一种基于方向行波的平行双回线保护方案

A relay scheme of double-circuit lines based on directional traveling wave

在分析故障后电气量特征的基础上,提出了一种基于方向行波的平行双回线保护方案,利用线路两侧方向行波之间的关系判别区内、区外故障和故障线路,该方案可以保护线路全长,不受母线出线数目的影响,在双回线单回运行时,可以正确动作。与传统基于工频量的保护相比,动作速度快,不受CT饱和影响,且不受负荷电流影响。仿真计算验证了该方案的可行性。

Through analyzing the character of electric quantity after fault, a protection scheme of double-circuit lines is presented based on directional traveling wave, which utilizes characters of directional traveling wave of two ends of lines to identify internal, external fault and fault line. This scheme can protect the whole line and is unlimited to lines number of bus. It can act correctly in the situation of one line operation of double-circuit lines. Comparing with the protection using main frequency quantity, it not only acts rapidly and is immune to CT saturation. The simulation verifies the feasibility of scheme.