电力系统继电保护外文翻译
电力系统继电保护技术中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：Relay protection development present situationAbstract: Reviewed our country electrical power system relay protection technological development process, has outlined the microcomputer relay protection technology achievement, propose the future relay protection technological development tendency will be: Computerizes, networked, protects, the control, the survey, the data communication integration and the artificial intellectualization.Key word: relay protection, present situation development, future development1 relay protection development present situation- 1 -The electrical power system rapid development to the relay protection propose unceasingly the new request, the electronic technology, computer technology and the communication rapid development unceasingly has poured into the new vigor for the relay protection technology development, therefore, the relay protection technology is advantageous, has completed the development 4 historical stage in more than 40 years time.After the founding of the nation, our country relay protection discipline, the relay protection design, the relay manufacture industry and the relay protection technical team grows out of nothing, has passed through the path in about 10 years which advanced countries half century passes through. The 50's, our country engineers and technicians creatively absorption, the digestion, have grasped the overseas advanced relay protection equipment performance and the movement technology , completed to have the deep relay protection theory attainments and the rich movement experience relay protection technical team, and grew the instruction function to the national relay protection technical team's establishment. The relay factory introduction has digested at that time the overseas advanced relay manufacture technology, has established our country relay manufacturing industry. Thus our country has completed the relay protection research, the design, the manufacture, the movement and the teaching complete system in the 60's. This is a time which the mechanical and electrical relay protection prospers, was our countries relay protection technology development has laid the solid foundation.From the end of the 50's, the transistor relay protection was starting to study. In the 60's to the 80's，it is the times which the transistor relay protection vigorous development and widely used. Tianjin University and the Nanjing electric power automation plant cooperation research 500kV transistor direction high frequency protection the transistor high frequency block system which develops with the Nanjing electric power automation research institute is away from the protection, moves on the Gezhou Dam 500kV line , finished the 500kV line protection to depend upon completely from the overseas import time.- 2 -From the 70's, start based on the integration operational amplifier integrated circuit protection to study. Has formed the completely series to at the end of 80's integrated circuit protection, substitutes for the transistor protection gradually. The development, the production, the application the integrated circuit protects which to the beginning of the 90's still were in the dominant position, this was the integrated circuit protection time. The integrated electricity road work frequency conversion quantity direction develops which in this aspect Nanjing electric power automation research institute high frequency protected the vital role, the Tianjin University and the Nanjing electric power automation plant cooperation development integrated circuit phase voltage compensated the type direction high frequency protection also moves in multi- strip 220kV and on the 500kV line.Our country namely started the computer relay protection research from the end of the 70's, the institutions of higher learning and the scientific research courtyard institute forerunner's function. Huazhong University of Science and Technology, southeast the university, the North China electric power institute, the Xian Jiao tong University, the Tianjin University, Shanghai Jiao tong University, the Chongqing University and the Nanjing electric power automation research institute one after another has all 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 evaluation and in the system the find application, had opened in our country relay protection history the new page, protect the promotion for the microcomputer to pave the way. In the host equipment protection aspect, the generator which southeast the university and Huazhong University of Science and Technology develop loses magnetism protection, the generator protection and the generator? Bank of transformers protection also one after another in 1989、1994 through appraisal and investment movement. The Nanjing electric power automation research institute develops microcomputer line protective device also in 1991 through appraisal. The Tianjin University and the Nanjing electric power automation plant cooperation development- 3 -microcomputer phase voltage compensated the type direction high frequency protection, the Xian Jiao tong University and the Xuchang Relay Factory cooperation development positive sequence breakdown component direction high frequency protection also one after another in 1993, in 1996 through the appraisal. Here, the different principle, the different type microcomputer line and the host equipment protect unique, provided one batch of new generation of performance for the electrical power system fine, the function has been complete, the work reliable relay protection installment. Along with the microcomputer protective device research, in microcomputer aspect and so on protection software, algorithm has also yielded the very many theories result. May say started our country relay protection technology from the 90's to enter the time which the microcomputer protected.2 relay protections future developmentThe relay protection technology future the tendency will be to computerizes, networked, the intellectualization, will protect, the control, the survey and the data communication integration development.2.1 computerizesAlong with the computer hardware swift and violent development, the microcomputer protection hardware also unceasingly is developing. The original North China electric power institute develops the microcomputer line protection hardware has experienced 3 development phases: Is published from 8 lists CPU structure microcomputer protection, does not develop to 5 years time to the multi- CPU structure, latter developed to the main line does not leave the module the big modular structure, the performance enhances greatly, obtained the widespread application. Huazhong University of Science and Technology develops the microcomputer protection also is from 8 CPU, develops to take the labor controlling machine core partially as the foundation 32 microcomputers protection.The Nanjing electric power automation research institute from the very beginning has developed 16 CPU is the foundation microcomputer line protection,- 4 -obtained the big area promotion, at present also is studying 32 protections hardware system. Southeast the university develops the microcomputer host equipment protects the hardware also passed through improved and the enhancement many times. The Tianjin University from the very beginning is the development take more than 16 CPU as the foundation microcomputer line protection, in 1988 namely started to study take 32 digital signals processor (DSP) as the foundation protection, the control, the survey integration microcomputer installment, at present cooperated with the Zhuhai automatic equipment company develops one kind of function complete 32 big modules, a module was a minicomputer. Uses 32 microcomputers chips only to focus by no means on the precision, because of the precision the a/d switch resolution limit, is surpassed time 16 all is accepts with difficulty in the conversion rate and the cost aspect; 32 microcomputers chips have the very high integration rate more importantly, very high operating frequency and computation speed, very big addressing space, rich command system and many inputs outlet. The CPU register, the data bus, the address bus all are 32, has the memory management function, the memory protection function and the duty transformation function, and (cache) and the floating number part all integrates the high speed buffer in CPU.The electrical power system the request which protects to the microcomputer enhances unceasingly, besides protection basic function, but also should have the large capacity breakdown information and the data long-term storage space, the fast data processing function, the formidable traffic capacity, with other protections, the control device and dispatches the networking by to share the entire system data, the information and the network resources ability, the higher order language programming and so on. This requests the microcomputer protective device to have is equal to a pc machine function. In the computer protection development initial period, once conceived has made the relay protection installment with a minicomputer. At that time because the small machine volume big, the cost high, the reliability was bad, this tentative plan was not realistic. Now, with the microcomputer protective device size similar labor controlling machine function, the speed, the storage capacity greatly- 5 -has surpassed the same year small machine, therefore, made the relay protection with complete set labor controlling machine the opportunity already to be mature, this will be one of development directions which the microcomputer protected. The Tianjin University has developed the relay protection installment which Cheng Yong tong microcomputer protective device structure quite same not less than one kind of labor controlling machine performs to change artificially becomes. This kind of equipment merit includes: has the 486pc machine complete function, can satisfy each kind of function request which will protect to current and the future microcomputer. size and structure and present microcomputer protective device similar, the craft