基于离散傅立叶变换的配电网小电流接地线路故障选线

Fault Line Selection for Small Current Grounded Lines in Distribution Networks Based on Discrete Fourier Transform

为确保小电流电网正常运行,精准发现故障线路,引用离散傅立叶变换算法,提出一种接地线路故障选线方法。通过分析暂态电容电流与暂态电感电流特征,获取小电流接地线路故障暂态量中存在的有效故障信息,递推离散傅立叶变换算法,解得与傅立叶级数相对应的基波系数以及零序电流投影值,架构接地故障发生判定依据,依据解得的最大投影值,完成接地线路故障选线。经对比小电流线路故障测度与不同噪声比例下评估指标仿真实验结果发现,方法具有理想的选线精度与噪声免疫性能,选线环境适应能力较强。

In order to ensure the normal operation of small-current power grids and accurately find faulty lines,a discrete fourier transform algorithm is used to propose a fault line selection method for grounding lines.By analyzing the characteristics of transient capacitance current and transient inductance current,the effective fault information existing in the transient quantity of small current grounding line fault is obtained,and the discrete Fourier transform algorithm is recursively solved to obtain the fundamental wave coefficient and zero corresponding to the Fourier series.The sequence current projection value is the basis for determining the occurrence of a ground fault,and the grounding line fault line selection is completed based on the maximum projection value obtained.By comparing the simulation results of comparison of the low-current line fault measurement and the evaluation index under different noise ratios it is found that the proposed method has ideal line selection accuracy and noise immunity performance,and the line selection environment has strong adaptability.