基于阻抗比较的同杆并架选相新方法

首先对综合比相阻抗继电器在同杆并架双回线故障下的动作行为进行了研究,在此基础上提出一种结合综合比相继电器的选相新方法。这种选相元件根据改进后的综合比相继电器的选相结果,参考测量阻抗值对已选出的动作相再次进行筛选。同杆并架的后备距离保护应用此选相元件,通过适当的整定配合,能可靠地区分靠近线路末端跨线故障和区内相间故障,提高距离保护I段的正确动作率。数字仿真结果表明,基于阻抗比较的同杆并架选相新方法受同杆并架线路拓扑结构和对称性等因素影响小,能保证后备距离保护I段在各种线路运行方式下正确选相跳闸。

A new fault phase selector for double circuit lines on the same tower based on impedance comparison

The multiplex phase-comparison type ground and phase distance relay for double circuit lines on the same tower is studied.Then a new fault selection scheme based on impedance comparison is presented.According to the measure impedances,this new scheme selects the phases again which have been selected by the improved multiplex phase-comparison type distance relay.Using this fault phase selector,back-up distance relay for double circuit lines on the same tower can distinguish between cross country faults near to the end line and internal phase-phase faults responsibly by set coordination.The digital simulation indicates that the new fault selection scheme based on the impedance comparison is hardly influenced by topological structure and symmetry of double circuit lines on the same tower is lightly and the back-up distance relay in zone I may cut off the selected fault circuit correctly.