excellent, quakeproof, guards against has been hot, guards against electromagnetic interference ability, may move in the very severe working conditions, the cost may accept. Uses the STD main line or the pc main line, the hardware modulation, may select the different module willfully regarding the different protection, the disposition nimble, and is easy to expand.Relay protection installment, computerizes is the irreversible development tendency. How but to satisfies the electrical power system request well, how further enhances the relay protection the reliability, how obtains the bigger economic efficiency and the social efficiency, still must conduct specifically the thorough research.2.2 networkedThe computer network has become the information age as the information and the data communication tool the technical prop, caused the human production and the social life appearance has had the radical change. It profoundly is affecting each industry domain, also has provided the powerful means of communication for each industry domain. So far, besides the differential motion protection and the vertical association protection, all relay protections installment all only can respond the protection installment place electricity spirit. The relay protection function also only is restricted in the excision breakdown part, reduces the accident to affect the scope. This mainly is because lacks the powerful data communication method. Overseas- 6 -already had proposed the system protection concept, this in mainly referred to the safe automatic device at that time. Because the relay protection function not only is restricted in the excision breakdown part and the limit accident affects the scope (this is most important task), but also must guarantee the entire system the security stable movement. This requests each protection unit all to be able to share the entire system the movement and the breakdown information data, each protection unit and the superposition brake gear in analyze this information and in the data foundation the synchronized action, guarantees the system the security stable movement. Obviously, realizes this kind of system protection basic condition is joins the entire system each main equipment protective device with the computer network, that is realization microcomputer protective device networked. This under the current engineering factor is completely possible.Regarding the general non- system protection, the realization protective device computer networking also has the very big advantage. The relay protection equipment can obtain system failure information more, then to the breakdown nature, the breakdown position judgment and the breakdown distance examination is more accurate. Passed through the very long time to the auto-adapted protection principle research, also has yielded the certain result, but must realize truly protects to the system movement way and the malfunction auto-adapted, must obtain the more systems movement and the breakdown information, only then realization protection computer networked, can achieve this point.Regarding certain protective device realization computer networking also can enhance the protection the reliability. The Tianjin University in 1993 proposed in view of the future Three Gorges hydroelectric power station 500kv ultrahigh voltage multi-return routes generatrix one kind of distributional generatrix protection principle, developed successfully this kind of equipment initially. Its principle is disperses the traditional central generatrix protection certain (with to protect generatrix to return way to be same) the generatrix protection unit, the dispersible attire is located in on various return routes protection screen, each protection unit- 7 -joins with the computer network, each protection unit only inputs this return route the amperage, after transforms it the digital quantity, transmits through the computer network for other all return routes protection unit, each protection unit acts according to this return route the amperage and other all return routes amperage which obtains from the computer network, carries on the generatrix differential motion protection the computation, if the computed result proof is the generatrix interior breakdown then only jumps the book size return route circuit breaker, Breakdown generatrix isolation. When generatrix area breakdown, each protection unit all calculates for exterior breakdown does not act. This kind the distributional generatrix protection principle which realizes with the computer network has the high reliability compared to the traditional central generatrix protection principle. Because if a protection unit receives the disturbance or the miscalculation when moves by mistake, only can wrongly jump the book size return route, cannot create causes the generatrix entire the malignant accident which excises, this regarding looks like the Three Gorges power plant to have the ultrahigh voltage generatrix the system key position to be extremely important.By above may know, microcomputer protective device may enhance the protection performance and the reliability greatly, this is the microcomputer protection development inevitable trend.2.3 protections, control, survey, data communication integrationsIn realization relay protection computerizing with under the condition, the protective device is in fact a high performance, the multi-purpose computer, is in an entire electrical power system computer network intelligent terminal. It may gain the electrical power system movement and breakdown any information and the data from the net, also may protect the part which obtains it any information and the data transfer for the network control center or no matter what a terminal. Therefore, each microcomputer protective device not only may complete the relay protection function, moreover in does not have in the breakdown normal operation situation also to be- 8 -possible to complete the survey, the control, the data communication function that is realization protection, control, survey, data communication integration.At present, in order to survey, the protection and the control need, outdoor transformer substation all equipment, like the transformer, the line and so on the secondary voltage, the electric current all must use the control cable to direct to . Lays the massive control cable not only must massively invest, moreover makes the secondary circuit to be extremely complex. But if the above protection, the control, the survey, the data communication integration computer installation, will install in outdoor transformer substation by the protection device nearby, by the protection device voltage, the amperage is changed into after this installment internal circulation the digital quantity, will deliver through the computer network, then might avoid the massive control cable. If takes the network with the optical fiber the transmission medium, but also may avoid the electromagnetic interference. Now the optical current transformer (OTA) and the optical voltage transformer (OTV) in the research trial stage, future inevitably obtained the application in the electrical power system. In uses OTA and in the OTV situation, the protective device should place is apart from OTA and the OTV recent place, that is should place by the protection device nearby. OTA and the OTV light signal inputs after this integration installment in and transforms the electrical signal, on the one hand serves as the protection the computation judgment; On the other hand took the survey quantity, delivers through the network. May to deliver from through the network by the protection device operation control command this integrated installment, carries out the circuit breaker operation from this the integrated installment. In 1992 the Tianjin University proposed the protection, the control, the survey, the correspondence integration question, and has developed take the tms320c25 digital signal processor (DSP) as a foundation protection, the control, the survey, the data communication integration installment.2.4 intellectualizations- 9 -In recent years, the artificial intelligence technology like nerve network, the genetic algorithms, the evolution plan, the fuzzy logic and so on all obtained the application in electrical power system each domain, also started in the relay protection domain application research. The nerve network is one non-linear mapping method, very many lists the complex non-linear problem with difficulty which the equation or solves with difficulty, the application nerve network side principle may be easily solved. For example exhibits in the situation in the transmission line two sides systems electric potential angle to occur after the transition resistance short-circuits is a non-linear problem, very difficult correctly to make the breakdown position from the protection the distinction, thus creates moves by mistake or resists to move; If thinks after the network method, passes through the massive breakdowns sample training, so long as the sample centralism has fully considered each kind of situation, then in breaks down time any all may correctly distinguish. Other likes genetic algorithms, the evolution plan and so on also all has its unique solution complex question the ability. May cause the solution speed these artificial intelligence method suitable unions to be quicker? The Tianjin University carries on the nerve network type relay protection from 1996 the research, has yielded the preliminary result. May foresee, the artificial intelligence technology must be able to obtain the application in the relay protection domain, by solves the problem which solves with difficulty with the conventional method.3 conclusionsSince the founding of China's electric power system protection technology has undergone four times. With the rapid development of power systems and computer technology, communications technology, relay technology faces the further development of the trend. Domestic and international trends in the development of protection technologies: computerization, networking, protection, control, measurement, data communications integration and artificial intelligence, which made protection workers difficult task, but also opened up the activities of vast.- 10 -继电保护发展现状摘要：回顾我国电力系统继电保护技术的发展过程，概述了微机继电保护技术成果，提出了未来继电保护技术的发展趋势将是：计算机化，网络化，保护，控制，调查，数据通信一体化和人工智能化。
