基于双端电气量的故障测距迭代算法

Iterative Algorithm for Fault Ranging Based on Two-terminal Electrical Parameters

基于双端电气量的故障测距从理论上来说可消除过渡电阻对测距结果的影响,但是在实际应用中存在线路两侧电气量信息不同步等问题,使得最终测得的故障距离存在一定误差。为此提出了一种基于双端测量信息的故障测距迭代算法,通过引入对端保护的零序阻抗,代入经典测距公式中,再结合本端保护测得的电气量,构建迭代方程从而实现故障测距。PSCAD仿真结果证明了该算法的有效性和准确性,且不受过渡电阻的影响,较好地解决了双端保护中测量信息不同步等问题,避免了传统算法中将零序电流分配系数角近似为零带来的测距误差,提高了测距结果的精确度。

The fault distance measurement based on the two-terminal electrical volume can theoretically eliminate the influence of transition resistance on the ranging result.However,in practical application,there are some problems such as the information of the electrical volume on both sides of the line is not synchronized,resulting in a certain error in the final fault distance measured.In order to solve the fault location accuracy problem,an iterative fault location algorithm based on two-terminal measurement information is proposed in this paper.By introducing the zero-sequence impedance of the opposite end protection and substituting it into the classical ranging formula,combined with the electrical quantity measured by the local end protection,an iterative equation is constructed to realize fault location.PSCAD simulation results show the effectiveness and accuracy of the algorithm,which is not affected by the transition resistance,solves the problems of asynchronous measurement information in double terminal protection,avoids the ranging error caused by the approximate zero angle of zero sequence current distribution coefficient in the traditional algorithm,and improves the accuracy of ranging results.