Analyzing And Research Based On Signal Injection Method Of Selection On Single-phase To Ground Fault Line In Distribution Network

Fault detection for the non-effective single-phase earth system is an important task for ensuring the continuity of power supply. But the spot records show that the effect is not perfect. Most of the fault detection device in the past is used in a single passive fault line detection method, and it collects signals by the means of transient volume of the zero-sequence current or steady volume. Pulse injection method is proposed in this paper. It is a controllable cycle pulse responds method and can detect the fault positively. A simulation model is built by using Matlab/Simulink. And simulations of various ground faults under different conditions are performed. It is presented in the paper that in the fault detection of NUS system impulse response signal is extracted based on the method of margin calculation, and the fault line selection method is carried out by the waveform recognition. In the fault detection of NES system the impulse response signal is extracted based on wavelet transform, then the fault is detected by colony amplitude comparison. After theoretical analysis and simulation, the results show that this approach is practicable.