電氣專業(yè)畢業(yè)設計英文文獻

1、外文資料與中文翻譯外文資料：Relay protection present situation and development1、 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 sw

2、ift 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

3、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 creative

4、ly 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 fu

5、nction to the national relay protection technical team's establishment. The Acheng relay factory introduction has digested at that time the overseasadvanced relay technique of manufacture, has established our country own relay manufacturing industry.Therefore our country has completedthe relay p

6、rotectionresearch,the design, the manufacture, themovement 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 transisto

7、r 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 p

8、rotection 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, st

9、arted 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 th

10、e early 90s integrated circuit were still in the dominant position, this was the integrated circuit protection time. The integrated circuit power frequency change quantity direction which develops in this aspectNanjing Electric power Automation Research institute high frequency protected the influen

11、tial role 3, the Tianjin University and theNanjing Electric power Automation Plant cooperation development's integrated circuit phase voltage compensation type direction high frequency protection also moved in many 220kv and on the 500kv line.Our country namely started the computer relay protect

12、ion 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 Tianj

13、in 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

14、 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

15、 aspect, the generator which the Southeast University andHuazhong University of Science and Technology develops loses magnetism protection,the generator protection and the generator? Bank oftransformers protection also one after another in 1989, in 1994 through appraisal, investment movement. The Na

16、njing Electric power Automation Research institute develops microcomputer line protective device also in 1991 through appraisal. Tianjin University and Nanjing Electricpower Automation Plant cooperation development microcomputer phase voltage compensation type direction high frequency protection, Xi

17、'an Jiaotong Universityand Xuchang relay factory cooperation developmentpositive sequence breakdown component direction high frequency protection also one after another in 1993, in 1996 through appraisal. Hence, the different principle, the different type's microcomputerline and the main equ

18、ipment 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

19、 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.2、 future development of Relay protectionThe future trend of relay protection technology is to computerization, net

20、working 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 electric circuit or a machine is greater than

21、 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 which the function would be accomplished. Because the functions of electromechan

22、ical devices are easily described, their performance wills ever as a basis for presenting a description of relays and relay systems in 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

23、be required to operate with fast responds, as intended, the first time. The penalty for failure to operate properly may run into millions of dollars.Selectivity-Therelay must not respond to abnormal, but harmless,system conditions such as switching transients or sudden changes in load.Sensitivity-Th

24、erelay must not fail to operate, even inborderline 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

25、 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

26、, 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 toconducting(or vice versa). Electromagnetic relays are o

27、lder and more widely used; solid state relays are more versatile, potentiallymorereliable, 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 co

28、nstantly, besides basic function protected, should with trouble information of the large capacity and data the long-term parking space also, fast data processing function, strong communication capacity,network in orderto share the whole system data , information , ability , network of resource with

29、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 th

30、e 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 w

31、ith 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 whomtransformation act as continue the electric protector with computer protector structure self-s

32、ame one worker person who accuse 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 computer protect future. (2)The size and structure are similar to present computer

33、 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 sel

34、ect 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 re

35、lay protection further, how make heavy economic benefits and social benefit, need carry on concrete deep research.2 ) NetworkedComputer network become the technological pillar of informationage as message and data communication tool, madethe mankind producing basic change has taken place in the appe

36、arance with social life. Itis influencingeach industrial fielddeeply,has offeredthe powerfulcommunicationmeans for eachindustrial fieldtoo. Up till now, exceptthat protect differentially and unite protecting vertically, all continue electric protector can only react that protect the electric quantit

37、y 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

38、 mainly at that time. Because the function of relay protection is not only limited to excising the troublecomponent and restrictionaccident coverage(thisis primarytask), the peace and steadiness that will be guaranteed the whole systemrun . This require eachprotectunit cansharethe wholeoperation and

39、 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

40、of capital equipment 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 to

41、o. 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 a

42、chievement 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 someprotect

43、ors realize computer networking can improve the dependability protected . Tianjin Sanxia vltrahigh voltage many return circuit bus bar , 500kv of power station , putforward one distributed principle that bus bar protected to future 1993 such as university, succeed in developing this kind of device t

44、entatively. 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 n

45、etwork, 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

46、 circuit and electriccurrent amount of other return circuits got from 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 troub

47、le outside the bus bar district , each protect the unit and calculate for movements of the external trouble. This kind protect principle by distributed bus bar thatnetwork realize with computer,bus bar protect principle have higher dependability than traditional concentration type. Because if one pr

48、otect unit interfere or mistake in computation and when working up by mistake, can only jump formatreturn 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 San

49、xiaCan 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 development3 ) Protect , control , measure , data communication integratesOn terms that realize computerizatio

50、n 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 netw

51、ork control centre or any terminal function , and can also finish the measurement , control , data communication function in there isno normal running of trouble cases, namely realize protecting,controlling , measuring , data communication integrates.At present, for measurement, need that protects a

52、nd 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 return ci

53、rcuit2 timesin a large amount. But ifabove-mentioned protection,control,measure, data communicationintegrated 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 tr

54、ansformer substation on the spot, send to the top management room through the computer network, can avoid a large number of control cables . If use optic fibre as the transmission medium of the network , can avoid and interfere electromagnetically. The photocurrent mutual inductor of now (ota ) and

55、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 i

56、nput in the integrated device here and changes into an electric signal, what ison 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 integ

57、rated 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

58、 (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

59、inthe 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 course of emergence is a non-linear problem in transmit electricity