毕业设计智能电网相关文献翻译中文英文
智能电网构架毕业论文中英文翻译文献
中英文资料外文翻译文献场域网络的标准化和灵活的IPv6架构最后一英里的智能电网构架本文旨在为智能电网的最后一英里的基于开放标准IPv6的基础设施提供一个综合和全面的视角，用于支持一系列先进的应用程序（如读表，需求响应，遥测，遥信和电网监控和自动化），同时作为多服务平台也从中受益。
在本文中，我们将展示IPv6网络基础设施的各种模块如何提供一个高效，灵活，安全和多业务的基于开放标准的网络。
为了讨论电业在转型过程中需要处理的一些问题例如遗留的老设备，网络和应用程序集成，在过渡期推出的混合网络结构的操作，随后的文件会有更进一步的阐述。
1.介绍在过去几年，由于在智能电网基础设施的突出作用，最后一英里网络已经获得了相当大的发展势头。
这些网络在本文件称为邻区网络（NAN），他们支持一系列应用不仅包括用电计量和管理，而且包括需求响应（DR）和配电自动化（DA）应用高级应用；需求响应应用为用户提供机会可以基于实时电价信息而优化其能源使用；配电自动化（DA）应用它允许分布的监测和控制，自动故障检测，1隔离和管理，并作为未来的虚拟电厂，其中包括分布式发电，住宅能源存储（例如，电动汽车（EV）充电），以及小规模的社区电力交易。
场区网络（FAN）（(NAN和具有回程广域网接口的通讯设备的组合)已经成为一个智能电网的网络基础设施的核心组成部分。
事实上，他们作为回程网络可以为各种其他电网控制设备提供服务;例如多租户服务（煤气表和水表），家庭局域网（HAN）设备的数据交换服务，这些都通过各种无线连接或有线线路连接的技术。
这就形成了对部署的IP协议套件的需求，并使的公开标准的使用提供了可靠性，可扩展性，安全性，跨网络和灵活性，从而能为应付数量快速增长的电网配电网络的关键应用提供支持。
IP也使得领区网络（NAN）容易整合到到端到端的网络架构。
通过场区网络正在运行的应用程序之一是抄表，每个电表定期把使用数据发向一个事业单位端点的应用服务器。
电气供配电系统大学毕业论文英文文献翻译及原文
毕业设计（论文）外文文献翻译文献、资料中文题目：供配电系统文献、资料英文题目：POWER SUPPLY AND DISTRIBUTIONSYSTEM文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：班级：姓名：学号：指导教师：翻译日期： 2017.02.14POWER SUPPLY AND DISTRIBUTION SYSTEMABSTRACTThe basic function of the electric power system is to transport the electric power towards customers. The l0kV electric distribution net is a key point that connects the power supply with the electricity using on the industry, business and daily-life. For the electric power, allcostumers expect to pay the lowest price for the highest reliability, but don't consider that it's self-contradictory in the co-existence of economy and reliable.To improve the reliability of the power supply network, we must increase the investment cost of the network construction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic,between the investment and the loss by calculating the investment on power net and the loss brought from power-off.KEYWARDS：power supply and distribution,power distribution reliability，reactive compensation,load distributionTEXTThe revolution of electric power system has brought a new big round construction,which is pushing the greater revolution of electric power technique along with the application of new technique and advanced equipment. Especially, the combination of the information technique and electric power technique, to great ex- tent, has improved reliability on electric quality and electric supply. The technical development decreases the cost on electric construction and drives innovation of electric network. On the basis of national and internatio- nal advanced electric knowledge, the dissertation introduces the research hotspot for present electric power sy- etem as following.Firstly, This dissertation introduces the building condition of distribution automation(DA), and brings forward two typical construction modes on DA construction, integrative mode and fission mode .It emphasize the DA structure under the condition of the fission mode and presents the system configuration, the main station scheme, the feeder scheme, the optimized communication scheme etc., which is for DA research reference.Secondly, as for the (DA) trouble measurement, position, isolation and resume, This dissertation analyzes the changes of pressure and current for line problem, gets math equation by educing phase short circuit and problem position under the condition of single-phase and works out equation and several parameter s U& , s I& and e I& table on problem . It brings out optimized isolation and resume plan, realizes auto isolation and network reconstruction, reduces the power off range and time and improves the reliability of electric power supply through problem self- diagnoses and self-analysis. It also introduces software flow and use for problem judgement and sets a model on network reconstruction and computer flow.Thirdly, electricity system state is estimated to be one of the key techniques in DA realization. The dissertation recommends the resolvent of bad measurement data and structure mistake on the ground of describing state estimate way. It also advances a practical test and judging way on topology mistake in state estimate about bad data test and abnormity in state estimate as well as the problem and effect on bad data from state measure to state estimate .As for real time monitor and control problem, the dissertation introduces a new way to solve them by electricity break and exceptional analysis, and theway has been tested in Weifang DA.Fourthly, about the difficulty for building the model of load forecasting, big parameter scatter limit and something concerned, the dissertation introduces some parameters, eg. weather factor, date type and social environment effect based on analysis of routine load forecasting and means. It presents the way for electricity load forecasting founded on neural network(ANN),which has been tested it’s validity by example and made to be good practical effect.Fifthly, concerning the lack of concordant wave on preve nting concordant wave and non-power compensation and non-continuity on compensation, there is a topology structure of PWM main circuit and nonpower theory on active filter the waves technique and builds flat proof on the ground of Saber Designer and proves to be practical. Meanwhile, it analyzes and designs the way of non-power need of electric network tre- nds and decreasing line loss combined with DA, which have been tested its objective economic benefit throu- gh counting example.Sixthly, not only do the dissertation design a way founded on the magrginal electric price fitted to our present national electric power market with regards to future trends of electric power market in China and fair trade under the government surveillance, that is group competitio n in short-term trade under the way of grouped price and quantity harmony, but also puts forward combination arithmetic, math model of trading plan and safty economical restriction. It can solve the original contradiction between medium and long term contract price and short term competitive price with improvement on competitive percentage and cut down the unfair income difference of electric factory, at the same time, it can optimize the electric limit for all electric factories and reduce the total purchase charge of electric power from burthen curve of whole electric market network.The distribution network is an important link among the power system. Its neutral grounding mode and operation connects security and stability of the power system directly. At the same time, the problem about neutral grounding is associated with national conditions, natural environment, device fabrication and operation. For example, the activity situation of the thunder and lightning, insulating structure and the peripheral interference will influence the choice of neutral grounding mode Conversely, neutral grounding mode affects design, operation, debugs and developing. Generally in the system higher in grade in the voltage, the insulating expenses account for more sizable proportion at the total price of the equipment. It is very remarkable to bring the economic benefits by reducing the insulating level. Usually such system adopt the neutral directly grounding andadopt the autoreclosing to guarantee power supply reliability. On the contrary, the system which is lower in the voltage adopts neutral none grounding to raise power supply reliability. So it is an important subject to make use of new- type earth device to apply to the distribution network under considering the situation in such factors of various fields as power supply reliability, safety factor, over-voltage factor, the choice of relay protection, investment cost, etc.The main work of this paper is to research and choice the neutral grounding mode of the l0kV distribution network. The neutral grounding mode of the l0kV network mainly adopts none grounding, grounding by arc suppressing coil, grounding by reactance grounding and directly grounding. The best grounding mode is confirmed through the technology comparison. It can help the network run in safety and limit the earth electric arc by using auto-tracking compensate device and using the line protection with the detection of the sensitive small ground current. The paper introduces and analyzes the characteristic of all kind of grounding modes about l0kV network at first. With the comparison with technological and economy, the conclusion is drawn that the improved arc suppressing coil grounding mode shows a very big development potential.Then, this paper researches and introduces some operation characteristics of the arc suppressing coil grounding mode of the l0kV distribution network. And then the paper put emphasis on how to extinguish the earth electric arc effectively by utilizing the resonance principle. This paper combines the development of domestic and international technology and innovative achievement, and introduces the computer earth protection and autotracking compensate device. It proves that the improved arc suppressing coil grounding mode have better operation characteristics in power supply reliability, personal security, security of equipment and interference of communication. The application of the arc suppressing coil grounding mode is also researched in this paper.Finally, the paper summarizes this topic research. As a result of the domination of the arc suppressing coil grounding mode, it should be more popularized and applied in the distribution network in the future.The way of thinking, project and conclusions in this thesis have effect on the research to choose the neutral grounding mode not only in I0kV distribution network but also in other power system..The basic function of the electric power system is to transport the electric power towards customers. The l0kV electric distribution net is a key point that connects the power supply with the electricity using on the industry, business and daily-life. For the electric power, all costumers expect to pay the lowest price for the highest reliability, butdon't consider that it's self-contradictory in the co-existence of economy and reliable. To improve the reliability of the power supply network, we