过涡轮轮转换为功。
涡轮必需包括安装在轴承上并封锁于汽缸中的轴或转子。
转子由汽缸周围喷嘴喷射出的蒸汽流带动而平稳地转动。
蒸汽流撞击轴上的叶片。
中央电站采纳冷凝涡轮，即蒸汽在离开涡轮后会通过一冷凝器。
冷凝器通过其导管中大量冷水的循环来达到冷凝的成效，从而提高蒸汽的膨胀率、后继效率及涡轮的输出功率。
毕业论文外文翻译-高层建筑供配电系统设计
毕业论文外文翻译-高层建筑供配电系统设计Design of Power Supply and Distribution System for High-rise BuildingsAbstractPower supply and distribution system is the lifeline of high-rise buildings. The design of power supply and distribution system is based on the characteristics of high-rise buildings, which requires not only reliable supply of power, but also the safety of electricity utilization and efficient energy consumption. In this paper, the design of power supply and distribution system for high-rise buildings is discussed, focusing on the selection of power supply mode, the design of power distribution system, the design of grounding system, the selection of electrical equipment and the design of lightning protection system. The application of advanced technologies such as distributed power supply, energy management and control system, and intelligent electrical equipment can improve the energy efficiency and utilization of high-rise buildings, reduce energy consumption and carbon emissions, and promote the development of green buildings.Keywords: high-rise buildings; power supply and distribution system; energy efficiency; green buildingsIntroductionHigh-rise buildings are an important symbol of urban development and represent the trend of modern architecture. With the continuous improvement of people’s living standards, the demand for high-rise buildings is increasing. Power supply and distribution system is an essential part of high-rise buildings, which plays a crucial role in the operation and maintenance of buildings. The design of power supply and distribution system for high-rise buildings needs to consider many factors, such as technical performance, safety and reliability, energy efficiency, economic benefits and environmental protection, etc. In recent years, with the rapid development of new energy and advanced technology, the design of power supply and distribution system for high-rise buildings has undergone significant changes, which focus on improving energy efficiency and reducing emissions. This paper analyzes the design of power supply and distribution system for high-rise buildings, summarizes the selection principles and design methods of various systems, and explores the application of new technologies to improve energy efficiency and promote the development of green buildings.1. Selection of Power Supply ModeThe power supply mode is the basic foundation of power supply and distribution system of high-rise buildings. In the selection of power supply mode, it is necessary to consider the characteristics of the building and the surrounding environment, and ensure the reliability and safety of power supply. Currently, the main power supply modes for high-rise buildings are grid-connected power supply and distributed power supply.1.1 Grid-connected Power SupplyGrid-connected power supply is a traditional power supply mode, which is widely used in high-rise buildings. It has the advantages of reliable power supply, convenient operation and maintenance, and stable voltage and frequency. However, grid-connected power supply is vulnerable to natural disasters such as typhoons and earthquakes, and may cause power outages, which will affect the normal life and work of residents. Moreover, the development of distribution network is limited by the capacity of the grid, which may cause overloaded operation and reduce the energy efficiency of high-rise buildings.1.2 Distributed Power SupplyDistributed power supply is a new power supply mode, which can improve the energy efficiency of high-rise buildings and reduce the dependence on the grid. Distributed power supply includes combined heat and power (CHP), solar power, wind power and other renewable energy sources. CHP is a highly efficient power generation technology, which can generate electricity and heat at the same time, and utilize the waste heat for air conditioning and domestic hot water. Solar power and wind power are clean energy sources, which have the advantages of zero emissions and long service life. Distributed power supply can reduce the transmission and distribution losses of power supply, and improve the energy efficiency of high-rise buildings. However, the initial investment of distributed power supply is relatively high, and the technical level of electrical equipment and maintenance management is demanding.2. Design of Power Distribution SystemThe power distribution system is responsible for the power transmission and distribution of high-rise buildings, which should ensure the safety and reliability of the power supply. The design of power distribution system includes the selection of power distribution equipment, the layout of power distribution room, and the calculation of power load.2.1 Selection of Power Distribution EquipmentThe selection of power distribution equipment should meet the requirements of technical performance, safety and reliability, and energy efficiency. The main power distribution equipment includes switchgear, transformer, busbar, distribution panel, etc. The switchgear should have the function of over-current protection, short-circuit protection and earth leakage protection, and should have the advantages of small volume, low noise and high reliability. The transformer should be selected according to the capacity and voltage level, and should have the advantages of low loss, high efficiency and small size. The busbar should have the advantages of high strength, good conductivity and low resistance. The distribution panel should have the functions of metering, control, protection and communication, and should be easy to operate and maintain.2.2 Layout of Power Distribution RoomThe layout of power distribution room should be reasonable and convenient for operation and maintenance. The power distribution room should be located near the power supply entrance, and should have the advantages of good ventilation, dry, clean and spacious. The power distribution room should be equipped with the necessary security measures, such as fire prevention, explosion-proof, and lightning protection.2.3 Calculation of Power LoadThe calculation of power load is the key to the design of power distribution system. The power load includes lighting load, air conditioning load, power load and special load, etc. The calculation of power load should take into account the diversity of load, the possibility of peak load, and the capacity of power supply equipment. The primary consideration is to ensure the safety and reliability of power supply, and then to improve the energy efficiency of power utilization.3. Design of Grounding SystemThe grounding system is an important safety measure for high-rise buildings. The design of grounding system should meet the requirements of electrical safety and electrostatic discharge protection.3.1 Electrical SafetyThe grounding system should have the functions of lightning protection, over-voltage protection, over-current protection and earth leakage protection, etc. The grounding resistance should be less than the specified value, and the grounding wire should have good conductivity and corrosion resistance. The grounding system should be comprehensively tested and maintained regularly.3.2 Electrostatic Discharge ProtectionThe electrostatic discharge protection is to prevent the accumulation of static electricity and the damage of electrical equipment. The design of electrostatic discharge protection includes the selection of anti-static grounding material, the setting of anti-static floor, and the installation of anti-static equipment. The electrostatic discharge protection is especially important for data centers and sensitive electrical equipment.4. Selection of Electrical EquipmentThe selection of electrical equipment is an important part of the design of power supply and distribution system for high-rise buildings. The selection of electrical equipment should meet the requirements of technical performance, safety and reliability, environmental protection and energy efficiency.4.1 Technical PerformanceThe electrical equipment should meet the relevant national and international standards, and have the characteristics of high efficiency, low noise, long service life and easy maintenance. The electrical equipment should have the functions of protection, control, measurement and communication, and should be compatible with the automation system.4.2 Safety and ReliabilityThe electrical equipment should have the functions of over-current protection, short-circuit protection, ground connection protection and lightning protection, etc. The electrical equipment should be installed and maintained by qualified personnel, and should be tested and checked regularly to ensure the safety and reliability of power supply and distribution system.4.3 Environmental Protection and Energy EfficiencyThe electrical equipment should have the advantages of environmental protection and energy efficiency, and should meet the requirements of green building standards. The electrical equipment should have the functions of power monitoring, energy management and control, and should be able to optimize the energy utilization and reduce the energy consumption.5. Design of Lightning Protection SystemThe lightning protection system is an important safety measure for high-rise buildings, which can prevent the damage of lightning to electrical equipment and human life. The design of lightning protection system includes the selection of lightning protection device, the installation of lightning rod, the connection of grounding wire, and the calculation of lightning protection zone.5.1 Selection of Lightning Protection DeviceThe lightning protection device should have the functions of lightning protection, over-voltage protection, surge protection and electromagnetic pulse protection, etc. The lightning protection device should be reliable and durable, and should meet the relevant national and international standards.5.2 Installation of Lightning RodThe lightning rod should be installed on the roof of high-rise buildings, and should be connected with the grounding system. The lightning rod should be placed in a high position, and should be made of light and strong materials, such as aluminum alloy or stainless steel. The lightning rod should be inspected regularly to ensure its effectiveness.5.3 Connection of Grounding WireThe grounding wire should be connected with the lightning rod, the grounding system, and the electrical equipment. The grounding wire should have the advantages of low resistance, good conductivity and corrosion resistance. The grounding wire should be tested and checked regularly to ensure its effectiveness.5.4 Calculation of Lightning Protection ZoneThe calculation of lightning protection zone is the basis for the design of lightning protection system. The lightning protection zone includes the direct lightning strike zone and the induced lightning zone. The direct lightning strike zone is the area covered by the lightning rod, and the induced lightning zone is the area beyond the direct lightning strike zone. The calculation of lightning protection zone should consider the characteristics of lightning, such as the stroke current, the distance from the lightning source, and the soil resistivity.ConclusionThe design of power supply and distribution system for high-rise buildings is a complex and important work. The selection of power supply mode, the design of power distribution system, the design of grounding system, the selection of electrical equipment, and the design of lightning protection system are the main aspects of the design of power supply and distribution system. The application of advanced technologies such as distributed power supply, energy management and control system, and intelligent electrical equipment can improve the energy efficiency and utilization of high-rise buildings, reduce energy consumption and carbon emissions, and promote the development of green buildings. The design of power supply and distribution system for high-rise buildings should adhere to the principles of safety, reliability, energy efficiency, economic benefits and environmental protection, and strive to create a better living and working space for residents.。
供配电设计参考文献
供配电设计参考文献以下是供配电设计的一些参考文献:1. "Power System Design", by W. H. McLeod (John Wiley & Sons, 1987).2. "Power System Stability and Control", by V. C. Waymouth (IEEE Press, 1997).3. "Transmission System Design", by R. W. Journal (John Wiley & Sons, 1994).4. "Power System Protection", by H. J. Latimer (IEEE Press, 1999).5. "Power System Dynamics", by G. C. Sethia and V. R. Shreehari (IEEE Press, 1998).6. "Electric Power Systems Engineering", by J. B. subject (Pearson Education, 2010).7. "Power System Instrumentation and Control", by T. K. Laxmi and G. D. Duggal (IEEE Press, 2000).8. "Electric Power Systems: Analysis, Design, and Control", by F. C. Middlebrook and J. B. subject (John Wiley & Sons, 1997).9. "Power System Protection: Design and Practice", by H. J. Latimer and R. W. Journal (IEEE Press, 1996).10. "Power System Stabilization", by V. C. Waymouth (IEEE Press, 1995).这些书籍涵盖了供配电系统设计的各个方面，包括电力系统稳定性、控制、保护、Instrumentation 和 Control、Power System Analysis、Design 和 Control 等。
配电系统英文对照
附录一、英文原文Distribution network analysisThe 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.The 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 andjudging 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 the way 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 and adopt 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 canhelp 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, 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 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..At present high-rise buildings, international and domestic universal power supply is based on the dual-power supply was equipped with a diesel generator as an emergency power supply, which is especially important to meet a load of power supply load requirements (Figure 1 does not include the dotted line part of the ). However, dual power plus the power supply of diesel generating sets in most parts of northern China are still subject to weather conditions. As a long time in the north in winter, the temperature low. As an emergency power supply diesel generator sets at low temperatures is difficult to immediately start power supply, and some even two or three minutes can not start.The dual power supply in most parts of 10KV substation quoted from the same strict sense, its essence is a power failure when the substation, the two power supplies also failed, causing power supply system completely paralyzed. In fire cases, this will expand the fire, causing serious losses is not allowed. Therefore, I envisage the dual power on diesel generator sets based on the season, plus a power supply, and enable it to their own independent power supply.In the case of low winter temperatures, reducing the reliability of diesel generators, we will connect the power this season, for increasing theElectric system reliability. When the temperatures rise, we stopped the season to the power supply department reported that power supply, you can save running costs. And this season there are three power options: First, quoted all the way from the substation 10KV high voltage power supply as the season (Figure 1), the advantage of high reliability power supply, the shortfall is that the higher investment in infrastructure; second is from a nearby high-rise buildings along 10KV transformer high-voltage end of the quoted or cited all the way low end of the season as a 380/220V power supply; third all the way from the city network cited as the season 380/200V power supply.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.二、英文翻译配电网分析电力系统的基本功能是向用户输送电能。
外文翻译及文献：电力系统The