Protection relay(继电保护) 外文翻译资料
Protection relayProtective relayingProtective relaying is that area of power system design concerned with minimizing service interruption and limiting damage to equipment when failures occur. The function of protective relaying is to cause the prompt removal of a defective element from a power system. The defective element may have a short circuit or it may be operating in an abnormal manner. Protective relaying systems are designed to detect such failures or abnormal conditions quickly and to open a minimum of circuit breakers to isolate the defective element. The effect of quick isolation is threefold: (1) it minimizes or prevents damage to the defective element, thus reducing the time and expense of repairs and permitting quicker restoration of the element to service; (2) it minimizes the seriousness and duration of the defective elements affecting on the normal operation of the power system; and (3) it maximizes the power that can be transferred on power systems. The second and third points are of particular significance because they indicate the important role protective relaying plays in assuring maximum service reliability and in system design. The power that can be transmitted across system without the loss of synchronism is the function of fault clearing times. It is apparent that fast fault clearing times permit a higher power transfer than longer clearing times. High-speed clearing of faults can often provide a means for achieving higher power transfers and thereby defer investment in additional transmission facilities.A protective relaying system is based on detecting fault conditions by continuously monitoring the power system variables such as current, voltage, power, frequency, and impedance. Measuring of currents and voltage is performed by instrument transformers of the potential type (PT) or current type (CT). Instrument transformers feed the measured variables to the relay system, which in turn, upon detecting a fault, commands circuit breaker (CB) to disconnect the faulted section of the system.An electric power system is divided into several protective zones for generators, transformers, buses, transmission and distribution circuit, and motors. The division is such that zones are given adequate protection while keeping service interruption to a minimum. It is to be noted that each zone is overlapped to avoid unprotect (blind) areas. The connections of current transformers achieve the overlapping. The general philosophy ofrelay application is to divide the power system into zones that can be adequately protected by suitable protective equipment and can be disconnected from the power system in a minimum amount of time and with the least effect on the remainder of the power system. The protective relaying provided for each zone is divided into two categories: (1) primary relaying and (2) backup relaying. Primary relaying is the first line of defense when failures occur, and is connected to trip only the faulted element from the system. If a failure occurs in any primary zone the protective relays will operate to trip all of the breakers within that zone. If a breaker is omitted between two adjacent elements, both elements will be disconnected for a failure in either one. This latter arrangement is illustrated by the unit generator-transformer connection in the power plant. On bulk power generating and transmission systems, primary protection is designed to operate at high speed for all faults. Slower protection may be used in less important system areas but, in general, any system area will benefit by the fastest possible primary relaying.If the fault is not cleared by the primary protection, backup relaying operates to clear the fault from the system. In general, backup relaying disconnects a greater portion of the system to isolate the fault. Backup protection is provided for possible failure in the primary relaying system and for possible circuit breaker failures. Any backup scheme must provide both relay backup as well as breaker backup. Ideally, the backup protection should be arranged so that anything that may cause the primary protection to fail will not also cause failure of the backup protection. Moreover, the backup protection must not operate until the primary protection has been given an opportunity to function. As a result, there is time delay associated with any backup operation. When a short circuit occurs, both the primary and the backup protection start to operate. If the primary protection clears the fault, the backup protection will reset without completing its function. If the fault is not cleared by the primary protection, the backup relaying will time out and trip the necessary breakers to clear the fault from the system.There are two forms of backup protection in common use on power systems. They are remote backup and local backup.(1)Remote backup. In remote backup relaying, faults are cleared from the system onestation away from where the failure has occurred.(2)Local backup. In local backup relaying, faults are cleared locally in the samestation where the failure has occurred. For faults on the protected line, both the primary and the backup relays will operate to prepare tripping the line breaker. Relay backup may be just as fast as the front line relays. When either of these relays operates to initiate tripping of the line breaker, it also energizes a timer to start the breaker backup function. If the breaker fails to clear the fault, the line relays will remain picked up, permitting the timer to time out and trip the necessary other breakers on the associated bus section.Computer relayingThe electric power industry has been one of the earliest users of the digital computer as a fundamental aid in the various design and analysis aspects of its activity. Computer-based systems have evolved to perform such complex tasks as generation control, economic dispatch (treated in chapter 11)and load-flow analysis for planning and operation , to name just a few application areas. research efforts directed at the prospect using digital computers to perform the tasks involved in power system protection date back to the mien-sixties and were motivated by the emergence of process-control computers a great deal of research is going on in this field, which is now referred to as computer relaying. Up to the early 1980s there had been no commercially availability protection systems offering digital computer-based relays.However, the availability of microprocessor technology has provided an impetus to computer relaying.*Microprocessors used as a replace*and solid state relays non provide a number of advantages while meeting the basic protection philosophy requirement of decentralization.There are many perceived benefits of a digital relaying system:1.Economics: with the steady decrease in cost of digital hardware, coupled with theincrease in cost of conventional relaying. It seems reasonable to assume that computer relaying is an attractive alternative. Software development cost can be expected to be evened out by utilizing economies of scale in producing microprocessors dedicated to basic relaying tasks.2.Reliability: a digital system is continuously active providing a high level of aself-diagnosis to detect accidental failures within the digital relaying system.3.Flexibility: revisions or modifications made necessary by changing operationalconditions can be accommodated by utilizing the programmability features of a digitalsystem. This would lead to reduced inventories of parts for repair and maintenance purposes4.System interaction: the availability of digital hardware that monitors continuously thesystem performance at remote substations can enhance the level of information available to the control center. Post fault analysis of transient data can be performed on the basis of system variables monitored by the digital relay and recorded by the peripherals.The main elements of a digital computer-based relay are indicated in Figure 9-59. The input signals to the relay are analog (continuous) and digital power system variables. The digital inputs are of the order of five to ten and include status changes (on-off) of contacts and changes in voltage levels in a circuit. The analog signals are the 60-Hz currents and voltages. The number of analog signals needed depends on the relay function but is in the range of 3 to 30 in all cases. The analog signals are scaled down (attenuated) to acceptable computer input levels ( 10 volts maximum) and then converted to digital (discrete) form through analog/digital converters (ADC). These functions are performed in the block labeled “Analog Input Subsystem.”The digital output of the relay is available through the computer’s parallel output port, five-to-ten digital outputs are sufficient for most applications.The analog signals are sampled at a rate between 210 Hz to about 2000 Hz. The sampled signals are entered into the scratch pad (RAM) and are stored in a secondary data file for historical recording. A digital filter removes noise effects from the sampled signals. The relay logic program determines the functional operation of the relay and uses the filtered sampled signals to arrive at a trip or no trip decision which is then communicated to the system.The heart of the relay logic program is a relaying algorithm that is designed to perform the intended relay function such as over currents detection, differential protection, or distance protection, etc. It is not our intention in this introductory text to purse this involved in a relaying algorithm, we discuss next one idea for peak current detection that is the function of a digital over current relay.Microcomputer-based RelayingA newer development in the field of power system protection is the use of computers(usually microcomputers) for relaying. Although computers provide the same protection as that supplied by conventional relays, there are some advantages to the use of computer-based relaying. The logic capability and application expansion possibilities for computer-based, relaying