must increase the investment cost of the network con- struction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic, between the investment and the loss by calculating the investment on power net and the loss brought from power-off. The thesis analyses on the economic and the reliable of the various line modes, according to the characteristics various line modes existed in the electric distribution net in foshan..First, the thesis introduces as the different line modes in the l0kV electric distribution net and in some foreign countries. Making it clear tow to conduct analyzing on the line mode of the electric distribution net, and telling us how important and necessary that analyses are.Second, it turns to the necessity of calculating the number of optimization subsection, elaborating how it influences on the economy and reliability. Then by building up the calculation mode of the number of optimization subsection it introduces different power supply projects on the different line modes in brief. Third, it carries on the calculation and analyses towards the reliability and economy of the different line modes of electric distribution net, describing drafts according by the calculation. Then it makes analysis and discussion on the number of optimization subsection.At last, the article make conclusion on the economy and reliability of different line modes, as well as, its application situation. Accordion to the actual circumstance, the thesis puts forward the beneficial suggestion on the programming and construction of the l0kV electric distribution net in all areas in foshan. Providing the basic theories and beneficial guideline for the programming design of the lOkV electric distribution net and building up a solid net, reasonable layout, qualified safe and efficiently-worked electric distribution net.。
智能电网发展现状英文作文
智能电网发展现状英文作文很多人都在关心智能电网的发展现状，我也是其中之一。
智能电网是指利用先进的通信、计算和控制技术，实现对电力系统的智能化管理和运行。
它能够实现电力的高效利用、提高供电可靠性、降低能源消耗等多种优势。
目前，智能电网发展已经取得了一定的成就，但也面临着一些挑战和问题。
英文：The development of smart grid is a topic of great concern for many people, myself included. A smart grid refers to the use of advanced communication, computing, and control technologies to achieve intelligent management and operation of the power system. It can achieve efficient use of electricity, improve power supply reliability, and reduce energy consumption. At present, the development of smart grid has made some achievements, but it also faces some challenges and problems.中文：智能电网的发展是许多人关注的话题，我也是其中之一。
智能电网是指利用先进的通信、计算和控制技术，实现对电力系统的智能化管理和运行。
它能够实现电力的高效利用、提高供电可靠性、降低能源消耗等多种优势。
目前，智能电网发展已经取得了一定的成就，但也面临着一些挑战和问题。
英文：One of the achievements of the development of smartgrid is the integration of renewable energy sources intothe power grid. For example, in my city, we have a large-scale solar power plant that is connected to the smart grid. This allows the power generated from the solar panels to be efficiently distributed and used, reducing the reliance on traditional fossil fuels and decreasing greenhouse gas emissions. This is a great example of how smart grid technology can promote the use of clean and sustainable energy.中文：智能电网发展的成就之一是将可再生能源整合到电力网中。
毕业设计外文原文+翻译(电力系统)
河南理工大学HENAN POLYTECHNIC UNIVERSITY英文文献翻译En glish literature tran slati on学院：电气工程与自动化学院专业班级：___________ 电气11-4班_______ 姓名： __________________ 宋家鹏_______ 学号：311008001120 __________ 扌旨导老师：____________ 汪旭东_______2014年6月5日河南理工大学HENAN POLYTECHNIC UNIVERSITY2.5 对称三相电路在这一部分，我们介绍三相对称电路的一下几个话题：丫连接,相电压，线电压，线电流，△形连接负荷，△ - Y变换，以及等效的相图。
c Ca Ab B图2-10三相Y连接电源带Y连接对称负荷电路图对称Y连接图2-10显示的是一个三相Y连接电源带Y连接对称负荷电路图。
对于Y连接电路，每个相的中性点是连接起来的。
在图2-10中电源中性点标记的是n,而负载中性点标记的是N。
把三相电源假设为理想电源，即阻抗忽略不计。
同时，电源和负载之间线路阻抗，中性点n与N之间的线路阻抗也可忽略不计。
三相负荷是对称的，意味着三相之中任意两相间的阻抗是相同的。
对称相电压在图2-10中,三相电源的终端呗标记为a、b、c,电源相电压标记为E an ,E bn，E cn，当电源的三相电压有相同的幅度，任意两相之间互差120度角时，电源是对称的。
当以E an 作为参考相量时，相电压的幅值是10V，对称三相相电压如下所示：E an=10 0E bn10 120 10 240 (2.5.1 )E cn10 120 10 240河南理工大学HENAN POLYTECHNIC UNIVERSITY图2-11以E an 作为参考的对称正序相电压向量图当E an 超前E bn 120度，E bn 超前E cn 以120度角时，此时的相序称为正相序或 者abc 相序。
智能电网的优势英语作文
智能电网的优势英语作文English:Smart grids offer numerous advantages in the modern energy landscape. Firstly, they enhance reliability and efficiency by allowing real-time monitoring and control of energy distribution, minimizing disruptions and optimizing resource allocation. Secondly, smart grids facilitate the integration of renewable energy sources, such as solar and wind power, by managing their variability and intermittency through advanced forecasting and demand response mechanisms. Additionally, they empower consumers with greater awareness and control over their energy usage through smart meters and home automation technologies, enabling them to make informed decisions and potentially reduce their electricity bills. Moreover, smart grids enable grid operators to detect and respond to faults and outages more swiftly, enhancing overall system resilience. Furthermore, they promote the adoption of electric vehicles by offering convenient charging infrastructure and grid-friendly charging schedules, thereby reducing greenhouse gas emissions and reliance on fossil fuels in the transportation sector. Overall, smart grids represent a pivotal advancement in the modernization of energy infrastructure, offeringa pathway towards a more sustainable, resilient, and efficient energy system.中文翻译:智能电网在现代能源格局中具有许多优势。
电气毕业设计用外文翻译(中英文对照)
The Transformer on load ﹠Introduction to DC Machine sThe Transformer on loadIt has been shown that a primary input voltage 1V can be transformed to any desired open-circuit secondary voltage 2E by a suitable choice of turns ratio. 2E is available for circulating a load current impedance. For the moment, a lagging power factor will be considered. The secondary current and the resulting ampere-turns 22N I will change the flux, tending to demagnetize the core, reduce m Φ and with it 1E . Because the primary leakage impedance drop is so low, a small alteration to 1E will cause an appreciable increase of primary current from 0I to a new value of 1I equal to ()()i jX R E V ++111/. The extra primary current and ampere-turns nearly cancel the whole of the secondary ampere-turns. This being so , the mutual flux suffers only a slight modification and requires practically the same net ampere-turns 10N I as on no load. The total primary ampere-turns are increased by an amount 22N I necessary to neutralize the same amount of secondary ampere-turns. In the vector equation , 102211N I N I N I =+; alternatively, 221011N I N I N I -=. At full load, the current 0I is only about 5% of the full-load current and so 1I is nearly equal to 122/N N I . Because in mind that 2121/N N E E =, the input kV A which is approximately 11I E is also approximately equal to the output kV A, 22I E .The physical current has increased, and with in the primary leakage flux to which it is proportional. The total flux linking the primary ,111Φ=Φ+Φ=Φm p , is shown unchanged because the total back e.m.f.,（dt d N E /111Φ-）is still equal and opposite to 1V . However, there has been a redistribution of flux and the mutual component has fallen due to the increase of 1Φ with 1I . Although the change is small, the secondary demand could not be met without a mutual flux and e.m.f. alteration to permit primary current to change. The net flux s Φlinking the secondary winding has been further reduced by the establishment of secondary leakage flux due to 2I , and this opposes m Φ. Although m Φ and2Φ are indicated separately , they combine to one resultant in the core which will be downwards at the instant shown. Thus the secondary terminal voltage is reduced to dt d N V S /22Φ-= which can be considered in two components, i.e. dt d N dt d N V m //2222Φ-Φ-=or vectorially 2222I jX E V -=. As for the primary, 2Φ is responsible for a substantially constant secondaryleakage inductance 222222/Λ=ΦN i N . It will be noticed that the primary leakage flux is responsiblefor part of the change in the secondary terminal voltage due to its effects on the mutual flux. The two leakage fluxes are closely related; 2Φ, for example, by its demagnetizing action on m Φ has caused the changes on the primary side which led to the establishment of primary leakage flux.If a low enough leading power factor is considered, the total secondary flux and the mutual flux are increased causing the secondary terminal voltage to rise with load. p Φ is unchanged in magnitude from the no load condition since, neglecting resistance, it still has to provide a total back e.m.f. equal to 1V . It is virtually the same as 11Φ, though now produced by the combined effect of primary and secondary ampere-turns. The mutual flux must still change with load to give a change of 1E and permit more primary current to flow. 1E has increased this time but due to the vector combination with 1V there is still an increase of primary current.Two more points should be made about the figures. Firstly, a unity turns ratio has been assumed for convenience so that '21E E =. Secondly, the physical picture is drawn for a different instant of time from the vector diagrams which show 0=Φm , if the horizontal axis is taken as usual, to be the zero time reference. There are instants in the cycle when primary leakage flux is zero, when the secondary leakage flux is zero, and when primary and secondary leakage flux is zero, and when primary and secondary leakage fluxes are in the same sense.The equivalent circuit already derived for the transformer with the secondary terminals open, can easily be extended to cover the loaded secondary by the addition of the secondary resistance and leakage reactance.Practically all transformers have a turns ratio different from unity although such an arrangement issometimes employed for the purposes of electrically isolating one circuit from another operating at the same voltage. To explain the case where 21N N ≠ the reaction of the secondary will be viewed from the primary winding. The reaction is experienced only in terms of the magnetizing force due to the secondary ampere-turns. There is no way of detecting from the primary side whether 2I is large and 2N small