基于扩展Prony算法的煤矿电网单相接地故障选线方法

Single-phase Grounding Fault Line Selection Method of Coal Mine Power Grid Based on Extended Prony Algorithm

煤矿中性点不接地电网发生单相接地故障后,其故障线路与非故障线路零序电流的幅值与相位存在显著差异,据此能可靠选出故障线路。传统上采用傅氏算法提取故障信号的工频分量,但该算法建立在故障信号为周期性不衰减的基础上,与实际的信号特征差距较大,影响选线的准确性。基于此,考虑利用扩展Prony算法提取各线路零序电流的工频幅值与相位,然后比较其值选出故障线路。MATLAB仿真分析表明,此种选线方法正确率高,适应性强。

After single phase-to-ground fault occurred in coal mine isolated neutral power grid,the amplitude and phase of the zerosequence current between the fault line and the non-fault line are significantly different.According to this,fault line can be selected reliably.Traditionally,Fourier algorithm is used to extract the power frequency components of fault signals.However,this algorithm is based on the fact that the fault signal is not decaying periodically.The difference between the signal characteristics and the actual signals is large,which affects the accuracy of fault line selection.Based on this,the extended Prony algorithm is used to extract the amplitude and phase of the zero-sequence current of each line in this paper,and then the extracted amplitude and phase is compared to select the fault line.MATLAB simulation results and adaptability analysis verify that the proposed method has a high accuracy and strong adaptability.