Characteristics of Lightning Strikes on High-Speed Rail Corridors in Jiangsu Province, China

Cloud-to-ground (CG) lightning occurs frequently in Jiangsu Province, China. High-speed rail (HSR) spans across the province, covering a large geographic area. Studying the occurrence of lightning and the characteristics of strikes in HSR corridors is of great significance for the lightning protection and safe operation of the HSR. Based on the terrain, lightning detection data, and catenary engineering parameters along 12 HSR corridors in Jiangsu Province, this study provides detailed analyses of the lightning characteristics, the cumulative probability distribution (CPD) of lightning current amplitudes, and the lightning strike characteristics on the catenary in these areas. The results show that CG lightning mainly occurs from 05:00 a.m. to 10:00 a.m. and mostly happens in the summer season. The CG lightning density along the HSR corridors in southern Jiangsu Province is relatively high. According to the CPD of lightning current amplitudes and the fitting curves obtained by the Levenberg–Marquardt method, the “a” values are relatively larger for the Nanjing–Anqing, Nanjing–Hangzhou, and Shanghai–Chengdu HSR lines, which indicates that the lightning current amplitudes along these three HSR corridors are larger than those along other lines. In terms of the CG lightning intensity index, which is the combination of lightning current intensity and CG lightning frequency, its values are relatively larger in the Zhenjiang section of the Shanghai–Nanjing riverside line, the Wuxi section of the Shanghai–Nanjing intercity line, and the Yangzhou section of the Lianyungang–Zhenjiang line. The large-value areas of the tripping rate of the catenary caused by direct lightning strikes are relatively consistent with those of CG lightning density. The direct-lightning-strike tripping rate along the feeder F wire is considerably larger than that along the trolley wire T. In the absence of overhead lightning shield wires along HSR lines, the maximum tripping rate of wire F caused by direct lightning strikes is 24.3 times (100 km)⁻¹ a⁻¹, the minimum tripping rate is 2.6 times (100 km)⁻¹ a⁻¹, and the average tripping rate is 10.6 times (100 km)⁻¹ a⁻¹. In contrast, along wire T, the maximum tripping rate caused by direct lightning strikes is 7.6 times (100 km)⁻¹ a⁻¹, the minimum value is 0.8 times (100 km)⁻¹ a⁻¹, and the average value is 3.3 times (100 km)⁻¹ a⁻¹. When considering overhead lightning shield wires, the probability of direct lightning strikes on wire F drops to 0.12 times (100 km)⁻¹ a⁻¹, and that on wire T is negligible. Accordingly, the average tripping rate caused by backflashovers is 3.5 times (100 km)⁻¹ a⁻¹.