一种考虑线路参数变化的输电线路双端测距算法

在输电线路运仃过程中，其线路参数并非固定不变，而是随环境条件的不同会有一定的变化，这种变化会对故障测距的精度产生很大的影响。本文提出一种基于参数估计和分布参数模型的双端测距算法，该算法仪使用故障前后电压电流的正序分量，将线路正序参数、故障距离和两端非同步误差等量作为未知量，利用故障发生时刻前后输电线路两端的电压电流相量求解非线性方程组来获得这些未知量，能在线估计出线路参数的变化，提高了测距精度。EMTP仿真结果和实际数据的验证均表明，该算法较之不带参数估计的算法测距精度明显提高，尤其在线路参数不准确的情况下，该算法具有很强的参数自适应能力和很高的测距精度。

A fault location algorithm for two terminal lines considering the variation of line parameter

The transmission line parameters are not always constant, they may vary with different environment conditions, and the variation has much influence on the accuracy of fault location. In this paper, a fault location algorithm for two terminal lines is proposed, the algorithm is based on the parameter estimation and the distributed parameter model. In the algorithm, only the positive sequence voltage and current are used. The line positive sequence parameter, fault distance and sampling a synchronization error are considered as unknown quantities, and a group of non-linear equation are solved to obtain these unknown quantities. The algorithm is able to estimate the variation of line parameter on-line, so the accuracy of the fault location is improved greatly. The presented algorithm is tested by transient data generated by EMTP and actual transient data recorded by fault recorder. Compared with the algorithm not based on the parameter estimation, the results show that the presented algorithm has improved the location accuracy very much. Especially under the condition of the provided line parameter are not accurate, the proposed algorithm has strong adaptability of parameter and high accuracy.