is much greater than for electromechanical devices. Computer-base relaying samples the values of the current, voltage, and by use of A/D converters, change these analog values to digital form and then send them to the computer. In the event of a fault, the computer can calculate the fault’s current values and characteristics, and settings can be changed merely by reprogramming. Computer-based relaying are also capable of locating faults, which has been one of the most popular features in their application. In addition, self-checking features can be built in and sequence of events information can be downloaded to remote computers for fast analysis of relaying operations.Computer-based relaying system consists of subsystems with well defined functions. Although a specific subsystem may be different in some of its details, these subsystems are most likely to be incorporated in its design in some form. The block diagram in Figure 13-1 shows the principal subsystems of a computer-base relaying. The processor is the center of its organization. It is responsible for the execution of relaying programs, maintenance of various timing functions, and communicating with its peripheral equipment. Several types of memories are shown in Figure13-1-each of them serves a specific need. The Random Access Memory (RAM) holds the input sample data as they are brought in and processed. The Read Only Memory (ROM) or Programmable Read Only Memory (PROM) is used to store the programs permanently. In some cases the programs may execute directly from the ROM if its read time is short enough. If this is not the case, the programs must be copied from the ROM into the RAM during an initialization stage, and then the real-time execution would take place from the RAM. The Erasable PROM (EPROM) is needed for storing certain parameters (such as the relaying settings) which may be changed from time to time, but once it is set it must remain fixed even if the power supply to the computer is interrupted.The relaying inputs are currents and voltages—or, to a lesser extent—digital signals indicating contact status. The analog signals must be converted to voltage signals suitable for conversion to digital from. The current and voltage signals obtained from current andvoltage transformer secondary windings must be restricted to a full scale value of +10 volts. The current inputs must be converted to voltages by resistive shunts. As the normal current transformer secondary currents may be as high as hundreds of amperes, shunts of resistance of a few milliohms are needed to produce the desired voltage for the Analog to Digital Converter (ADC). An alternative arrangement would be to use an auxiliary current transformer to reduce the current to a lower level. An auxiliary current transformer serves another function: that of providing electrical isolation between the main CT secondary and the computer input system.Since the digital computer can be programmed to perform several functions as long as it has the input and output signals needed for those functions. It is a simple matter to the relaying computer to do many other substation tasks, for example, measuring and monitoring flows and voltages in transformers and transmission lines, controlling the opening and closing of circuit breakers and switches, providing backup for other devices that have failed, are all functions that can be taken over by the relaying computer. With the program ability and communication capability, the computer-based relaying offers yet another possible advantage that is not easily realizable in a conventional system. This is the ability to change the relay characteristics (settings) as the system conditions warrant it. With reasonable prospects of having affordable computer-based relaying which can be dedicated to a single protection function, attention soon turned to the opportunities offered by computer-based relaying to integrate them into a substation, perhaps even a system-wide network. Integrated computer systems for substations which handle relaying, monitoring, and control tasks offer novel opportunities for improving overall system performance.International Journal of Electrical Power & Energy Systems继电保护1. 继电器当故障发生的时候继电器将电力系统的停电范围减小到最小，并且减小对设备的破坏。
电力系统继电保护专业词汇中英文互译-secret
87
Power rheostat
电力变阻器
88
Electrically op erated valve
电动阀门
89
Electrical gover ning system
电力调速系统
90
Field app licati on relay
励磁继电器；激励继电器
91
High tension electrical p orcelain in sulator
交流方向过流继电器
52
Breaker point wrench
开关把手
53
Breaker trip coil
断路器跳闸线圈
54
Bus bar
母线；导电条
55
Bus bar curre nt tran sformer
母线电流变压器
56
Bus bar disc onn ect ing switch
分段母线隔离开关
149
Oscillatory surge
振荡冲击
150
Fail safe in terlock
五防装置
151
Differen tial motio n
差动
152
Cap acitive curre nt
电容电流
154
Time delay
延时
156
Normal in verse
反时限
157
Defi nite time
电流平衡式差动电流继电器；差 动平衡式电流继电器
77
Current cha nger
换流器
78
Current compen sati onal ground dista nee relay
电力系统继电保护-1绪论
1.1.1 正常工作状态
• 不等式约束条件——涉及供电质量和电力设备安全运行的
某些参数，它们应处于安全运行的范围（上限及下限）内，
例如
Sk Sk max
Ui min Ui Ui max Iij Iij mx表示发电机、变压器或用电设备的功率潮流及其上限； Ui、Ui max、Ui min表示母线电压及其上、下限； Iij、Iij max表示输、配电线路中的电流及其上限； f 、fmax、fmin表示系统频率及其上、下限。
[4]杨奇逊, 黄少锋. 微型机继电保护基础.第4版[M]. 中国电力出版社, 2013
[5]张保会, 潘贞存. 电力系统继电保护习题集[M]. 中国电力出版社, 2008.
[6]刘晓军. 电力系统继电保护原理辅导与训练[M]. 中国电力出版社, 2014.
[7]国家电力调度通信中心. 国家电网公司继电保护培训教材[M]（上下册）. 中国电力出版社, 2009.
1.1.1 正常工作状态
• 正常运行状态——在正常状态下运行的电力 系统，所有的等式和不等式约束条件均满 足，表明电力系统以足够的电功率满足负 荷对电能的需求；
• 电力系统中各发电、输电和用电设备均在 规定的长期安全工作限额内运行；
• 电力系统中各母线电压和频率均在允许的 偏差范围内，提供合格的电能。
尹项根，1954年出生，华中科技大 学电气与电子工程学院教授，博士 生导师。国家标技委静态保护分委 会委员，中国电机学会主设备保护 分委会委员，湖北省电机工程学会 继电保护专委会副主任，电子信息 电气学科全国教指委委员，教育部 电气工程专业全国教指分委副主任。
规范及参考资料
1.GB/T14285-2006继电保护和安全自动装置技术规程 2.GB/T50062-2008 电力装置的继电保护和自动化装置设计规范 3.DL/T559-2007 220kV~750kV电网继电保护装置运行整定规程 4.DL/T584-2007 3kV~110kV电网继电保护装置运行整定规程 5.DL/T684-2012 大型发电机变压器继电保护整定计算导则 6.DL/T1502-2016 厂用电继电保护整定计算导则 7.电力工程电力设计手册（二次部分）2018版 8.DL/T866-2015 电流互感器和电压互感器选择及计算规程 9.DL/T5014-2010 330kV~750kV变电站无功补偿装置设计技术规定 10. GB 50227-2017 并联电容器装置设计规范 11. DL/T 5153-2014火力发电厂厂用电设计技术规程 12. GB 50660-2011大中型火力发电厂设计规范 13. GB 50049-2011 小型火力发电厂设计规范 14. DL/T 5155-2016 220kV~1000kV变电站站用电设计技术规程 15.电力工程电力设计手册（一次部分）2018版
Power System Protections 电力系统继电保护
Power System ProtectionsThe 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 place is removed, i.e. deleted from the rest of the system as soon as possible. This is necessary because the power system component can never be designed to withstand the worst possible conditions due to the fact that this will make the whole system highly uneconomical. And therefore, if such an abnormality takes place in any element or component of the power system network, it is desirable that the affected element / component is removed from the rest of the system reliably and quickly in order to restore power in the remaining system under the normal condition as soon as possible.A power system represents a very large capital investment. To maximize the return on this outlay. the system must be loaded as much as possible. For this reason it is necessary not only to provide a supply of energy which is attractive to prospective users by operating the system ,but also to keep the system in full operation as far as possible continuously, so that it may give the best service to the consumer, and earn the most revenue for the supply authority. Absolute freedom from failure of the plant and system network cannot be Guarani- teed. The risk of a fault occurring, however slight for each item, is multiplied by the number of such items which are closely associated in an extensive system, as any fault produces repercussions throughout the network. When the system is large, the chance of a fault occurring and the disturbance that a fault would bring are bothso great that with ou equipment to remove faults the system will become, in practical terms, inoperable. The object of the system will be defeated if adequate provision for fault clearance is not made. Nor is the installation of switch gear alone sufficient; discriminant protective gear, designed according to the characteristics and requirements of the power system. must be provided to control the switch gear. A system is not properly designed and managed if it is not adequately protected.The protection scheme includes both the protective relays and switching circuits, i.e. circuit breakers. The protective relay which functions as a brain is a very important component. The protective relay is a sensing device, which senses the fault, determines its location and then send command to the proper circuit breaker by closing its trip coil. The circuit breaker after getting command from the protective relay, disconnects only the faulted element. This is why the protective relay must be reliable, maintainable and fast in operation.In early days, there used to be electromagnet relay of induction disk-type. However, very soon the disk was replaced by inverted cup, i.e. hollow cylinder and the new relay obtained was known as an induction cup or induction cylinder relay. This relay, which is still in use, possesses several important features such as higher speed, higher torque for a given power input and more uniform torque.However, with the advent of electronic tubes, electronic relays having distinct features were developed during 1940s. With the discovery of solid state components during 1950s, static relays with numerous advantages were developed. The use of digital computers for protective relaying purposes has been engaging the attention of research and practicing engaging the attention of research and practicing engineers since late 1960s and 1980s. Now, the microprocessor/mini computer-basedrelaying scheme, because of its numerous advantages such as self-checking feature and flexibility, has been widely used in power systems all over the world.The overall system protection is divided into following sections:(i) Generator protection,(ii) Transformer protection,(iii) Bus protection,(iv) Feeder protection,(v) Transmission line protection.Basic Requirements to Protective RelaysAny protection scheme, which is required to safeguard the power system components against abnormal conditions such as faults, consists basically of two elements: (i) Protective relay and (ii) Circuit breaker. The protective relay which is primarily the brain behind the whole scheme plays a very important role. Therefore proper care should be taken in selecting an appropriate protective relay which is reliable, efficient and fast in operation. The protective relay must satisfy the following requirements:(1) Since faults on a well designed and healthy system are normally rare, the relays are called upon to operate only occasionally. This means that the relaying scheme is normally idle and must operate whenever fault occurs. In other words, it must be reliable.