Minimum Pow er SystemA minimum electric pow er system is show n in Fig. 1. the system cons ists of an energy source, a prime mover, a g enerator, and a load.The energy source may be coal, gas, or oil burned in a furnace to heat w ater and generate steam in a boiler; it m ay be fissionable mater ial w hich, in a nuclear reactor, w ill heat w ater to produce steam; it may be w ater in a pond at an elevation above the generating station; or it may be oil or gas burned in an internal combust ion engine.Fig. 1. The minimum electric pow er systemThe prime mover may be a steam-driven turbine, a hydraulic turbine or w ater wheel, or an internal combustion engi ne. E ach one of these prime movers has the ability to convert energy in the form of heat, falling w ater, or fuel into rotation of a shaft, w hich in turn w ill drive the generator.The electrical load on the generator may be lights, motors, heaters, or other devices, alone or in combination. P rob ably the load w ill vary from minute to minute as different demands occur.The control system functions to keep the speed of the machines substantially constant and the voltage w ithin prescr ibed limits, even though the load may change. To meet these load conditions, it is necessary for fuel input to chan ge, for the prime mover input to vary, and for the torque on the shaft from the pr ime mover to the generator to ch ange in order that the generator may be kept at constant speed. In addition, the field current to the generator must be adjusted to maintain constant output voltage. The control system may include a man stationed in the pow er pla nt that w atches a set of meters on the generator-output ter minals and makes the necessary adjustments manually. 3In a modem station, the control system is a servomechanis m that senses a generator-output conditions and autom atically makes the necessary changes in energy input and field current to hold the electrical output w it hin certain specifications.More Complicated SystemsIn most situations the load is not directly connected to the generator ter minals. More commonly the load is some di stance from the generator, requir ing a pow er line connecting them. It is desirable to keep the electric pow er supply at the load w ithin specifications. How ever, the controls are near the generator, w hich may be in another building, p erhaps several miles aw ay.If the distance from the generator to the load is considerable, it may be desir able to install transformers at the gen erator and at the load end, and to trans mit the pow er over a high-voltage line (Fig. 2). For the same pow er, the hi gher-voltage line carries less current, has low er losses for the same w ire size, and provides more stable v oltage.In some cases an overhead line may be unacceptable. Instead it may be advantageous to use an under ground ca ble. With the pow er systems talked above, the pow er supply to the load must be interrupted if, for any reason, any component of the system must be removed from service for maintenance or repair..Fig 2A generators connected through transfor mers and a high-voltage line to a distant loadAdditional system load may requir e more pow er than the generator can supply. Another generator w ith its associate d transformers and high-voltage line might be added.It can be show n that there are some advantages in making ties betw een the generators (1) and at the ends of the high-voltage lines (2and 3), as show n in Fig. 3. This system w ill operate satisfactorily as long as no trouble develo ps or no equipment needs to be taken out of service.The above system may be vastly improved by the introduction of circuit br eakers, w hich may be opened and closed as needed. Circuit breakers added to the system, Fig. 4, per mit selected piece of equipment to sw itch out of servi ce w ithout disturbing the remainder of system. With this arrangement any element of the system may be r eenergize d for maintenance or repair by oper ation of circuit breakers. Of course, if any piece of equipment is taken out of s ervice, the total load must then carried by the remaining equipment. Attention must be given to avoid over loads dur i ng such circumstances. If possible, outages of equipment are scheduled at times w hen load requirements are below nor mal.Fig. 1-3 A system w ith parallel oper ation of the generators, of the transformers and of the trans mission linesFig. 4A system w ith necessary circuit breakersFig. 5Three generators supplying three loads over high-voltage trans mission linesFig. 5 show s a system in w hich three generators and three loads are tied together by three trans mission lines. No circuit breakers are show n in this diagram, although many w ould be required in such a system.Typical System LayoutThe gener ators, lines, and other equipment w hich form an electric system are arranged depending on the manner in w hich load grow s in the area and may be rearranged from time to time.Fig. 6 A radial pow er system supply ing several loadsHow ever, there are certain plans in to w hich a particular system des ign may be classified. Three types are illustrate d: the radial system, the loop system, and the netw ork system. All of these are show n w ithout the necessary circuit breakers. In each of these systems, a single generator serves four loads.The radial system is show n in Fig. 6. Here the lines form a “tree” spreading out from the generator. Opening any li ne results in interruption of pow er to one or more of the loads.The loop system is illustrated in Fig. 7. With this arrangement all loads may be served even though one line sectio n is removed from service. In some instances dur ing nor mal operation, the loop may be open at some point, such as A. In case a line section is to be taken out, the loop is first closed at A and then the line section removed. In this manner no service interruptions occur.Fig. 1-7A loop arrangement of lines for supplying several loadsFig. 8 show s the same loads being served by a netw ork. With this arrangement each load has tw o or more circuits over w hich it is fed.Distribution circuits are commonly des igned so that they may be classified as radial or loop circuits. The high-voltag e trans mission lines of most pow er systems are arranged as netw orks. The interconnection of major pow er systems results in netw orks made up many line sections.Fig. 8A netw ork of lines for supplying several loadsAuxiliary E quipmentCircuit breakers are necessary to deenergize equipment either for normal operation or on the occurrence of short ci rcuits. Circuit breakers must be designed to carry nor mal-load currents continuously, to w ithstand the extremely high currents that occur during faults, and to separate contacts and clear a circuit in the presence of fault. Circuit break ers are rated in ter ms of these duties.When a circuit breaker opens to deenergize a piece of equipment, one side of the circuit breaker usually rem ains e nergized, as it is connected to operating equipment. Since it is sometimes necessary to w ork on the circuit breaker itself, it is also necessary to have means by w hich the circuit breaker may be completely disconnected from other energized equipment. For this purpose disconnect sw itches are placed in series w ith the circuit breakers. By openin g these disconnests, the circuit breaker may be completely deenergized, per mitting w ork to be carried on in safety.Various instruments are necessary to monitor the operation of the electr ic pow er system. Usually each generator, ea ch transformer bank, and each line has its ow n set of instruments, frequently consisting of voltmeters, ammeters, w attmeters, and var meters.When a fault occurs on a system, conditions on the system undergo a sudden change. Voltages usually drop and currents increase. These changes are most noticeable in the immediate vicinity of fault. On-line analog computers, c ommonly called relays monitor these changes of conditions, make a deter minat ion of w hich breaker should be open ed to clear the fault, and energize the trip circuits of those appropriate breakers. 'With modern equipment, the relay action and breaker opening causes removal of fault w ithin three or four cycles after its initiation.The instruments that show circuit conditions and the relays that protect the circuits are not mounted directly on the pow er lines but are placed on sw itchboards in a control house. Instrument transformers are installed on the high-vol tage equipment, by means of which it is possible to pass on to the meters and relays representative samples of th e conditions on the operating equipment. The primary of a potential transformer is connected directly to the high-vol tage equipment. The secondary provides for the instruments and relays a voltage w hich is a constant fraction of vol tage on the operating equipment and is in phase w ith it. Similarly, a current transformer is connected w ith its primar y in the high-voltage circuit. The secondary w inding provides a current w hich is a know n fraction of the pow er-equip ment current and is in phase w ith it.Bushing potential devices and capac itor potential devices serve the same purpose as potential transformers but usually w ith less accuracy in regard to ratio and phase angle.Faults on Pow er SystemsFaults and its DamageEach year new designs of pow er equipment bring about increased reliability of operation. Nevertheless, equipment f ailures and interference by outside sources occasionally result in faults on electric pow er syst ems. On the occurrenc e of a fault, current and voltage conditions become abnor mal, the delivery of pow er from the generating stations to the loads may be unsatisfactory over a considerable area, and if the faulted equipment is not promptly disconnected from the remainder of the system, damage may result to other pieces of operating equipment.A fault is the unintentional or intentional connecting together of tw o or more conductors w hich ordinarily operate w it h a difference of potential betw een them. The connection betw een the conductors may be by physical metallic cont act or it may be through an arc. At the fault, the voltage betw een the tw o parts is reduced to zero in the case of metal-to-metal contacts, or to a very low value in case the connection is through an arc. Currents of abnor mally hig h magnitude flow through the netw ork to the point of fault. These short-circuit currents w ill usually be much greater than the designed ther mal ability of the conductors in the lines or machines feeding the fault. The resultant rise in t emperature may cause damage by the annealing of conductors and by the charring of insulation. In the period duri ng w hich the fault is per mitted to exist, the voltage on the system in the near vicinity of the fault w ill be so low th at utilization equipment w ill be inoperative. It is apparent that the pow er system designer must anticipate points at which faults may occur, be able to calculate conditions that exist during a fault, and provide equipment properly adj usted to open the sw itches necessary to disconnect the faulted equipment from the remainder of the system1. Ordi narily it is desirable that no other sw itches on the system are opened, as such behavior w ould result in unnecessar y modification of the system circuits.OverloadA distinction must be made betw een a fault and an overload. An overload implies only that loads greater than the designed values have been imposed on system. Under such a circumstance the voltage at the overload point may be low, but not zero. This under voltage condition may extend for some distance beyond the overload point into the remainder of the system. The currents in the overloaded equipment are high and may exceed the ther mal des ign l imits. Nevertheless, such currents are substantially low er than in the case of a fault. Service frequently may be mai ntained, but at below-standard voltage.Overloads are rather common occurrences in homes. For example, a housew ife might plug five w affle irons into the kitchen circuit during a neighborhood party. Such an overlo ad, if per mitted to continue, w ould cause heating of the w ires from the pow er center and might eventually start a fire. To prevent such trouble, residential circuits are prote cted by fuses or circuit breakers w hich open quickly w hen currents above specified values persist. Distribution transf or mers are sometimes overloaded as customers install more and more appliances. The continuous monitoring of dist ribution circuits is necessary to be certain that transfor mer sizes are increased as load grow s.Various FaultsFaults of many types and causes may appear on electric pow er systems. Many of us in our homes have seen fray ed lamp cords w hich permitted the tw o conductors of the cord to come in contact w ith each other. When this occur s, there is a resulting flash, and if breaker or fuse equipment functions properly, the circuit is opened.Overhead lines, for the most part, are constructed of bare conductors. These are sometimes accidentally brought to gether by action of w ind, sleet, trees, cranes, airplanes, or dama ge to supporting structures. Over voltages due to li ghtning or sw itching may cause flashover of supporting or from conductor to conductor. Contamination on insulators sometimes results in flashover even dur ing nor mal voltage conditions.The conductors of underground cables are separated from each other and from ground by solid insulation, w hich m ay be oil-impregnated paper or a plastic such as polyethylene. These materials undergo some deter ioration w ith ag e, particularly if overloads on the cables have resulted in their operation at elevated temperature. Any small void pr esent in the body of the insulating material w ill result in ionization of the gas contained therein, the products of w hi ch react unfavorably w ith the insulation, deterior ation of the insulation may result in failur e of the material to retain i ts insulating properties, and short circuits w ill develop betw een the cable conductors. The possibility of cable failure is increased if lightning or sw itching produces transient voltage of abnor mally high values betw een the conductors.Transfor mer failures may be the result of insulation deterioration combined w ith over-voltages due to lightning or sw i tching trans ients. Short circuits due to insulation failure betw een adjacent turns of the same w inding may result from suddenly applied over voltages. Major insulation may fail, per mitting arcs to be established betw een primary and se condary w indings or betw een a w inding and grounded metal part such as the core or tank.Generators may fail due to breakdow n of the insulation betw een adjacent turns in the same slot, resulting in a shor t circuit in a single turn of the generator. Insulation breakdow n may also occur betw een one of the w indings and th e grounded steel structure in w hich the coils are embedded. Breakdow n betw een different w indings lying in the sam e slot results in short-circuiting extensive sections of machine.Balanced three- phase faults, like balanced three-phase loads, may be handled on a line to-neutr al bas is or on an equivalent single-phase basis. P roblems may be solved either in ter ms of volts, amperes, and ohms. The handling of faults on single-phase lines is of course identical to the method of handling three-phase faults on an equivalent s ingle-phase basis.Per manent Faults and Temporary FaultsFaults may be classified as per manent or temporary. P er manent faults are those in w hich insulation failure or struct ure failure produces damage that makes operation of the equipment impossible and requires repairs to be made. T emporary faults are those w hich may be removed by deenergiz ing the equipment for a short period of time, short ci rcuits on overhead lines frequently are of this nature. High w inds may cause tw o or more conductors to sw ing toget her momentar ily. During the short period of contact, an arc is formed w hich may continue as long as the line remai ns energized. How ever i f automatic equipment can be brought into operation to deenergize the line quickly, little ph ysical damage may result and the line may be restored to service as soon as the are is extinguished. Arcs across insulators due to over voltages from lightning or sw itching trans ients usually can be cleared by automatic circuit-brea ker operation before significant structure damage occurs.Because of this characteristic of faults on lines, many companies operate follow ing a procedure know n as high-spee d reclosing. On the occurrence of a fault, the line is promptly deenergized by opening the circuit breakers at each end of the line. The breakers remain open long enough for the arc to clear, and then reclose automatically. In man y instances service is restored in a fraction of a second. Of course, if structure damage has occurred and the fault persists,it is necessary for the breakers to reopen and lock open.电力系统最低限度的电力系统最低电力系统显示图.1 .该系统包括能源，主要动力，一台发电机和负荷。
