Fault line selection using multiple disturbance characteristics of fault phase active grounding in resonant grounded distribution networks

To improve the detection accuracy of a single-phase grounding fault (SPGF) in resonant grounded distribution networks, this paper proposes a fault line selection (FLS) scheme based on multiple disturbance characteristics of the zero-sequence voltage and zero-sequence current changes, which is produced by an arc extinguishing device (AED) that has the ability to perform fault phase bus grounding and resistance grounding at parallel neutral points. To demonstrate the effect of the AED timing sequence on the faulty feature of the SPGF in detail, an analytical expression for the zero-sequence equivalent analysis circuit of each stage is derived in this paper. The analysis results show that, at any adjacent disturbance stage, the relative rates of change of the zero-sequence voltage and zero-sequence current of any sound line have a theoretical value of 1. In contrast, the relative rate of change of the fault line is much greater than 1 in an adjacent disturbance stage, and a minimum rate close to 0 occurs in another adjacent disturbance stage. Subsequently, an FLS criterion is constructed by fusing the characteristics of the incremental change in the active grounding period. Extensive simulations are conducted to verify the feasibility and effectiveness of the proposed FLS scheme. Furthermore, field tests are conducted to further evaluate the performance of the proposed FLS scheme.