A Multi-index Comprehensive Analysis Method for Waveform Consistency of Single-phase Ground Fault of Power Source Output

A multi-index comprehensive analysis method is proposed for the consistency of the output signal and the input signal of the power source about single-phase ground fault. Compared with the traditional single-index waveform similarity comparison method, this method combines the time-domain characteristics of the steady-state waveform, the time-domain ,frequency-domain and time-frequency domain characteristics of the transient state.The consistency of power source grounding fault waveform is comprehensively evaluated. On the basis of investigation and analysis of the field identification method of short-circuit and grounding faults in distribution network, the key characteristic parameters including the voltage amplitude changes of steady-state signals , harmonic distortion rate and amplitude of transient zero-sequence voltage, or the other characteristic parameters that cover the essential characteristics of transient signal waveform.All the parameters are divided into their importance grades. At the same time, the weight rank of each parameter is determined by the combination of the analytic hierarchy process (AHP) and the correlation coefficient method. Finally, the waveforms of field grounding fault from the power grid and a power source are extracted, and a comprehensive evaluation model of transient signal output consistency is established.