Zero-Sequence Fault Diagnosis and Wave Recording System Based on Transient Components Analysis

When the single-phase ground occurs in the power system with neutral point non-effectively grounding, the real-time awareness of magnitude and direction of the zero-sequence current is a difficult problem in engineering practice. In this paper, a zero-sequence fault diagnosis and wave recording system based on the transient components analysis is proposed. The proposed system can record the zero-sequence fault process completely, including the steady state before the fault, the transient state during the fault and both of the transient and steady state after the fault. In addition, the proposed system can analyze the fault data and process the transient components in pre-fault, mid-fault and post-fault. Through application analysis for waveform under various fault conditions and comparisons of line selection accuracy, the effectiveness of the method is verified. And the application result indicates that the proposed system can identify various type of faults effectively and improve the accuracy of faulty line selection.