A single-phase ground fault detection and location system has been researched and developed to solve the problem of difficulties in locating small current grounding faults in distribution network. It is determined that the zero mode voltage is obtained by the Karenbauer phase-mode transformation to judge whether a fault has occurred. Meanwhile, the fault is located by measuring the time difference of waveform by B-type traveling wave method. The system first uses the capacitor divider to extract the fault transient voltage signal. After simple analysis and processing of the data by the DSP (Digital Signal Processing), the fault information is summarized into the upper computer through the IoT (Internet of Things) communication module to select the fault line. The nanosecond timing module is used to synchronously time the system, which can improve the measurement accuracy of the line wave arrival time of the line monitoring device to the nanosecond level. Finally, the function of the module and the feasibility of the system are verified by debugging the modules of the system.

Capacitor voltage-dividing,Distribution network single-phase ground fault system,IoT communication,Nanosecond synchronous timing,Transient voltage