Objective To address the urgent need for standardized implementation of 25 kV AC catenary short-circuit testing in suburban railways, a set of systematic and comprehensive short-circuit test methods is proposed.

Method Four representative short-circuit points are selected for testing. Connecting the catenary to the rails with R95 conductive cables, the single-phase ground fault conditions are simulated via a circuit breaker. The measured parameters include short-circuit voltage, short-circuit current, short-circuit impedance, track potential, and induced EMF (electromotive force) in core wires. Data collection is jointly completed by the fault monitoring system in the traction substation and the short-circuit point test instruments. Statistical analysis plus graphical analysis methods are used for data processing.

Result & Conclusion The maximum short-circuit voltage at the test points ranges from 19 005.5 to 25 759.1 V, the maximum current from 2 863.2 to 6 000.0 A, and the impedance from 1.29 to 2.36 Ω. The aforementioned short-circuit voltage, current, and impedance are highly correlated with the fault location and transition resistance. The catenary fault locator exhibits a positioning error of 260 ~ 1 700 m with an average error rate of 1.2%, demonstrating a certain locating capability despite the presence of systematic errors. The traction power supply protection devices functions normally, with reasonable and reliable protection action timing and logical relationships across all points. Rail potential remains within 0.1~1.7 V when the duration is no less than 0.6 s; when the duration is 0.1 s, the rail potential reaches its peak value, with the rail potentials at each short-circuit point all below the evaluation thresholds. The induced electromagnetic field from the catenary short circuits causes no damage or interference to the wayside facilities, and the integrated grounding and electromagnetic compatibility results meet the requirements of relevant specifications.