发变组断路器断口闪络保护改进措施

Improvement Approach to Circuit Breaker Flashover Protection of Generator-Transformer Unit

通过主断路器断口闪络导致断路器爆炸的两个典型案例分析,认识闪络时电流电压变化特点。从理论上分析了闪络振荡最小电流,提出了闪络保护改进措施。建议增加500 kV和220 kV的断路器闪络失灵保护,可以在闪络后的两百多毫秒通过闪络失灵保护切除故障,有效减小断路器爆炸和主设备损坏的风险。

This paper introduces the characteristics of current and voltage variation during flashover through analyzing two typical cases of breaker explosion caused by flashover of main circuit breaker,and then theoretically analyzes the minimum current during flashover oscillation,and puts forward the improvement measures of flashover protection.Finally,the paper suggests adding 500kV and 220kV circuit breaker flashover failure protection,where flashover failure protection can function to remove faults in over 200 milliseconds after flashover,effectively reducing the risk of breaker explosion and main equipment damage.