Grounding fault line selection method of power system of coal mine based on fuzzy theory

For problem that fail selection often happened in single grounding fault line selection method, a new method combining zero sequence current power direction principle, wavelet transform analysis principle and gray relational analysis principle was proposed. The method uses the zero-sequence voltage multifractal spectrum to determine weights of the methods, and uses fuzzy inference theory for multi-criteria information fusion. Matlab simulation results show that the compound criterion which determines the weight through positioning method is suitable for single-phase grounding fault line selection in a variety of circumstances, and is not affected by system neutral grounding mode, run mode, out line number and grounding position, which achieves high accuracy single-phase grounding fault location.