(2) Since the reliability partly depends upon the maintenance, the relay must be easily maintainable.(3) The alliteration of the relay can be in two ways. One is the failure to operate in case a fault occurs and second is the relay operation when there is no fault. As a matter of fact, relay must operate if there isa fault and must not operate if there is no fault.(4) Relaying scheme must be sensitive enough to distinguish betweennormal and the faulty system.Protective RelaysThe function of the protective relays is to sense the fault and energize the trip coil of the circuit breaker. The following types of protective relays are used for the apparatus such as synchronous machines, bus bar, transformer and the other apparatus and transmission line protection.(1)Crosscurrent relays.(2)Under voltage relays.(3)Infrequence relays.(4)Directional relays.(5)Thermal relays.(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. Ho 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.There are different types of the relaying scheme based on construction. They are: (i) electromagnet type, (ii) thermal relays, (iii) transactor relays, (iv) rectifier bridge relay, (v) electronic relays, (vi) static relays, (vii) digital relaying schemes.Faults and Their Damages on Power SystemsFaults on Transmission LinesBecause transmission lines are exposed to lightning and otheratmospheric hazards, faults on them occur more frequently than those in apparatus. The types of faults taking place on a transmission line are listed, in the order of severity, as following:(1)3-φ fault (LLL fault) or 3-φ to ground fault (LLLG fault) with or without fault impedance. This fault which is most severe but least common is only one in number.(2)Double line to ground (LLG) fault with or without fault impedance. This fault is less severe but more common than 3-φ fault. However, this type of faults are three in number.(3)Line to line (LL) fault. This fault is more common but less severe than the above faults. These faults are also three in number.(4)Single line to ground (LG) fault. This fault is the least severe but the most common one. These faults are also three in number.From the above, we conclude that are four types of faults which are ten in number. The first three faults such as LLL or LLLG, LLG and LL faults involving two or more phases are known as phase fault while the fourth fault, namely, LG fault, is called ground fault. All of the line faults will bring the system into abnormal operating conditions, and may damage electrical equipment. Therefore, the faulty lines must be isolated from the system by protection relays.Faults in Synchronous MachinesGenerators are subjected to varieties of possible hazards when they are in operation. The possible hazards or faults which may occur in a synchronous generator can broadly be classified into two categories: (i) internal faults within the generator, (ii) abnormal operating and/or abnormal system conditions caused by external faults. Internal faults of a generator mainly include gustatory faults and rotor faults.Gustatory Faults----Within the gustatory winding, faults can occurdue to failure of insulation (i.e. dielectric) and open circuit of conductor. Failure of insulation can lead to the short circuit between: (i) two or more phases, (ii) phase and core, (iii) two or more turns of the same phase (i.e. inter turn fault).Failure of insulation can occur due to over voltage, overheating caused by unbalanced loading, by overloading, by ventilation troubles, and by improper cooling of lubrication oil. It may also be caused by conductor movement due to forces exerted by short circuit currents or out of step operation. The most common fault in the gustatory winding is ground fault; about 85% of the faults are phase to ground faults in any generator winding. Phase to ground fault if persists may lead to phase to phase fault and even to phase-phase-phase fault (three-phase short circuit), which is the most severe fault though least common. The cause of over voltage which ultimately results into failure of insulation can be due to over speed of the prime mover, or due to defective voltage regulator; however, these days governors and voltage regulators act very fast and prevent any damage to the winding insulation.Rotor Faults----In the rotor winding also failure of insulation between field winding and core or two or more turns can occur. These faults may ultimately result in unbalanced currents and heating of the rotor. If the rotor is foregrounded, first earth fault does not show any effect but a second earth fault increases the current in the affected portion of winding which may cause distortion and permanent damage. It is advisable to open the field circuit breaker even with single earth fault to avoid second earth fault to avoid second earth fault so as to prevent local heating.Abnormal operating conditions / miscellaneous faults----There are a number of abnormal conditions which do not occur in the gustatory or rotor winding, but are undesirable since they can damage the generator. Eachof these conditions is discussed in the following.(1)Loss of synchronic. This condition can occur either due to loss of field excitation or governor becomes defective. During out of step condition, as the swing angle between the generated voltage of the machine and that of other units in the system changes, the current in any such unit varies in magnitude. The current surges that result are cyclical in nature, their frequency being a function of reactive rate of slip of the poles in the machine. The resulted high peak currents and off-frequency operation can cause winding stresses, and pulsating torques which can excite mechanical resonances that can be potentially damaging to the generator and to the shifts. Thus generator should be tripped without any delay within the first slip cycle to avoid any major damage.(2)Over speed. The cause of over speed is sudden loss of a very large load; sometimes this happens due to tripping of circuit breaker near the generator end. In the case of steam turbine, the steam can be shut off immediately but in case of hydro turbine, the water flow cannot be stopped quickly, due to the mechanical and hydraulic inertia. The governor controls the over speeding so as to avoid any high voltage, high frequency and manically damage to the generators. The setting of an over speed rating may be 115% for steam turbines and 140% for hydro-disturbing.(3)Motoring. In a mufti-generator system, when prime mover fails to provide required speed, the generator may act as a motor, drawing power from the system, instead of supplying power. Generally motoring is prevented by sensitive reverse power relay which operates on about 0.5% reverse power.(4)Under speed. Due to failure of steam or water supply to the prime mover, the speed of the generator will reduce and if the reverse power relay fails, then under speed and/or infrequence relay comes into picture and trips the circuit breaker.(5)Loss of excitation. Excitation failure may be caused by a faulty field circuit breaker or failure of the exciter. It can be detected by an undercurrent dc relay. Due to failure of excitation, the synchronous generator may act as an induction generator thereby absorbing reactive power (i.e. sink of reactive power). Turbine generator tends to overheat the rotor and the slot wedges under these conditions because of heavy currents in these parts and sometimes arcing occurs at metal wedges in the slots.(6)Over voltage. This may be caused due to over speed or elicitation when speed governor or voltage regulator fails to act as desired.(7)Gustatory overheating. Overheating may occur due to bearing failure, overloading, inadequate lubrication, or improper cooling of lubricating oil, etc. Overheating affects the dielectric strength of insulation.(8)External faults. Whenever abnormal conditions occur beyond the generator protection zone, the generator is also affected since the very source of power to the external fault is the generator itself. These conditions can be detected by the magnitude of negative sequence current, second harmonic current in field current and line crosscurrent relay.Power System ProtectionsIntroductionThe 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 place is removed, i.e.deleted from the rest of the system as soon as possible. This is necessary because the power system component can never be designed to withstand the worst possible conditions due to the fact that this will make the whole system highly uneconomical. And therefore, if such an abnormality takes place in any element or component of the power system network, it is desirable that the affected element / component is removed from the rest of the system reliably and quickly in order to restore power in the remaining system under the normal condition as soon as possible.The protection scheme includes both the protective relays and switching circuits, i.e. circuit breakers. The protective relay which functions as a brain is a very important component. The protective relay is a sensing device, which senses the fault, determines its location and then send command to the proper circuit breaker by closing its trip coil. The circuit breaker after getting command from the protective relay, disconnects only the faulted element. This is why the protective relay must be reliable, maintainable and fast in operation.In early days, there used to be electromagnet relay of induction disk-type. However, very soon the disk was replaced by inverted cup, i.e. hollow cylinder and the new relay obtained was known as an induction cup or induction cylinder relay. This relay, which is still in use, possesses