or vice versa, it is the product of current and turns which causes the reaction. Consequently, a secondary winding can be replaced by any number of different equivalent windings and load circuits which will give rise to an identical reaction on the primary .It is clearly convenient to change the secondary winding to an equivalent winding having the same number of turns 1N as the primary.With 2N changes to 1N , since the e.m.f.s are proportional to turns, 2212)/('E N N E = which is the same as 1E .For current, since the reaction ampere turns must be unchanged 1222'''N I N I = must be equal to 22N I .i.e. 2122)/(I N N I =.For impedance , since any secondary voltage V becomes V N N )/(21, and secondary current I becomes I N N )/(12, then any secondary impedance, including load impedance, must become I V N N I V /)/('/'221=. Consequently, 22212)/('R N N R = and 22212)/('X N N X = .If the primary turns are taken as reference turns, the process is called referring to the primary side. There are a few checks which can be made to see if the procedure outlined is valid.For example, the copper loss in the referred secondary winding must be the same as in the original secondary otherwise the primary would have to supply a different loss power. ''222R I must be equal to 222R I . ）222122122/()/(N N R N N I ∙∙ does in fact reduce to 222R I .Similarly the stored magnetic energy in the leakage field )2/1(2LI which is proportional to 22'X I will be found to check as ''22X I . The referred secondary 2212221222)/()/(''I E N N I N N E I E kVA =∙==.The argument is sound, though at first it may have seemed suspect. In fact, if the actual secondarywinding was removed physically from the core and replaced by the equivalent winding and load circuit designed to give the parameters 1N ,'2R ,'2X and '2I , measurements from the primary terminals would be unable to detect any difference in secondary ampere-turns, kVA demand or copper loss, under normal power frequency operation.There is no point in choosing any basis other than equal turns on primary and referred secondary, but it is sometimes convenient to refer the primary to the secondary winding. In this case, if all the subscript 1’s are interchanged for the subscript 2’s, the necessary referring constants are easily found; e.g. 2'1R R ≈,21'X X ≈; similarly 1'2R R ≈ and 12'X X ≈.The equivalent circuit for the general case where 21N N ≠ except that m r has been added to allow for iron loss and an ideal lossless transformation has been included before the secondary terminals to return '2V to 2V .All calculations of internal voltage and power losses are made before this ideal transformation is applied. The behaviour of a transformer as detected at both sets of terminals is the same as the behaviour detected at the corresponding terminals of this circuit when the appropriate parameters are inserted. The slightly different representation showing the coils 1N and 2N side by side with a core in between is only used for convenience. On the transformer itself, the coils are , of course , wound round the same core.Very little error is introduced if the magnetising branch is transferred to the primary terminals, but a few anomalies will arise. For example ,the current shown flowing through the primary impedance is no longer the whole of the primary current. The error is quite small since 0I is usually such a small fraction of 1I . Slightly different answers may be obtained to a particular problem depending on whether or not allowance is made for this error. With this simplified circuit, the primary and referred secondary impedances can be added to give: 221211)/(Re N N R R += and 221211)/(N N X X Xe +=It should be pointed out that the equivalent circuit as derived here is only valid for normal operation at power frequencies; capacitance effects must be taken into account whenever the rate of change of voltage would give rise to appreciable capacitance currents, dt CdV I c /=. They are important at high voltages and at frequencies much beyond 100 cycles/sec. A further point is not theonly possible equivalent circuit even for power frequencies .An alternative , treating the transformer as a three-or four-terminal network, gives rise to a representation which is just as accurate and has some advantages for the circuit engineer who treats all devices as circuit elements with certain transfer properties. The circuit on this basis would have a turns ratio having a phase shift as well as a magnitude change, and the impedances would not be the same as those of the windings. The circuit would not explain the phenomena within the device like the effects of saturation, so for an understanding of internal behaviour .There are two ways of looking at the equivalent circuit:(a) viewed from the primary as a sink but the referred load impedance connected across '2V ,or (b) viewed from the secondary as a source of constant voltage 1V with internal drops due to 1Re and 1Xe . The magnetizing branch is sometimes omitted in this representation and so the circuit reduces to a generator producing a constant voltage 1E (actually equal to 1V ) and having an internal impedance jX R + (actually equal to 11Re jXe +).In either case, the parameters could be referred to the secondary winding and this may save calculation time .The resistances and reactances can be obtained from two simple light load tests.Introduction to DC MachinesDC machines are characterized by their versatility. By means of various combination of shunt, series, and separately excited field windings they can be designed to display a wide variety of volt-ampere or speed-torque characteristics for both dynamic and steadystate operation. Because of the ease with which they can be controlled , systems of DC machines are often used in applications requiring a wide range of motor speeds or precise control of motor output.The essential features of a DC machine are shown schematically. The stator has salient poles and is excited by one or more field coils. The air-gap flux distribution created by the field winding is symmetrical about the centerline of the field poles. This axis is called the field axis or direct axis.As we know , the AC voltage generated in each rotating armature coil is converted to DC in the external armature terminals by means of a rotating commutator and stationary brushes to which the armature leads are connected. The commutator-brush combination forms a mechanical rectifier,resulting in a DC armature voltage as well as an armature m.m.f. wave which is fixed in space. The brushes are located so that commutation occurs when the coil sides are in the neutral zone , midway between the field poles. The axis of the armature m.m.f. wave then in 90 electrical degrees from the axis of the field poles, i.e., in the quadrature axis. In the schematic representation the brushes are shown in quarature axis because this is the position of the coils to which they are connected. The armature m.m.f. wave then is along the brush axis as shown.. (The geometrical position of the brushes in an actual machine is approximately 90 electrical degrees from their position in the schematic diagram because of the shape of the end connections to the commutator.)The magnetic torque and the speed voltage appearing at the brushes are independent of the spatial waveform of the flux distribution; for convenience we shall continue to assume a sinusoidal flux-density wave in the air gap. The torque can then be found from the magnetic field viewpoint.The torque can be expressed in terms of the interaction of the direct-axis air-gap flux per pole d Φ and the space-fundamental component 1a F of the armature m.m.f. wave . With the brushes in the quadrature axis, the angle between these fields is 90 electrical degrees, and its sine equals unity. For a P pole machine 12)2(2a d F P T ϕπ= In which the minus sign has been dropped because the positive direction of the torque can be determined from physical reasoning. The space fundamental 1a F of the sawtooth armature m.m.f. wave is 8/2π times its peak. Substitution in above equation then gives a d a a d a i K i mPC T ϕϕπ==2 Where a i =current in external armature circuit;a C =total number of conductors in armature winding;m =number of parallel paths through winding;And mPC K a a π2=Is a constant fixed by the design of the winding.The rectified voltage generated in the armature has already been discussed before for an elementary single-coil armature. The effect of distributing the winding in several slots is shown in figure ,in which each of the rectified sine waves is the voltage generated in one of the coils, commutation taking place at the moment when the coil sides are in the neutral zone. The generated voltage as observed from the brushes is the sum of the rectified voltages of all the coils in series between brushes and is shown by the rippling line labeled a e in figure. With a dozen or so commutator segments per pole, the ripple becomes very small and the average generated voltage observed from the brushes equals the sum of the average values of the rectified coil voltages. The rectified voltage a e between brushes, known also as the speed voltage, is m d a m d a a W K W mPC e ϕϕπ==2 Where a K is the design constant. The rectified voltage of a distributed winding has the same average value as that of a concentrated coil. The difference is that the ripple is greatly reduced.From the above equations, with all variable expressed in SI units:m a a Tw i e =This equation simply says that the instantaneous electric power associated with the speed voltage equals the instantaneous mechanical power associated with the magnetic torque , the direction of power flow being determined by whether the machine is acting as a motor or generator.The direct-axis air-gap flux is produced by the combined m.m.f. f f i N ∑ of the field windings, the flux-m.m.f. characteristic being the magnetization curve for the particular iron geometry of the machine. In the magnetization curve, it is assumed that the armature m.m.f. wave is perpendicular to the field axis. It will be necessary