基于卡尔曼滤波状态估计的输电线路故障测距

Transmission Line Fault Location Based on Kalman Filtering State Estimation

为提高在外部复杂条件下线路故障测距精度,提出一种基于自适应卡尔曼滤波(adaptive kalman filtering,AKF)状态估计的输电线路测距方法。首先分析短路时电压信号特性,建立状态变量为基波与各次谐波的状态空间模型;然后用AKF实现状态估计,通过对谐波分量进行行波检测分析,确定行波抵达终端的时刻,并结合双端测距法确定故障距离;最后通过在三节点环网进行仿真分析,验证所提方法在不同故障条件下故障测距的有效性。在不同故障距离与强度噪声情况下,均能精确测量出故障点在线路上的位置。

In order to improve the accuracy of line fault location under complex external conditions,a transmission line location method based on adaptive Kalman filtering(AKF)state estimation was proposed.Firstly,the characteristics of the voltage signal during short-circuit were analyzed,and the state-space model with the state variables as fundamental wave and harmonics was established;then,AKF was used to realize the state estimation,through the traveling wave detection and analysis of the harmonic components,the time when the traveling wave arrives at the terminal was determined,and the fault distance was determined by combining the double-end ranging method,finally,through simulation analysis in a three-node ring network,the effectiveness of the proposed method in fault location under different fault conditions was verified.The method can accurately measure the position of the fault point on the line under different fault distances and noise intensities.