(完整版)电力系统外文英语文献资料
Electric Power SystemElectrical power system refers to remove power and electric parts of the part,It includes substation, power station and distribution. The role of the power grid is connected power plants and users and with the minimum transmission and distribution network disturbance through transport power, with the highest efficiency and possibility will voltage and frequency of the power transmission to the user fixed .Grid can be divided into several levels based on the operating voltage transmission system, substructure, transmission system and distribution system, the highest level of voltage transmission system is ZhuWangJia or considered the high power grids. From the two aspects of function and operation, power can be roughly divided into two parts, the transmission system and substation. The farthest from the maximum output power and the power of the highest voltage grade usually through line to load. Secondary transmission usually refers to the transmission and distribution system is that part of the middle. If a plant is located in or near the load, it might have no power. It will be direct access to secondary transmission and distribution system. Secondary transmission system voltage grade transmission and distribution system between voltage level. Some systems only single second transmission voltage, but usually more than one. Distribution system is part of the power system and its retail service to users, commercial users and residents of some small industrial users. It is to maintain and in the correct voltage power to users responsible. In most of the system, Distribution system accounts for 35% of the total investment system President to 45%, and total loss of system of the half .More than 220kv voltage are usually referred to as Ultra high pressure, over 800kv called high pressure, ultra high voltage and high pressure have important advantages, For example, each route high capacity, reduce the power needed for the number of transmission. In as high voltage to transmission in order to save a conductor material seem desirable, however, must be aware that high voltage transmission can lead to transformer, switch equipment and other instruments of spending increases, so, for the voltage transmission to have certain restriction, allows it to specific circumstances in economic use. Although at present, power transmission most is through the exchange of HVDC transmission, and the growing interest in, mercury arc rectifier and brake flow pipe into the ac power generation and distribution that change for the high voltage dc transmission possible.Compared with the high-voltage dc high-voltage ac transmission has the following some advantages: (1) the communication with high energy; (2) substation of simple maintenance and communication cost is low; (3) ac voltage can easily and effectively raise or lower, it makes the power transmission and high pressure With safety voltage distributionHVDC transmission and high-voltage ac transmission has the following advantages: (1) it only need two phase conductors and ac transmission to three-phase conductors; (2) in the dc transmission impedance, no RongKang, phase shift and impact overvoltage; (3) due to the same load impedance, no dc voltage, and transfer of the transmission line voltage drop less communication lines, and for this reason dc transmission line voltage regulator has better properties; (4) in dc system without skin effect. Therefore, the entire section of route conductors are using; (5) for the same work, dc voltage potential stress than insulation. Therefore dc Wire need less insulation; (6) dc transmission line loss, corona to little interference lines of communication; (7) HVDC transmission without loss of dielectric, especially in cable transmission; (8) in dc system without stability and synchronization of trouble.A transmission and the second transmission lines terminated in substation or distribution substations, the substation and distribution substations, the equipment including power and instrument transformer and lightning arrester, with circuit breaker, isolating switch, capacitor set, bus and a substation control equipment, with relays for the control room of the equipment. Some of the equipment may include more transformer substations and some less, depending on their role in the operation. Some of the substation is manual and other is automatic. Power distribution system through the distribution substations. Some of them by many large capacity transformer feeders, large area to other minor power transformer capacity, only a near load control, sometimes only a doubly-fed wire feeders (single single variable substation)Now for economic concerns, three-phase three-wire type communication network is widely used, however, the power distribution, four lines using three-phase ac networks.Coal-fired power means of main power generating drive generators, if coal energy is used to produce is pushing the impeller, then generate steam force is called the fire. Use coal produces steam to promote the rotating impeller machine plant called coal-fired power plants. In the combustion process, the energy stored in the coal to heat released,then the energy can be transformed into the form within vapor. Steam into the impeller machine work transformed into electrical energy.Coal-fired power plants could fuel coal, oil and natural gas is. In coal-fired power plant, coal and coal into small pieces first through the break fast, and then put out. The coal conveyer from coal unloader point to crush, then break from coal, coal room to pile and thence to power. In most installations, according to the needs of coal is, Smash the coal storage place, no coal is through the adjustable coal to supply coal, the broken pieces of coal is according to the load changes to control needs. Through the broken into the chamber, the coal dust was in the second wind need enough air to ensure coal burning.In function, impeller machine is used to high temperature and high pressure steam energy into kinetic energy through the rotation, spin and convert electricity generator. Steam through and through a series of impeller machine parts, each of which consists of a set of stable blade, called the pipe mouth parts, even in the rotor blades of mobile Li called. In the mouth parts (channel by tube nozzle, the steam is accelerating formation) to high speed, and the fight in Li kinetic energy is transformed into the shaft. In fact, most of the steam generator is used for air is, there is spread into depression, steam turbine of low-pressure steam from the coagulation turbine, steam into the condenses into water, and finally the condensate water is to implement and circulation.In order to continuous cycle, these must be uninterrupted supply: (1) fuel; (2) the air (oxygen) to the fuel gas burning in the configuration is a must; (3) and condenser, condensed from the condensed water supply, sea and river to lake. Common cooling tower; (4) since water vapour in some places in circulation, will damage process of plenty Clean the supply.The steam power plant auxiliary system is running. For a thermal power plant, the main auxiliary system including water system, burning gas and exhaust systems, condensation system and fuel system. The main auxiliary system running in the water pump, condensation and booster pump, coal-fired power plants in the mill equipment. Other power plant auxiliary equipment including air compressors, water and cooling water system, lighting and heating systems, coal processing system. Auxiliary equipment operation is driven by motor, use some big output by mechanical drive pump and some of the impeller blades, machine drive out from the main use of water vaporimpeller machine. In coal-fired power plant auxiliary equipment, water supply pump and induced draft fan is the biggest need horsepower.Most of the auxiliary power generating unit volume increased significantly in recent years, the reason is required to reduce environment pollution equipment. Air quality control equipment, such as electrostatic precipitator, dust collection of flue gas desulfurization, often used in dust in the new coal-fired power plants, and in many already built in power plant, the natural drive or mechanical drive, fountain, cooling tower in a lake or cooling canal has been applied in coal-fired power plants and plants, where the heat release need to assist cooling system.In coal-fired power stations, some device is used to increase the thermal energy, they are (1) economizer and air preheater, they can reduce the heat loss; (2) water heater, he can increase the temperature of water into boiling water heaters; (3) they can increase and filter the thermal impeller.Coal-fired power plants usually requires a lot of coal and coal reservoirs, however the fuel system in power plant fuel handling equipment is very simple, and almost no fuel oil plants.The gas turbine power plants use gas turbine, where work is burning gas fluid. Although the gas turbine must burn more expensive oil or gas, but their low cost and time is short, and can quickly start, they are very applicable load power plant. The gas turbine burn gas can achieve 538 degrees Celsius in the condensing turbine, however, the temperature is lower, if gas turbine and condenser machine, can produce high thermal efficiency. In gas turbine turbine a combined cycle power plant. The gas through a gas turbine, steam generator heat recovery in there were used to generate vapor heat consumption. Water vapor and then through a heated turbine. Usually a steam turbine, and one to four gas turbine power plant, it must be rated output power.。
（完整版）电力系统外文英语文献资料
（完整版）电力系统外文英语文献资料Electric Power SystemElectrical power system refers to remove power and electric parts of the part,It includes substation, power station and distribution. The role of the power grid is connected power plants and users and with the minimum transmission and distribution network disturbance through transport power, with the highest efficiency and possibility will voltage and frequency of the power transmission to the user fixed .Grid can be divided into several levels based on the operating voltage transmission system, substructure, transmission system and distribution system, the highest level of voltage transmission system is ZhuWangJia or considered the high power grids. From the two aspects of function and operation, power can be roughly divided into two parts, the transmission system and substation. The farthest from the maximum output power and the power of the highest voltage grade usually through line to load. Secondary transmission usually refers to the transmission and distribution system is that part of the middle. If a plant is located in or near the load, it might have no power. It will be direct access to secondary transmission and distribution system. Secondary transmission system voltage grade transmission and distribution system between voltage level. Some systems only single second transmission voltage, but usually more than one. Distribution system is part of the power system and its retail service to users, commercial users and residents of some small industrial users. It is to maintain and in the correct voltage power to users responsible. In most of the system, Distribution system accounts for 35% of the total investment system President to 45%, andtotal loss of system of the half .More than 220kv voltage are usually referred to as Ultra high pressure, over 800kv called high pressure, ultra high voltage and high pressure have important advantages, For example, each route high capacity, reduce the power needed for the number of transmission. In as high voltage to transmission in order to save a conductor material seem desirable, however, must be aware that high voltage transmission can lead to transformer, switch equipment and other instruments of spending increases, so, for the voltage transmission to have certain restriction, allows it to specific circumstances in economic use. Although at present, power transmission most is through the exchange of HVDC transmission, and the growing interest in, mercury arc rectifier and brake flow pipe into the ac power generation and distribution that change for the high voltage dc transmission possible.Compared with the high-voltage dc high-voltage ac transmission has the following some advantages: (1) the communication with high energy; (2) substation of simple maintenance and communication cost is low; (3) ac voltage can easily and effectively raise or lower, it makes the power transmission and high pressure With safety voltage distribution HVDC transmission and high-voltage ac transmission has the following advantages: (1) it only need two phase conductors and ac transmission to three-phase conductors; (2) in the dc transmission impedance, no RongKang, phase shift and impact overvoltage; (3) due to the same load impedance, no dc voltage, and transfer of the transmission line voltage drop less communication lines, and for this reason dc transmission line voltage regulator has better properties; (4) in dc system withoutskin effect. Therefore, the entire section of route conductors are using; (5) for the same work, dc voltage potential stress than insulation. Therefore dc Wire need less insulation; (6) dc transmission line loss, corona to little interference lines of communication; (7) HVDC transmission without loss of dielectric, especially in cable transmission; (8) in dc system without stability and synchronization of trouble.A transmission and the second transmission lines terminated in substation or distribution substations, the substation and distribution substations, the equipment including power and instrument transformer and lightning arrester, with circuit breaker, isolating switch, capacitor set, bus and a substation control equipment, with relays for the control room of the equipment. Some of the equipment may include more transformer substations and some less, depending on their role in the operation. Some of the substation is manual and other is automatic. Power distribution system through the distribution substations. Some of them by many large capacity transformer feeders, large area to other minor power transformer capacity, only a near load control, sometimes only a doubly-fed wire feeders (single single variable substation)Now for economic concerns, three-phase three-wire type communication network is widely used, however, the power distribution, four lines using three-phase ac networks.Coal-fired power means of main power generating drive generators, if coal energy is used to produce is pushing the impeller, then generate steam force is called the fire. Use coal produces steam to promote the rotating impeller machine plant called coal-fired power plants. In the combustion process, the energy stored in the coal to heat released,then the energy can be transformed into the form within vapor. Steam into the impeller machine work transformed into electrical energy.Coal-fired power plants could fuel coal, oil and natural gas is. In coal-fired power plant, coal and coal into small pieces first through the break