Reliability Evaluation for Traction Power Supply System of High-Speed Railway Considering Relay Protection

Failures in the traction power supply system (TPSS) may cause high-speed trains to run behind the schedule or even suffer from downtime, which would directly affect the entire scheduling and cause inestimable loss. Therefore, it is crucial to evaluate the reliability of the TPSS to ensure that it can operate with high reliability. This paper proposes a method for evaluating the overall reliability of the TPSS associated with high-speed railway (HSR) considering relay protection. The impact of relay protection on the reliability of the TPSS is analyzed; then, the failure mode and effect analysis (FMEA) tables are established based on the main wiring diagram of the TPSS and its equipment composition to qualitatively analyze the failure modes of the primary and secondary equipment and their influence. According to the FMEA tables, the fault tree model of the traction substation and catenary system considering the relay protection is established, respectively, and the system reliability indexes are calculated through the Monte Carlo simulation. Different from existing studies, the reliability models established in this paper take into account the primary and secondary equipment of the TPSS and coupling relationship between them, and highlight the configuration of relay protection and its logic cooperating with each equipment. Through the analysis of practical example concerning the TPSS serving China’s HSR, it shows that rich and direct system reliability indexes can be obtained through simulation with the proposed reliability models and the evaluation method, and the impact of the relay protection on system reliability can be reflected, which provides an effective means for evaluating the overall reliability of the TPSS.