to reexamine this assumption later in this chapter, where the effects of saturation are investigated more thoroughly. Because the armature e.m.f. is proportional to flux timesspeed, it is usually more convenient to express the magnetization curve in terms of the armature e.m.f. 0a e at a constant speed 0m w . The voltage a e for a given flux at any other speed m w is proportional to the speed,i.e. 00a m m a e w w e Figure shows the magnetization curve with only one field winding excited. This curve can easily be obtained by test methods, no knowledge of any design details being required.Over a fairly wide range of excitation the reluctance of the iron is negligible compared with that of the air gap. In this region the flux is linearly proportional to the total m.m.f. of the field windings, the constant of proportionality being the direct-axis air-gap permeance.The outstanding advantages of DC machines arise from the wide variety of operating characteristics which can be obtained by selection of the method of excitation of the field windings. The field windings may be separately excited from an external DC source, or they may be self-excited; i.e., the machine may supply its own excitation. The method of excitation profoundly influences not only the steady-state characteristics, but also the dynamic behavior of the machine in control systems.The connection diagram of a separately excited generator is given. The required field current is a very small fraction of the rated armature current. A small amount of power in the field circuit may control a relatively large amount of power in the armature circuit; i.e., the generator is a power amplifier. Separately excited generators are often used in feedback control systems when control of the armature voltage over a wide range is required. The field windings of self-excited generators may be supplied in three different ways. The field may be connected in series with the armature, resulting in a shunt generator, or the field may be in two sections, one of which is connected in series and the other in shunt with the armature, resulting in a compound generator. With self-excited generators residual magnetism must be present in the machine iron to get the self-excitation process started.In the typical steady-state volt-ampere characteristics, constant-speed primemovers being assumed. The relation between the steady-state generated e.m.f. a E and the terminal voltage t V isa a a t R I E V -=Where a I is the armature current output and a R is the armature circuit resistance. In a generator, a E is large than t V ; and the electromagnetic torque T is a countertorque opposing rotation.The terminal voltage of a separately excited generator decreases slightly with increase in the load current, principally because of the voltage drop in the armature resistance. The field current of a series generator is the same as the load current, so that the air-gap flux and hence the voltage vary widely with load. As a consequence, series generators are not often used. The voltage of shunt generators drops off somewhat with load. Compound generators are normally connected so that the m.m.f. of the series winding aids that of the shunt winding. The advantage is that through the action of the series winding the flux per pole can increase with load, resulting in a voltage output which is nearly constant. Usually, shunt winding contains many turns of comparatively heavy conductor because it must carry the full armature current of the machine. The voltage of both shunt and compound generators can be controlled over reasonable limits by means of rheostats in the shunt field. Any of the methods of excitation used for generators can also be used for motors. In the typical steady-state speed-torque characteristics, it is assumed that the motor terminals are supplied from a constant-voltage source. In a motor the relation between the e.m.f. a E generated in the armature and the terminal voltage t V isa a a t R I E V +=Where a I is now the armature current input. The generated e.m.f. a E is now smaller than the terminal voltage t V , the armature current is in the opposite direction to that in a motor, and the electromagnetic torque is in the direction to sustain rotation ofthe armature.In shunt and separately excited motors the field flux is nearly constant. Consequently, increased torque must be accompanied by a very nearly proportional increase in armature current and hence by a small decrease in counter e.m.f. to allow this increased current through the small armature resistance. Since counter e.m.f. is determined by flux and speed, the speed must drop slightly. Like the squirrel-cage induction motor ,the shunt motor is substantially a constant-speed motor having about 5 percent drop in speed from no load to full load. Starting torque and maximum torque are limited by the armature current that can be commutated successfully.An outstanding advantage of the shunt motor is ease of speed control. With a rheostat in the shunt-field circuit, the field current and flux per pole can be varied at will, and variation of flux causes the inverse variation of speed to maintain counter e.m.f. approximately equal to the impressed terminal voltage. A maximum speed range of about 4 or 5 to 1 can be obtained by this method, the limitation again being commutating conditions. By variation of the impressed armature voltage, very wide speed ranges can be obtained.In the series motor, increase in load is accompanied by increase in the armature current and m.m.f. and the stator field flux (provided the iron is not completely saturated). Because flux increases with load, speed must drop in order to maintain the balance between impressed voltage and counter e.m.f.; moreover, the increase in armature current caused by increased torque is smaller than in the shunt motor because of the increased flux. The series motor is therefore a varying-speed motor with a markedly drooping speed-load characteristic. For applications requiring heavy torque overloads, this characteristic is particularly advantageous because the corresponding power overloads are held to more reasonable values by the associated speed drops. Very favorable starting characteristics also result from the increase in flux with increased armature current.In the compound motor the series field may be connected either cumulatively, so that its.m.m.f.adds to that of the shunt field, or differentially, so that it opposes. The differential connection is very rarely used. A cumulatively compounded motor hasspeed-load characteristic intermediate between those of a shunt and a series motor, the drop of speed with load depending on the relative number of ampere-turns in the shunt and series fields. It does not have the disadvantage of very high light-load speed associated with a series motor, but it retains to a considerable degree the advantages of series excitation.The application advantages of DC machines lie in the variety of performance characteristics offered by the possibilities of shunt, series, and compound excitation. Some of these characteristics have been touched upon briefly in this article. Still greater possibilities exist if additional sets of brushes are added so that other voltages can be obtained from the commutator. Thus the versatility of DC machine systems and their adaptability to control, both manual and automatic, are their outstanding features.负载运行的变压器及直流电机导论负载运行的变压器通过选择合适的匝数比，一次侧输入电压1V 可任意转换成所希望的二次侧开路电压2E 。
毕业设计论文外文文献翻译中英文对照电气对中国智能电网的研究
1Research on Smart Grid in ChinaJingjing Lu, Da Xie, Member, IEEE and Qian Ai, Member, IEEEAbstract--The Smart Grid is the latest direction for the futurepower system development. In this paper, firstly the backgroundof Smart Grid, its meaning, as well as the concept and structurewere presented. Typical diagram of Smart Grid was illustrated.Then, the current development of Smart Grid in United States and Europe were described, development ideas and the future trends in these countries were summarized and compared as well.Besides, the driving force of Smart Grid in China was analyzed,with detailed introduction of current related projects in China.The relation between the UHV Power Grid and the Smart Grid was discussed. Finally, the potential role of Smart Grid in future power grids in China was prospected and a new direction for China’s Smart Grid development was charted.Index Terms—Smart Grid, UHV power grid, planning,operation, managementI. INTRODUCTIONWith the promotion of world economy modernization, theprice of oil has been kept on a upward trend. What is also noticeable is the shortage of energy supply around the world, the increasing pressures on resources and environment pressure, and the enormous power losses in energy delivery due to the low eff iciency of the current power grid. What’s more, owing to the growing electricity demands and the users’increasing requirements for reliability and quality, the power industry is now facing unprecedented challenges and opportunities. Therefore, a new sort of power system of environment friendly, economic, high performance, low investment, safety, reliability and flexibility has been a goal of engineers in power industry.Still, the emergence of advanced meter infrastructure and more extensive usage of the Internet accelerate the process [1]. Since 1990's, with the increasing use of distributed generation power, more demands and requirements have been proposed for power grid intensity [2], [3]. To find out a optimal solution for these problems, power companies should accept the idea of new technology adoption, potential mining of the existing power system and improvement of its application and utilization. Consensus has been reached by experts and scholars from different countries that future power gird must be able to meet various requirements of energy generating and the demands of highly market-oriented power transaction so that the needs of the self-selection from customers can be satisfied individually. All of these will become the future development direction of Smart Grid.This paper focuses