计及系统稳定需求的500kV断路器失灵及死区保护优化

Improvement of 500kV Breaker Failure and Dead-zone Prevention Based on Requirement on Stability of Grid

当前,电网系统稳定性对故障极限切除时间的要求已越来越高,断路器拒动对系统稳定的影响也越来越大。基于对影响故障切除时间的因素,如主保护动作时间、断路器固有分闸时间、燃弧时间、失灵动作元件返回时间的分析,说明了影响断路器失灵及死区保护动作延时取值的主要因素及各影响因素的时间分布特性;同时,基于以上因素提出了失灵及死区保护的优化方案,并已成功应用于南方电网。

Nowadays, with the rapid development of power grid, the critical clearing time （CCT） is required to be shorter and shorter, while the breaker failure is exerting more and more influence on system stability. Based on a description of the main factors of the fault clearing time, including the protection releasing time, the inherent breaker opening time, the arc extinction time and current element returning time, the distribution and maximum of each component are analyzed, and the setting and logic optimization of both breaker failure prevention and dead zone prevention are proposed. The proposed optimization strategy is now applied in China Southern Power Grid.