基于Stehfest算法的配网单相接地故障双端测距方法

摘要

提出了一种基于Stehfest算法的双端测距方法.该方法采用配网单相接地故障后半周期内的零序电压、电流暂态信息,由Prony算法得到其时域表达式,利用零序网络以及线路分布参数的象函数模型,在不考虑线路零序参数的频率特性和考虑其频率特性两种情况下,分别列写出线路的象函数测距方程.通过 Stehfest 算法对测距方程进行数值反演计算,并用搜索法求取区间内测距方程的最小值,得到方程的数值计算矩阵,进而以该矩阵行元素平方和最小为目标,确定故障距离.大量的EMTP-ATP仿真实验验证了该方法的正确性.%This paper proposes a new two-terminal fault location method based on Stehfest algorithm. The method uses zero-sequence transient information within first half-cycle after a single-phase ground fault occurred in the distribution network, adopts Prony algorithm to obtain time domain expression of zero-sequence transient information, combines with zero sequence network and image function of distributed parameter line, takes frequency characteristics of lines' zero sequence parameters into account and gets the image function location equation by using the fault feature. Then Stehfest algorithm is adopted to get location equation's numerical inversion and search algorithm is used to find the minimum value of function location equation and obtain the numerical matrix. Last, the method calculates square sums of matrix row elements and takes the minimum value as the target to determine the fault distance. The accuracy and effectiveness of the method has been verified by EMTP-ATP simulation experiments.