A New Method for Single-phase Grounding Fault Line Selection Based on Fuzzy Fusion

A single line selection method cannot accurately identify all single-phase ground faults in low-current grounding systems, this paper proposes a new method for fault line selection of single-phase grounding faults based on fuzzy fusion based on the mutability, energy and polarity of zero-sequence current before and after the fault. This method first uses wavelet transform to reduce noise and divide the frequency of each feeder's transient zero-sequence current, continuing using the sensitivity of the zero-sequence energy method to detect the fault of the bus to detect the bus. If it is a fault of the bus, the line selection is ended. Otherwise, continue to find the membership of the three methods to the fault decision, and use fuzzy fusion to calculate the comprehensive fault credibility Degree, the highest credibility is the failure route. Matlab / Simulink is used to build a simulation model for experiments. The experimental results show that the method is not affected by the fault distance, initial fault angle, transition resistance, and noise; it selects lines accurately and can correctly identify bus faults.