电气英文文献+翻译
电气外文文献 翻译
Circuit breaker断路器Compressed air circuit breaker is a mechanical switch equipment, can be i 空气压缩断路器是一种机械开关设备,能够在n normal and special conditions breaking current (such as short circuit cur 正常和特殊情况下开断电流(比如说短路电流)。
rent). For example, air circuit breaker, oil circuit breaker, interference circ 例如空气断路器、油断路器,干扰电路的导体uit conductor for the application of the safety and reliability of the circuit 干扰电路的导体因该安全可靠的应用于其中,breaker, current in arc from is usually divided into the following grades: a 电流断路器按灭弧远离通常被分为如下等级:ir switch circuit breaker, oil circuit breaker, less oil circuit breaker, compr 空气开关断路器、油断路器、少油断路器、压缩空essed air circuit breaker, a degaussing of isolating switch, six sulfur hexaf 气断路器、具有消磁性质的隔离开关、六氟luoride circuit breaker and vacuum breaker. Their parameters of voltage, 化硫断路器和真空断路器。
他们的参数有电压等级、current, insulation level of breaking capacity, instantaneous voltage off ti 开断容量的电流、绝缘等级开断时间的瞬时电压恢复和me of recovery and a bombing. Breaker plate usually include: 1 the maxi 轰炸时间。
电气工程及其自动化专业_外文文献_英文文献_外文翻译_plc方面.
1、外文原文A: Fundamentals of Single-chip MicrocomputerTh e si ng le -c hi p m ic ro co mp ut er i s t he c ul mi na ti on of both t h e de ve lo pm en t of the dig it al com pu te r an d th e in te gr at ed c i rc ui t arg ua bl y t h e tow m os t s ig ni f ic an t i nv en ti on s o f t he 20th c e nt ur y [1].Th es e tow type s of arch it ec tu re are foun d in sin g le -ch i p m i cr oc om pu te r. Som e empl oy the spli t prog ra m/da ta me mo ry of the H a rv ar d ar ch it ect u re , sh ow n in Fig.3-5A -1, oth ers fo ll ow the p h il os op hy , wi del y ada pt ed for gen er al -p ur po se com pu te rs and m i cr op ro ce ss o r s, o f ma ki ng no log i ca l di st in ct ion be tw ee n p r og ra m and dat a me mo ry as in the Pr in ce to n arch ite c tu re , show n i n Fig.3-5A-2.In gen er al ter ms a sin gl e -chi p mic ro co mp ut er i sc h ar ac te ri zed b y t he i nc or po ra ti on of a ll t he un it s of a co mp uter i n to a sin gl e d ev i ce , as sho wn inFi g3-5A -3.Fig.3-5A-1 A Harvard typeFig.3-5A-2. A conventional Princeton computerFig3-5A-3. Principal features of a microcomputerRead only memory (ROM.R OM is usua ll y for the pe rm an ent,n o n-vo la ti le stor a ge of an app lic a ti on s pr og ra m .M an ym i cr oc om pu te rs and m are inte nd e d for high -v ol um e ap pl ic at ions a n d he nc e t h e eco n om ic al man uf act u re of th e de vic e s re qu ir es t h at t he cont en t s o f t he prog ra m me m or y be co mm it t ed perm a ne ntly d u ri ng the man ufa c tu re of ch ip s .Cl ea rl y, thi s im pl ie s a r i go ro us app ro ach to ROM cod e deve l op me nt sin ce cha ng es can not b e mad e afte r manu f a c tu re .Th is dev e lo pm en t proc ess may invo lv e e m ul at io n us in g aso ph is ti ca te d de ve lo pm en t sy ste m wit h a h a rd wa re emu la tio n cap ab il it y as w el l as the use o f po we rf ul s o ft wa re too ls.So me man uf act u re rs pro vi de add it io na l RO M opt i on s by i n cl ud in g in their ra n ge dev ic es wit h (or int en de d fo r use wit h u s er pro gr am ma ble me mo ry. Th e sim p le st of th es e is usu al ly d e vi ce whi ch can op er at e in a micro p ro ce ssor mod e by usi ng som e o f the inp ut /outp u t li ne s as an ad dr es s an d da ta b us fora c ce ss in g ex te rna l mem or y. Thi s t y pe of de vi ce can beh av ef u nc ti on al ly as th e sing le chip mi cr oc om pu te r from whi ch it is d e ri ve d al be it wit h re st ri ct ed I/O and a mod if ied ex te rn al c i rc ui t. The use of thes e d ev ic es is com mo n eve n in prod uc ti on c i rc ui ts wher e t he vo lu me does no tj us ti f y t h e d ev el o pm en t c osts o f c us to m o n -ch i p R OM [2];t he re c a n s ti ll bea s ignif i ca nt saving i n I /O and o th er c h ip s com pa re d to a conv en ti on al mi c ro pr oc es sor b a se d ci rc ui t. Mor e ex ac t re pl ace m en t fo r RO M dev i ce s ca n be o b ta in ed in th e fo rm of va ri an ts w it h 'p ig gy -b ack 'E P RO M(Er as ab le pro gr am ma bl e ROM s oc ke ts or dev ic e s with EPROM i n st ea d o f RO M 。
电气工程及其自动化专业英语 Chapter 7 Power System Protections
Section 1 Introduction
(6)Phase sequence relays such as (i) negative sequence relays and, (ii) zero sequence relays, (7)Differential relays and percentage differential relays, (8)Distance relays such as (i) plane impedance relays, (ii) angle impedance relays, i.e. Ohm or reactance relays, (iii) angle admittance relays, i.e. Mho relays and, (iv) offset and restricted relays, (9)Pilot relays such as (i) wire pilot relays, (ii) carrier channel pilot relays, (iii) microwave pilot relays.
