Power supply system, ground fault detection method and program

A feeding system that feeds power to a load includes only a single device configured to have neutral point high-resistance between a feeding line and the earth. The device functions as a ground fault overvoltage detection type of ground fault detector. The feeding system further comprises a control device. When the ground fault overvoltage detection type of ground fault detector detects a ground fault, the ground fault overvoltage detection type of ground fault detector transmits, to the control device via a signal line, a signal indicating that the ground fault has occurred. The control device instructs a breaker corresponding to the specific distributed unit in which it is determined that the ground fault has occurred to perform breaking.