一起220 kV断路器非全相保护误动事件分析及回路改进方法

Analysis of a Maloperation Event of Non Full Phase Protection of 220kV Circuit Breaker and the Method of Circuit Improvement

针对电力系统中频繁出现的断路器非全相保护误动作问题,以一起220kV线路断路器本体非全相保护误动事件为例,深入分析保护误动的原因,并结合实际运维情况,在传统的断路器非全相保护回路的基础上,提出了基于断路器的三对常开常闭辅助触点的非全相保护回路改进方法。此方法能有效避免由于外部环境、开关辅助触点或继电器故障等因素引起的本体非全相保护误动。并以220kV备用甲乙线断路器本体非全相保护回路为例进行验证,试验结果证明了该方法的有效性和可行性。

Aiming at the malfunction problem of non-full-phase protection of circuit breaker which is frequently happens in the power system, taking the maloperation of non-full-phase protection of a 220 kV line circuit breaker as an example, the causes of maloperation of protection are analyzed in depth. Considering the actual operation and maintenance situation, an improvement method of non-full phase protection circuit based on three pairs of normally open and normally closed auxiliary contacts is proposed. This method is based on the traditional circuit breaker non-full phase protection circuit, which can effectively avoid the misoperation of non-full-phase protection caused by external environment, switching auxiliary contacts and relay faults. Taking a 220 kV standby line A and B circuit breaker body non-full phase protection circuit as an example, the method is proved to be effective and feasible by the experiment.