综合输电线路差动保护继电器Word文档下载推荐.docx

1、the protection of every line sections connected to the substationbusbar.The current differential algorithms with multiple settingsare implemented into the relay to cover all the protected linesections.The scheme is supported by advanced communicationnetwork and standard.Studies show that the new sch

2、eme not onlyoffers the new protection features for individual power line,butalso provides the characteristics of integrated protection.Studiesalso show that the new relay offers more protection functions andsignificant economic advantages over the conventional currentdifferential relays.Index Terms-

3、Centralized Protection,Current DifferentialProtection,Integrated Protection.I.INTRODUCTIONURRENT differential protection has been playing a majorrole in power transmission line protection1.Inparticular with the development of optical communicationtechnology,the current differential relay has become

4、the mainprotection device for transmission lines at and above EHVlevel.In recent years,there has also the fast development inboth microprocessor and transducer technologies.This hasenabled protection techniques to be considered which wereimpractical in the past.Studies have found that the faultgener

5、ated high frequency transients can be detected andquantified and open the possibility for developing newprotection principles and techniques.Considerable effort hasnow been devoted to research on high frequency transientdetection2.A number of new techniques have beenproposed and their associated mea

6、surement and signalprocessing techniques investigated.At the same time,thedramatic growth in signal processing power of relay platforms,and the availability of suitable communications schemes,hasZ Q Bo and A Klimek are with the AREVA T&DAutomation,UK.（e-mail:zhiqian.boareva-）.Y L Ren and J H He are

7、with the Department of Electrical Engineering,Beijing Jiaotong University,China.978-1-4244-1762-9/08/$25.00?2008 IEEEprovided a new opportunity to improve the existing anddevelop new protection techniques based on power frequencymeasurements.Research shows that information obtained frommultiple powe

8、r plants and components can be used to derivenew protection principles and schemes3-14,which couldhave significant advantages over the existing protectiontechniques based on individual plant or component.In thisrespect,it has been found that the new transient basedprotection techniques not only inhe

9、rit the capability to protectindividual plant,but can also be used to produce novelschemes for the integrated protection of a power network whensupported by modern communication technology.Recently,anovel integrated protection scheme based on fault transientdetection is proposed15.In the scheme,a ce

10、ntralizedprotection relay is installed at a substation and interfaced toevery line,through the CTs.The fault generated transientsignals are captured by the relay,the polarities and levels ofthe signals are then compared,from which the direction of thefault can be derived.The directional decision is

11、thenforwarded to relevant substation relays and the integratednetwork protection and automation unit,the faulted linesection can be isolated by local protection or networkprotection.This paper presents a completed integrated protectionscheme.In the scheme,an integrated current differential relay,int

12、erfaced to the CTs on all of the output lines connected to thesubstation busbar and connected to neighboring substations atthe remote ends of the lines,is responsible for the protection ofall the transmission lines associated with the substation.Thecurrent differential algorithm with multiple settin

13、gs to cover allthe protected line sections is used as the main protectiontechnique and the design of the new integrated currentdifferential relay is also described in this paper.Studies showthat the new scheme is not only use friendly but also economic,at the same time provide the features of integr

14、ated protection,which could represent the direction of future development inpower system protection.II.CONCEPT OF INTEGRATED PROTECTIONWith the development of digital technology,more and moreprotection functions for an apparatus（line,transformer,generator etc.）have been implemented within one protectivedevice to achieve a certain degree of integration.For example,a numeric line protection relay may ha