Fault-Location of AT Traction Network Adopting Bilateral Power Supply Mode Based on Generalized Symmetrical Components Method

Autotransformer (AT) traction network with bilateral power supply mode is an effective and economical electrified railway feeding scheme. However, due to the nonlinear relationship between measured reactance and distance, as well as the complex power flow distribution, the accuracy of fault location is facing severe challenges. This paper proposes a precise fault location method applicable to various fault scenarios in the AT traction network. By employing a generalized symmetrical components method, a composite sequence network model including four-sequence components is developed, and the boundary conditions are derived to describe the characteristics of various fault types. Furthermore, a fault-location algorithm is developed to determine the fault positions based on the busbar voltages and the feeder currents at trackside traction substations. The impact factors, such as the rail impedance and the parameter differences between contact wires and feeder wires, are investigated, and then a reasonable correction method is applied to improve the fault location accuracy. Finally, simulations, experimental setups, and field tests show that the proposed method can obtain accurate fault-location results, with an improvement of at least 29%. Certainly, this work has significant application prospects in fault analysis and location for electrified railways.