Research On Fault Location Algorithm Of Extra High Voltage Transmission Lines

Extra High Voltage(EHV)transmission lines has already become the support of strong smart grid.Since the parameter error between EHV transmission line setting and actual motion and date non-synchronous problem at each end of the line,considering the high cost of the fault location based on traveling wave,the traditional Single-ended fault analysis has the theoretical error,intelligent distance-measuring is on the stage of theoretical research,this paper use Double ended fault location method.Though EHV transmission line has barely installed the same type of PMU and GPS at present.most of them equip with relatively good performance of the fault wave recording device.So the non-synchronous fault location method based on the distributed parameter model of error compensation of double end data asynchronous is studied in this paper.The paper consists of three parts:(1)The principle of algorithm.Filtering the voltage and current at each end of the EHV transmission line before and after the fault,then can calculate the coefficient of error compensation and non-synchronous angle,real-time correct the error of line parameter and non-synchronous angle at each end,so as to realize the double end asynchronous fault location;(2)Complete transposition of the EHV transmission lines.Refer to the Beijing-Tianjin-Tangshan 500 kv EHV single circuit transmission line,builds the simulation model based on Matlab,the positive sequence component method is adopted to verify the effectiveness of the proposed algorithm,and derives its process of implementation by using the method of equal propagation constant mode components;(3)Untransposition or parameter asymmetric EHV transmission lines in practice.The paper uses the method of mode components analysis,explains the calculating method of phase-mode transformation matrix in detail,the process of algorithm implementation is deduced,and also builds its corresponding simulation mode under Pscad environment.Furthermore,the results of simulation and verification indicate that the proposed algorithm of double ended asynchronous fault location is general,which is not affected by the asynchronous error,ranging accuracy is higher,has certain engineering application value.