Chapter 7
Power System Protections
Section 1 Introduction
Text
New Words and Expressions Resume
Exercises
End
Section 1 Introduction
The steady-state operation of a power system is frequently disturbed by various faults on electrical equipment. To maintain the proper operation of the power system, an effective, efficient and reliable protection scheme is required. Power system components are designed to operate under normal operating conditions. However, if due to any reason, say a fault, there is an abnormality, it is necessary that there should be a device which senses these abnormal conditions and if so, the element or component where such an abnormality has taken
电气工程及其自动化专业 外文文献 英文文献 外文翻译 plc方面
1、外文原文(复印件)A: Fundamentals of Single-chip MicrocomputerTh e si ng le-ch i p mi cr oc om pu ter is t he c ul mi nat i on o f bo th t h e d ev el op me nt o f th e d ig it al com p ut er an d t he int e gr at ed ci rc ui ta r gu ab ly th e t ow m os t s i gn if ic ant i nv en ti on s o f t h e 20t h c en tu ry[1].Th es e to w typ e s of a rc hi te ctu r e ar e fo un d i n s in gl e-ch ip m i cr oc om pu te r. So m e em pl oy t he sp l it p ro gr am/d ata me mo ry o f th e H a rv ar d ar ch it ect u re, sh ow n i n -5A, ot he rs fo ll ow th e ph i lo so ph y, w i de ly a da pt ed fo r g en er al-p ur pos e c om pu te rs an d m i cr op ro ce ss or s, o f m a ki ng no lo gi c al di st in ct io n b e tw ee n p ro gr am a n d da t a m em ory a s i n th e Pr in cet o n ar ch it ec tu re,sh ow n in-5A.In g en er al te r ms a s in gl e-chi p m ic ro co mp ut er i sc h ar ac te ri zed b y the i nc or po ra tio n of al l t he uni t s o f a co mp ut er i n to a s in gl e dev i ce, as s ho wn in Fi g3-5A-3.-5A-1 A Harvard type-5A. A conventional Princeton computerFig3-5A-3. Principal features of a microcomputerRead only memory (ROM).R OM i s u su al ly f or th e p er ma ne nt, n o n-vo la ti le s tor a ge o f an a pp lic a ti on s pr og ra m .M an ym i cr oc om pu te rs an d mi cr oc on tr ol le r s a re in t en de d fo r h ig h-v ol ume a p pl ic at io ns a nd h en ce t he e co nom i ca l ma nu fa ct ure of t he d ev ic es r e qu ir es t ha t the co nt en ts o f the pr og ra m me mo ry b e co mm it te dp e rm an en tl y d ur in g th e m an uf ac tu re o f c hi ps . Cl ear l y, th is im pl ie sa ri g or ou s a pp roa c h t o R OM co de d e ve lo pm en t s in ce c ha ng es ca nn otb e m ad e af te r man u fa ct ur e .T hi s d e ve lo pm en t pr oce s s ma y in vo lv e e m ul at io n us in g a s op hi st ic at ed deve lo pm en t sy st em w i th a ha rd wa re e m ul at io n ca pa bil i ty a s we ll a s th e u se of po we rf ul so ft wa re t oo ls.So me m an uf act u re rs p ro vi de ad d it io na l RO M opt i on s byi n cl ud in g i n th ei r ra ng e de vi ce s wi th (or i nt en de d fo r us e wi th) u s er pr og ra mm ab le m em or y. Th e s im p le st of th es e i s us ua ll y d ev ice w h ic h ca n op er ate in a m ic ro pr oce s so r mo de b y usi n g so me o f th e i n pu t/ou tp ut li ne s as a n ad dr es s an d da ta b us f or acc e ss in g e xt er na l m e mo ry. T hi s t ype o f d ev ic e c an b e ha ve fu nc ti on al l y a s t he si ng le c h ip mi cr oc om pu te r fr om wh ic h i t i s de ri ve d a lb eit w it h r es tr ic ted I/O an d a mo di fie d e xt er na l ci rcu i t. T he u se o f t h es e RO Ml es sd e vi ce s is c om mo n e ve n in p ro du ct io n c ir cu it s wh er e t he v ol um e do es n o t ju st if y th e d e ve lo pm en t co sts of c us to m on-ch i p RO M[2];t he re c a n st il l b e a si g ni fi ca nt s a vi ng in I/O a nd ot he r c hi ps co mp ar ed t o a c on ve nt io nal mi cr op ro ce ss or b as ed c ir cu it. M o re e xa ctr e pl ac em en t fo r RO M d ev ic es c an b e o bt ai ne d in t he f o rm o f va ri an ts w i th 'pi gg y-ba ck'EP RO M(Er as ab le p ro gr am ma bl e ROM)s oc ke ts o rd e vi ce s w it h EP ROM i ns te ad o f R OM 。
电气自动化的英文作文高中
电气自动化的英文作文高中英文:Electric automation is a crucial part of modernindustrial processes. It involves the use of variouscontrol systems to operate different types of equipment, such as machinery, processes in factories, boilers, andheat treating ovens. These control systems can range from simple on-off switches to complex computer-based systemsthat monitor and control entire production processes.One of the key benefits of electric automation is its ability to improve efficiency and productivity. For example, in a manufacturing plant, automated systems can perform repetitive tasks with precision and speed, reducing theneed for human intervention and minimizing the risk of errors. This not only increases the overall output but also ensures consistent quality of the products.Moreover, electric automation plays a vital role inenhancing safety in industrial environments. By automating hazardous tasks, such as handling of toxic chemicals or working in extreme temperatures, it reduces the exposure of workers to potential risks and hazards. This ultimately leads to a safer work environment and reduces the number of workplace accidents.In addition, electric automation also enables real-time monitoring and control of processes, allowing for quick adjustments and interventions when necessary. For instance, in a power plant, automated systems can continuously monitor the performance of turbines and generators and make immediate adjustments to optimize efficiency and prevent equipment failures.Furthermore, electric automation contributes to cost savings by reducing the consumption of energy and raw materials. Automated systems can regulate the usage of resources more efficiently, minimizing waste and lowering operational costs. This not only benefits the company's bottom line but also has positive environmental impacts by reducing the overall carbon footprint.In conclusion, electric automation is a critical component of modern industrial operations, offering numerous benefits such as improved efficiency, enhanced safety, real-time monitoring, and cost savings. Its widespread adoption continues to drive advancements in industrial processes, making them more reliable, productive, and sustainable.中文:电气自动化是现代工业过程中至关重要的一部分。
电气 自动化 外文文献 外文翻译 英文文献
外文出处:Farhadi, A. (2008). Modeling, simulation, and reduction of conducted electromagnetic interference due to a pwm buck type switching power supply. Harmonics and Quality of Power, 2008. ICHQP 2008. 13th International Conference on, 1 - 6.Modeling, Simulation, and Reduction of Conducted Electromagnetic Interference Due to a PWM Buck Type Switching Power Supply IA. FarhadiAbstract:Undesired generation of radiated or conducted energy in electrical systems is called Electromagnetic Interference (EMI). High speed switching frequency in power electronics converters especially in switching power supplies improves efficiency but leads to EMI. Different kind of conducted interference, EMI regulations and conducted EMI measurement are introduced in this paper. Compliancy with national or international regulation is called Electromagnetic Compatibility (EMC). Power electronic systems producers must regard EMC. Modeling and simulation is the first step of EMC evaluation. EMI simulation results due to a PWM Buck type switching power supply are presented in this paper. To improve EMC, some techniques are introduced and their effectiveness proved by simulation.Index Terms:Conducted, EMC, EMI, LISN, Switching SupplyI. INTRODUCTIONFAST semiconductors make it possible to have high speed and high frequency switching in power electronics []1. High speed switching causes weight and volume reduction of equipment, but some unwanted effects such as radio frequency interference appeared []2. Compliance with electromagnetic compatibility (EMC) regulations is necessary for producers to present their products to the markets. It is important to take EMC aspects already in design phase []3. Modeling and simulation is the most effective tool to analyze EMC consideration before developing the products. A lot of the previous studies concerned the low frequency analysis of power