on the status of the development of the Smart Grid, analyzing the driving force of the Smart Grid and introducing the current demonstration projects in China. It also discusses the relation between UHV power grid and Smart Grid, and then prospect the significance of Smart Grid in the future. A new direction for Chinese Smart Grid development is charted as well, which might be the reference for the development of Smart Grid in China.II. CONCEPT OF SMART GRIDSmart Grid is a gradual development process accompanied with the technology innovation, demands of energy saving and managements needs. People will have their own understandingfor Smart Grid, no matter if they are facility suppliers, IT companies, consulting firms, public power companies or power generation companies. From the earlier smart intelligence meteringto electrical intelligence, from transmission and distribution automation to a whole intelligent process, the concept of smart power grid has been enriched substantially [4]. In 2006, US IBM presented a "Smart Grid" solution. This is a relatively complete concept for current Smart Grid which indicates its official birth [5].As shown in Fig.1, a Smart Grid is basically overlaying the physical power system with an information system which links a variety of equipments and assets together with sensors to form a customer service platform. It allows the utility and consumers to constantly monitor and adjust electricity use. The management of operation will be more intelligent and scientific based on the dynamic analysis of needs both from user-side and demand side which can increase capital investment efficiency due to tighter design limits and optimized use of grid assets.In comparison with traditional grid, Smart Grid includes integrated communication systems, advanced Sensing,metering, measurement infrastructure, complete decision support and human interfaces.III. CURRENT RESEARCH ACTIVITIESA. Comparison of researches in Smart Grid area between European and the United statesIn the United States, there were several large power outages in recent years. Because of which, electric power industry pays closer attention to power quality and reliability;customers draw out more requests for electricity supply. The ever-increasing demands of national security and environmental protection policy of the United States leads to the establishment of a higher standard for power grid construction and management [6]. At the same time, in recent years’ researches of basic materials, power and information technologies, breakthroughs have been achieved for implementation target which shows the significant improvement of reliability, efficiency in power network. Such as the emergence of superconducting cables, it assures Obama’s new gove rnment of United States has seen the daylights of the Smart Grid.Similarly, the European power users also raise higher requirements for electricity supply & power quality [7].Because of the extreme attention for environmental protection,compared with the construction of power grid in US,Europeans have more concerns about the construction of renewable energy access, the impact on wildlife, as well as the actively research on real-time monitoring and remotecontrolling.All is about to realize the "Plug & Play use" idea,ensuring a more friendly, flexible access and interaction with the user. In both Europe and United States, the most common direction for grid development is to seek new and renewable sources for energy generation. However, Smart Grid is not a fixed, static project, according to their particular status and main problems, all countries need to simplify the Smart Grid and make it adjusted to fit their own features.B. Driving force of the Smart Grid in ChinaThe drivers for Smart Grid construction can be concluded into market, circumstances, safety and power quality. Chinese power industry is also facing the similar situation as in Europe and the United States.At Market-oriented reforms level, the national network and unified national electricity market has not completely formed.In national wide, power exchanges are not effective; neither does the true meaning of the online bidding. From a long term view,China's transaction approaches of power markets and pricing structure is developing, market demand and supply sides will have more frequent interactions. In order to attract more users to join the market competition, power companies must improve their service, strengthen the interaction with users and provide more products for selection, so as to meet the demands of different types of users.At the macro policy level, the power industry needs to meet the requirements ofresource-saving and environment-friendly society’s construction, adapt to climate change and suitable for sustainable development.Regarding the Chinese power grid itself, a strong backbone network has not been built yet, and it is still not strong enough to withstand multiple faults circumstances. The regional power grid backbone is also in a lower stability level, which results in a limited flexibility for system operation, etc. The snow storm weather in early 2008 which led to a blackout in major area of China vividly exposed the weakness of the current Chinese grid in safeguard of electricity supply aspect.Moreover, the lack of intelligent power distribution leads to a regional, seasonal shortage of electricity and coexistent in some areas with both surplus & shortages of electricity.There still remain challenges that how to improve the efficiency of power investment and construction, how to ensure the security and reliability of power grid’s operation, to ensure power quality; how to improve the maintenance of power system; how to enhance the service quality to users, as well as how to improve the power grid management in China.For these issues, Smart Grid would be an ideal solution.C. Current research activities in ChinaIn the year of 2006, IBM published the guideline named ‘Establishing Smart Power Grid and Innovating Management Methods – A New Thought of the Development of Electric in China’. Directed at the current opportunities and challenges of the power grid companies in China, the guideline suggests improving the efficiency of electrical investments and construction, the stability of power grid, and the companies’service and ma nagement level through the construction of smart power grid and the innovation of management methods.Meanwhile, IBM proposed that it can provide a whole scheme - Solution Architecture for Energy (SAFT) for the power companies in China to use the smart power grid effectively. SAFT contains several parts: first is to improvethe digital level by connecting the equipments with sensors;Second is to establish the data collecting and integrating system; Third is to analyze: SAFT optimize the operating progress and management based on the analyzing of the data[5]. This is the bud of smart power grid in Chin.In October 2007, East China Power Grid Company embarked on the research area of the feasibility of smart power grid. The research project was not only correlated with the progress of those advanced companies and research facilities abroad, but also take the current situation and future needs of east china power grid into consideration. The result came out as, based on the high equipment level and strong technological innovation ability, the construction of smart power grid is feasible in east china power grid. East China Power Grid Company would follow the belief that‘Concerning the future and change fast with needs, and providing high quality service’, when bui lding smart power grid. There is a three step strategy with an advanced power grid distributing center built by 2010, the construction of digital power grid with primary intelligence completed by 2020, and a smart power grid with the ability of self-healing built by 2030 [8]. The construction plan is still under consideration.On Feb. 28, 2009, as a part of the smart power grid of East China Power Grid Company, the three-state security defense and power generation monitoring system passed the acceptance check in Beijing, which stands for stable-state,transient-state and dynamic-state. The system integrated three single systems altogether for the first time, which includes power management system, power grid dynamic wan monitor system and online stability analysis and warning system. The operator has full access to the whole view of the power grid operating situation andthe decision-making assistance without switching in systems or platforms. Besides, the system can effectively improve the management standardization and the level of flow of the related power plants through establishing the management checking platform and the assistance marketservice quality analyzing platform.The development of smart power grid research in China is slow and far behind the west. So far, only East China Power Grid Company and North China Power Grid Company have carried out researches about the developing and implementation plan. It is a tradition for China to emphasize technology development, and in fact, the equipments in China are more advanced than those in developed countries. Thus,smart power grid has a bright prospect in China.IV. PROSPECTS OF SMART GRID IN CHINAIn order to solve the problems of imbalance distribution for generation resources and power loads, the transmission capacity should be enhanced by building long-distance and large-capacity power transmission systems. And unity or united UHV power grids should be constructed under coordinated plan. The transmission of power on a large scale from west and north China to middle and east China can reduce the pressure of energy in the east China and the pressure of transmission and environmental protection.Furthermore, this can expedite the conversion from resource advantage to economy advantage and realize the coordinated development of nation economy. Chinese politics system,economic environment and management system also promotes UHV power grids in its development. At present, China is studying the future large power