Abstract
In this paper, some of the major lightning troubles in traction power supply system are described. Different from power companies' grid, traction power supply system in urban area adopted D. C. 1500V as a voltage level and it is difficult to detect ground fault which resulted in more critical transport disorders. The troubles of breaking of feeder messenger wires and breaking of silicon rectifier are explained in detail to figure out the peculiarities of traction power supply system.