交、直流滤波电容器故障分析及对策

南桥换流站自１９８９ 年投运以来，直流场中交、直流滤波电容器损坏严重。华东电力集团公司委托华东电力试验研究院对滤波电容器损坏原因进行了分析，研究表明：滤波电容器的损坏既有工艺方面的原因，如密封不良导致漏油，浸渍不良导致介质中存在局部薄弱点，也有电容器设计场强选择过低的原因，尤其是直流滤波电容器在污秽和潮湿条件下，其工作电压远高于设计电压。针对以上情况，提出了改善电容器的制造工艺，并联低阻值均压电阻及降低设计场强等技术措施。

Failure Analysis on AC and DC Filtering Capacitor and the Countermeasure

DC and AC filtering capacitors in Nanqiao converting station have been seriously damaged since the commerce operation in 1989 and the cause of the damage is analysed by ECEPRTI under the entrustment of ECEPGC. The cmelusion shows that the cause of the failure are defects in both manufacturing(such as oil leak due to insufficient sealing and local weak point in insulating medium due to inadequote soaking) and design excessive lowfield strength gelecteet, especially under contaminated and wet environment the working voltage of the capacitor is far higher than the design roltage. The comtermeasutes suggested indude in provement of manufocturing process and deevease of design field strength and etc.