electronics components []4[]5. Different types of power electronics converters are capable to be considered as source of EMI. They could propagate the EMI in both radiated and conducted forms. Line Impedance Stabilization Network (LISN) is required for measurement and calculation of conducted interference level []6. Interference spectrum at the output of LISN is introduced as the EMC evaluation criterion []7[]8. National or international regulations are the references forthe evaluation of equipment in point of view of EMC []7[]8.II. SOURCE, PATH AND VICTIM OF EMIUndesired voltage or current is called interference and their cause is called interference source. In this paper a high-speed switching power supply is the source of interference.Interference propagated by radiation in area around of an interference source or by conduction through common cabling or wiring connections. In this study conducted emission is considered only. Equipment such as computers, receivers, amplifiers, industrial controllers, etc that are exposed to interference corruption are called victims. The common connections of elements, source lines and cabling provide paths for conducted noise or interference. Electromagnetic conducted interference has two components as differential mode and common mode []9.A. Differential mode conducted interferenceThis mode is related to the noise that is imposed between different lines of a test circuit by a noise source. Related current path is shown in Fig. 1 []9. The interference source, path impedances, differential mode current and load impedance are also shown in Fig. 1.B. Common mode conducted interferenceCommon mode noise or interference could appear and impose between the lines, cables or connections and common ground. Any leakage current between load and common ground couldbe modeled by interference voltage source.Fig. 2 demonstrates the common mode interference source, common mode currents Iandcm1 and the related current paths[]9.The power electronics converters perform as noise source Icm2between lines of the supply network. In this study differential mode of conducted interference is particularly important and discussion will be continued considering this mode only.III. ELECTROMAGNETIC COMPATIBILITY REGULATIONS Application of electrical equipment especially static power electronic converters in different equipment is increasing more and more. As mentioned before, power electronics converters are considered as an important source of electromagnetic interference and have corrupting effects on the electric networks []2. High level of pollution resulting from various disturbances reduces the quality of power in electric networks. On the other side some residential, commercial and especially medical consumers are so sensitive to power system disturbances including voltage and frequency variations. The best solution to reduce corruption and improve power quality is complying national or international EMC regulations. CISPR, IEC, FCC and VDE are among the most famous organizations from Europe, USA and Germany who are responsible for determining and publishing the most important EMC regulations. IEC and VDE requirement and limitations on conducted emission are shown in Fig. 3 and Fig. 4 []7[]9.For different groups of consumers different classes of regulations could be complied. Class Afor common consumers and class B with more hard limitations for special consumers are separated in Fig. 3 and Fig. 4. Frequency range of limitation is different for IEC and VDE that are 150 kHz up to 30 MHz and 10 kHz up to 30 MHz respectively. Compliance of regulations is evaluated by comparison of measured or calculated conducted interference level in the mentioned frequency range with the stated requirements in regulations. In united European community compliance of regulation is mandatory and products must have certified label to show covering of requirements []8.IV. ELECTROMAGNETIC CONDUCTED INTERFERENCE MEASUREMENTA. Line Impedance Stabilization Network (LISN)1-Providing a low impedance path to transfer power from source to power electronics converter and load.2-Providing a low impedance path from interference source, here power electronics converter, to measurement port.Variation of LISN impedance versus frequency with the mentioned topology is presented inFig. 7. LISN has stabilized impedance in the range of conducted EMI measurement []7.Variation of level of signal at the output of LISN versus frequency is the spectrum of interference. The electromagnetic compatibility of a system can be evaluated by comparison of its interference spectrum with the standard limitations. The level of signal at the output of LISN in frequency range 10 kHz up to 30 MHz or 150 kHz up to 30 MHz is criterion of compatibility and should be under the standard limitations. In practical situations, the LISN output is connected to a spectrum analyzer and interference measurement is carried out. But for modeling and simulation purposes, the LISN output spectrum is calculated using appropriate software.基于压降型PWM开关电源的建模、仿真和减少传导性电磁干扰摘要:电子设备之中杂乱的辐射或者能量叫做电磁干扰(EMI)。
电气工程及其自动化专业外文文献英文文献外文翻译方面
1、 外文原文(复印件)A: Fundamentals of Single-chip MicrocomputerT h e sin gle -ch ip mi c ro co m p u t e r is t h e cu lm in at io n of b ot h t h e d e ve lo p me nt of t h e d ig ita l co m p u t e r a n d t h e i nte g rated c ircu it a rgu ab l y t h e to w mo st s ign if i cant i nve nt i o n s of t h e 20t h c e nt u ry [1].T h ese to w t yp e s of arch ite ct u re are fo u n d in s in gle -ch ip m i cro co m p u te r. S o m e e mp l oy t h e sp l it p ro gra m /d at a m e m o r y of t h e H a r va rd arch ite ct u re , s h o wn in -5A , ot h e rs fo l lo w t h e p h i lo so p hy, wid e l y ad a p ted fo r ge n e ral -p u rp o se co m p u te rs an d m i cro p ro ce ss o rs , of m a kin g n o l o g i ca l d i st in ct i o n b et we e n p ro gra m an d d ata m e m o r y as in t h e P rin c eto n a rch ite ct u re , sh o wn in -5A.In ge n e ra l te r m s a s in g le -ch ip m ic ro co m p u t e r is ch a ra cte r ized b y t h e in co r p o rat io n of all t h e u n its of a co mp u te r into a s in gle d e vi ce , as s h o w n in F i g3-5A-3.-5A-1A Harvard type-5A. A conventional Princeton computerProgrammemory Datamemory CPU Input& Output unitmemoryCPU Input& Output unitResetInterruptsPowerFig3-5A-3. Principal features of a microcomputerRead only memory (ROM).RO M is u su a l l y fo r t h e p e r m an e nt , n o n -vo lat i le sto rage of an ap p l i cat io n s p ro g ram .M a ny m i c ro co m p u te rs a n d m i cro co nt ro l le rs are inte n d ed fo r h i gh -vo lu m e ap p l i cat io n s a n d h e n ce t h e e co n o m i cal man u fa c t u re of t h e d e vi ces re q u ires t h at t h e co nt e nts of t h e p ro gra m me mo r y b e co mm i ed p e r m a n e nt l y d u r in g t h e m a n u fa ct u re of c h ip s . C lea rl y, t h i s imp l ies a r i go ro u s ap p ro a ch to ROM co d e d e ve lo p m e nt s in ce ch an ges can n o t b e mad e af te r m an u fa ct u re .T h i s d e ve l o p m e nt p ro ces s m ay i nvo l ve e mu l at i o n u sin g a so p h ist icated d e ve lo p m e nt syste m wit h a h ard wa re e mu l at i o n capab i l it y as we ll as t h e u s e of p o we rf u l sof t war e to o l s.So m e m an u fa ct u re rs p ro vi d e ad d it i o n a l ROM o p t io n s b y in clu d in g in t h e i r ran ge d e v ic es w it h (o r inte n d ed fo r u s e wit h ) u se r p ro g ram m a b le m e mo r y. T h e s im p lest of t h e se i s u su a l l y d e v i ce wh i ch can o p e rat e in a m i cro p ro ce s so r mo d e b y u s in g s o m e of t h e in p u t /o u t p u t l in es as an ad d res s a n d d ata b u s fo r a cc es sin g exte rn a l m e m o r y. T h is t yp e o f d e vi ce can b e h ave f u n ct i o n al l y as t h e s in gle ch ip m i cro co m p u t e r f ro m wh i ch it i s d e ri ved a lb e it wit h re st r icted I/O an d a m o d if ied exte rn a l c ircu it. T h e u s e of t h e se RO M le ss d e vi ces i s co mmo n e ve n in p ro d u ct io n circu i ts wh e re t h e vo lu m e d o e s n ot ju st if y t h e d e ve lo p m e nt co sts of cu sto m o n -ch ip ROM [2];t h e re ca n st i ll b e a si gn if i cant sav in g in I/O an d o t h e r ch ip s co m pared to a External Timing components System clock Timer/ Counter Serial I/O Prarallel I/O RAM ROMCPUco nve nt io n al m i c ro p ro ces so r b ased circ u it. M o re exa ct re p l a ce m e nt fo rRO M d e v ice s can b e o b tain ed in t h e fo rm of va ria nts w it h 'p i g g y-b a c k'E P ROM(E rasab le p ro gramm ab le ROM )s o cket s o r d e v ice s w it h E P ROMin stead of ROM 。