several important features such as higher speed, higher torque for a given power input and more uniform torque.However, with the advent of electronic tubes, electronic relays having distinct features were developed during 1940s. With the discovery of solid state components during 1950s, static relays with numerous advantages were developed. The use of digital computers for protective relaying purposes has been engaging the attention of research and practicing engaging the attention of research and practicing engineerssince late 1960s and 1980s. Now, the microprocessor/mini computer-based relaying scheme, because of its numerous advantages such as self-checking feature and flexibility, has been widely used in power systems all over the world.The overall system protection is divided into following sections: (i) Generator protection, (ii) Transformer protection, (iii) Bus protection, (iv) Feeder protection, (v) Transmission line protection.Basic Requirements to Protective RelaysAny protection scheme, which is required to safeguard the power system components against abnormal conditions such as faults, consists basically of two elements: (i) Protective relay and (ii) Circuit breaker. The protective relay which is primarily the brain behind the whole scheme plays a very important role. Therefore proper care should be taken in selecting an appropriate protective relay which is reliable, efficient and fast in operation. The protective relay must satisfy the following requirements:(1) Since faults on a well designed and healthy system are normally rare, the relays are called upon to operate only occasionally. This means that the relaying scheme is normally idle and must operate whenever fault occurs. In other words, it must be reliable.(2) Since the reliability partly depends upon the maintenance, the relay must be easily maintainable.(3) The alliteration of the relay can be in two ways. One is the failure to operate in case a fault occurs and second is the relay operation when there is no fault. As a matter of fact, relay must operate if there isa fault and must not operate if there is no fault.(4) Relaying scheme must be sensitive enough to distinguish between normal and the faulty system.Protective RelaysThe function of the protective relays is to sense the fault and energize the trip coil of the circuit breaker. The following types of protective relays are used for the apparatus such as synchronous machines, bus bar, transformer and the other apparatus and transmission line protection.(1)Crosscurrent relays.(2)Under voltage relays.(3)Infrequence relays.(4)Directional relays.(5)Thermal relays.(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. Ho 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.There are different types of the relaying scheme based on construction. They are: (i) electromagnet type, (ii) thermal relays, (iii) transactor relays, (iv) rectifier bridge relay, (v) electronic relays, (vi) static relays, (vii) digital relaying schemes.Faults and Their Damages on Power SystemsFaults on Transmission LinesBecause transmission lines are exposed to lightning and other atmospheric hazards, faults on them occur more frequently than those in apparatus. The types of faults taking place on a transmission line are listed, in the order of severity, as following:(1)3-φ fault (LLL fault) or 3-φ to ground fault (LLLG fault) with or without fault impedance. This fault which is most severe but least common is only one in number.(2)Double line to ground (LLG) fault with or without fault impedance. This fault is less severe but more common than 3-φ fault. However, this type of faults are three in number.(3)Line to line (LL) fault. This fault is more common but less severe than the above faults. These faults are also three in number.(4)Single line to ground (LG) fault. This fault is the least severe but the most common one. These faults are also three in number.From the above, we conclude that are four types of faults which are ten in number. The first three faults such as LLL or LLLG, LLG and LL faults involving two or more phases are known as phase fault while the fourth fault, namely, LG fault, is called ground fault. All of the line faults will bring the system into abnormal operating conditions, and may damage electrical equipment. Therefore, the faulty lines must be isolated from the system by protection relays.Faults in Synchronous MachinesGenerators are subjected to varieties of possible hazards when they are in operation. The possible hazards or faults which may occur in a synchronous generator can broadly be classified into two categories: (i) internal faults within the generator, (ii) abnormal operating and/or abnormal system conditions caused by external faults. Internal faults of a generator mainly include gustatory faults and rotor faults.Gustatory Faults----Within the gustatory winding, faults can occur due to failure of insulation (i.e. dielectric) and open circuit of conductor. Failure of insulation can lead to the short circuit between: (i) two or more phases, (ii) phase and core, (iii) two or more turns of the same phase (i.e. inter turn fault).Failure of insulation can occur due to over voltage, overheating caused by unbalanced loading, by overloading, by ventilation troubles, and by improper cooling of lubrication oil. It may also be caused by conductor movement due to forces exerted by short circuit currents or out of step operation. The most common fault in the gustatory winding is ground fault; about 85% of the faults are phase to ground faults in any generator winding. Phase to ground fault if persists may lead to phase to phase fault and even to phase-phase-phase fault (three-phase short circuit), which is the most severe fault though least common. The cause of over voltage which ultimately results into failure of insulation can be due to over speed of the prime mover, or due to defective voltage regulator; however, these days governors and voltage regulators act very fast and prevent any damage to the winding insulation.Rotor Faults----In the rotor winding also failure of insulation between field winding and core or two or more turns can occur. These faults may ultimately result in unbalanced currents and heating of the rotor. If the rotor is foregrounded, first earth fault does not show any effect but a second earth fault increases the current in the affected portion of winding which may cause distortion and permanent damage. It is advisable to open the field circuit breaker even with single earth fault to avoid second earth fault to avoid second earth fault so as to prevent local heating.Abnormal operating conditions / miscellaneous faults----There are a number of abnormal conditions which do not occur in the gustatory or rotor winding, but are undesirable since they can damage the generator. Each of these conditions is discussed in the following.(1)Loss of synchronic. This condition can occur either due to loss of field excitation or governor becomes defective. During out of step condition, as the swing angle between the generated voltage of the machineand that of other units in the system changes, the current in any such unit varies in magnitude. The current surges that result are cyclical in nature, their frequency being a function of reactive rate of slip of the poles in the machine. The resulted high peak currents and off-frequency operation can cause winding stresses, and pulsating torques which can excite mechanical resonances that can be potentially damaging to the generator and to the shifts. Thus generator should be tripped without any delay within the first slip cycle to avoid any major damage.(2)Over speed. The cause of over speed is sudden loss of a very large load; sometimes this happens due to tripping of circuit breaker near the generator end. In the case of steam turbine, the steam can be shut off immediately but in case of hydro turbine, the water flow cannot be stopped quickly, due to the mechanical and hydraulic inertia. The governor controls the over speeding so as to avoid any high voltage, high frequency and manically damage to the generators. The setting of an over speed rating may be 115% for steam turbines and 140% for hydro-disturbing.(3)Motoring. In a mufti-generator system, when prime mover fails to provide required speed, the generator may act as a motor, drawing power from the system, instead of supplying power. Generally motoring is prevented by sensitive reverse power relay which operates on about 0.5% reverse power.(4)Under speed. Due to failure of steam or water supply to the prime mover, the speed of the generator will reduce and if the reverse power relay fails, then under speed and/or infrequence relay comes into picture and trips the circuit breaker.(5)Loss of excitation. Excitation failure may be caused by a faulty field circuit breaker or failure of the exciter. It can be detected by an undercurrent dc relay. Due to failure of excitation, the synchronous generator may act as an induction generator thereby absorbing reactivepower (i.e. sink of reactive power). Turbine generator tends to overheat the rotor and the slot wedges under these conditions because of heavy currents in these parts and sometimes arcing occurs at metal wedges in the slots.(6)Over voltage. This may be caused due to over speed or elicitation when speed governor or voltage regulator fails to act as desired.(7)Gustatory overheating. Overheating may occur due to bearing failure, overloading, inadequate lubrication, or improper cooling of lubricating oil, etc. Overheating affects the dielectric strength of insulation.(8)External faults. Whenever abnormal conditions occur beyond the generator protection zone, the generator is also affected since the very source of power to the external fault is the generator itself. These conditions can be detected by the magnitude of negative sequence current, second harmonic current in field current and line crosscurrent relay.。
电力系统继电保护(英文简介)
In the future, with the continuous development of technology, relay protection will continue to develop in the direction of high-speed, highprecision, intelligence and networking. It will also be more widely used in power systems, energy transportation fields and other fields.