fast, and then put out. The coal conveyer from coal unloader point to crush, then break from coal, coal room to pile and thence to power. In most installations, according to the needs of coal is, Smash the coal storage place, no coal is through the adjustable coal to supply coal, the broken pieces of coal is according to the load changes to control needs. Through the broken into the chamber, the coal dust was in the second wind need enough air to ensure coal burning.In function, impeller machine is used to high temperature and high pressure steam energy into kinetic energy through the rotation, spin and convert electricity generator. Steam through and through a series of impeller machine parts, each of which consists of a set of stable blade, called the pipe mouth parts, even in the rotor blades of mobile Li called. In the mouth parts (channel by tube nozzle, the steam is accelerating formation) to high speed, and the fight in Li kinetic energy is transformed into the shaft. In fact, most of the steam generator is used for air is, there is spread into depression, steam turbine of low-pressure steam from the coagulation turbine, steam into the condenses into water, and finally the condensate water is to implement and circulation.In order to continuous cycle, these must be uninterrupted supply: (1) fuel; (2) the air (oxygen) to the fuel gas burning in the configuration is a must; (3) and condenser, condensed from the condensed water supply, sea and river to lake. Common coolingtower; (4) since water vapour in some places in circulation, will damage process of plenty Clean the supply.The steam power plant auxiliary system is running. For a thermal power plant, the main auxiliary system including water system, burning gas and exhaust systems, condensation system and fuel system. The main auxiliary system running in the water pump, condensation and booster pump, coal-fired power plants in the mill equipment. Other power plant auxiliary equipment including air compressors, water and cooling water system, lighting and heating systems, coal processing system. Auxiliary equipment operation is driven by motor, use some big output by mechanical drive pump and some of the impeller blades, machine drive out from the main use of water vaporimpeller machine. In coal-fired power plant auxiliary equipment, water supply pump and induced draft fan is the biggest need horsepower.Most of the auxiliary power generating unit volume increased significantly in recent years, the reason is required to reduce environment pollution equipment. Air quality control equipment, such as electrostatic precipitator, dust collection of flue gas desulfurization, often used in dust in the new coal-fired power plants, and in many already built in power plant, the natural drive or mechanical drive, fountain, cooling tower in a lake or cooling canal has been applied in coal-fired power plants and plants, where the heat release need to assist cooling system.In coal-fired power stations, some device is used to increase the thermal energy, they are (1) economizer and air preheater, they can reduce the heat loss; (2) water heater, he can increase the temperature of water into boiling water heaters; (3) they can increase and filter the thermal impeller.Coal-fired power plants usually requires a lot of coal and coal reservoirs, however the fuel system in power plant fuel handling equipment is very simple, and almost no fuel oil plants.The gas turbine power plants use gas turbine, where work is burning gas fluid. Although the gas turbine must burn more expensive oil or gas, but their low cost and time is short, and can quickly start, they are very applicable load power plant. The gas turbine burn gas can achieve 538 degrees Celsius in the condensing turbine, however, the temperature is lower, if gas turbine and condenser machine, can produce high thermal efficiency. In gas turbine turbine a combined cycle power plant. The gas through a gas turbine, steam generator heat recovery in there were used to generate vapor heat consumption. Water vapor and then through a heated turbine. Usually a steam turbine, and one to four gas turbine power plant, it must be rated output power.。
(完整word版)关于变配电的英文文献1
On architectural design of electrical energy saving methods Abstract : In this paper the architectural design of electrical energy saving, energy—saving methods， from the choice of transformer capacity， power factor compensation， lighting dimmers equipment， motor starter equipment selection, Electrical Design exposition of several energy—saving methods.Keywords : loss of electrical energy saving transformer power factor VVVF lighting energy saving soft starter ，as a result of population increase , industrial development, the improvement of living standards, the consumption of energy has increased dramatically, the energy crisis was imminent.Therefore, the businesses of the energy—saving requirements, secondary energy conservation -- Energy, civil construction, it has become the focus of electrical design。
自动化输配电系统中英文对照外文翻译文献
中英文资料翻译A Maintenance Optimization Program for Utilities’Transmission and Distribution SystemsABSTRACT: Today, preserving and enhancing system reliability and reducing operations and maintenance costs are top priorities for electric utilities. As system equipment continue to age and gradually deteriorate, the probability of service interruption due to component failure increases. An effective maintenance strategy is essential in delivering safe and reliable electric power to customers economically. The objective of this paper is to provide a framework for a predictive, condition-based, and cost effective maintenance optimization program for transmission and distribution systems.1 INTRODUCTIONIn principle, improving system reliability and reducing Operations and Maintenance costs are top priorities of electric utilities. In an increasingly competitive power delivery environment, electric utilities are forced to apply more proactive methods of utility asset management. One of the main components of electric power delivery asset management is the capital budgeting and Operations and Maintenance of existing facilities. Since in many cases the cost of construction and equipment purchases are fixed, Operations and Maintenance expenditures is the primary candidate for cost cutting and potential savings. As system equipment continue to age and gradually deteriorate, the probability of service interruption due to component failure increases.Electric utilities are confronted with many challenges in this new era of competition: rising Operations and Maintenance costs, growing demand on systems, maintaining high levels of reliability and power quality, and managing equipment aging.Therefore, the health of equipment is of utmost importance to the industry because revenues are affected by the condition of equipment. When demand is high and equipment is in working order, substantial revenues can be realized. On the contrary, unhealthy equipment can result in service interruption, customer dissatisfaction, loss of good will, and eventual loss of customers. An effective maintenance strategy is essential to delivering safe and reliable electric power to customers economically.2 RELIABILITY CENTERED MAINTENANCE (RCM)During the late 1960’s, t he aircraft industry was on the verge of manufacturing the first “jumbo jets”. The new 747’s were three times the size ofany other passenger jets currently in the air. The recognized size of the 747, its new engines, and its many technology advances in structures, avionics, and the like, all led to Federal Aviation Administration (FAA) to initially take the position that preventive maintenance on the 747 would be very extensive – so extensive, in fact, that the airlines could not likely operate this airplane in a profitable fashion. This problem led the aircraft industry to completely reevaluate its PM program. What resulted from this effort was a whole new approach that employed a decision-tree process for ranking PM tasks that were necessary to preserve critical aircraft functions during flight [3]. This new technique was eventually approved by the FAA and soon thereafter evolved into what is known as Reliability Centered Maintenance (RCM). RCM used by the airline industry led to major reduction in labor,material cost and inventory cost. Further it applied to nuclear power industry in the 1980’s. Today,RCM is the maintenance technique of choice for many industries including power industries.Unlike the airline industry which had the advantage of being able to work with manufacturers to create an RCM program for a new generation of equipment, the utility industry, especially the electric power generation industry, has had to adopt RCM as a modification of long-established maintenance practices at existing plants [4]. Despite the costs associated with the implementation of these RCM programs in “midstream”, they have been found to pay for themselves in very short order.RCM, as has been mainly applied to nuclear power plants, often requires the largest amount of maintenance because of safety and environmental considerations. However, with these successful programs now operating, fossil power plants and power transmission and distribution systems have recently been getting into the mix. Because these facilities face a less restrictive regulatory environment, they should be able to directly apply the streamlines forms of RCM much more easily, thus reducing the implementation costs.The first step in revamping a maintenance program is to implement an RCM approach whichwill help establish priorities for a new program. Specifically, RCM is a set of methods and tools aimed at helping a utility to determine the minimum set of preventive maintenance tasks necessary to appropriately address critical equipment failures without compromising service reliability. RCM is a structured process used to determine optimal maintenance requirements for equipment in a particular operating environment. Itcombines the strategies of corrective maintenance, preventive maintenance and predictive maintenance, and applies these strategies where each is appropriate, based on the consequence and frequency of functional failures. This combination produces a maintenance program which optimizes both reliability and cost effectiveness. For major pieces of equipment, such as power transformers, RCM may indicate that predictive maintenance is an attractive option, given the decreasing cost of sensor and diagnostic technology and the increasing cost of running the equipment to failure.RCM is a condition-based maintenance program that focuses on preventing failures that are likely to be the most serious. RCM and Predictive Maintenance (PDM) analyses complement each other, and when they are performed concurrently, offer an excellent approach to maintenance optimization. In the last few years, the sophistication of monitoring equipment on the market and the falling price of electronics and computers have made the on-site monitoring applications a cost effective reality.The very basic concepts and underlying principles of the RCM can be explained very easily. Its main methodology can be reduced to the following four points:1) preserve system functions2) identify dominant failure modes3) prioritize function needs so that budget can be focused on preserving most critical functions4) select only applicable and effective maintenance tasksSome of the benefits of RCM are:1) Reduces major corrective actions2) Eliminates unnecessary overhauls and routine tasks that provide little benefits3) Optimizes the frequency of required overhauls4) Increases use of predictive technology that help with resource planning5) Decreases use of intrusive tasks that can induce equipment failures6) Improves cost-effectiveness of routine tasks7) Creates documented technical bases for maintenance programs8) Allows easy implementation by incorporating existing maintenance practices that have proven to be cost-effective9) Processes Knowledge, communications, and teamworkInexpensive solid state sensors are being developed, for example, that can be inserted in transformer oil to detect the presence of gases produced when insulation begins to deteriorate. Once the information from predictive maintenance technology becomesavailable, it needs to be integrated with on-line data from across a power network and from historical records.3 NEW TECHNOLOGIESThere are many technologies available today, and several new methods are being investigated to determine the equipment condition [5]. The following are just a few applications for monitoring power delivery equipment:Ultrasonic Noise AnalysisThe presence of tones in the ultrasonic range can be an indication of leaks of air, gas, steam, and vacuum. Ultrasonic noise can be emitted as a result of friction between moving parts.Partial Discharge DetectionThis technology employs an electrical sensor to detect the initial insulation breakdown in electrical equipment such as insulators and terminators. Partial discharge detection is used to detect incipient failures before significant damage occurs. Transformer Gas-in-Oil AnalysisThis is needed to keep the transformer on-line as much as possible. One indicator of abnormalities is the dissolved gas content in the transformer oil. Certain gas levels can indicate aging, the need for maintenance, or potential failure.Infrared ThermographyThermography surveys involving the use of an infrared camera to detect hot spots in large motors used in power plants.Sound Intensity MeasurementSound Intensity Meter is needed to identify potential problems in equipment and record the historical changes in sound and output of equipmentFor transmission and distribution systems, sensors such as transformer fault gas analyzer might prove to be beneficial. This device provides real-time measurement of the four key gases associated with fault currents in transformer: carbon monoxide, hydrogen, acetylene, and ethylene. The next step is to incorporate an additional sensor to detect the presence of moisture which can reduce dielectric strength and lead to failure. This will be used with another device that measures the transformer loading so that the evolution of key gases and moisture can be characterized as a function of the load. With the moisture sensor and load current monitor we can develop accurate criteria for loading transformers under stressful conditions rather than having to rely on the overly conservative ratings now provided.4 PROPOSED INTEGRATED APPROACHAn integrated approach for transmission and distribution systems would ensure that equipment or subsystems leading to serve a particular load would receive uniform and consistent level of maintenance in all departments, thus enhancing and optimizing the maintenance process.In order to establish a maintenance program, the RCM process needs to be the driving point. Figure 2. Shows different strategies required for a maintenance optimization program. The classical RCM process involves identifying the systems to be studied, their functions, functional failures, failure modes, failure causes, and the maintenance task selectio.The most critical pieces of equipment which affect the overall function of the system need to be identified. In other words, we need to identify equipment with severe consequences when failed. Also, critical customers and the equipment leading to their loads need to be identified. All equipment affecting these customers need to be analyzed, and the most critical pieces of equipment should be determined. We also need to understand the customer needs in terms of reliability, safety, power quality, cost, etc. These attributes must be weighted to determine the optimum maintenance policy to deal with these customers.In order to optimize the utilities’ maintenance program, all relevant information must be used to most effectively initiate, schedule, track, record, and analyze maintenance tasks. An open communication protocol that enables various monitoring devices (regardless of the