一种基于电压序分量的高压线路保护选相元件

通过对零序、负序电流构成的序分量选相元件所存在问题的探讨，以及对单相接地和两相接地故障时，零序电压和正序电压不同相位关系的分析，得出了一种由零序、负序、正序电压所构成的新型故障序分量选相元件。该元件原理简单，选相可靠，不仅能对一般性故障正确选相，而且在转换性故障，同杆并架上的跨线故障等特殊故障情况下也能正确选相，满足了高压及超高压线路保护中对选相元件的要求。

A New Scheme of Faulty-phase-selection by voltage-sequence-component

According to the research on the defect of zero sequence current and negative sequence current faulty phase selection, and the analysis of the different phase relation of zero sequence voltage and negative sequence voltage when the system has two phase fault or single phase fault, a new faulty phase selecting scheme making up of the zero sequence voltage, negative sequence voltage and positive sequence voltage is put forward in this paper. The principle is simple and can select faulty phase correctly and unfailingly, not only for the normal fault, but also for the transferring fault, and the cross over fault on double circuit tower. It meets the demand of ultra high voltage line protection.