Ground fault identification and location of autotransformer traction network for high-speed railway based on multi-terminals synchronous measure information

With the rapid development of high-speed railway, the auto-transformer traction network (ATN) is also expanding. However, due to the improved performance of electric multiple units (EMUs) and the non-linear relationship between impedance and ground fault distance, distance protection has limited coverage and cannot accurately locate the fault distance by measuring impedance. This paper presents a model of the ATN considering the presence of EMUs, which effectively demonstrates the characteristics of current distribution under the ground faults. Furthermore, a ground fault identification method based on multi-terminal currents is proposed to enhance the accuracy of fault identification and differentiate faults and EMUs. The mapping relationship between current distribution and fault location is derived, and an accurate fault location method is proposed. Compared to existing methods, this method is not affected by EMUs and AT parameters. The fault identification and location scheme for ATN employs multi-terminal synchronous information. Finally, through simulation and experimental setups, case studies have been conducted to verify the accuracy and robustness of the proposed method in various fault scenarios. Certainly, this research has significant application prospects in fault analysis and detection for HSR. To address the challenges of incorrect fault identification and location due to the influence of EMUs, this paper proposes a protection scheme based on the synchronous information from the multiple terminals of HSR, which can identify and locate ground faults in critical conditions.image