manufacturer) to talk to each other, with utilityoffices, and with control centers would best suit the needs of electric utilities by integrating various data sources and other software modules.Currently, many large utility organizations perform some equipment diagnostic tests. Many have computerized their maintenance work management functions including retaining maintenance histories, logging significant operational activities, and maintaining a library of design information for equipment. The proper communication, integration and analysis of all of this information would result in more accurate recommendations concerning when to perform maintenance and/or how to operate a specific piece of equipment.A typical problem in the industry is that, at times, a large amount of data is collected but it is not integrated and processed expediently for a quick evaluation. This results in the inability to make immediate Operations and Maintenances, therebyadding cost for thecollection of data while failing to provide cost benefit which could have been realized.Other factors that may contribute to maintenance improvement are: application of inexpensive sensor techniques and effective diagnostics to maintain equipment’s health; data coordination from multiple sources for analysis and decision making; a system for efficient exchange of information across T&D and substations; and experienced pool of trained professionals.The management should be prepared to invest in staff and hardware/software to actively manage the maintenance program. A team approach to RCM must be retained and the concept of RCM must be accepted in the organization.In order to use appropriate software and hardware, education and training efforts should be an integral part of this process. The understanding of the basics of utility’s maintenance program and the working knowledge of the tools required by the staff must be assured.The key to sustaining a successful maintenance program is the development of a process that will ensure the continuance of maintenance program over a long period of time. It is necessary to periodically review and update the maintenance program using a structured method.5 CONCLUSIONToday, cutting operations and maintenance costs and preserving service reliability are the top priorities for managers of utility transmission and distribution systems. The concept of RCM is sound and should provide utilities with a structured approach to a maintenance program with an optimum balance between cost of maintenance and reliability improvement. RCM and PDM analyses complement each other, and when performed simultaneously, offer an excellent approach to maintenance optimization.一种实用的输配电系统的维护优化计划摘要：今天，维护和提高系统的可靠性和降低运营和维护成本是电力的首要任务。
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。
电力系统维护的外文文献-论文赏析
Academic essay reading appreciation Reading Task: To learn the main structure of an academic essayQuestion 1: How many parts are there in this easy?Question 2.How does the automatic transfer switch work? Question 3.What is the Grounding System？Power System Equipment Maintenance and Long-Term Servicing Requirements for Data CentersKen Agent, PE, Square D/Schneider Electric Engineering Services SummarySummary (2)Abstract (3)Introduction (3)Electrical Preventive Maintenance Program (EPM) (3)Typical Data Center Power Distribution Equipment (5)Design (12)Conclusion (14)References (14)AbstractNo engineered system can run indefinitely without the need for maintenance, and the electric power equipment found in data centers is no exception to this rule. This paper discusses how equipment servicing and maintenance is crucial to the long-term operation of a data center power system, typical maintenance intervals and servicing activities for different types of equipment and how the consideration of maintenance in the initial design of a data center enhances reliability in the long-term.IntroductionAn effective electrical preventive maintenance (EPM) program is critical to any power system. Without such a program, those with a vested interest in the operation of the facility may be unaware of potential problems and cannot prevent them. In addition, the risk of failures greatly decreases with the frequency and quality of an EPM program.Each individual program should be tailored to the types of equipment in the facility, the availability of downtimes, and the critical nature of the loads. Hostile environments, overloads, and severe duty cycles can increase the need for regular maintenance. In addition, if equipment feeds critical loads, it should be maintained regularly to decrease the likelihood of failure.The ideal first step in an electrical preventive maintenance program is a good design. Dual feeds, draw-out equipment, standardized equipment, etc. can all make maintenance much more realistic during the normal operation of a facility. Otherwise, the necessary downtimes will increase and maintenance will either be delayed or eliminated. In addition, if the equipment is excessively complex or extremely unique, repairs can be overly expensive.Electrical Preventive Maintenance Program (EPM)The three parts of an EPM program are inspection, testing, and repair. Each part is vital to the program’s overall success. It is vital to tailor each part around the operations and critical nature ofthe facility.Before an inspection can begin, up to date drawings and diagrams must be obtained, along with applicable manufacturers’ operation and maintenance manuals for the equipment; otherwise the inspection could be incomplete, inaccurate, or unsafe. This information will help determine where to prioritize maintenance and how to implement lock-out/tag-out before testing begins.In a facility where down time is a premium, running inspections are vital. However, these should only be performed by qualified personnel who have been properly trained on the potential hazards. An example of a running inspection would be infrared scanning. These types of inspections can increase the effectiveness of a complete inspection once a shut-down is scheduled.Only once the equipment has been shut-down, all of the energy sources have been locked-out/tagged-out, equipment has been verified “dead,” and proper grounds have been applied (if applicable), can a complete inspection begin. This type of inspection should be planned in detail before the shut-down so time is not wasted. The areas of interest for inspection will be unique for each type of equipment in the facility, and the equipment manufacturers’ operation and maintenance manuals should be consulted for guidance as to key areas upon which to concentrate. Both age and environment should be considered during planning and implementation. In addition, all personnel involved should be properly trained so the inspection is both effective and safe and time is not wasted during the process.As with inspection, testing will be unique for each type of equipment and the equipment manufacturers’ operation and maintenance manuals should be consulted. The proper testing equipment should be available before the shut-down begins. This equipment should be tested in advance to both determine its accuracy and insure that it will work as planned during the shut-down. In addition, if the equipment needs an external source of power, it should be part of the plan to make such power available.A vital outcome from inspection and testing should be accurate and complete records. Without them, planning for repairs can become extremely difficult. In addition, future trouble shooting will be much more effective with good records.Based on the outcome of the inspection and testing, repairs should be scheduled. Repairs should first be targeted at equipment that is either close to failure or vital to a critical load.Typical Data Center Power Distribution EquipmentMedium-voltage transformers are some of the most critical components in a power system. They can cause drastic service interruptions and can take weeks or months to replace if they fail. In addition, they are also one of the most expensive components in a power system.A typical data center will contain either liquid-filled or dry-type (including cast-coil) substation transformers.Medium-voltage Liquid-filled TransformersNewer liquid-filled transformers can contain mineral oil, seed oil (less flammable) or silicone fluid. However, some older transformers could contain askarel, which contains PCBs. These fluids should never be mixed.The designer should work with the insurance underwriter to specify clearances and necessary containment means to contain the fluid, in case of a leak or spill.Like all other components in an electrical power system, the frequency of maintenance depends on the operating conditions. Clean and dry conditions could require annual maintenance, while a hot, dirty environment will require more frequent maintenance. However, major maintenance is recommended at least every three to six years.A visual inspection should be part of routine maintenance. This will consist of monitoring the load current, voltage, liquid level, liquid temperature, winding temperature, ambient temperature and any fluid leaks. In addition, the transformer fluid should be sampled at regular intervals and dissolved gas analysis performed. Fluid should never be sampled while energized, unless an external sampling valve is present. Most of these inspections should be able to take place with the transformer in service. However, the transformer must be equipped with all of the necessary gauges and monitors for this to take place while energized. The results of these tests are best utilized by tracking the results of multiple tests as trends over time.During a shut-down, more testing should take place. These tests would include insulation tests such as power-factor testing and insulation-resistance testing. The transformer instrumentation and protection, such as gauges, sudden-pressure relays, etc., should be checked as well. Diagnostic tests such as turns-ratio testing and exciting-current testing should also occur. Any readings outside of the manufactures specifications should be investigated. Any fans, relays, control power, control power wiring, etc. should be inspected along with the general condition ofthe enclosure. Bushing and surge arrestor should be cleaned and loose connections should be tightened. The transformer should also be checked for pressure and bushing leaks.Medium-voltage Dry-type TransformersVentilated and cast-coil dry-type ANSI/IEEE C57.12.01 medium-voltage transformers are another option to liquid-filled. Clean and dry conditions could require maintenance at least every three to six years, while a hot, dirty environment will require more frequent maintenance.During the shut-down, dirt and debris should be removed from the core, coil and insulators. Special care should be made to insure air flow is not impeded. Loose connections should be tightened. Insulation-resistance testing, turns-ratio testing, and core Megger tests should also take place. Any readings outside of the manufactures specifications should be investigated.Medium-voltage Metal-clad SwitchgearANSI/IEEE C37.20.2 metal-clad switchgear in a power system distributes power and contains circuit breakers and overcurrent protection, usually in addition to other types of, protection. The construction of this switchgear can vary widely based on manufacturer and age, so accurate drawings and documentation is essential for use and maintenance.Like all other components in an electrical power system, the frequency of maintenance depends on the operating conditions. Moisture combined with dirt will deteriorate the insulation in the equipment at a highly accelerated rate. Major maintenance is recommended at least every three to six years.During a shut-down the busbars, supports and insulating barriers should be inspected and cleaned. The busbars should be tightened to manufacturer’s specifications. The interior should be thoroughly vacuumed and adequate ventilation verified. All parts should be inspected for signs of corona, tracking or thermal damage. All cable terminations should be inspected for indication of insulation deterioration. If space heaters are present, they should be tested.It is vital to also inspect the circuit breaker compartments. Once the circuit breaker(s) have been withdrawn,all of the moving mechanisms in the compartment should be inspected. The shutters should also beinspected and tightened. In addition, the primary contacts should be inspected for signs of loose hardware or poor contact with the circuit breaker contacts. All contacts and joints should be lubricated per the manufacturer’s specifications.It is also important to service the VT and CPT compartments. Parts should be inspected,cleaned, tightened and lubricated per the manufacturer’s specifications.In addition, all surge arrestors, interlocks, and battery systems should be checked and maintained per the manufacturer’s specif ications.Medium-voltage Circuit BreakersThe ANSI/IEEE C37.04 and C37.06 circuit breakers within the medium-voltage switchgear are controlled by external protective relays to provide overcurrent, and probably other types of, protection. In addition, they can be used to switch between various sources of power.There are basically four types of medium-voltage circuit breakers: vacuum, gas, air and oil. However, most new installations will have vacuum circuit breakers.Like all other components in an electrical power system, the frequency of maintenance depends on the operating conditions. However, one manufacturer recommends inspection ever year, or every 1,000 operations.Inspection and maintenance should take place after any fault operations.Circuit breakers should be completely withdrawn from their cubicles before being maintained. They should be inspected for signs of overheating, and excessive dirt or moisture. Check for loose parts or connections. The operating mechanisms should be snug and friction free. Both the insulators and the vacuum interrupters should be cleaned. The drawout primary contact clusters should be checked for signs of wear or damage.Contact erosion, hi-pot (dielectric), and resistance measurement tests should take place to check the vacuum interrupters against the manufacturer’s specifications. In addition, it is highly recommended to have spares of each amperage size and manufacturer available, in case of failure. Protective RelaysProtective relays utilize inputs from CTs and PTs, along with their characteristic curves and settings, to provide protection to cables, transformer, motors, and other equipment within the power system. Relays will shunt trip their associated medium-voltage circuit breaker if they detect an over current, or other anomaly, that falls within their settings.There are basically two types of protective relays: Electronic and electro-mechanical. While some owners still specify electromechanical, electronic relays are much more common in new installations.Electronic relays are designed to be maintenance-free. However, like all other components inan electrical power system, harsh operating conditions could dramatically reduce the lifespan of the device. In general, once an electronic relay has been commissioned, it should be maintenance free, unless settings changes are needed in the future.Electromechanical relays should be tested on a regular basis. One manufacturer, for example, recommends every six months. In addition to testing the calibration, the unit should be inspected for damage and the contacts should be cleaned.Medium-voltage Metal-enclosed SwitchgearIn most cases, ANSI/IEEE C37.20.3 medium-voltage metal-enclosed switchgear is located at the primary side of unit substations in data centers. However, it also can be used as the main switchgear to distribute power downstream. It generally consists of load interrupter switches, either fused or non-fused, that are infrequently used for load interruption. Their primary task is to protect the downstream load, if fusible, and to provide a disconnect for lock-out/tag-out.Like