同杆双回线的六相序阻抗距离保护方案研究

The study on six phase sequence distance relay protection scheme for double-circuit lines on the same pole

指出了传统距离保护应用于同杆双回线时所存在的一些问题,如发生单回线接地故障时,由于相邻线零序电流的影响,会使测量阻抗的大小不能正确反映故障距离,导致保护拒动或超越;由于只使用单回线单侧电气量,使距离保护不能正确地反映双回线的跨线不接地故障等,提出了新型的同杆双回线的距离保护方案——基于六相序的距离保护方案,分析了六相序距离保护应用于同杆双回线时保护特性及相应的问题,并针对这些问题提出了改进方法。改进后的六相序距离保护可以很好地应用于同杆并架双回输电线路中,作为差动保护的后备保护,可以在单回线故障或跨线故障情况下正确地选择出故障线路。

This paper points out the existence of a series of problems about double-circuit lines on the same pole with the distance relay,such as measure resistance is influenced by adjacent line zero sequence compensation current on single-circuit line ground faults.A new distance relay protection scheme——six phase sequence distance relay scheme is introduced in this paper.Some question of the scheme applied in double-circuit lines on the same pole is pointed,at the same time,a new modified six phase sequence distance relay scheme is introduced.The modified six phase sequence distance relay protection introduces adjacent line zero sequence current only on ground faults single-circuit line.It can reflect the cross-country fault and single-circuit lines faults.The scheme can be used as back up protection as the differential protection in high voltage double-circuit lines on the same pole.