断路器开断短路电流累积烧蚀效应研究

Study on Cumulative Ablation Effect of Circuit Breaker due to Breaking Short-circuit Current

断路器在多次开断短路电流后,准确评估电流能量对灭弧室弧触头的烧蚀程度是一个困扰运维人员的技术难题,特别是在不解体断路器灭弧室的条件下,采用电气试验手段以何种特征参量准确反映弧触头的寿命状态是该难题的关键。文中重点研究断路器开断短路电流后触头的累积烧蚀效应,采用4台真型500 kV柱式断路器作为研究对象,结合动态电阻测试手段,在短路开断合成回路中跟踪检测断路器电寿命试验过程中弧触头状态的演化趋势,研究得到了电寿命试验前后弧触头烧蚀特性,以及表征弧触头状态的特征参量(有效接触位移、接触电阻和累积电流开断能量)的关联性,揭示了短路电流累积开断效应对断路器寿命状态的影响规律,可为运维人员评估断路器灭弧室状态以及制定后续检修策略提供依据。

To accurately evaluate the ablation degree of contacts of a circuit breaker after repeatedly breaking shortcircuit current,four full-size 500 kV circuit breakers were investigated via electrical endurance tests with respect to the cumulative ablation effects of the contacts after interrupting short-circuit current,where dynamic contact resistance measurement(DRM)was adopted.The relationships of effective contact displacement,effective contact resistance,and cumulative current interrupting energy were established according to the variation of the contact ablation conditions in the electrical endurance tests.This study reveals the cumulative ablation effect of circuit breaker on its lifetime state,and may facilitate the condition evaluation of the circuit breaker chamber and the design of the maintenance strategy.