all other components in an electrical power system, the frequency of maintenance depends on the operating conditions. For example, one manufacturer recommends inspection every one to five years, or every 100 operations. Inspection and maintenance should take place after any fault downstream.During the shut-down, a hi-pot (dielectric) test should take place to measure insulation integrity along with general cleaning and tightening of the insulators, busing , and mechanical parts. The contacts and operating mechanism should be cleaned and lubricated per the manufacturer’s specifications.Low-voltage SwitchgearLike medium-voltage switchgear, ANSI C37.20.1 low-voltage switchgear distributes power and contains circuit breakers with over current protection. Some facilities might choose UL 891 low-voltage switchboards, which can be almost identical to switchgear.Like all other components in an electrical power system, the frequency of maintenance depends on the operating conditions. Moisture combined with dirt will deteriorate the insulation in the equipment at a highly accelerated rate.Maintenance on low-voltage switchgear is very similar to maintenance on medium-voltage switchgear. Construction can vary widely based on manufacturer and age, so accurate drawings and documentation is essential for use and maintenance. The equipment should be cleaned,lubricated and exercised on a regular basis. One manufacturer, for example, recommends inspection every year as a maximum. However, under ideal circumstances, maintenance could only be required every five years.Like with other equipment, an inspection should take place after a short circuit involving the switchgear in the path of current flow. In particular, Insulation and conductors should be inspected for damage.Low-voltage Circuit BreakersThere are essentially two classes of low-voltage circuit breakers that can be applied in a power system: Power circuit breakers (ANSI C37.13) or molded and insulated case circuit breakers (UL 489). Power breakers are used in draw-out switchgear while molded and insulated case circuit breakers are used in switchboards, panel boards and other applications.Like medium-voltage circuit breakers, low-voltage power breakers should be completely withdrawn from their cubicles before being maintained. The primary drawout contact clusters should be checked for signs of wear or damage. Insulation should be checked using dielectric tests (hi-pot or insulation resistance).Unlike medium-voltage breakers, low-voltage breakers usually have an integral trip unit. There are usually two ways to test the trip unit: primary and secondary injection. Primary injection is recommended since it tests the complete system, including the current sensors, while secondary injection only tests the trip unit itself. It is important to note that primary injection requires a large test set that could need single-phase 480V for operation. Planning for this power is necessary prior to any shut-down.Insulated case circuit breakers can sometimes be maintained similar to power circuit breakers. However, in many cases, their maintenance is similar to a molded case breaker. Manufa cturer’s literature should be consulted for recommended practices.Molded case circuit breakers require a minimal amount of maintenance. In fact, opening the case will void the manufacture warranty. Maintenance is limited to inspection and good operating conditions, and in some cases primary injection testing with the circuit breaker removed from the enclosure. They should be manually operated annually. In addition, the “push to trip” button should be utilized to exercise the tripping mechanism.Switchboards and Panel boardsSwitchboards and panel boards are built per UL 489. They are for low-voltage applications and contain either molded-case circuit breakers or fusible switches. Both are typically found downstream of the switchgear in a data center.Maintenance is mostly limited to insuring good electrical and mechanical connections plus good housekeeping. Regular infrared scanning and cleaning is recommended to insure dependable operation.Low-voltage Motor Control Centers (MCCs)One of the most versatile components in a power system are the UL 845 low-voltage motor control centers (MCCs). These are designed to contain starters for motors, located within buckets, or control units, in the enclosure. The buckets can also contain drives, or simply molded case circuit breakers or fusible switches.Maintenance on the enclosure and busbars of MCCs is very similar to switchgear, the major difference being the maintenance of the drawout buckets. The buckets should be removed from the MCC before maintenance. Once removed, the primary contact stabs should be examined for signs of arcing or overheating. If a stab is badly pitted, it may be necessary to replace the vertical bus within the MCC. Within the bucket, any circuit breakers, switches, starters, control devices and wiring should be examined.Low-voltage TransformersNEMA low-voltage dry-type transformers are typically used for lighting applications within data centers. The frequency of inspection is based upon the operating conditions. Clean and dry conditions require less maintenance, while dusty, hot environments will require more frequent inspections. During maintenance, connections should be checked for looseness. In addition, any dust that restricts air flow or lies on insulating surfaces should be removed. A visual inspection for overheating, tracking and overall enclosure condition should also take place.Automatic Transfer Switches (ATSs)Automatic transfer switches (ATSs) are critical in data center power systems. They switch their downstream loads between power sources in the event of source failure.There are basically two types of ATSs: standard and bypass-isolation. Either can be open- or closed-transition. Bypass-isolation ATSs allow the switch to be racked out for inspection, testing and maintenance without any interruption of power to the load.The controller/switch combination should be checked often. One manufacturer recommendsa once a month test. Any test should verify the proper electrical operation of the controller and switch per the manufacturer’s specifications.One manufacturer recommends annual maintenance of the switch itself. The maintenance should include general cleaning of the enclosure, inspection of the contacts, lubrication and inspection of all cable connections.Uninterruptible Power Supply (UPS) SystemsUninterruptible Power Supply (UPS) systems provide the final safety net for a data center power system. They also can remove the momentary power interruption during open transition switching between utility and generator sources.There are basically two types of UPS systems: static (or battery) and rotary (or flywheel). There are advantages to both systems. However, a detailed description is outside of the scope of this paper.Due to the unique and technical nature of a UPS system, most manufacturers recommend that their service personnel perform any major maintenance and system tests. In addition, since a UPS is designed and applied to provide constant power to its loads, extreme caution should be used to not interrupt power. As a result of the need to not lose power, the system should be design so that switching can occur to allow the UPS (or each module of a multi-module UPS) to be isolated while maintaining power to critical loads. This furthers the need for qualified and trained personnel.However, some less-complex routine maintenance can take place. It is important to keep the room clean and cool. In addition, the air filters should be replaced and the battery system inspected on a regular basis. Also, depending on the UPS size and manufacturer, it is possible individual components of the system (molded case circuit breakers, etc.) can be maintained, as detailed in other parts of this paper.Bus wayWhile not every data center has bus way, it is becoming more common in this environment. NEMA low-voltage Bus way is typically found downstream of the PDUs, feeding critical loads. However, ANSI medium-voltage metal-enclosed bus way can be found at the service level. Bus way is designed to be low-maintenance equipment. However, a regular visual inspection and IR scan are recommended to look for exterior damage and loose connections. An inspection shouldbe made if a short-circuit or ground fault has taken place downstream of the bus way. Connections should be torqued and insulation resistance should be tested also.In addition to the bus way itself, plug-in bus way will have “plugs” that contain either fusible switches or molded case circuit breakers. These switches and breakers should also be inspected and maintained as recommended above.Grounding SystemThe grounding system is vital to both the operation of the over current devices in the system and personnel safety. Grounding and bonding within the system should be inspected on a regular basis. The electrical connection to earth should be measured. In addition, voltage should be measured between the equipment grounding conductor and the grounded conductor at multiple locations. Also, current should be measured on the grounded conductor. If any of these readings are outside of standard levels, their cause should be immediately found and corrected.DesignIn an ideal world, the initial design of a power system should account for both the loads being serviced in the facility and the ease of maintenance. However, many owners are left to deal with systems that have been value-engineered where maintenance is extremely difficult to schedule and implement. There are several design opportunities that can make both scheduling and implementing maintenance much more realistic.Tie breakers allow power from alternate sources to feed downstream loads, while a main breaker, and possibly another tie breaker, is opened. This allows maintenance on some of the upstream distribution system. In addition, depending on the system, trip unit settings can be applied to the tie breaker to allow another level of selectivity in the protection system.ATSs and UPSs are vital to a data center. ATSs quickly switch between various power sources during a voltage interruption, sag, loss of phase, etc. ATSs can be applied as closed-transition, if the downstream equipment has the proper AIC and WCR ratings. Regardless, the use of ATSs with downstream UPSs provide maximum reliability to the system. If all available power sources go down, the UPSs will provide power for a certain amount of time,depending on the model. In addition, the UPS will provide continuous power during open-transition switching of upstream ATSs or circuit breakers. The use of ATSs and UPSs will also allow upstream maintenance without critical load interruption. As mentioned above, high-reliability systems should be designed with appropriate switching to allow each UPS (or each module of a multi-module UPS) to be isolated individually while maintaining power to the critical load.Draw-out equipment provides an advantage during both maintenance and system failures. Draw-out equipment can be quickly removed from service for testing, while fixed-mounted equipment usually requires an extended shut-down for removal from the equipment. Also, if spares are available, they can be utilized while other equipment is tested. In addition, if a draw-out device fails, it can be replaced with a spare much quicker than fixed mounted equipment.Standardized equipment is also recommended as part of the initial design and any expansions. If draw-out equipment is used, they can be taken between different parts of the building during maintenance and failure if such a standard is employed. However, if multiple types and manufactures are utilized, the equipment will not be as versatile.In a data center, down time for maintenance is a critical commodity. Grouping of equipment can speed up this process. If all of the personnel and test equipment can be staged and located in one part of the facility, the process should become smoother and quicker.Part of the initial design should insure the proper operating environment for the power system equipment. This will reduce the amount of necessary maintenance and probability of failure. Equipment rooms should have clean, filtered air with very low levels of vibration. Also, while the exact conditions will vary between equipment and manufacturer, ambient conditions between 60 degrees to 85 degrees F and 40–70% humidity are generally recommended.An extremely useful tool for both detecting potential problems and trouble shooting is a robust power monitoring system. This system will allow the owner to detect potential power quality issues before they cause a major problem in the system. In addition, it will provide the necessary data for planning for expansions and the installation of new equipment.Several equipment features can allow easy inspection during operation, which could extend time between necessary downtimes for maintenance. Infrared (IR) windows, hinged doors and barriers between sections all provide an added level of safety for running inspections.Both acceptance testing and inspection before shipment are recommended for the more vital components in a power system. This will allow the owner to find problems before the equipment is energized and utilized and will provide the necessary data points when preventative maintenance takes place in the future.ConclusionNo critical power system should be without an effective electrical preventive maintenance (EPM) program. Potential failures cannot be detected without such a system in place. Failures within the system will decrease with the frequency and quality of the EPM.The EPM should be tailored to each individual system. Details such as types of equipment, availability of downtimes, operating conditions, and the nature of the loads must be considered. Two systems with identical designs could have different EPMs if they are operated in a different manner.The first step to an effective EPM is the design. The system can be designed to allow shutdowns of a small portion of the system to allow for maintenance. Such a design can all for decreased time periods between maintenance. In addition, the specified equipment should be easily repairer or replaced, if a failure does occur.ReferencesNFPA 70B., Recommended Practice for Electrical Equipment Maintenance, Quincy, MA: NFPA。
供配电系统中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)POWER 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 balancepoint 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 the way 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 examp le 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 quantityharmony, 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 and adopt 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 putemphasis 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, 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 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 andanalyses 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.References[1] Wencheng Su. Factories power supply [M]. Machinery Industry Publishing House. 1999.9[2] Jiecai Liu. Factories power supply design guidance [M]. Machinery Industry Publishing House.1999.12[3] Power supply and distribution system design specifications[S].China plans Press. 1996[4] Low-voltage distribution design specifications [S].China plans Press. 1996.6供配电系统摘要电力系统的基本功能是向用户输送电能。
英文文献及翻译：供配电系统（1800字）
英文文献及翻译：供配电系统（1800字）供配电系统摘要：电力系统的基本功能是向用户输送电能。
lOkV配电网是连接供电电源与工业、商业及生活用电的枢纽，其网络庞大及复杂。
对于所有用户都期望以最低的价格买到具有高度可靠性的电能。
然而，经济性与可靠性这两个因素是互相矛盾的。
要提高供电网络的可靠性就必须增加网络建设投资成本。
但是，如果提高可靠性使用户停电损失的降低小于用于提高可靠性所增加的投资，那么这种建设投资就没有价值了。
通过计算电网的投资和用户停电的损失，最终可找到一个平衡点，使投资和损失的综合经济性最优。
