Lightning Overvoltage Protection Technologies for High‐Speed Railway Traction Power Supply Systems: Current Status and Future Prospects

The traction power supply system of high‐speed railways is exposed to complex lightning environments over the long term. Overvoltage generated by direct lightning or induced lightning can propagate along the overhead contact line, traction substations, onboard high‐voltage system and mobile grounding system, thereby threatening equipment insulation and affecting the reliable operation of the system. In this paper, the issue of lightning overvoltage protection for high‐speed railway traction systems is addressed. The mechanism and intrusion paths of lightning overvoltage are systematically examined, and current research progress, existing limitations and future development directions are reviewed from three aspects, namely, ground‐side protection, onboard‐side protection and grounding‐side discharge. This review shows that lightning overvoltage protection for high‐speed railways is a systemic issue extending throughout the entire process of overvoltage intrusion, propagation, withstand and discharge. In the future, coordinated lightning protection design of the overhead contact line and traction substations should be further strengthened, overvoltage response analysis of the onboard high‐voltage system under complex operating conditions should be further advanced, and adaptive optimisation of grounding parameters in the mobile grounding system should be further promoted so that lightning overvoltage protection for high‐speed railway traction systems can be developed from local protection towards overall optimisation.