grids technology and has the ability to construct the national united power grids. On Jan, 16,2009, the first UHV power line in China was finished and put into operation.Unity or united UHV power grid, distributed power generating or scattered interactive power supplying grid are the trends of development. China, as the delegate in unity or united UHV power grid development trend, is different from any western countries. In China, is it in contradiction to develop both UHV power grid and Smart Grid? Though the large power grid with linkage effect has the advantage of optimizing the resources, it has the potential risk of power outage in large area. The ability to control the large power grid and maintain its stability is required by the fast development of power grid. And the smart power gird with self-healing and high reliability matches such requirements.Thus, smart power grid is the direction of China power grid development while building UHV power grid and the grid of different level, as well as improving the operating and management level of the grid.According to the precondition and the background of UHVpower grid development in current China, the aspects which should be paid more attention on are as follows:Smart Planning: The power grid should become selfhealing and smart. The ability of power grid planning optimization should be enhanced. So should be the ability of receive-side power grid planning, on the premise of the UHV AC/ DC feed-in and differentvoltage level coordinated development. The most important thing is to change the concepts and methods of power planning, and to make the traditional power development concept such like regarding building new power stations as a wide-ranging concept of resourcesdistribution.Smart Operation: The dispatching pattern is developing towards a coordinated control direction, aiming at the enhancement of control and mastering of large power grid. The future Smart Grid should be coordinated with a matching control center equipped with more advanced power system management ability, for the purpose of improving the functions and performanceof existing EMS, MOS, WAMMAP system in an integral manner, at the same time to track down the correlations between different power grid monitoring and controlling indexes,and to construct a logic structure based power system monitoring and controlling index system. Through thegradual process of implementation of dynamic security monitoring, power system pre-alarm processing and precontrol,much more accurate and comprehensive knowledge of the operation state of the power systemcan be obtained, based on which, the most effective and timely measures and actions can be taken to fulfill the power system control and dispatching strategy, finally to improve the safeguard of the whole power system’sstability and security.Smart Management: The management pattern of power system is undergoing an evolution from vertical mode to distributed mode, from function management to process management, from grid construction to both construction and operation modes.V. CONCLUSIONSmart Grid is a hot spot in today's electric power system,also regarded as one of the vanes in 21st century for the major scientific and technological innovation and development in power system. Many countries in the world are involved in this big trend, and have set up a lot of Smart Grid demonstration projects and test platforms. Also, the theoretical and experimental research in Smart Grid has made some achievements. The international exchanges have greatly promoted the development of Smart Grid. Because of China's electricity distribution and extremely uneven distribution of electricity load, it is the right time to develop special highvoltage power grid. As the development of Smart Grid is still at the very beginning stage of our country, how to combine the special high-voltage power grids with intelligent power grid is the main problem confronted. The direction to development and the characteristics of smart power grids in China are still open for our experts and scholars for further study.VI. REFERENCES[1] David G. Hart, " Using AMI to Realize the Smart Grid," in Proc. 2008IEEE Power and Energy Society General Meeting - Conversion andDelivery of Electrical Energy in the 21st Century, pp. 1-2.[2] S. Massoud Amin and B.F. Wollenberg, “Toward a Smart Grid: powerdeli very for the 21st century,” IEEE Power and Energy Magazine, Vol.3, No. 5 Sept.-Oct. 2005, pp. 34-41.[3] D. Divan and H. Johal, “A Smarter Grid for Improving SystemReliability and Asset Utilization,” Power Electronics and MotionControl Conference, August, 2006.[4] Tai, H. and Hogain, E.O., “Behind the buzz [In My View]," IEEE Trans.Power and Energy Magazine, vol. 7, pp. 96 - 92, Mar.-Apr. 2009.[5] Fujie Sun, Ming Lei and Chengbin Yang, “Establishing Smart PowerGrid and Innovating Management Methods– A New Thought of theDevelopment of Electric in China," IBM Corp, [Online]. Available:[6] Richard E. Brown, " Impact of Smart Grid on distribution systemdesign," in Proc. 2008 IEEE Power and Energy Society General Meeting- Conversion and Delivery of Electrical Energy in the 21st Century, pp.1-4.[7] European Commission, Directorate-General for Research, “Draft -Strategic Deployment Document for Europe’s Electricity Networks ofthe future”, 2008[8] Junqing Shuai, Aiming at the forefront and Establishing SmartGrid, State Grid, issue 2, pp.54-57, 2008.VII. BIOGRAPHIESJingjing Lu was born in Hunan, China in 1985. Shereceived her B.Sc. degree in electrical engineeringfrom Shanghai Jiao Tong University, Shanghai,China in 200 . Now she is a gradate student ofDepartment of Electrical Engineering, Shanghai Jiaoong University in Shanghai, China. She mainlyfocuses her research on power system simulation,FACTS and Smart Grid.Da Xie (M’03) was born in Heilongjiang, China in1969. He received his B.Sc. degree in electricalengineering from Shanghai Jiao Tong University,Shanghai, China in 1991, the M.Sc. degree inelectrical engineering from Harbin Institute ofTechnology, Harbin, China in 1996,and the Ph.D.degree in electrical engineering from Shanghai JiaoTong University, Shanghai, China in 1999. Now heis associate professor in Shanghai Jiao TongUniversity, EE department. He mainly focuses hisresearch on FACTS and power system simulation.Qian Ai (M’03) was born in Hubei, China in1969.He received the B.Sc. degree in electricalengineering from Shanghai Jiao Tong University,Shanghai, China, the M.Sc. degree in electricalengineering from Wuhan University, Wuhan, China,and the Ph.D. degree in electrical engineering fromTsinghua University, Beijing, China. He worked asa Research Fellow from 1999 to 2002 in NanyangTechnological University, Singapore, and theUniversity of Bath, Bath, U.K. He is currently anAssociate Professor at Shanghai Jiao Tong University. His interests includepower system modeling, power quality, FACTS and Micro grid.对中国智能电网的研究摘要 -智能电网是电力系统的未来发展的新方向。
电气专业毕业设计英文文献
电气专业毕业设计英文文献电气专业毕业设计英文文献外文资料与中文翻译外文资料:Relay protection present situation anddevelopment一、Relay protection development present situationElectrical power system's swift development to the relay protection proposed unceasingly the new request, the electronic technology, the computer technology and communication's swift development unceasingly has infused the new vigor for the relay protection technology's development, therefore, the relay protection technology is advantageous, has completed the development 4 historical stage in 40 remaining years of time.After the founding of the nation, our country relay protection discipline, the relay protection design, the relay factory industry and the relay protection technical team grows out of nothing, has passed through the path which in about 10 year the advanced countries half century pass through. In the 50s, our country engineers and technicians creatively absorption, the digestion, have grasped the overseas advanced relay protection equipment performance and the movement technology [1], completed one to have the deep relay protection theory attainments and the rich service experience's relay protection technical team, and grew the instruction function to the national relay protection technical team's establishment. The Achengrelay factory introduction has digested at that time the overseas advanced relay technique of manufacture, has established our country own relay manufacturing industry.Therefore our country has completed the relay protection research, the design, the manufacture, the movement and the teaching complete system in the 60s. This is the mechanical and electrical -like relay protection prosperous time, was our country relay protection technology development has laid the solid foundation.From the late 50s, the transistor relay protection was starting to study. In the 60s to the 80s in is the time which the transistor relay protection vigorous development and widely uses. And the Tianjin University and the Nanjing Electric power Automation Plant cooperation research's 500kv transistor direction high frequency protection develops with the Nanjing Electric power Automation Research institute the transistor high frequency block system is away from the protection, moves on the Gezhou Dam 500 kv lines [2], finished the 500kv line protection to depend upon completely from the overseas import time.From the 70s, started based on the integration operational amplifier's integrated circuit protection to study. Has formed the complete series to the late 80s integrated circuit protection, substitutes for the transistor protection gradually. The development which, the production, the application protected to the early 90s integrated circuit were still in the dominant position, this was theintegrated circuit protection time. The integrated circuit power frequency change quantity direction which develops in this aspect Nanjing Electric power Automation Research institute high frequency protected the influential role [3], the Tianjin University and the Nanjing Electric power Automation Plant cooperation development's integrated circuit phase voltage