基于参数估计的双端不同步故障测距算法

Unsynchronous two-terminal fault location algorithm based on line parameter estimaton

提出一种利用双端不同步采样数据并基于线路参数估计的故障测距算法,将输电线路参数、两端数据采样非同步误差角和故障距离作为未知量,利用故障时线路两端的非同步采样得到的电压和电流,通过牛顿-拉夫逊法求解非线性方程得到这些未知量。并将故障测距结果采用故障距离占线路全长的比例来表示,可以避免输电线路受温度影响产生长度变化导致的故障定位误差。利用线路杆塔在线路上所处的位置来估测故障点位置,更方便查找故障点。该算法减小了因线路参数不准确所带来的测距误差,仿真结果和实际数据验证表明该算法具有较高的测距精度。

The paper presents a fault location algorithm that takes the transmission line parameters, the asynchronous sampling error angle between two-terminal and fault distance as unknown variables. The voltages and currents during fault at two-terminal are assumed to be available. The unknowns can be obtained by utilizing the Newton-Raphson approach to solve the nonlinear equations. The result of fault location expressed by the percentage corresponding to the ratio of fault distance to whole-length of transmission line can avoid the error produced by the transmission line length that changes with temperature. It is convenient to find the fault point by the location of the towers on the line. The proposed algorithm avoids the fault location error caused by inaccuracy of line parameters. Simulation results show that high accuracy of fault location can be obtained by use of the proposed algorithm.