电气工程及其自动化专业英语课文翻译
unit1 taxe A 电力变压器的结构和原理在许多能量转换系统中,变压器是一个不了缺少的原件。
它使得在经济的发电机所产生电能并以最经历的传输电压传输电能,同时对于特定的使用者合适的电压使用电能成为可能。
变压器同样广泛的应用于低功率低电流的电子电路和控制电路中,来执行像匹配电源组抗和负载以求得最大的传输效率。
隔离一个电路与另一个电路在两个电路之间隔离直流电而保证交流电继续通道的功能。
在本质上,变压器是一个由两个或多个绕组通过相互的磁通耦合而组成的,如果这其中的一个绕组,原边连接到交流电压源将产生交流磁通它的幅值决定于原边的电压所提供的电压频率及匝数。
感应磁通将与其他绕组交链,在副边中将感应出一个电压其幅值将取决于副边的匝数及感应磁通量和频率。
通过使原副边匝数比例适应,任何所期望的电压比例或转换比例都可以得到。
变压器工作的本质仅要求存在与两个绕组相交链的时变的感应磁通。
这样的作用也可以发生在通过空气耦合的两组绕组中,但用铁心或其他铁磁材料可以使绕组之间的耦合作用增强,因为一大部分磁通被限制在与两个绕组交链的高磁导率的路径中。
这种变压器通常被称作为心式变压器。
大部分变压器都是这种类型。
以下的讨论几乎全部围绕心事变压器。
为减少铁心中的涡流所产生的损耗,磁路通常由一叠薄的叠片所组成。
如图1.1所示两种常见的结构形式用示意图表示出来。
芯式变压器的绕组绕在两个矩形铁心柱上,壳式变压器的绕组绕在三个铁心柱中间的那个铁心柱上,。
0.14毫米厚的硅钢片通常被用于在低频率低于几百Hz下运行的变压器中,硅钢片具有价格低铁心损耗小,在高磁通密度下,磁导率高的理想性能,能用做高频率低能耗的标准的通讯电路中的小型变压器的铁心是由被称为铁氧体的粉末压缩制成的铁磁合金所构成的。
在这些结构中,大部分的磁通被限制在固定的铁心中与两个绕组相交链。
绕组也产生多余的磁通,像漏磁通,只经过一个绕组和另外的绕组不相交链。
虽然漏磁通只是所有磁通的一小部分,但它在决定变压器的运行情况中起着重要的作用。
电气工程的外文文献(及翻译)
电气工程的外文文献(及翻译)文献一:Electric power consumption prediction model based on grey theory optimized by genetic algorithms本文介绍了一种基于混合灰色理论与遗传算法优化的电力消耗预测模型。
该模型使用时间序列数据来建立模型,并使用灰色理论来解决数据的不确定性问题。
通过遗传算法的优化,模型能够更好地预测电力消耗,并取得了优异的预测结果。
此模型可以在大规模电力网络中使用,并具有较高的可行性和可靠性。
文献二:Intelligent control for energy-efficient operation of electric motors本文研究了一种智能控制方法,用于电动机的节能运行。
该方法提供了一种更高效的控制策略,使电动机能够在不同负载条件下以较低的功率运行。
该智能控制使用模糊逻辑方法来确定最佳的控制参数,并使用遗传算法来优化参数。
实验结果表明,该智能控制方法可以显著降低电动机的能耗,节省电能。
文献三:Fault diagnosis system for power transformers based on dissolved gas analysis本文介绍了一种基于溶解气体分析的电力变压器故障诊断系统。
通过对变压器油中的气体样品进行分析,可以检测和诊断变压器内部存在的故障类型。
该系统使用人工神经网络模型来对气体分析数据进行处理和分类。
实验结果表明,该系统可以准确地检测和诊断变压器的故障,并有助于实现有效的维护和管理。
文献四:Power quality improvement using series active filter based on iterative learning control technique本文研究了一种基于迭代研究控制技术的串联有源滤波器用于电能质量改善的方法。
电气工程英语作文模板
电气工程英语作文模板英文回答:Introduction。
Electrical engineering is a vast and complex field that encompasses the study, design, and application ofelectrical systems, devices, and technologies. It plays a pivotal role in modern society, powering everything from our homes and workplaces to our transportation and communications networks.Areas of Concentration。
Electrical engineering has many different areas of concentration, including:Power systems: The generation, transmission, and distribution of electricity。
Control systems: The design and implementation of systems that automatically control physical processes。
Electronics: The development and application of electronic devices and circuits。
Signal processing: The analysis and manipulation of electrical signals。
Telecommunications: The transmission of information over long distances。
电气的英文单词
电气的英文单词全文共四篇示例,供读者参考第一篇示例:Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics, and electromagnetism. It encompasses a wide range of topics, from basic circuit theory to advanced power systems and electronic devices. In this article, we will explore some common electrical engineering terms in English.第二篇示例:Electricity is a fundamental part of modern society, powering everything from homes and businesses to industrial equipment and transportation. As such, it is important to have a good understanding of the vocabulary associated with electricity in order to effectively communicate about electrical systems and devices. In this article, we will explore a wide range of electrical terms in English to help you build your knowledge and improve your communication skills in this area.2. Current: Current is the flow of electric charge through a conductor, and is measured in amperes (A). It represents the rate at which electric charge is flowing in a circuit.第三篇示例:1. Voltage: Voltage, also known as electric potential difference, is the force that pushes the electric current through a circuit. It is measured in volts and determines the flow of electricity in a circuit.第四篇示例:Voltage: Voltage is a measure of the electrical potential difference between two points in a circuit. It is typically measured in volts (V) and represents the force that drives electrons through the circuit. A higher voltage means that there is a greater potential for electricity to flow.。
电气工程及其自动化 外文翻译 外文文献 英文文献 电力系统的简介
Brief Introduction to The Electric Power SystemPart 1 Minimum electric power systemA minimum electric power system is shown in Fig.1-1, the system consists of an energy source, a prime mover, a generator, and a load.The energy source may be coal, gas, or oil burned in a furnace to heat water and generate steam in a boiler; it may be fissionable material which, in a nuclear reactor, will heat water to produce steam; it may be water in a pond at an elevation above the generating station; or it may be oil or gas burned in an internal combustion engine.The prime mover may be a steam-driven turbine, a hydraulic turbine or water wheel, or an internal combustion engine. Each one of these prime movers has the ability to convert energy in the form of heat, falling water, or fuel into rotation of a shaft, which in turn will drive the generator.The electrical load on the generator may be lights, motors, heaters, or other devices, alone or in combination. Probably the load will vary from minute to minute as different demands occur.The control system functions (are)to keep the speed of the machines substantially constant and the voltage within prescribed limits, even though the load may change. To meet these load conditions, it is necessary for fuel input to change, for the prime mover input to vary, and for torque on the shaft from the prime mover to change 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. Thecontrol system may include a man stationed in the power plant who watches a set of meters on the generator output terminals and makes the necessary adjustments manually. In a modern station, the control system is a servomechanism that senses generator-output conditions and automatically makes the necessary changes in energy input and field current to hold the electrical output within certain specifications..Part 2 More Complicated SystemsIn most situations the load is not directly connected to the generator terminals. More commonly the load is some distance from the generator, requiring a power line connecting them. It is desirable to keep the electric power supply at the load within specifications. However, the controls are near the generator, which may be in another building, perhaps several miles away.If the distance from the generator to the load is considerable, it may be desirable to install transformers at the generator and at the load end, and to transmit the power over a high-voltage line (Fig.1-2). For the same power, the higher-voltage line carries less current, has lower losses for the same wire size, and provides more stable voltage.In some cases an overhead line may be unacceptable. Instead it may be advantageous to use an underground cable. With the power systems talked above, the power supply to the load must be interrupted if, for any reason, any component of the system must be moved from service for maintenance or repair. Additional system load may require more power than the generator can supply. Another generator with its associated transformers and high-voltage line might be added.It can be shown that there are some advantages in making ties between the generators (1) and at the end of the high-voltage lines (2 and 3), as shown in Fig.1-3. This system will operate satisfactorily as long as no trouble develops or no equipmentneeds to be taken out of service.The above system may be vastly improved by the introduction of circuit breakers, which