compensation type direction high frequency protection alsomoved in many 220kv and on the 500kv line.Our country namely started the computer relay protection research from the late 70s [4], the institutions of higher learning and the scientific research courtyard institute forerunner's function. Huazhong University of Science and Technology, the Southeast University, the North China electric power institute, Xi'an Jiaotong University, the Tianjin University, Shanghai Jiaotong University, the Chongqing University and the Nanjing Electric power Automation Research institute one after another has developed the different principle, the different pattern microcomputer protective device. in 1984 the original North China electric power institute developed the transmission line microcomputer protective device first through the appraisal, and obtained the application in the system [5], has opened in our country relay protection history the new page, protected the promotion for the microcomputer to pave the way. In the main equipment protection aspect, the generator which the Southeast University and Huazhong University of Science and Technology develops loses magnetism protection, the generator protection and the generator? Bank of transformers protectionalso one after another in 1989, in 1994 through appraisal, investment movement. The Nanjing Electric power Automation Research institute develops microcomputer line protective device alsoin 1991 through appraisal. Tianjin University and Nanjing Electric power Automation Plant cooperation development microcomputer phase voltage compensation type direction high frequency protection, Xi'an Jiaotong University and Xuchang relay factory cooperation development positive sequence breakdown component direction high frequencyprotection also one after another in 1993, in 1996 through appraisal. Hence, the different principle, the different type's microcomputer line and the main equipment protect unique, provided one group of new generation performance for the electrical power system to be fine, the function was complete, operation reliable relay protection installment. Along with the microcomputer protective device's research, in microcomputer aspects and so on protection software, algorithm has also made many theory progresses. May say that started our country relay protection technology from the 90s to enter the time which the microcomputer protected.二、future development of Relay protectionThe future trend of relay protection technology is to computerization, networking is intelligent, protect, control, measure and data communication developing by integration. The principles of protection of electric power circuits are quite independent of the relay designs which may be applied. For example, if the current to an electriccircuit or a machine is greater than that which can be tolerated, it is necessary to take remedial action. The device for recognizing the condition and initiating corrective measures would be termed as an over-current relay regardless of the mechanists by whichthe function would be accomplished. Because the functions of electromechanical devices are easily described, their performance wills ever as a basis for presenting a description of relays and relay systemsin general.Relays must have the following characteristics: Reliability---The nature of the problem is that the relay may be idle for periods extending into years and then be required tooperatewith fast responds, as intended, the first time. The penalty for failure to operate properly may run into millions of dollars.Selectivity---The relay must not respond to abnormal, but harmless, system conditions such as switching transients or sudden changes in load.Sensitivity---The relay must not fail to operate, even in borderline situations, when operation was planned.Speed---The relay should make the decision to act as close to instantaneously as possible. If intentional time delay is available, it should be predictable and precisely adjustable.Instantaneous---The term means no intentional time delay.There are several possible ways to classify relays: by function, by construction, by application. Relays are one of two basic types of construction: electromagnetic or solid-state. The electromagnetic type relies on the development of electromagnetic forces on movable members,which provide switching action by physically opening or closing sets of contacts. The solid state variety provides switching action with no physical motion by changing the state of serially connected solid state component from no conducting to conducting(or vice versa). Electromagnetic relays are older and more widely used; solid state relays are more versatile, potentially more reliable, and fast.1)ComputerizationWith swift and violent development of computer hardware, computer protect hardware develop constantly even. The power system is improving to the demand that the computer protects constantly, besides basic function protected, should with trouble information of the large capacity and data the long-term parkingspace also, fast data processing function, strong communication capacity, network in order to share the whole system data , information , ability , network of resource with other protection , control device , dispatcher, high-level language programming ,etc.. This requires computer protector to have function which is equivalent to a pc machine. In computer is it develop initial stage to protect, is it make with one minicom relay protection install to imagine. Because the small-scale organism was accumulated greatly, with high costs at that time, dependability was bad, this imagined it was unrealistic . Now, exceed the minicomputer of those years greatly with computer protector size similar worker function , speed , memory capacity of accusing of machine, so make with complete sets of worker person who accuse of opportunity of relay protection already ripe, this will be one of the developing direction that a computer is protected . Tianjin university is it spend whom transformation act as continue the electric protector with computer protector structure self-same one worker person whoaccuse of to develop into already. The advantage of this kind of device is as follows, (1)it have functions of 486pc,it can meet to at present and it is various kinds of function demand where computerprotect future. (2)The size and structure are similar to present computer protector , the craft is superior, takes precautions against earthquakes , defends overheatedly and defending the electromagnetic ability of interfering strongly, can operate it in very abominable working environment , the cost is acceptable.(3)Adopting std bus or pc bus, hardware module , can select different module for use to different protection wantonly , it is flexible , easy to expand to dispose.It is an irreversible development trend to continue the computer , computerization of the electric protector. But to how better meet power system demand, how about raise the dependability of relay protection further, how make heavy economic benefits and social benefit, need carry on concrete deep research.2) NetworkedComputer network become the technological pillar of information age as message and data communication tool, made the mankind producing , basic change has taken place in the appearance with social life. It isinfluencing each industrial field deeply, has offered the powerful communication means for each industrial field too. Up till now, except that protect differentially and unite protecting vertically, all continue electric protector can only react that protect the electric quantity of installing office. The function of relay protection is only limited to excising the trouble component too , narrow the accident coverage. This mainly lack the powerful data communication means. Having already put forward the concept protected systematically abroad, this meant the safe automatics mainly at that time. Because the function of relay protection is not only limited to excising the trouble component and restriction accident coverage (this is primary task), the peace and steadiness that will be guaranteed the whole system run . This require each protect unit can share the whole operation and data , trouble of information of system, each protect unit and coincident floodgate device coordination on the basis of analysing the information and data, guarantee systematic peace and steadiness run . Obviously , realize the primary condition that system protect the whole system every protector of capitalequipment link with the computer network, namely the one that realized the computer protector is networked. This is totally possible under present technological condition .To general protecting systematically , realize the computer networking of the protector has a very great advantage too. It continue electric trouble not the less many in information not systematic can receiving protector ,for trouble nature , judgement and the trouble,trouble of position from measuring the less accurate. Protect to self-adaptation research of principle pass long time very already , make certain achievement too, but should really realize protecting the self-adaptation to the operation way of the system and trouble state, must obtain more system operating and trouble information , the computer that only realizes protecting is networked, could accomplish this . As to the thing that some protectors realize computer networking , can improve the dependability protected . Tianjin Sanxia vltrahigh voltage many return circuit bus bar , 500kv of power station , put forward one distributed principle that bus bar protected to future 1993 such as university, succeed in developing this kind of device tentatively. Principle its bus bar is it disperse several (with protect into bus bar back to way the same ) bus bar protect Entrance to protect traditional concentration type, disperse and install it in every return circuit is protected and rejected , each protect the unit to link with the computer network, each one protects the electric current amount that