Fault Line Selection Method Based on Zero Sequence Current Phase Angle Offset

Abstract

Aiming at the problem that the fault characteristic quantity of high resistance grounding fault in small current grounding system is small and the fault line can not be selected accurately, a fault line selection method based on zero sequence current phase angle offset is proposed. After the fault is detected, the current signal is injected. By measuring the zero-sequence current at the beginning of each line before and after the injection signal, and calculating the phase angle of the zero-sequence current change before and after the injection signal and the ratio of the zero-sequence current before the injection signal, the line selection and section of the grounding fault can be realized. This method has strong anti-transition resistance ability, is not affected by the system parameters in theory, has high accuracy, simple calculation method, fast speed, and has strong engineering practicability.