基于罗氏线圈二次信的煤矿高压电网接地故障区段定位

煤矿高压电网的单相接地保护仍需依靠动作时间的级差配合以实现纵向的选择性，这对井下供电安全是潜在的威胁。为此，分析并阐明了煤矿高压电网单相接地故障时各线路区段零序电流的基波有功分量、高次谐波无功分量的分布特点；同时提出将罗氏线圈引入到零序电流信号的检测中，对其二次侧电压信号的幅值与相角特性的分析表明利用罗氏线圈测量零序电流可有效提升谐波分量在被测电流中的含量比例。在此基础上构造了基于罗氏线圈二次侧信号的综合零序电流判据，并给出了煤矿高压电网单相接地故障区段定位算法。该算法不仅可实现无级差的单相接地故障区段定位，而且可有效提高单相接地保护的灵敏度。建立了基于PSCAD/EMTDC的10 kV煤矿高压电网模型，通过典型故障仿真验证了算法的正确性。

Secondary signal of Rogowski coil based ground fault section location in coalmine high-voltage distribution network

Currently，single-phase ground protection in coalmine high-voltage distribution network still relies on time stage difference coordination to realize the longitudinal selectivity，which poses a potential threat to power supply security.Therefore，distribution characteristics of both the active component of zero-sequence current fundamental wave and the reactive component of zero-sequence current harmonic component in the coalmine distribution network were analyzed and elaborated；meanwhile Rogowski coil was introduced into the detection of zero-sequence current，the analysis of the amplitude and phase angle characters of secondary voltage signal generated in measurement of the zero-sequence current using Rogowski coil shows that the percentage of zero-sequence current harmonic component in the current being measured can be effectively amplified when measured by Rogowski coil.On this basis，the criterion of synthetic zero-sequence current based on the secondary signal of Rogowski coil is proposed，and the algorithm of single-phase ground fault section location in coalmine high-voltage distribution network is presented.This algorithm not only achieves location of single-phase ground fault section without stage difference coordination，but also effectively improves the sensitivity of the single-phase ground protection.The correctness of the proposed algorithm is verified by typical single-phase grounding fault simulation in 10 kV coalmines high-voltage distribution network system in PSCAD/EMTDC.