Research Of On-line Detecting And Faulty Location For The Fault In A10kV Distribution System

Due to that the dimensions of distribution system increases gradually, therequirements of power quality and reliability are improved by cons umers. Therefore,the construction of automatic distribution system becomes more and more important.In order to realize the automation of distribution system, the faulty detection andlocation is one of the great important research directions in many rese arch areas. Itplays a significant role in development of automation of distribution system andsmart grid. Based on the research project, this dissertation gives a brief introductionabout structure of distribution system, faulty location and basic concep t of on-linemonitoring. Furthermore, a particular analysis of single line-to-ground fault indistribution system under different grounded methods is illustrated in the dissertation,and then the related characteristics of fault are collected. To be compar ed withdifferent simulations of single line-to-ground fault selective methods in MatLab forexample, amplitude comparative method of zero-sequence currents and directionalmethod of zero-sequence power flow, the efficiency, advantages and disadvantages ofabove methods are verified and summarized. The principles of faulty location offeeder’s automation are introduced in particularly. This dissertation analyzes aspecific mode of faulty location, as a result, it comes out an accurate output and willbe useful for application in engineering.First of all, this dissertation introduces concepts and operational characteristicsof distribution system. It represents current and major research works in the faultydetection and location of distribution system and reveals the important meaning ofsuch method. Based on domestic and international research methods of faultylocation, the research contents of this dissertation are clarified.First of all, this dissertation introduces characteristics of distribution syste m. Itrepresents current research works in automation of distribution system and revealsthe important meaning of faulty location. Based on domestic and internationalresearch methods of faulty location, the research contents of this dissertation areclarified.Moreover, based on the different fault currents of single line-to-ground fault, thedistribution system is divided into large current grounded method and small currentgrounded method. This dissertation focuses on the research of small current ground ed method, in which characteristics of transient and steady states are analyzed and usedonce the single line-to-ground fault occurs in system. The selective methods whichbased on signal of steady state include pulling line method, harmonics method, realpower component method and signal injection method. The first half wave method,transient current directional method and wavelet method belonged to the selectivemethod which based on the transient signal. Amplitude comparative method ofzero-sequence currents and directional method of zero-sequence power flow are usedto make simulations in MatLab and verify the accuracy of different methods. As aconsequence, if the principles of selective methods are satisfied, both of abovemethods shall detect and judge the faulty line accurately.Last but not least, the functions and structures of automation of feeder areintroduced. According to different working principles, the control modes ofautomation of feeder are classified. Based on the accurate analysis of st ructures andfunctions in a termination of automation of feeder, the faulty location method whichbased on the termination of automation of feeder is used to analyze a specific modeof faulty location. Finally, it provides believable results to practical a pplication infaulty location.