After a single-phase-to-earth fault occurs in a mining high-voltage power supply system with non-effectively grounded neutral points,the transient process of the fault has severe cross interference,and the fault signal exhibits strong nonlinearity,non stationarity,high time variability and complexity,making fault localization difficult.To address this problem,a fault location method based on distri-bution divergence was proposed.Firstly,the fault characteristics were analyzed through an equivalent circuit,and the Choi-Williams Dis-tribution(CWD)time-frequency energy spectrum was used to overcome the cross interference of multiple frequency components in the fault signal.Then,an improved KL divergence was proposed to characterize the time-frequency distribution difference between the up-stream and downstream signals in the fault section,and the overlapping parts in the CWD time-frequency energy spectrum of upstream and downstream signals were processed to eliminate the adverse effects of similar components in the upstream and downstream signals of the fault section.On this basis,the fault location criterion was constructed by using the CWD-KL divergence of zero sequence current signal.Finally,the feasibility and superiority of the proposed method were verified by simulation test and comparative analyses.
关键词
矿山供电系统/中性点非有效接地/单相接地故障/分布散度/故障定位
Key words
mine power supply system/non-effectively grounded neutral points/single-phase-to-earth fault/distribution divergence/fault location
维普
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