Abstract Faulty phase recognition under single-line-to-ground (SLG) fault condition is critical for some arc suppression methods in medium voltage (MV) distribution networks. Conventional methods tend to be invalid due to network asymmetry in high-resistance ground-fault condition and the difficulty of detecting phase-to-ground parameters in practice. In this paper, the variation of the three phase-to-ground voltages with the change of SLG fault resistance is analyzed in detail, and the magnitude and phase angle variation rules of the voltages are obtained. Then, the unique variation rules on SLG fault for each phase are separately and strictly discussed in theory and numerical analysis. Furthermore, a faulty phase recognition method is proposed based on the variation rules of three-phase voltages. Simulation results in PSIM verify the proposed variation rules and validate the effectiveness of the proposed faulty phase recognition method, which ensures accurate recognition of faulty phase in high-resistance ground fault.

中文翻译：

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基于相地电压变化的中性点不接地配电网故障相识别方法

摘要 单线对地 (SLG) 故障条件下的故障相识别对于中压 (MV) 配电网络中的某些电弧抑制方法至关重要。由于高阻接地故障条件下的网络不对称以及实际检测相接地参数的困难，传统方法往往无效。本文详细分析了三相对地电压随SLG故障电阻变化的变化规律，得到了电压幅值和相角变化规律。然后，分别从理论上和数值分析上，分别严格地讨论了各相SLG故障的独特变化规律。此外，提出了一种基于三相电压变化规律的故障相识别方法。