the unit only inputs a return circuit , after changing it into figure amount, convey to the protection units of other return circuits through the computer network, each protect the unit according to the electric current amount of this return circuit and electric current amount of other return circuits gotfrom computer network, carry on bus bar differential calculation that protect, if result of calculation prove bus bar trouble jump format return circuit circuit breaker only, isolate the bus bar of the trouble. At the time of the trouble outside the bus bar district , each protect the unit and calculate for movements of the external trouble. This kind protect principle by distributed bus barthat network realize with computer, bus bar protect principle have higher dependability than traditional concentration type. Because if one protect unit interfere or mistake in computation and when working up by mistake, can only jump format return circuit , can is it make bus bar to be whole of malignant accident that excise to cause wrong, this is very important to systematic pivot with supervoltage bus bar of hydropower station like SanxiaCan know computer protector networked to can raise and protect the performance and dependability greatly while being above-mentioned, this is an inexorable trend that a computer protects development 3) Protect , control , measure , data communication integratesOn terms that realize computerization of relay protection and networked, the protector is a high performance , multi-functional computer in fact, it is a intelligent terminal on the computer network of whole power system. It can obtain any information and data of operating and trouble of the power system from network , can convey network control centre or any terminal function , and can also finish the measurement , control , data communication function in there is no normal running of trouble cases, namely realize protecting ,controlling , measuring , data communication integrates.At present, for measurement, need that protects and controlling, all equipment of the outdoor transformer substation, two voltage, electric current of voltage transformer, circuit,etc. must with control cable guide to the top management room for instance. Lay control cable take a large amount of investment, make the very much complicated returncircuit 2 times in a large amount. But if above-mentioned protection, control, measure, data communication integrated computer device, install in to is it by the equipment , protect into voltage , electric current amount of equipment in device this after changing into the figure amount to protect outdoor transformer substation on the spot, send to the top management room through the computer network, can avoid a large number of controlcables . If use optic fibre as the transmission medium of the network , can avoid and interfere electromagnetically. The photocurrent mutual inductor of now (ota ) and photovoltage mutual inductor (otv ) have been already during the course of studying and testing, must get application in the power system in the future. In case of adopting ota and otv, namely should be putting and is being protected near the equipment.After the optical signals of ota and otv are input in the integrated device here and changes into an electric signal, what is on one hand uses as being protected calculation is judged ; As measurement amount on the other hand, send to the top management room through the network. Can to protect operation of equipment control order send this integrated device to through network from top management room, therefore the integrated device carries out the operation of the circuit breaker. The university of Tianjin put forward protecting,controlled , measured , communication integration in 1992, develop based on tms320c25 digital signal processor (dsp ) first protecting , control , measure , the integrated device of data communication.4)IntelligentIn recent years, if artificial intelligence technology neural network, hereditary algorithm, evolve plan , fuzzy logic ,etc. get application in power system all field, the research that is used in the field of relay protection has already begun too. Neural network one non-linear method that shine upon, a lot of difficult to list equation or difficult in order to the complicated non-linear question that is solved, use the method of the neural network to be very easily solved .For example the short circuit of crossing the resistance of courseof emergence is a non-linear problem in transmit electricity in the systematic electric potential angle of both sides of line and lay cases, it is very difficult to make discrimination , trouble of position while being correct for distance to protect, is it work up or is it work up to refuse by mistake to lead to the fact; If use neural network method, through a large number of trouble training of sample, so long as sample centralized to fully consider various kinds of situations, can differentiate correctly while any trouble takes place. Other if hereditary algorithm , is it is it have is it solve complicated abilityof problem to asking unique their too to plan to evolve. Artificial intelligence the being method proper to is it can make it solve speed to be fast not to ask to combine. Can predict , the artificial intelligence technology must get application in the field of relay protection, in order to solve the problem difficult to solvewith the routine method.中文翻译:继电保护的现状与发展一、继电保护发展现状电力系统的飞速发展对继电保护不断提出新的要求，电子技术、计算机技术与通信技术的飞速发展又为继电保护技术的发展不断地注入了新的活力，因此，继电保护技术得天独厚，在40余年的时间里完成了发展的4个历史阶段。
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智能电网智能电网就是电网的智能化（智电电力），也被称为“电网2.0”，它是建立在集成的、高速双向通信网络的基础上，通过先进的传感和测量技术、先进的设备技术、先进的控制方法以及先进的决策支持系统技术的应用，实现电网的可靠、安全、经济、高效、环境友好和使用安全的目标，其主要特征包括自愈、激励和包括用户、抵御攻击、提供满足21世纪用户需求的电能质量、容许各种不同发电形式的接入、启动电力市场以及资产的优化高效运行。
美国能源部《Grid 2030》：一个完全自动化的电力传输网络，能够监视和控制每个用户和电网节点，保证从电厂到终端用户整个输配电过程中所有节点之间的信息和电能的双向流动。
中国物联网校企联盟：智能电网由很多部分组成，可分为：智能变电站，智能配电网，智能电能表，智能交互终端，智能调度，智能家电，智能用电楼宇，智能城市用电网，智能发电系统，新型储能系统。
现在对其中的一部分做简单介绍。
欧洲技术论坛：一个可整合所有连接到电网用户所有行为的电力传输网络，以有效提供持续、经济和安全的电力。
中国科学院电工研究所：智能电网是以包括各种发电设备、输配电网络、用电设备和储能设备的物理电网为基础，将现代先进的传感测量技术、网络技术、通讯技术、计算技术、自动化与智能控制技术等与物理电网高度集成而形成的新型电网，它能够实现可观测（能够监测电网所有设备的状态）、可控制（能够控制电网所有设备的状态）、完全自动化（可自适应并实现自愈）和系统综合优化平衡（发电、输配电和用电之间的优化平衡），从而使电力系统更加清洁、高效、安全、可靠。
美国电力科学研究院：IntelliGrid是一个由众多自动化的输电和配电系统构成的电力系统，以协调、有效和可靠的方式实现所有的电网运作：具有自愈功能；快速响应电力市场和企业业务需求；具有智能化的通信架构，实现实时、安全和灵活的信息流，为用户提供可靠、经济的电力服务。
国家电网中国电力科学研究院：以物理电网为基础(中国的智能电网是以特高压电网为骨干网架、各电压等级电网协调发展的坚强电网为基础)，将现代先进的传感测量技术、通讯技术、信息技术、计算机技术和控制技术与物理电网高度集成而形成的新型电网。
它以充分满足用户对电力的需求和优化资源配置、确保电力供应的安全性、可靠性和经济性、满足环保约束、保证电能质量、适应电力市场化发展等为目的，实现对用户可靠、经济、清洁、互动的电力供应和增值服务。
背景坚强智能电网的发展在全世界还处于起步阶段，没有一个共同的精确定义，其技术大致可分为四个领域：高级量测体系、高级配电运行、高级输电运行和高级资产管理。
高级量测体系主要作用是授权给用户，使系统同负荷建立起联系，使用户能够支持电网的运行；高级配电运行核心是在线实时决策指挥，目标是灾变防治，实现大面积连锁故障的预防；高级输电运行主要作用是强调阻塞管理和降低大规模停运的风险；高级资产管理是在系统中安装大量可以提供系统参数和设备（资产）“健康”状况的高级传感器，并把所收集到的实时信息与资源管理、模拟与仿真等过程集成，改进电网的运行和效率。
智能电网是物联网的重要应用，《计算机学报》刊登的《智能电网信息系统体系结构研究》一文对此进行了详细论述，并分析了智能电网信息系统的体系结构。
市场份额智能电网的建立是一个巨大的历史性工程。
目前很多复杂的智能电网项目正在进行中，但缺口仍是巨大的。
对于智能电网技术的提供者来说，所面临的推动发展的挑战是配电网络系统升级、配电站自动化和电力运输、智能电网网络和智能仪表。
根据派克调查机构的最新报告，智能电网技术市场将从2012年的330亿美元增长到2020年的730亿美元，8年间，市场累积达到4940亿美元。
《中国智能电网行业市场前瞻与投资战略规划分析前瞻》中指出，我国在“十二五”期间将建成“三纵三横一环网”的特高压交流线，并建设11回特高压直流输电工程，投资高达3000亿元;“十三五”期间投资虽略有放缓，投资额度也达到2500亿元。
到2015年，国家电网大范围、远距离的输电能力将达到2.5亿千瓦，每年输送电量1.15万亿千瓦时，可支撑新增1.45亿千瓦的清洁能源发电消纳和送出，能够满足超过100万辆电动汽车的使用要求，电网的资源优化配置能力、经济运行效率、安全水平和智能化水平将得到全面提升。
国外应用情况分析在电网发展基础方面，各国电力需求趋于饱和，电网经过多年的快速发展，架构趋于稳定、成熟，具备较为充裕的输配电供应能力。
德国制定了“E—Energy”计划，总投资1亿4千万欧元，2009年至2012年4年时间内，在全国6个地点进行智能电网实证实验。
同时还进行风力发电和电动汽车实证实验，并对互联网管理电力消费进行检测。
德国西门子、SAP及瑞士ABB等大企业均参与了这一计划。
预计西门子公司2014年智能电网年度市场规模将达300亿欧元，并计划抢占20%市场份额，每年确保60亿欧元订单。
先进性与现有电网相比，智能电网体现出电力流、信息流和业务流高度融合的显著特点，其先进性和优势主要表现在：（1）具有坚强的电网基础体系和技术支撑体系，能够抵御各类外部干扰和攻击，能够适应大规模清洁能源和可再生能源的接入，电网的坚强性得到巩固和提升。
（2）信息技术、传感器技术、自动控制技术与电网基础设施有机融合，可获取电网的全景信息，及时发现、预见可能发生的故障。
故障发生时，电网可以快速隔离故障，实现自我恢复，从而避免大面积停电的发生。
（3）柔性交/直流输电、网厂协调、智能调度、电力储能、配电自动化等技术的广泛应用，使电网运行控制更加灵活、经济，并能适应大量分布式电源、微电网及电动汽车充放电设施的接入。
（4）通信、信息和现代管理技术的综合运用，将大大提高电力设备使用效率，降低电能损耗，使电网运行更加经济和高效。
（5）实现实时和非实时信息的高度集成、共享与利用，为运行管理展示全面、完整和精细的电网运营状态图，同时能够提供相应的辅助决策支持、控制实施方案和应对预案。
（6）建立双向互动的服务模式，用户可以实时了解供电能力、电能质量、电价状况和停电信息，合理安排电器使用；电力企业可以获取用户的详细用电信息，为其提供更多的增值服务。
发展性趋势“十二五”期间，国家电网将投资5000亿元，建成连接大型能源基地与主要负荷中心的“三横三纵”的特高压骨干网架和13回长距离支流输电工程，初步建成核心的世界一流的坚强智能电网。
国家电网制定的《坚强智能电网技术标准体系规划》，明确了坚强智能电网技术标准路线图，是世界上首个用于引导智能电网技术发展的纲领性标准。
国网公司的规划是，到2015年基本建成具有信息化、自动化、互动化特征的坚强智能电网，形成以华北、华中、华东为受端，以西北、东北电网为送端的三大同步电网，使电网的资源配置能力、经济运行效率、安全水平、科技水平和智能化水平得到全面提升。
（1）智能电网是电网技术发展的必然趋势。
通讯、计算机、自动化等技术在电网中得到广泛深入的应用，并与传统电力技术有机融合，极大地提升了电网的智能化水平。
传感器技术与信息技术在电网中的应用，为系统状态分析和辅助决策提供了技术支持，使电网自愈成为可能。
调度技术、自动化技术和柔性输电技术的成熟发展，为可再生能源和分布式电源的开发利用提供了基本保障。
通信网络的完善和用户信息采集技术的推广应用，促进了电网与用户的双向互动。
随着各种新技术的进一步发展、应用并与物理电网高度集成，智能电网应运而生。
（2）发展智能电网是社会经济发展的必然选择。
为实现清洁能源的开发、输送和消纳，电网必须提高其灵活性和兼容性。
为抵御日益频繁的自然灾害和外界干扰，电网必须依靠智能化手段不断提高其安全防御能力和自愈能力。
为降低运营成本，促进节能减排，电网运行必须更为经济高效，同时须对用电设备进行智能控制，尽可能减少用电消耗。
分布式发电、储能技术和电动汽车的快速发展，改变了传统的供用电模式，促使电力流、信息流、业务流不断融合，以满足日益多样化的用户需求。
计划日本计划在2030年全部普及智能电网，同时官民一体全力推动在海外建设智能电网。
在蓄电池领域，日本企业的全球市场占有率目标是力争达到50%，获得约10万亿日元的市场。
日本经济产业省已经成立“关于下一代能源系统国际标准化研究会”，日美已确立在冲绳和夏威夷进行智能电网共同实验的项目[6]。
在中电联获悉，2020年中国将建成以华北、华东、华中特高压同步电网为中心，东北特高压电网、西北750千伏电网为送端，联结各大煤电基地、大水电基地、大核电基地、大可再生能源基地，各级电网协调发展的坚强智能电网。
华北、华东、华中特高压同步电网形成“五纵六横”主网架。
方向在绿色节能意识的驱动下，智能电网成为世界各国竞相发展的一个重点领域。
智能电网是电力网络，是一个自我修复，让消费者积极参与，能及时从袭击和自然灾害复原，容纳所有发电和能量储存，能接纳新产品，服务和市场，优化资产利用和经营效率，为数字经济提供电源质量。
智能电网建立在集成的、高速双向通信网络基础之上，旨在利用先进传感和测量技术、先进设备技术、先进控制方法，以及先进决策支持系统技术，实现电网可靠、安全、经济、高效、环境友好和使用安全的高效运行。
它的发展是一个渐进的逐步演变,是一场彻底的变革,是现有技术和新技术协同发展的产物，除了网络和智能电表外还饱含了更广泛的范围。
建设以特高压电网为骨干网架，各级电网协调发展，以信息化、自动化、互动化为特征的坚强智能电网，全面提高电网的安全性、经济性、适应性和互动性，坚强是基础, 智能是关键。
意义其重要意义体现在以下几个方面：（1）具备强大的资源优化配置能力。
我国智能电网建成后，将实现大水电、大煤电、大核电、大规模可再生能源的跨区域、远距离、大容量、低损耗、高效率输送，区域间电力交换能力明显提升。
（2）具备更高的安全稳定运行水平。
电网的安全稳定性和供电可靠性将大幅提升，电网各级防线之间紧密协调，具备抵御突发性事件和严重故障的能力，能够有效避免大范围连锁故障的发生，显著提高供电可靠性，减少停电损失。
（3）适应并促进清洁能源发展。
电网将具备风电机组功率预测和动态建模、低电压穿越和有功无功控制以及常规机组快速调节等控制机制，结合大容量储能技术的推广应用，对清洁能源并网的运行控制能力将显著提升，使清洁能源成为更加经济、高效、可靠的能源供给方式。
（4）实现高度智能化的电网调度。
全面建成横向集成、纵向贯通的智能电网调度技术支持系统，实现电网在线智能分析、预警和决策，以及各类新型发输电技术设备的高效调控和交直流混合电网的精益化控制。
（5）满足电动汽车等新型电力用户的服务要求。
将形成完善的电动汽车充放电配套基础设施网，满足电动汽车行业的发展需要，适应用户需求，实现电动汽车与电网的高效互动。