may be opened and closed as needed. Circuit breakers added to the system, Fig.1-4, permit selected piece of equipment to switch out of service without disturbing the remainder of system. With this arrangement any element of the system may be deenergized for maintenance or repair by operation of circuit breakers.Of course, if any piece of equipment is taken out of service, then the total load must be carried by the remaining equipment. Attention must be given to avoid overloads during such circumstances. If possible, outages of equipment are scheduled at times when load requirements are below normal.Fig.1-5 shows a system in which three generators and three loads are tied together by three transmission lines. No circuit breakers are shown in this diagram, although many would be required in such a system.Part 3 Typical System LayoutThe generators, lines, and other equipment which form an electric system are arranged depending on the manner in which load grows in the area and may be rearranged from time to time.However, there are certain plans into which a particular system design may be classified. Three types are illustrated: the radial system, the loop system, and the network system. All of these are shown without the necessary circuit breakers. In each of these systems, a single generator serves four loads.The radial system is shown in Fig.1-6. Here the lines form a “tree” spreading out from the generator. Opening any line results in interruption of power to one or more of the loads.The loop system is illustrated in Fig.1-7. With this arrangement all loads may be served even though one line section is removed from service. In some instances during normal 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.1-8 shows the same loads being served by a network. With this arrangement each load has two or more circuits over which it is fed.Distribution circuits are commonly designed so that they may be classified as radial or loop circuits. The high-voltage transmission lines of most power systems are arranged as network. The interconnection of major power system results in networks made up by many line sections.Part 4 Auxiliary EquipmentCircuit breakers are necessary to deenergize equipment either for normal operation or on the occurrence of short circuits. Circuit breakers must be designed to carry normal-load currents continuously, to withstand the extremely high currents that occur during faults, and to separate contacts and clear a circuit in the presence of fault. Circuit breakers are rated in terms of these duties.When a circuit breaker opens to deenergize a piece of equipment, one side of the circuit breaker usually remains energized, as it is connected to operating equipment. Since it is sometimes necessary to work on the circuit breaker itself, it is also necessary to have means by which the circuit breaker may be completely disconnected from other energized equipment. For this purpose disconnect switches are placed in series with the circuit breakers. By opening these disconnectors, thecircuit breaker may be completely deenergized, permitting work to be carried on in safety.Various instruments are necessary to monitor the operation of the electric power system. Usually each generator, each transformer bank, and each line has its own set of instruments, frequently consisting of voltmeters, ammeters, wattmeters, and varmeters.When a fault occurs on a system, conditions on the system undergo a sudden change. V oltages usually drop and currents increase. These changes are most noticeable in the immediate vicinity of fault. On-line analog computers, commonly called relays, monitor these changes of conditions, make a determination of which breaker should be opened 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 within 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 power lines but are placed on switchboards in a control house. Instrument transformers are installed on the high-voltage equipment, by means of which it is possible to pass on to the meters and relays representative samples of the conditions on the operating equipment. The primary of a potential transformer is connected directly to the high-voltage equipment. The secondary provides for the instruments and relays a voltage which is a constant fraction of voltage on the operating equipment and is in phase with it;similarly, a current transformer is connected with its primary in the high-current circuit. The secondary winding provides a current that is a known fraction of the power-equipment current and is in phase with it.Bushing potential devices and capacitor potential devices serve the same purpose as potential transformers but usually with less accuracy in regard to ratio and phase angle.中文翻译:电力系统的简介第一部分:最小电力系统一个最小电力系统如图1-1所示,系统包含动力源,原动机,发电机和负载。
毕业设计文献翻译完美版
《毕业设计》文献翻译院系:电子电气工程学院学号:021309208姓名:吴骁奕指导教师:曾国辉完成时间:2013/2/15文献翻译021309208 吴骁奕A Flexible LED Driver for Automotive Lighting Applications: IC Design and E xperimental Characterization一个灵活的LED驱动汽车照明应用:集成电路设计和实验特征Abstract—This letter presents a smart driver for LEDs, particularly摘要:这文章提出了一个智能驱动发光二极管,for automotive lighting applications, which avoid ringing尤其是用于避免振荡和超调现象的汽车照明应用上,and overshoot phenomena. To this aim, advanced Soft Start and为了这个目的,在芯片上集成了优化软启动和电流升降控制技术。
Current Slope Control techniques are integrated on-chip. This letter这篇文章讨论了设计于集合于高电压的互补金属氧化半导体上的驱动技术,discusses the driver design integrating in high voltage CMOStechnology, the digital circuitry for programming and electronic用于编程和电子控制单元连接的数字电路以及功率元件提高到10瓦特。
control units interfacing, and the power devices up to 10W. Experimental同时也展示了不同功率等级使用的发光二极管和与不同类型的连接时的实验特征。
电气工程高层建筑论文中英文资料外文翻译文献
电气工程高层建筑论文中英文资料外文翻
译文献
本文的主要目标是翻译一些电气工程和高层建筑方面的外文文献。
这些文献分别为:
1. "Application of lateral tuned mass damper to high-rise structure under random wind excitations",这篇文章主要介绍了侧向调谐质量阻尼器(lateral tuned mass damper)在高层建筑中的应用。
该文通过计算分析和试验研究,得出了调谐阻尼器的结构参数和其对建筑物抗震能力的影响。
2. "Reliability Analysis of Power Supply System in High-rise Building",这篇文章主要介绍了高层建筑电力供应系统的可靠性分析。
该文分别从电力系统的结构、功能和基本原理入手,阐述了电力系统的可靠性分析方法,并根据有关标准和规范,对高层建筑电力系统的可靠性进行了分析。
3. "Dynamic Analysis on Earthquake Resistance of High-rise Buildings Based on Pushover Method",该文介绍了基于 Pushover 方
法对高层建筑的抗震性能进行动力学分析。
该方法通过对结构的位移、剪力和弯矩等特性进行预测,可以更加准确地评估高层建筑的抗震性能。
以上三篇文献分别介绍了高层建筑中的电气工程和抗震技术方面的研究成果,对于高层建筑的设计和建造具有一定的参考价值。
电气工程专业英文作文
电气工程专业英文作文英文,As an electrical engineering major, I havelearned a lot of knowledge and skills in this field. Electrical engineering is a branch of engineering thatdeals with the study of electricity, electronics, and electromagnetism. It is a broad field that covers a wide range of topics, including power generation, transmission, and distribution, as well as the design and development of electrical systems and devices.One of the most important skills I have learned as an electrical engineering major is problem-solving. Electrical engineering involves a lot of problem-solving, whether itis designing a new electrical system or troubleshooting an existing one. I have learned how to approach problems systematically, break them down into smaller, more manageable parts, and use my knowledge and skills to find solutions.Another important skill I have learned is communication.Electrical engineering is a team-oriented field, and effective communication is essential to the success of any project. I have learned how to communicate technical information clearly and concisely, both verbally and in writing, to colleagues, clients, and other stakeholders.In addition to these technical skills, I have also developed a range of soft skills, such as time management, teamwork, and leadership. These skills have helped me to work effectively in a variety of settings, from group projects in the classroom to internships and co-op experiences in the industry.Overall, my experience as an electrical engineering major has been challenging, but also rewarding. I have gained a deep understanding of the principles and practices of electrical engineering, as well as the skills and qualities needed to be successful in this field.中文,作为一名电气工程专业的学生,我在这个领域学习了很多知识和技能。
