基于分布参数的电力电缆故障定位新型算法研究

摘要

在分析地下电缆系统单相接地故障的等效电路的基础上,提出了一种基于分布参数和序网变换的电力电缆故障定位新算法.该算法考虑了三相电缆之间互感及线芯与外皮之间互感的影响,将高阶的三相故障系统矩阵转化为独立的序网矩阵,从发送端、故障点和接收端三处分别确立了序网方程和相量网络方程的多个边界条件,应用发送端的电压、电流等参数,最后通过牛顿一拉夫讯迭代法求解故障点位置,经过PSCAD/EMTDC仿真软件校验,该方法在不同的短路阻抗下均具有很高的精度.%After analyzing the single phase grounding fault's equivalent circuit of underground power cable system, this paper proposes a new algorithm of power cable fault location based on the sequence network transformation and distributed parameters.This algorithm considers the influence of mutual inductance between core and sheath, and the mutual inductance among three-phase cables, transforms the matrix of high tank three-phase fault system into three individual sequence network matrix. It sets up the boundary conditions of the sequence network equation and phase network equation from sending end, fault point and receiving end,uses the voltage, current and other parameters of sending end, and finally gets the position of fault point by using Newton-Raphson iterative method. The algorithm is tested by using PSCAD/EMTDC simulation software, which shows high precision under different short circuit impedances.