关键词：供配电，供电可靠性，无功补偿，负荷分配1 引言电力体制的改革引发了新一轮大规模的电力建设热潮从而极大地推动了电力技术革命新技术新设备的开发与应用日新月异特别是信息技术与电力技术的结合在很大程度上提高了电能质量和电力供应的可靠性由于技术的发展又降低了电力建设的成本进而推动了电网设备的更新换代本文就是以此为契机以国内外配电自动化中一些前沿问题为内容以配电自动化建设为背景对当前电力系统的热点技术进行一些较深入的探讨和研究主要完成了如下工作.(1)提出了配电自动化建设的两个典型模式即―体化模式和分立化模式侧重分析了分立模式下的配电自动化系统体系结构给出了软硬件配置主站选择管理模式最佳通讯方式等是本文研究的前提和实现平台.(2)针对配电自动化中故障测量定位与隔离以及供电恢复这一关键问题分析了线路故障中电压电流等电量的变化导出了相间短路工况下故障定位的数学描述方程并给出了方程的解以及故障情况下几个重要参数s U& s I& e I& 选择表通过对故障的自动诊断与分析得出了优化的隔离和恢复供电方案自动实现故障快速隔离与网络重构减少了用户停电范围和时间有效提高配网供电可靠性文中还给出了故障分段判断以及网络快速重构的软件流程和使用方法.(3)状态估计是实现配电自动化中关键技术之一本文在阐述状态估计方法基础上给出了不良测量数据的识别和结构性错误的识别方法针对状态估计中数据对基于残差的坏数据检测和异常以及状态量中坏数据对状态估计的影响及存在的问题提出了状态估计中拓扑错误的一种实用化检测和辩识方法针对窃电漏计电费问题独创性提出一种通过电量突变和异常分析防止窃电的新方法并在潍坊城区配电得到验证.(4)针对配电网负荷预测建模困难参数离散度大以及相关因素多等问题本文在分析常规负荷预测模型及方法基础上引入了气象因素日期类型社会环境影响等参数给出了基于神经网络的电力负荷预测方法实例验证了方法的正确性.(5)针对无源滤波在抑制谐波和无功补偿方面的不足以及补偿度的不连续性本文提出了一种PWM 主电路拓朴结构和基于无功功率理论的有源滤波方案建立了基于Saber Designer 仿真平台仿真分析证明了方案的可行性同时结合配电自动化技术对配电网动态无功优化补偿和降低线损的方法进行了设计分析通过实例计算验证了其客观的经济效益.(6)针对中国电力市场未来的发展趋势以及政府监管下的电力市场公平交易设计了一种适合我国电力市场现状按照电价分组电量协调分组竞价的短期电力交易模式给出了基于边际电价的机组组合算法制订交易计划的数学模型以及安全经济约束等在竞争比例逐步提高的情况下能够较好地解决原有中长期合同电价和短期竞争电价的矛盾减少电厂不公平的收益差异同时也可在电力市场全网的负荷曲线上对所有电厂进行限量优化减少总的系统购电费用.2 配电网分析配电网是电力系统中的一个重要环节，配电网接地方式和安全运行直接关系到电力系统的安全和稳定。
高层建筑供配电系统设计毕业论文中英文对照资料外文翻译文献
高层建筑供配电系统设计毕业论文中英文对照资料外文翻译文献外文资料翻译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。
供配电系统设计英文文献
供配电系统设计英文文献以下是一些供配电系统设计的英文文献:1. "Power System Design" by James A. Reedy, published in 2012 by John Wiley & Sons.2. "Power System Stabilization" by R. W. Knapp and H. W. Zacharias, published in 1963 by John Wiley & Sons.3. "Power System Protection" by E. H. Elser, published in 1968 by John Wiley & Sons.4. "Transmission System Design" by William A. Crothers, published in 1973 by John Wiley & Sons.5. "Power System Control" by T. W. Anderson and R. B. Francis, published in 1968 by John Wiley & Sons.6. "Power System Engineering" by W. J. Lathrop, published in 1976 by John Wiley & Sons.7. "Power Distribution System Design" by R. C. Davis, published in 1970 by John Wiley & Sons.8. "Electric Power Systems Analysis and Design" by R. C. Davis and H. A. Thomas, published in 1975 by John Wiley & Sons.9. "Power System Stability and Control" by P. M. S. Black, published in 1962 by John Wiley & Sons.10. "Electric Power System Security" by G. A. Czarnecki and T. J. Mclaughlin, published in 2000 by John Wiley & Sons.这些文献涵盖了供配电系统设计的各个方面，包括电力系统设计、电力系统稳定控制、电力系统保护和控制、输电系统设计、配电系统设计等。
推荐-供配电类英文原文 精品
附录二：英文原文Electric power distributionAn electric power distribution system is the final stage in the delivery of electric power; it carries electricity from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2kV and 35kV with the use of transformers. Primary distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage of household appliances and typically feed several customers through secondary distribution lines at this voltage. mercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the sub transmission level.HistoryFurther information: History of electric power transmissionElectric power distribution only became necessary in the 1880s when electricity started being generated at power stations. Before that electricity was usually generated where it was used. The first power distribution systems installed in European and US cites were used to supply lighting: arc lighting running on very high voltage (usually higher than 3000 volt) alternating current (AC) or direct current (DC), and incandescent lighting running on low voltage (100 volt) direct current. Both were supplanting gas lighting systems, with arc lighting taking over large area/street lighting, and incandescent lighting replacing gas for business and residential lighting.Due to the high voltages used in arc lighting, a single generating station could supply a long string of lights, up to 7-mile (11 km) long circuits, since the capacity of a wire is proportional to the square of the current traveling on it, each doubling of the voltage would allow the same size cable to transmit the same amount of power four times the distance. Direct current indoor incandescent lighting systems (for example the firstEdison Pearl Street Station installed in 1882), had difficulty supplying customers more than a mile away due to the low 110 volt system being used throughout the system, from the generators to the final use. The Edison DC system needed thick copper conductor cables, and the generating plants needed to be within about 1.5 miles (2.4 km) of the farthest customer to avoid excessively large and expensive conductors. Introduction of the AC transformerTrying to deliver electricity long distance at high voltage and then reducing it to a fractional voltage for indoor lighting became a recognized engineering roadblock to electric power distribution with many, not very satisfactory, solutions tested by lighting panies. The mid-1880s saw a breakthrough with the development of functional AC transformers that allowed the voltage to be "stepped up" to much higher transmission voltages and then dropped down to a lower end user voltage. With much cheaper transmission costs and the greater economies of scale of having large generating plants supply whole cities and regions, the use of AC spread rapidly.In the US the petition between direct current and alternating current took a personal turn in the late 1880s in the form of a "War of Currents" when Thomas Edison started attacking George Westinghouse and his development of the first US AC transformer systems, pointing out all the deaths caused by high voltage AC systems over the years and claiming any AC system was inherently dangerous. Edison's propaganda campaign was short lived with his pany switching over to AC in 1892.AC became the dominant form of transmission of power with innovations in Europe and the US in electric motor designs and the development of engineered universal systems allowing the large number of legacy systems to be connected to large AC grids.In the first half of the 20th century, the electric power industry was vertically integrated, meaning they one pany did generation, transmission, distribution, and metering and billing. Starting in the 1970s and 1980s nations began the process of deregulation and privatisation, leading to electricity markets. The distribution system would remain regulated, but generation, retail, and sometimes transmission systems were transformed into petitive marketsGeneration and transmissionElectric power begins at a generating station, where the potential difference can be as high as 13,800 volts. AC is usually used. Users of large amounts of DC power such as some railway electrification systems, telephone exchanges and industrial processes such as aluminium smelting usually either operate their own or have adjacent dedicated generating equipment, or use rectifiers to derive DC from the public AC supply. However, High-voltage DC can be advantageous for isolating alternating-current systems or controlling the quantity of electricity transmitted. For example, Hydro-Quebec has a direct-current line which goes from the James Bay region to Boston.From the generating station it goes to the generating station’s switch yard where a step-up transformer increases the voltage to a level suitable for transmission, from 44,000 to 765,000 volts. Once in the transmission system, electricity from each generating station is bined with electricity produced elsewhere. Electricity is consumed as soon as it is produced. It is transmitted at a very high speed, close to the speed of light.Distribution overviewThe transition from transmission to distribution happens in a power substation, which has the following functions:•Circuit breakers and switches enable the substation to be disconnected from the transmission grid or for distribution lines to be disconnected.•Transformers step down transmission voltages, 35kV or more, down to primary distribution voltages. These are medium voltage circuits, usually 600-35,000 V.•From the transformer, power goes to the busbar that can split the distribution power off in multiple directions. The bus distributes power to distribution lines, which fan out to customers.Urban distribution is mainly underground, sometimes in mon utility ducts. Rural distribution is mostly above ground with utility poles, and suburban distribution is a mix. Closer to the customer, a distribution transformer steps the primary distribution power down to a low-voltage secondary circuit, usually 120 or 240V, depending on theregion. The power es to the customer via a service drop and an electricity meter. The final circuit in an urban system may be less than 50 feet, but may be over 300 feet for a rural customer.Primary distributionPrimary distribution voltages are 22kV or 11kV. Only large consumers are fed directly from distribution voltages; most utility customers are connected to a transformer, which reduces the distribution voltage to the low voltage used by lighting and interior wiring systems.V oltage varies according to its role in the supply and distribution system. According to international standards, there are initially two voltage groups: low voltage (LV): up to and including 1,000 V AC (or 1,500 V DC) and high voltage (HV): above 1kV AC (or 1.5kV DC).Network configurationsDistribution networks are divided into two types, radial or network. A radial system is arranged like a tree where each customer has one source of supply. A network system has multiple sources of supply operating in parallel. Spot networks are used for concentrated loads. Radial systems are monly used in rural or suburban areas.Radial systems usually include emergency connections where the system can be reconfigured in case of problems, such as a fault or required replacement. This can be done by opening and closing switches. It may be acceptable to close a loop for a short time.Long feeders experience voltage drop (power factor distortion) requiring capacitors to be installed.Reconfiguration, by exchanging the functional links between the elements of the system, represents one of the most important measures which can improve the operational performance of a distribution system. The problem of optimization through the reconfiguration of a power distribution system, in terms of its definition, is a historical single objective problem with constraints. Since 1975, when Merlin and Back introduced the idea of distribution system reconfiguration for active power loss reduction, until nowadays, a lot of researchers have proposed diverse methods andalgorithms to solve the reconfiguration problem as a single objective problem. Some authors have proposed Pareto optimality based approaches (including active power losses and reliability indices as objectives). For this purpose, different artificial intelligence based methods have been used: microgenetic, branch exchange, particle swarm optimization and non-dominated sorting genetic algorithm.Rural servicesRural electrification systems tend to use higher distribution voltages because of the longer distances covered by distribution lines (see Rural Electrification Administration). 7.2, 12.47, 25, and 34.5kV distribution is mon in the United States; 11kV and 33kV are mon in the UK, Australia and New Zealand; 11kV and 22 kV are mon in South Africa. Other voltages are occasionally used. Distribution in rural areas may be only single-phase if it is not economical to install three-phase power for relatively few and small customers.Rural services normally try to minimize the number of poles and wires. Single-wire earth return (SWER) is the least expensive, with one wire. It uses higher voltages (than urban distribution), which in turn permits use of galvanized steel wire. The strong steel wire allows for less expensive wide pole spacing. In rural areas a pole-mount transformer may serve only one customer.Higher voltage split-phase or three phase service, at a higher infrastructure and a higher cost, provide increased equipment efficiency and lower energy cost for large agricultural facilities, petroleum pumping facilities, or water plants.In New Zealand, Australia, Saskatchewan, Canada, and South Africa, single wire earth return systems (SWER) are used to electrify remote rural areas.Secondary distributionElectricity is delivered at a frequency of either 50 or 60 Hz, depending on the region. It is delivered to domestic customers as single-phase electric power. Seen in an oscilloscope, the domestic power supply in North America would look like a sine wave, oscillating between -170 volts and 170 volts, giving an effective voltage of 120 volts. Three-phase power is more efficient in terms of power delivered per cable used, and ismore suited to running large electric motors. Some large European appliances may be powered by three-phase power, such as electric stoves and clothes dryers.A ground connection is normally provided for the customer's system as well as for the equipment owned by the utility. The purpose of connecting the customer's system to ground is to limit the voltage that may develop if high voltage conductors fall down onto lower-voltage conductors which are usually mounted lower to the ground, or if a failure occurs within a distribution transformer. Earthing systems can be TT, TN-S, TN-C-S or TN-C.Regional variations220-240 volt systemsMost of the world uses 50 Hz single-phase 220 or 230 V residential and light industrial service. In this system, the primary distribution network supplies a few substations per area, and the 230 V power from each substation is directly distributed. A live (hot) wire and neutral are connected to the building from one phase of three phase service. Single-phase distribution is used where motor loads are light. In Europe, electricity is normally distributed for industry and domestic use by the three-phase, four wire system. This gives a three-phase voltage of 400 volts wye service and a single-phase voltage of 230 volts. For industrial customers, 3-phase 690 / 400 volt is also available. Large industrial customers have their own transformers with an input from 10kV to 220kV. In the UK a typical urban or suburban low-voltage substation would normally be rated between 315kV A and 1MV A and supply a whole neighborhood.110-120 volt systemsMost of the Americas use 60 Hz AC, the 120/240 volt split phase system domestically and three phase for larger installations. pared to European systems, North American ones have more step-down transformers near customers. This is because the higher domestic voltage used in Europe (230 V vs 120 V) may be carried over a greater distance with acceptable power loss.In the electricity sector in Japan, the standard frequencies for AC are 50 and 60 Hz. In Japan parts of the country use 50 Hz, while other parts use 60 Hz. This is a relic of the 1800s. Some local providers in Tokyo imported 50 Hz German equipment, while thelocal power providers in Osaka brought in 60 Hz generators from the United States. The grids grew until eventually the entire country was wired. Today the frequency is 50 Hz in Eastern Japan (including Tokyo, Yokohama, Tohoku, and Hokkaido) and 60 Hertz in Western Japan (including Nagoya, Osaka, Kyoto, Hiroshima, Shikoku, and Kyushu).Most household appliances are made to work on either frequency. The problem of inpatibility came into the public eye when the 20XX Tōhoku earthquake and tsunami knocked out about a third of the east’s capacity, and power in the west couldn’t be fully shared with the east, since the country does not have a mon frequency.There are four converter stations that move power across Japan’s AC frequency border. Shin Shinano is a back-to-back HVDC facility in Japan which forms one of four frequency changer stations that link Japan's western and eastern power grids. The other three are at Higashi-Shimizu, Minami-Fukumitsu and Sakuma Dam. Together they can move up to 1.2 GW of power east or west.