3-电气工程及其自动化专业 外文文献 英文文献 外文翻译
3-电气工程及其自动化专业外文文献英文文献外文翻译1、外文原文(复印件)A: Fundamentals of Single-chip MicrocomputerThe single-chip microcomputer is the culmination of both the development of the digital computer and the integrated circuit arguably the tow most significant inventions of the 20th century [1].These tow types of architecture are found in single-chip microcomputer. Some employ the split program/data memory of the Harvard architecture, shown in Fig.3-5A-1, others follow the philosophy, widely adapted for general-purpose computers and microprocessors, of making no logical distinction between program and data memory as in the Princeton architecture, shown in Fig.3-5A-2.In general terms a single-chip microcomputer is characterized by the incorporation of all the units of a computer into a single device, as shown in Fig3-5A-3.ProgramInput& memoryOutputCPU unitDatamemoryFig.3-5A-1 A Harvard typeInput&Output CPU memoryunitFig.3-5A-2. A conventional Princeton computerExternal Timer/ System Timing Counter clock componentsSerial I/OReset ROMPrarallelI/OInterrupts RAMCPUPowerFig3-5A-3. Principal features of a microcomputerRead only memory (ROM).ROM is usually for the permanent,non-volatile storage of an applications program .Many microcomputers and microcontrollers are intended for high-volume applications and hence the economical manufacture of the devices requires that the contents of the program memory be committed permanently during the manufacture of chips . Clearly, this implies a rigorous approach to ROM code development since changes cannot be made after manufacture .This development process may involve emulation using a sophisticated development system with a hardware emulation capability as well as the use of powerful software tools.Some manufacturers provide additional ROM options by including in their range devices with (or intended for use with) user programmablememory. The simplest of these is usually device which can operate in a microprocessor mode by using some of the input/output lines as an address and data bus for accessing external memory. This type of device can behave functionally as the single chip microcomputer from which itis derived albeit with restricted I/O and a modified external circuit. The use of these ROMlessdevices is common even in production circuits where the volume does not justify the development costs of custom on-chip ROM[2];there canstill be a significant saving in I/O and other chips compared to a conventional microprocessor based circuit. More exact replacement for ROM devices can be obtained in the form of variants with 'piggy-back' EPROM(Erasable programmable ROM )sockets or devices with EPROM instead of ROM 。
电气工程及其自动化专业英语第二章课文翻译
第二章第一篇To say that we live in an age of electronics is an understatement. From the omnipresent integrated circuit to the equally omnipresent digital computer, we encounter electronic devices and systems on a daily basis. In every aspect of our increasingly technological society— whether it is science, engineering, medicine, music, maintenance, or even espionage—the role of electronics is large, and it is growing.谈论关于我们生活在一个电子学时代的论调是一种空泛的论调。
从无处不在的集成电路到同样无处不在的数字计算机,我们在日常活动中总会遇到电子设备和电子系统。
在我们日益发展的科技社会的方方面面——无论是在科学、工程、医药、音乐、维修方面甚至是在谍报方面——电子学的作用是巨大的,而且还将不断增强。
In general, all of the tasks with which we shall be concerned can be classified as "signal-processing“tasks. Let us explore the meaning of this term一般说来,我们将要涉及到的工作被归结为“信号——处理”工作,让我们来探究这个术语的含义吧。
A signal is any physical variable whose magnitude or variation with time contains information. This information might involve speech and music, as in radio broadcasting, a physical quantity such as the temperature of the air in a room, or numerical data, such as the record of stock market transactions. The physical variables that can carry information in an electrical system are voltage and current. When we speak of "signals", therefore, we refer implicitly to voltages or currents. However, most of the concepts we discuss can be applied directly to systems with different information-carrying variables. Thus, the behavior of a mechanical system (in which force and velocity are the variables) or a hydraulic system (in which pressure and flow rate are the variables) can often be modeled or represented by an equivalent electrical system. An understanding of the behavior of electrical systems, therefore, provides a basis for understanding a much broader range of phenomena. 信号就是其与时间有关的量值或变化包含信息的任何物理变量。
变电站中英文资料对照外文翻译文献综述
变电站中英文资料对照外文翻译文献综述XXXns are an essential part of electrical power systems。
servingas the interface een high-voltage n lines and lower-voltage n lines。
They play a critical role in XXX homes。
businesses。
and industries.Types of nsThere are several types of ns。
including n ns。
n ns。
and customer XXX to the end-users and step down the voltage for n to XXX a single customer or group of customers.XXXns consist of us components。
including transformers。
circuit breakers。
switches。
XXX are used to step up or step down thevoltage of the electricity。
XXX are used to control the flow ofXXX to the system.XXXXXX stages。
including site n。
layout design。
equipment n。
XXX n lines。
land availability。
and environmental ns。
The layout design involves determining the placement of equipment。
XXX appropriate transformers。
circuit breakers。
and other components。
电气系统可编程序控制器毕业论文中英文资料外文翻译文献
电气系统可编程序控制器中英文资料外文翻译文献英文原文Programmable controller designed for electro-pneumatic systems This project deals with the study of electro-pneumatic systems and the programmable controller that provides an effective and easy way to control the sequence of the pneumatic actuators movement and the states of pneumatic system. The project of a specific controller for pneumatic applications join the study of automation design and the control processing of pneumatic systems with the electronic design based on microcontrollers to implement the resources of the controller.1.IntroductionThe automation systems that use electro-pneumatic technology are formed mainly by three kinds of elements: actuators or motors, sensors or buttons and control elements like valves. Nowadays, most of the control elements used to execute the logic of the system were substituted by the Programmable Logic Controller(PLC).Sensors and switches are plugged as inputs and the direct control valves for the actuators are plugged as outputs. An internal program executes all the logic necessary to the sequence of the movements, simulates other components like counter, timer and control the status of the system.With the use of the PLC the project wins agility, because it is possible to create and simulate the system as many times as needed. Therefore, time can be saved, risk of mistakes reduced and complexity can be increased using the same elements.A conventional PLC, that is possible to find on the market from many companies, offers many resources to control not only pneumatic systems, but all kinds of system that uses electrical components. The PLC can be very versatile and robust to be applied in many kinds of application in the industry or even security system and automation of buildings.Because of those characteristics, in some applications the PLC offers to much resources that are not even used to control the system, electro-pneumatic system is one of this kind of application. The use of PLC, especially for small size systems, can be very expensive for the automation project.An alternative in this case is to create a specific controller that can offer the exactly size and resources that the project needs[3,4].This can be made using microcontrollers as the base of thiscontroller.The controller, based on microcontroller, can be very specific and adapted to only one kind of machine or it can work as a generic controller that can be programmed as a usual PLC and work with logic that can be changed. All these characteristics depend on what is needed and how much experience the designer has with developing an electronic circuit and firmware for microcontroller. But