葛洲坝换流站直流滤波器场高压电容器污闪原因分析及措施

介绍了葛洲坝换流站运行期间,从导致多次出现500kV直流滤波器组高压电容器外绝缘污闪放电情况。对滤波电容器组污闪放电现象进行了介绍,归纳出导致高压电容器污闪放电的三个因素(恶劣天气、外绝缘污秽、外绝缘设计)出发,指出现场污秽程度的不断加重和直流设备设计时外绝缘爬距偏小是恶劣天气时葛洲坝站高压电容器污闪放电不断出现的原因。从设备运行和设计两个方面分别提出了避免葛洲坝站高压电容器污闪放电的应对措施。现场已通过高压电容器外绝缘表面喷涂PRTV材料,有效提高了恶劣天气下外绝缘的抗污闪能力,弥补了外绝缘设计裕度偏小的问题,消除了恶劣天气下葛洲坝站高压直流电容器污闪放电现象,提高了葛-南直流系统的运行可靠性。实践证明,对于外绝缘裕度偏小的设备,采用喷涂PRTV的方法可以提高设备的绝缘能力,防止恶劣天气下污闪事故的发生。

The Analysis and Solution of Flashover Discharge on HVDC Filter Capacitor in Gezhouba Converter Station

DC filter HV capacitor flashover discharge happens frequently during the Gezhouba-Nanqiao HVDC system operation. The flashover phenomenon is introduced in this paper of three reasons （bad weather,dirt and insulation design） lead to this flashover discharge,especially the local dirt level increase and insufficient insulation capability of design are the main reasons. Then two solution methods are put forward to prevent this flashover discharge such as operation anti-flashover measures and design improvement. To solve this problem,the PRTV was painted on the insulation surface of DC filter HV capacitor in Gezhouba Station. After that,the flashover discharge disappears when in bad weather during operation. At the end of the paper,the conclusion is drawn out that PRTV painting can increase the capability of insulation equipment and prevent the flashover accident.