发电机出口断路器冲击保护电容漏油分析及处理

Analysis and Treatment of the Oil Leakage Fault of the Impulse Protection Capacitor for Generator Outlet Circuit Breaker

针对大型发电机组出口GCB冲击保护电容的两起渗油故障,分析其对断路器及发变组运行的影响,在现有电容结构漏油时,会产生电容击穿的风险。由于其电容量较大,目前固体电容结构无法满足要求,只能采用充油电容结构,将电容首端极板接入至电容底座接地,使其在漏油时电容首端极板全部浸没在绝缘油中,保证高压侧极板的绝缘强度。

Two oil leakage faults observed in the impulse protection capacitor of the generator outlet circuit breaker(GCB)are analyzed.As the oil leakage of the capacitor structure may result in capacitor breakdown,the possible influences of the fault on the breaker and the generator-transformer unit are discussed.Considering the large capacitance and the specific working condition,the solid capacitor cannot meet the requirements and the oil-immersed capacitor is still adopted.While the internal structure of the capacitor should be modified to insert the head end plate of the capacitor to the base,so that the plate is immersed in the insulating oil even in case of oil leakage to ensure the insulation of the high voltage side plate.