Research On Fault Location Of Multi-terminal Transmission Line Based On Double Terminal Traveling Wave Method

With the scale of power system expanding and the structure of transmission network becoming more complex,the traditional two terminal traveling wave fault location method can not meet the requirements of accuracy and reliability of fault location in transmission network.Therefore,based on graph theory,this paper proposes an improved fault location algorithm for multi terminal transmission lines based on double terminal traveling wave method.The reliability and practicability of this method are verified by simulation.Firstly,this paper introduces the development of traveling wave fault location at home and abroad and the research status of multi transmission line fault location.The existing fault location algorithms for multi terminal transmission lines based on wavelet transform and the fault location algorithm for multi terminal transmission lines based on Hilbert Huang transform can only carry out the traditional double ended traveling wave fault location.When one of the traveling wave fault location devices fails,the fault location will fail.Traveling wave fault location method in the construction of network fault localization based on graph theory,using the shortest path algorithm,a simplified radiation network,and the use of data fusion technology to measure the distance weighted fault location.Even when one end of the traveling wave device breaks promise,accurate fault location results can also be obtained.But the algorithm of the fault location results by weighted fusion,only considering the substation on the transmission path to the effect of location results,ignoring the influence of transmission distance of adjacent substation on the fault location accuracy.In order to improve the accuracy and reliability of the algorithm,this algorithm is improved,which makes the algorithm more accurate and more reliable.Finally,an example of 220kV transmission network fault is introduced,and a simulation model is built by using Matlab.Simulation analysis of the above three ranging methods is carried out.The simulation results show that compared with the traditional wavelet transform method and HHT fault location method,this improved method of multi terminal transmission line fault location based on double terminal method of traveling wave distance with high accuracy and reliability.And it is not affected by the fault type and the error time of partial node recording.It is suitable for fault location of long distance transmission lines.The research results will lay a theoretical and technical foundation for the development and application of traveling wave protection devices.