Design And Development Of A New Monitoring System For Distribution Automation

This thesis presents a new monitoring scheme for distribution automation.The whole frame design,the hardware design,the communications design and the software design are involved.A high speed synchro sampling card,which is developed independently,is applied in the infrastructure.Its driver is developed independently to get a good effect.A integrated criteria of faultline select in small-current earthing system is presented in this paper.This dissertation proceeds with the analysis of the current and voltage after NUGS single-phase grounded, and then discusses the differences of the schemes of fault line selection among systems with different grounded methods. On the base of studying many references, it summarizes many fault selection schemes and point out that analysis in transient period should be the keystone for the solution.It takes actual fault wave as argument, testifies criteria that is the polarity of intial half-wave based on wavelet transform. In the same way,It points out that the recently research is focused on the transient signal analyzing and compressing,the wavelet transform is also used widely. It proves that the db4 wavelet transform has powerful utility in power quality transient signal compressing.It introduces the idea of object-oriented communicating data modeling based on IEC 61850.The IEC 61850"communication networks and system in substation"is the new international standard on substation automation The content of IEC 61850 is introduced in detail The paper presents the object modeling approach of microcomputer-based protective relay according to IEC 61850-7-3.The schedule and rule of GOOSE in fault handles are presented.The utility of network database is demonstrated afterwards.A new fault recorder of BLOB is introduced in this paper.It compares that with the file-record method.The hardware and software of background are introduced.It gives some advices in development,and bring forward a B/S monitoring mode,and then compare that with traditional C/S monitoring mode.