the main advantage of design the controller with the microcontroller is that the designer has the total knowledge of his controller, which makes it possible to control the size of the controller, change the complexity and the application of it. It means that the project gets more independence from other companies, but at the same time the responsibility of the control of the system stays at the designer hands2.Electro-pneumatic systemOn automation system one can find three basic components mentioned before ,plus a logic circuit that controls the system. An adequate technique is needed to project the logic circuit and integrate all the necessary components to execute the sequence of movements properly.For a simple direct sequence of movement an intuitive method can be used[1,5],but for indirect or more complex sequences the intuition can generate a very complicated circuit and signal mistakes. It is necessary to use another method that can save time of the project, make a clean circuit, can eliminate occasional signal overlapping and redundant circuits.The presented method is called step-by-step or algorithmic [1,5], it is valid for pneumatic and electro-pneumatic systems and it was used as a base in this work. The method consists of designing the systems based on standard circuits made for each change on the state of the actuators, these changes are called steps.Fig.1.Standard circuit for the pneumatic system.Fig.2.Standard circuit for the electro-pneumatic system.The first part is to design those kinds of standard circuits for each step, the next task is to link the standard circuits and the last part to connect the control element that receive signals from sensors, switches and the previous movement and give the air or electricity to the supply lines of each step. In Figs.1 and 2 the standard circuits are drawn for pneumatic and electro-pneumatic system [8].It is possible to see the relations with the previous and the next steps.3. The method applied inside the controllerThe result of the method presented before is a sequence of movements of the actuator that is well defined by steps. It means that each change on the position of the actuators is a new state of the system and the transition between states is called step.The standard circuit described before helps the designer to define the states of the systems and to define the condition to each change between the states. In the end of the design, the system is defined by a sequence that never chances and states that have the inputs and the outputs well defined. The inputs are the condition for the transition and the outputs are the result of the transition.All the configuration of those steps stays inside of the microcontroller and is executed the same way it was designed. The sequences of strings are programmed inside the controller with 5 bytes; each string has the configuration of one step of the process. There are two bytes for the inputs, one byte for the outputs and two more for the other configurations and auxiliary functions of the step. After programming, this sequence of strings is saved inside of a non-volatile memory of the microcontroller, so they can be read and executed.The controller task is not to work in the same way as a conventional PLC, but the purpose of it is to be an example of a versatile controller that is design for an specific area. A conventional PLC process the control of the system using a cycle where it makes an image of the inputs, execute all the conditions defined by the configuration programmed inside, and thenupdate the state of the outputs. This controller works in a different way, where it read the configuration of the step, wait the condition of inputs to be satisfied, then update the state or the outputs and after that jump to the next step and start the process again.It can generate some limitations, as the fact that this controller cannot execute, inside the program, movements that must be repeated for some time, but this problem can be solved with some external logic components. Another limitation is that the controller cannot be applied on systems that have no sequence. These limitations are a characteristic of the system that must be analyzed for each application.4. Characteristics of the controllerThe controller is based on the MICROCHIP microcontroller PIC16F877 [6,7] with 40 pins, and it has all the resources needed for this project. It ha enough pins for all the components, serial communication implemented in circuit, EEPROM memory to save all the configuration of the system and the sequence of steps. For the execution of the main program, it offers complete resources as timers and interruptions.The list of resources of the controller was created to explore all the capacity of the microcontroller to make it as complete as possible. During the step, the program chooses how to use the resources reading the configuration string of the step. This string has two bytes for digital inputs, one used as a mask and the other one used as a value expected. One byte is used to configure the outputs value. One bytes more is used for the internal timer, the analog input or time-out. The EEPROM memory inside is 256 bytes length that is enough to save the string of the steps, with this characteristic it is possible to save between 48 steps.The controller has also a display and some buttons that are used with an interactive menu to program the sequence of steps and other configurations.4.1.Interaction componentsFor the real application the controller must have some elements to interact with the final user and to offer a complete monitoring of the system resources that are available to the designer while creating the logic control of the pneumatic system:.Interactive mode of work; function available on the main program for didactic purposes, the user gives the signal to execute the step..LCD display, which shows the status of the system, values of inputs, outputs, timer and statistics of the sequence execution..Beep to give important alerts, stop, start and emergency..Leds to show power on and others to show the state of inputs and outputs.4.2. SecurityTo make the final application works property, a correct configuration to execute the steps in the right way is needed, but more then that it must offer solutions in case of bad functioning or problems in the execution of the sequence. The controller offers the possibility to configure two internal virtual circuits that work in parallel to the principal. These two circuits can be used as emergency or reset buttons and can return the system to a certain state at any time[2]. There are two inputs that work with interruption to get an immediate access to these functions. It is possible to configure the position, the buttons and the value of time-out of the system.er interfaceThe sequence of strings can be programmed using the interface elements of the controller. A computer interface can also be used to generate the user program easily. With a good documentation the final user can use the interface to configure the strings of bytes that define the steps of the sequence. But it is possible to create a program with visual resources that works as a translator to the user,it changes his work to the values that the controller understands.To implement the communication between the computer interface and the controller a simple protocol with check sum and number of bytes is the minimum requirements to guarantee the integrity of the data.4.4. FirmwareThe main loop works by reading the strings of the steps from the EEPROM memory that has all the information about the steps.In each step, the status of the system is saved on the memory and it is shown on the display too. Depending of the user configuration, it can use the interruption to work with the emergency circuit or time-out to keep the system safety. A block diagram of micro controller main program is presented.5.Example of electro-pneumatic systemThe system is not a representation of a specific machine, but it is made with some common movements