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详细介绍了鄂托克旗煤矿电网发生单相接地故障后系统故障特征,并利用零序网络分解法对故障网络进行分析,给出了零序网络接地故障时零序电流向量图,提出了一种基于从保护安装处到故障点的Kirchhoff回路电压定律的测距定位新算法,选择截止频率为100 Hz二阶巴特沃斯低通滤波器作为信号的前置滤波,利用改进的傅立叶算法消除直流偏移。通过PSCAD/EMTDC进行建模仿真,结果表明:该算法选线准确、动作可靠,可以有效提升煤矿供电的安全性。
The characteristics of system fault after single-phase ground fault occurred in Etuoke coal mine power grid are introduced in detail. The fault network is analyzed by using zero-sequence network decomposition method. The zero-sequence current vector diagram of zero-sequence network ground fault is given. Based on the Kirchhoff loop voltage law from the protection installation point to the fault location of the new algorithm of ranging and positioning, the choice of a cutoff frequency of 100 Hz second-order Butterworth low-pass filter as the signal pre-filtering, the use of improved Fourier algorithm to eliminate DC Offset. The results of simulation and simulation with PSCAD / EMTDC show that the proposed algorithm is accurate in line selection and reliable in operation, which can effectively improve the safety of coal mine power supply.