核电厂非1E级低压负荷中心接地故障保护可靠性问题分析

Analysis on Reliability Issues in Ground Fault Protection of Non Class 1E Low Voltage Circuit Breaker of NPPs

结合某堆型核电厂低压断路器接地故障保护功能发生误跳闸的实际案例,讨论电动机负荷启动瞬间存在包含多种频率的暂态谐波分量对接地故障保护的可靠性影响,以及解决方案和存在问题。

To deal with an actual false tripping of the ground fault protection system in the low voltage circuit breaker of a nuclear power plant （NPP）, an analysis was conducted on the impact of multiple frequency transient components occurring at the moment of motor starts on the reliability of the ground fault protection, and finally a solution and existing problems were presented.