and components found in a real one. The system is composed of four actuators. The actuators A,B and C are double acting and D-single acting. Actuator A advances and stays in specified position till the end of the cycle, it could work fixing an object to the next action for example(Fig.3), it is the first step. When A reaches the end position, actuator C starts his work together with B, making as many cycles as possible during the advancing of B. It depends on how fast actuator B is advancing; the speed is regulated by a flowing control valve. It was the second step. B and C are examples of actuators working together, while B pushes an objectslowly, C repeats. its work for some time.Fig.3.Time diagram of A,B,C and D actuators.When B reaches the final position, C stops immediately its cycle and comes back to the initial position. The actuator D is a single acting one with spring return and works together with the back of C, it is the third step. D works making very fast forward and backward movement, just one time. Its backward movement is the fourth step. D could be a tool to make a hole on the object.When D reaches the initial position, A and B return too, it is the fifth step.Fig.4 shows the first part of the designing process where all the movements of each step should be defined [2]. (A+)means that the actuator A moves to the advanced position and (A . )to the initial position. The movements that happen at the same time are joined together in the same step. The system has five steps.Fig.4.Step sequence of A,B,C and D actuators.These two representations of the system(Figs.3 and 4) together are enough to describe correctly all the sequence. With them is possible to design the whole control circuit with the necessary logic components. But till this time, it is not a complete system, because it is missing some auxiliary elements that are not included in this draws because they work in parallel with the main sequence.These auxiliary elements give more function to the circuit and are very important to the final application; the most important of them is the parallel circuit linked with all the others steps. That circuit should be able to stop the sequence at any time and change the state of the actuators to a specific position. This kind of circuit can be used as a reset or emergency buttons.The next Figs.5 and 6 show the result of using the method without the controller. Thesepictures are the electric diagram of the control circuit of the example, including sensors, buttons and the coils of the electrical valves.Fig.5.Electric diagram of the example.Fig.6.Electric diagram of the example.The auxiliary elements are included, like the automatic/manual switcher that permit a continuous work and the two start buttons that make the operator of a machine use their two hands to start the process, reducing the risk of accidents.6. Changing the example to a user programIn the previous chapter, the electro-pneumatic circuits were presented, used to begin thestudy of the requires to control a system that work with steps and must offer all the functional elements to be used in a real application. But, as explained above, using a PLC or this specific controller, the control becomes easier and the complexity can be increase also.It shows a resume of the elements that are necessary to control the presented example.With the time diagram, the step sequence and the elements of the system described in Figs.3 and 4 it is possible to create the configuration of the steps that can be sent to the controller.While using a conventional PLC, the user should pay attention to the logic of the circuit when drawing the electric diagram on the interface (Figs.5and 6), using the programmable controller, describe in this work, the user must know only the concept of the method and program only the configuration of each step.It means that, with a conventional PLC, the user must draw the relation between the lines and the draw makes it hard to differentiate the steps of the sequence. Normally, one needs to execute a simulation on the interface to find mistakes on the logic.The new programming allows that the configuration of the steps be separated, like described by the method. The sequence is defined by itself and the steps are described only by the inputs and outputs for each step.The structure of the configuration follows the order:1-byte: features of the step;2-byte: for the inputs;3-byte: value expected on the inputs;4-byte: value for the outputs;5-byte: value for the extra function.Fig.7.Actuators A and B, and sensors.Fig.8.Actuators C and D, and sensors.Table 5 shows how the user program is saved inside the controller, this is the program that describes the control of the example shown before.The sequence can be defined by 25 bytes. These bytes can be divided in five strings with 5 bytes each that define each step of the sequence (Figs.7 and 8).7. ConclusionThe controller developed for this work shows that it is possible to create a very useful programmable controller based on microcontroller. External memories or external timers were not used in case to explore the resources that the microcontroller offers inside. Outside the microcontroller, there are only components to implement the outputs, inputs, analog input, display for the interface and the serial communication.Using only the internal memory, it is possible to control a pneumatic system that has a sequence with 48 steps if all the resources for all steps are used, but it is possible to reach sixty steps in the case of a simpler system.The programming of the controller does not use PLC languages, but a configuration that is simple and intuitive. With electro-pneumatic system, the programming follows the same technique that was used before to design the system, but here the designer works directly with the states or steps of the system.With a very simple machine language the designer can define all the configuration of the step using four or five bytes. It depends only on his experience to use all the resources of the controller.The controller task is not to work in the same way as a commercial PLC but the purpose of it is to be an example of a versatile controller that is designed for a specific area. Because of that, it is not possible to say which one works better; the system made with microcontroller is an alternative that works in a simple way.References[1]E.Nelli Silva,Fluid-mechanics systems Manual, Escola Politecnica USP,2002(in Portuguese).[2]J.Swider,Control and Automation of Technological Process and Mechatronic systems,Silesian University Publishing Company,Gli-wice,2002(redaction in Polish).[3]J.Swider, G.Wszolek, W.Carvalho. Example of the system prepared to be controlled by the controller based on microcontroller,in:12 International Scientific Conference—Achievements in Mechanical and MaterialsEngineering,Gliwice-Zakopane,Poland,2003,pp.965-970.[4]J.Swider,G.Wszolek,W.Carvalho, Controller based on microcontroller designed to execute the logic control of pneumatic systems, in:12International Scientific Conference—Achievements in Mechanical and Materials Engineering,Gliwice-Zakopane,Poland,2003,pp. 959–964.[5]J.Swider,G.Wszoek, The methodical collection of laboratory and project tasks of technological process control in Pneumatic and Electro-pneumatic Systems with Logical PLC Control, Silesian University Publishing Company,Gliwice,2003.[6]PIC 16f87xDatasheet.MICROCHIP,2001.[7]Application notes AN587 and AN546.MICROCHIP,1997.[8]Fundamental of electro-pneumatic—FESTODidactic,2000.中文翻译应用于电气系统的可编程序控制器摘要此项目主要是研究电气系统以及简单有效的控制气流发动机的程序和气流系统的状态。
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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 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 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 tothe 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, 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 networkconstruction, 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.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。