A New Method for Fault Location of Metro Traction Network Based on Transient Ratio Method

Abstract

When the rail short-circuit fault occurs in the traction network of the railway, especially when the traction network is short-circuited through a large transition resistance or the fault occurs near the substation, the existing fault location methods often have larger error. Compared with traveling wave method and artificial intelligence-based fault location method, the two-terminal synchronous fault analysis method is more suitable for fast and accurate short-circuit fault location of metro traction network. Steady-state ratio method is derived from the steady-state of fault analysis method. However, due to the influence of post-fault protection tripping, the synchronous acquisition of steady-state values at both ends cannot be guaranteed. A new fault location method based on transient ratio method is proposed to solve the problem of low accuracy of existing fault location methods for metro traction network. Compared with the traditional fault analysis method and the steady-state ratio method, this method does not need the synchronization of two-terminal data and is not affected by the protection tripping after the fault occurs. Fault location can be realized by using the ratio of initial short-circuit current on both sides of fault point. The simulation results by MATLAB/Simulink show that this method is less affected by the inaccurate estimation of transition resistance and traction network parameters. The method is simple and accurate and has a certain application prospect.