同塔四回输电线路双端故障测距实用算法

基于输电线路的分布式参数模型，提出了一种适用于同塔四回输电线路差动保护装置的故障测距新算法。该算法首先对输电线路参数进行相模变换，选取相互独立的双端同向正序故障分量，依据输电线路双端口理论建立故障测距方程，从而得出精确的故障距离。该算法原理简单，计算量小，避免了一般测距算法需要计算双曲函数、超越方程、牛顿迭代法和搜索法的复杂过程。PSCAD/EMTDC仿真结果表明，该算法测距精度较高，且不受故障距离、过渡电阻、故障类型和两侧电源功角差的影响，有很强的工程实用价值。

A new method of fault location with two-terminal data for four-parallel transmission lines on the same tower

Based on distributed parameter model of transmission lines, this paper proposes a new fault locating practical algorithm suitable for the four-circuit transmission line on the same tower differential protection device. Firstly, the transmission line parameters are carried out phase-mode transformation, independent double-ended with the positive sequence fault components are selected, and according to the theory of establishing a dual-port transmission line fault location equation, the accurate fault location is obtained. The method is simple and has less calculation amount, which avoids the complex process of a general ranging method, such as calculating the hyperbolic functions, transcendental equations, Newton iterative method and search methods. PSCAD/EMTDC simulation results show that the algorithm has high fault accuracy, and is immune to fault distance, transition resistance, fault type and power angle difference of double sides power sources, so it has practical value of engineering. This work is supported by National Natural Science Foundation of China (No. 51177066).