Development history and trends of relay protection
Development history
Development trends
Relay protection technology has developed rapidly with the development of power systems. In the early days, it was mainly based on mechanical and electrical principles, but now it has developed into an integrated technology system that combines computer, communication, control and other technologies.
02
Principle and Technology of Relay Protection
Relay protection principle
Protection of power system: The power system is a very complex system, including power generation, transmission and distribution. Due to the long distance and high voltage of the power system, it is necessary to use relay protection to protect the power system.
电力系统继电保护外文及翻译演示教学
电力系统继电保护外文及翻译Power System ProtectionsThe 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, 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 place is removed, i.e. deleted from the rest of the system as soon as possible. This is necessary because the power system component can never be designed to withstand the worst possible conditions due to the fact that this will make the whole system highly uneconomical. And therefore, if such an abnormality takes place in any element or component of the power system network, it is desirable that the affected element/component is removed from the rest of the system reliably and quickly in order to restore power in the remaining system under the normal condition as soon as possible.The protection scheme includes both the protective relays and switching circuits, i.e. circuit breakers. The protective relay which functions as a brain is a very important component. The protective relay is a sensing device, which senses the fault, determines its location and then sends command to the proper circuit breaker by closing its trip coil. The circuit breaker after getting command from the protective relay disconnects only the faulted element. this is why the protective relay must be reliable, maintainable and fast in operation.In early days, there used to be electromechanical relay of induction disk-type.However, very soon the disk was replaced by inverted cup, i.e.hollow cylinder and the new relay obtained was known as an induction cup or induction cylinder relay. This relay, which is still in use, possesses several important features such as higher speed; higher torque for a given power input an more uniform torque.However, with the advent of electronic tubes, electronic relays having distinct features were developed during 1940s. With the discovery of solid state components during 1950s, static relays with numerous advantages were developed. The use of digital computers for protective relaying purposes has been engaging the attention of research and practicing engineers since layer 1960s and 1980s. Now, the microprocessor/mini computer-based relaying scheme, because of its numerous advantages such as self –checking feature and flexibility, has been widely used in power system all over the world.The overall system protection is divided into following sections: (i)Generator protection,(ii)Transformer protection,(iii)Bus protection,(iv)Feederprotection,(v)Transmission line protection.Basic Requirements to Protective RelaysAny protection scheme, which i.e. required to safeguard the power system components against abnormal conditions such as faults, consists basically of two elements(i)Protective relay and (ii) Circuit breaker .The protective relay which is primarily the brain behind the whole scheme plays a very important role. Therefore proper care should be taken in selecting an appropriate protective relay which is reliable, efficient and fast in operation. The protective relay must satisfy the following requirements:⑴ since faults on a well designed and healthy system are normally rare, therelays are called upon to operate only occasionally. This means that therelaying scheme is normally idle and must operate whenever fault occurs. Inother words, it must be reliable.⑵ Since the reliability partly depends upon the maintenance, the relay mustbe easily maintainable.⑶ The palpation of the relay can be in two ways. One is the failure to operatein case a fault occurs an second is the relay operation when there is no fault.As a matter of fact, relay must operate if there is a fault and must notoperate if there is no fault.⑷Relaying scheme must be sensitive enough to distinguish between normaland the faulty system.Protective RelaysThe function of the protective relay is to sense the fault and energize the tripcoil of the circuit breaker. The following types of the protective relays are usedfor the apparatus such as synchronous machines, bus bar, transformer and theother apparatus and transmission line protection.(1) Over current relays,(2) Under voltage relays,(3) Under frequency relays,(4) Directional relays,(5) Thermal relays,(6) Phase sequence relays such as(i)negative sequence relays and, (ii)zerosequence relays,(7) Differential relays and percentage differential relays,(8) Distance relays such as (I)plane impedance relays,(ii)angle impedance relay,i.e. Ohm or reactance relays,(iii)angle admittance relays,i.e. Mho relaysand ,(iv)offset and restricted relays,(9)Pilot relays such as (i) wire pilot relays,(ii)carrier channel pilotrelays,(iii)microwave pilot relays. There are different types of the relayingscheme based on construction. They are:(i)electromechanicaltype,(ii)thermal relays,(iii) transduction relays,(iv)rectifier bridgerelay,(v)electronic relays,(vi)digital relaying schemes.电力系统继电保护电力系统的稳态运行经常会因各种电力设备配故障原因而被扰乱。
Protectionrelay（继电保护）外文翻译资料