原文出处：https:///wiki/Electric_power_distributionThree-phase electric powerThree-phase electric power is a mon method of alternating-current electric power generation, transmission, and distribution.It is a type of polyphase system and is the most mon method used by electrical grids worldwide to transfer power. It is also used to power large motors and other heavy loads. A three-phase system is usually more economical than an equivalent single-phase at the same line to ground voltage because it uses less conductor material to transmit electrical power. The three-phase system was independently invented by Galileo Ferraris, Mikhail Dolivo-Dobrovolsky, Jonas Wenström and Nikola Tesla in the late 1880s.PrincipleIn a symmetric three-phase power supply system, three conductors each carry an alternating current of the same frequency and voltage amplitude relative to a mon reference but with a phase difference of one third the period. The mon reference isusually connected to ground and often to a current-carrying conductor called the neutral. Due to the phase difference, the voltage on any conductor reaches its peak at one third of a cycle after one of the other conductors and one third of a cycle before the remaining conductor. This phase delay gives constant power transfer to a balanced linear load. It also makes it possible to produce a rotating magnetic field in an electric motor and generate other phase arrangements using transformers (For instance, a two phase system using a Scott-T transformer).The symmetric three‐phase systems described here are simply referred to as three‐phase systems because, although it is possible to design and implement asymmetric three‐phase power systems (i.e., with unequal voltages or phase shifts), they are not used in practice because they lack the most important advantages of symmetric systems.In a three‐phase system feeding a balanced and linear load, the sum of the instantaneous currents of the three conductors is zero. In other words, the current in each conductor is equal in magnitude to, but with the opposite sign of, the sum of the currents in the other two. The return path for the current in any phase conductor is the other two phase conductors.pared to a single-phase AC power supply that uses two conductors (phase and neutral), a three-phase supply with no neutral, the same phase-to-ground voltage and current capacity per phase can transmit three times as much power using just 1.5 times as many wires (i.e., three instead of two). Thus, the ratio of capacity to conductor material is doubled. The same (but not the other properties of three-phase power) can also be attained with a center-grounded single-phase system.Three-phase systems may also utilize a fourth wire, particularly in low-voltage distribution. This is the neutral wire. The neutral allows three separate single-phase supplies to be provided at a constant voltage and is monly used for supplying groups of domestic properties which are each single-phase loads. The connections are arranged so that, as far as possible in each group, equal power is drawn from each phase. Further up the distribution system, the currents are usually well balanced. Transformers may be wired in a way that they have a four‐wire secondary but a three‐wire primary whileallowing unbalanced loads and the associated secondary‐side neutral currents.Three-phase supplies have properties that make them very desirable in electric power distribution systems:The phase currents tend to cancel out one another, summing to zero in the case of a linear balanced load. This makes it possible to reduce the size of the neutral conductor because it carries little or no current. With a balanced load, all the phase conductors carry the same current and so can be the same size.Power transfer into a linear balanced load is constant, which helps to reduce generator and motor vibrations.Three-phase systems can produce a rotating magnetic field with a specified direction and constant magnitude, which simplifies the design of electric motors.Most household loads are single-phase.In North American residences, three-phase power might feed a multiple-unit apartment block, but the household loads are connected only as single phase. In lower-density areas, only a single phase might be used for distribution.Some large European appliances may be powered by three-phase power, such as electric stoves and clothes dryers.Wiring for the three phases is typically identified by color codes which vary by country. Connection of the phases in the right order is required to ensure the intended direction of rotation of three-phase motors. For example, pumps and fans may not work in reverse. Maintaining the identity of phases is required if there is any possibility two sources can be connected at the same time; a direct interconnection between two different phases is a short-circuit.原文出处：https:///wiki/Three-phase_electric_power。
09电力配电系统设计总结英文版
09电力配电系统设计总结英文版Summary of 09 Power Distribution System DesignIn this document, we will provide an overview of the design process for a power distribution system. The design of a power distribution system is a critical aspect of ensuring that electricity is delivered safely and efficiently to consumers.The first step in designing a power distribution system is to conduct a thorough analysis of the electrical load requirements. This involves determining the amount of power needed to meet the demand of the consumers. Once the load requirements are known, the next step is to select the appropriate voltage levels for the distribution system.After determining the voltage levels, the next step is to design the layout of the distribution system. This includes determining the location of substations, transformers, and distribution lines. The design shouldtake into account factors such as voltage drop, fault current levels, and reliability requirements.Once the layout is finalized, the next step is to select the appropriate equipment for the distribution system. This includes selecting transformers, circuit breakers, and other protective devices. The equipment should be selected based on the load requirements and the voltage levels of the system.Finally, the design should include a plan for maintenance and repair of the distribution system. This includes scheduling regular inspections, testing equipment, and training personnel on proper maintenance procedures.Overall, the design of a power distribution system is a complex process that requires careful planning and consideration of various factors. By following the steps outlined in this document, engineers can ensure that the distribution system is designed to meet the needs of consumers and operate safely and efficiently.。
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Power Supply and Distribution System ABSTRACT:The basic function of the electric power system is to transport the el ectric power towards customers.The l0kV electric distribution net is a key point that connects the power supply with the electricity usin g on the industry,business and daily-life.For the electric power,allc ostumers expect to pay the lowest price for the highest reliability,b ut don't consider that it's self-contradictory in the co-existence of ec onomy and reliable.To improve the reliability of the power supply n etwork,we must increase the investment cost of the network constr uction But,if the cost that improve the reliability of the network con struction,but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the inc reasing investment on improving the reliability.Thus we find out a b alance point to make the most economic,between the investment a nd the loss by calculating the investment on power net and the loss brought from power-off.KEYWORDS:power supply and distribution,power distribution reliability，reactive compensation,load distributionThe revolution of electric power system has brought a new big round construction,which is pushing the greater revolution of electric po wer technique along with the application of new technique and adv anced equipment.Especially,the combination of the information te chnique and electric power technique,to great ex-tent,has improv ed reliability on electric quality and electric supply.The technical de velopment decreases the cost on electric construction and drives in novation of electric network.On the basis of national and internatio -nal advanced electric knowledge,the dissertation introduces the r esearch hotspot for present electric power sy-etem as following.Firstly,This dissertation introduces the building condition of distribu tion automation(DA),and brings forward two typical construction m odes on DA construction,integrative mode and fission mode.It emp hasize the DA structure under the condition of the fission mode and presents the system configuration,the main station scheme,the fe eder scheme,the optimized communication scheme etc.,which is f or DA research reference.Secondly,as for the(DA)trouble measurement,position,isolation a nd resume,This dissertation analyzes the changes of pressure and c urrent 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&ande I&tab le on problem.It brings out optimized isolation and resume plan,re alizes auto isolation and network reconstruction,reduces the power off range and time and improves the reliability of electric power su pply through problem self-diagnoses and self-analysis.It also introd uces software flow and use for problem judgement and sets a mode l on network reconstruction and computer flow.Thirdly,electricity system state is estimated to be one of the key tec hniques in DA realization.The dissertation recommends the resolve nt of bad measurement data and structure mistake on the ground of describing state estimate way.It also advances a practical test and j udging way on topology mistake in state estimate about bad data te st 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 wa y to solve them by electricity break and exceptional analysis,and th e way has been tested in Weifang DA.Fourthly,about the difficulty for building the model of load forecasti ng,big parameter scatter limit and something concerned,the disser tation introduces some parameters,eg.weather factor,date type and social environment effect based on analysis of routine load foreca sting and means.It presents the way for electricity load forecastingf ounded 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 conc ordant wave and non-power compensation and non-continuity on c ompensation,there is a topology structure of PWM main circuit and nonpower theory on active filter the waves technique and builds fla t proof on the ground of Saber Designer and proves to be practical. Meanwhile,it analyzes and designs the way of non-power need of e lectric network tre-nds and decreasing line loss combined with DA, which have been tested its objective economic benefit throu-gh co unting example.Sixthly,not only do the dissertation design a way founded on the m agrginal electric price fitted to our present national electric power market with regards to future trends of electric power market in Chi na and fair trade under the government surveillance,that is group c ompetitio n in short-term trade under the way of grouped price and quantity harmony,but also puts forward combination arithmetic,m ath model of trading plan and safty economical restriction.It can solve the original contradiction between medium and long term contra ct price and short term competitive price with improvement on com petitive percentage and cut down the unfair income difference of el ectric 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 syst em.Its neutral grounding mode and operation connects security an d stability of the power system directly.At the same time,the probl em 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 struct ure and the peripheral interference will influence the choice of neut ral grounding mode Conversely,neutral grounding mode affects desi gn,operation,debugs and developing.Generally in the system high er in grade in the voltage,the insulating expenses account for more sizable proportion at the total price of the equipment.It is very rem arkable to bring the economic benefits by reducing the insulating le ually such system adopt the neutral directly grounding and ad opt the autoreclosing to guarantee power supply reliability.On the c ontrary,the system which is lower in the voltage adopts neutral non e grounding to raise power supply reliability.So it is an important subject to make use of new-type earth device to apply to the distribut ion network under considering the situation in such factors of vario us 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 gr ounding mode of the l0kV distribution network.The neutral groundi ng mode of the l0kV network mainly adopts none grounding,groun ding by arc suppressing coil,grounding by reactance grounding and directly grounding.The best grounding mode is confirmed through t he technology comparison.It can help the network run in safety and limit the earth electric arc by using auto-tracking compensate devic e and using the line protection with the detection of the sensitive s mall ground current.The paper introduces and analyzes the charact eristic of all kind of grounding modes about l0kV network at first.Wi th the comparison with technological and economy,the conclusion i s drawn that the improved arc suppressing coil grounding mode sho ws a very big development potential.Then,this paper researches and introduces some operation charact eristics of the arc suppressing coil grounding mode of the l0kV distri bution network.And then the paper put emphasis on how to exting uish the earth electric arc effectively by utilizing the resonance principle.This paper combines the development of domestic and interna tional technology and innovative achievement,and introduces the c omputer earth protection and autotracking compensate device.It p roves 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 re searched 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 fut ure.The way of thinking,project and conclusions in this thesis have e ffect on the research to choose the neutral grounding mode not onl y in I0kV distribution network but also in other power system..The basic function of the electric power system is to transport the el ectric power towards customers.The l0kV electric distribution net is a key point that connects the power supply with the electricity usin g on the industry,business and daily-life.For the electric power,all c ostumers expect to pay the lowest price for the highest reliability,b ut don't consider that it's self-contradictory in the co-existence of ec onomy and reliable.To improve the reliability of the power supply network,we must increase the investment cost of the network con-s truction But,if the cost that improve the reliability of the network c onstruction,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 investme nt and the loss by calculating the investment on power net and the l oss brought from power-off.The thesis analyses on the economic an d the reliable of the various line modes,according to the characteris tics various line modes existed in the electric distribution net in fosh an..First,the thesis introduces as the different line modes in the l0kV el ectric distribution net and in some foreign countries.Making it clear tow to conduct analyzing on the line mode of the electric distributi on net,and telling us how important and necessary that analyses ar e.Second,it turns to the necessity of calculating the number of optimi zation subsection,elaborating how it influences on the economy an d reliability.Then by building up the calculation mode of the numbe r of optimization subsection it introduces different power supply pr ojects on the different line modes in brief.Third,it carries on the cal culation and analyses towards the reliability and economy of the different line modes of electric distribution net,describing drafts accor ding 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 o f different line modes,as well as,its application situation.Accordion to the actual circumstance,the thesis puts forward the beneficial s uggestion on the programming and construction of the l0kV electric distribution net in all areas in foshan.Providing the basic theories a nd beneficial guideline for the programming design of the10kV elec tric distribution net and building up a solid net,reasonable layout,q ualified safe and efficiently-worked electric distribution net.。