220kV母线保护系统中母联、分段开关典型死区保护分析

Analysis on Typical Dead Zone Protection of Bus Coupler and Section Switch in 220kV Bus Protection System

就目前220 kV母线保护系统中母联、分段开关典型死区故障时的保护动作行为进行了描述,分析了典型死区保护逻辑存在的问题;就此问题提出了母联、分段开关两侧TA电流判据策略,从而有效避免了合位死区故障时装置误跳正常母线区段的情况,可有效降低事故影响范围。与此同时,在各类母线故障情况下,也将改进后逻辑的选择准确性和出口动作时间上与目前的保护装置逻辑进行了对比,并对改进措施的优劣势进行了探讨,为此类保护设计及调试提供实用的参考。

The protection action during typical dead zone fault of bus coupler and section switch in 220 kV bus protection sys- tem at present is described, and the logic problems of typical dead zone protection are analyzed. The CT differential current criterion of both sides are put forward to judge dead zone fault ahead of time, thus the protection can effectively avoid tripping normal bus segment when the dead zone failure happens in closed position, so it can effectively reduce the influence scope of the accident. At the same time, in all kinds of bus faults, the improved logic selection accuracy and export action time are compared with the current protection logic, and the advantages and disadvantages of the improvement measures are also dis- cussed, which can provide a useful reference for the future protection designing and commissioning.