Protectionrelay（继电保护）外文翻译资料Protection relayProtective relayingProtective relaying is that area of power system design concerned with minimizing service interruption and limiting damage to equipment when failures occur. The function of protective relaying is to cause the prompt removal of a defective element from a power system. The defective element may have a short circuit or it may be operating in an abnormal manner. Protective relaying systems are designed to detect such failures or abnormal conditions quickly and to open a minimum of circuit breakers to isolate the defective element. The effect of quick isolation is threefold: (1) it minimizes or prevents damage to the defective element, thus reducing the time and expense of repairs and permitting quicker restoration of the element to service; (2) it minimizes the seriousness and duration of the defective elements affecting on the normal operation of the power system; and (3) it maximizes the power that can be transferred on power systems. The second and third points are of particular significance because they indicate the important role protective relaying plays in assuring maximum service reliability and in system design. The power that can be transmitted across system without the loss of synchronism is the function of fault clearing times. It is apparent that fast fault clearing times permit a higher power transfer than longer clearing times. High-speed clearing of faults can often provide a means for achieving higher power transfers and thereby defer investment in additional transmission facilities.A protective relaying system is based on detecting faultconditions by continuously monitoring the power system variables such as current, voltage, power, frequency, and impedance. Measuring of currents and voltage is performed by instrument transformers of the potential type (PT) or current type (CT). Instrument transformers feed the measured variables to the relay system, which in turn, upon detecting a fault, commands circuit breaker (CB) to disconnect the faulted section of the system.An electric power system is divided into several protective zones for generators, transformers, buses, transmission and distribution circuit, and motors. The division is such that zones are given adequate protection while keeping service interruption to a minimum. It is to be noted that each zone is overlapped to avoid unprotect (blind) areas. The connections of current transformers achieve the overlapping. The general philosophy of 1。
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附录1 电力系统继电保护1.1方向保护基础日期，对于远离发电站的用户，为改善其供电可靠性提出了双回线供电的设想。
当然，也可以架设不同的两回线给用户供电。
在系统发生故障后，把用户切换至任一条正常的线路。
但更好的连续供电方式是正常以双回线同时供电。
当发生故障时，只断开故障线。
图14-1所示为一个单电源、单负载、双回输电线系统。
对该系统配置合适的断路器后，当一回线发生故障时，仍可对负载供电。
为使这种供电方式更为有效，还需配置合适的继电保护系统，否则，昂贵的电力设备不能发挥其预期的作用。
可以考虑在四个断路器上装设瞬时和延时起动继电器。
显然，这种类型的继电器无法对所有线路故障进行协调配合。
例如，故障点在靠近断路器D的线路端，D跳闸应比B快，反之，B应比D快。
显然，如果要想使继电器配合协调，继电保护工程师必须寻求除了延时以外的其他途径。
无论故障点靠近断路器B或D的哪一端，流过断路器B和D的故障电流大小是相同的。
因此继电保护的配合必须以此为基础，而不是放在从故障开始启动的延时上。
我们观察通过断路器B或D的电流方向是随故障点发生在哪一条线路上变化的。
对于A和B之间的线路上的故障，通过断路器B的电流方向为从负载母线流向故障点。
对于断路器D，电流通过断路器流向负载母线。
在这种情况下，断路器B应跳闸，D不应跳闸。
要达到这个目的，我们可在断路器B和D上装设方向继电器，该方向继电器的联接应保证只有当通过它们的电流方向为离开负载母线时才起动。
对于图14-1所示的系统，在断路器B和D装设了方向过流延时继电器后，继电器的配合才能实现。
断路器A和C装设无方向的过流延时继电器及瞬时动作的电流继电器。
各个继电器整定配合如下：方向继电器不能设置延时，它们只有本身固有的动作时间。
A和C的延时过流继电器通过电流整定使它们作为负载母线或负载设备故障的后备保护。
断路器A和C的瞬时动作元件通过电流整定使它们在负载母线故障时不动作。
于是快速保护可以保护发电机和负载之间线路长度的大部分。
从图中A和C上的瞬时继电器不能真正瞬时切除故障，因为电力设备动作需要时间，在这个期间内，流过断路器B和D的电流很小甚至为0，因此在这种故障状态下，只有等到发电厂的断路器动作后，断路器B和D才动作。
这就是我们所说的顺序跳闸，通常在上述情况下这样做是允许的。
在一个交流系统中，通过电流矢量与其他参考矢量的比较，可以确定电流的方向。
图14-1所示系统的参考矢量可从负载母线电压矢量推出。
由于在该交流系统中，线路和设备含有电抗，电流和功率的瞬时方向不能确定，这是显而易见的，因为当有电压时，相位落后的电流取样的瞬时值取决于它在电压周期中的瞬间，可能为正，也可能为负或为零。
因此，电压、电流矢量必须在一个时间间隔内采样。
为了较为准确的采样，时间间隔可从一个半周期到一个周期。
目前正在进行更短时间的采样的研究工作。
这个研究工作是给继电器加上一个预测电路，试图以此确定未来时间内矢量的情况。
由于要在电力系统电磁暂态过程中预测，这项工作比较复杂。
通常用于判断方向的时间越短，所做判断的可靠性越差。
1.2差动保护用于电力系统的大多数电气设备与一般输电线路的长度相比，实际尺寸都比较小，因此利用导线直接连接就可以使设备两端之间的联络变得非常经济和可靠，保护配置就可采用简单而又非常有效的差动保护。
从概念上讲，流入设备的电流可以很简单地流出的电流进行比较。
这种保护原理可设计为对于设备内部故障相当灵敏，对于外部故障则非常不敏感。
因此采用差动原理的保护本身具有继电保护的选择性。
差动保护最简单的应用见图14-2，图中一段简单的电力线路就是采用差动继电器保护的。
该继电器通常由三个线圈组成，其一检测差动电流并起动跳闸回路，我们称之为工作线圈，在图中用符号O表示。
另外两个线圈是制动线圈，在图中用符号R表示。
在实际中，由于制造和其他一些原因，两侧电流互感器的特性不可能完全一致，存在一些差异，制动线圈能防止由此而产生的误动，而在理论上，制动线圈是不起作用的。
图14-2给出了在外部故障时，继电器不动作跳闸情况下的电流流向。
电流I1进入电力回路后，在离开回路时并未改变，为了简单起见，电流互感器的变比为1：1，两侧电流互感器的二次绕组连接后，使I1仅通过差动继电器的制动线圈循环流动。
如果在两个电流互感器之间，电流同时离开或进入电力回路，两个电流互感器中的电流将不同，差电流将通过继电器的工作线圈。
Chapter 1 RTU and SCADAPart 1 A Typical SCADA SystemThe MOSCAD Remote Terminal Unit(RTU) provides a data collection unit with the intelligence required to operate in sophisticated Supervisory Control and Acquisition(SCADA) system.. With MOSCAD ,local processes can be thoroughly supervised; control decisions , utilizing data from both local and remote sources, can be made ; informational message to supervisory centrals or to other remote units can occur. MOSCAD utilizes reliable Motorola FM two-way radio as the massage transmission medium to completely eliminate dependence on leased wireline networks.A typical SCADA system is shown as Fig.15-1.The Motorola Communication Processor for TCP/IP(MCP/T) Gateway provides a convenient connection for SCADA Hosts using TCP/IP protocol to access the MOSCAD RTUs in a client/server architecture. The Gateway connects the 10 Mbps Ethernet to the MDLC world of radio and wireline communications.MDLC is Motor ola’s built-in communication protocol .It is a seven layer protocol that conforms with ISO recommendations for Open System Interconnection(OSI). The protocol supports different communication media such as radio(VHF,UHF),wirelines,RS links (RS-232.,RS-485),etc.The Toolbox ,connected locally to the Gateway ,provides access to any RTU in the system ,performing all programming and diagnostics functions.The system may work in both redundancy mode and dual mode. Two MCP/T Gateways can be configured in a Primary /Secondary mode. This provides backup paths in case of failure of a single unit. Mode changes between Primary and Secondary are performed from the SCADA computer.Part 2 Three Levels of Control CentersControl centers may be broadly categorized according to thefunctions implemented. At the first level is the category with basic SCADA system comprising data acquisition, remote control of operating devices and some alarm and limit indications. At the next stage, basic SCADAsystems are found augmented by an economic dispatch calculation(EDS) and automatic generation control(AGC). Normally controlor for all telemetered plant .At the highest level are the security of th centers in this category will also have full security monitoring with generation reserve monitor and limit check and overload monite power system.. The functions normally implemented in this case are state estimation, on-line loadflow , contingency evaluation, reactive power optimization and possibly power flow .These control centers frequently also have a full energy management system (EMS) with energy accounting, interchange transaction evaluation and interchange scheduling.。