均压电容异常引起的500 kV避雷器过热试验分析

Analysis and test on 500 kV surge arrester overheating caused by ceramic capacitor abnormal

均压电容在避雷器内部起着改善内部电压分布、抑制外部杂散电容影响的作用。针对1例变电站500 k V避雷器过热案例进行研究分析。对避雷器进行了多种手段在线检测,表明避雷器内部存在均压电容异常;进一步的离线试验和解体分析发现该避雷器均压电容上、中节反装,验证了分析结论。针对避雷器的发热异常,提出了相应措施。

Ceramic capacitor plays an improve internal voltage distribution within the arrester,to inhibit the action of the external stray capacitance effects. In this paper analysis and test on500 kV surge arrester overheating caused by ceramic capacitor abnormal. A variety of on-line detection means shows that arrester within equalizing capacitor; further offline test and disassembly analysis found that existence of ceramic capacitor upper and middle section exists,verify the analysis. In view of the fever abnormal surge arrester,corresponding measures are put forward.