±800 kV特高压直流分压器内部故障的SF_6分解物测试特性

Test Characteristics of SF_6 Decomposition Components for Internal Fault of ±800 kV UHVDC Voltage Divider

SF_6分解物测试是判断SF_6绝缘设备内部放电故障有效的方法。笔者在对一起直流分压器故障的分析过程中发现,SF_6气体分析未能正确反映第一次跳闸时内部已经出现的放电故障。后对直流分压器进行解体发现,由于其内部电容器气室为单独密封设计,造成电容器内部放电故障产生的SF_6分解物未能在直流分压器取气口测出,以致不能正确判断设备健康状况。文中建议进行SF_6分解物测试必须清楚了解设备内部气路构成,并对在运的直流分压器故障诊断提出方案,对制造厂在直流分压器内部设计提出改进建议。

SF6 decomposition components test is an effective method to determine the internal discharge fault of SF6 insulation equipment. This paper proposes that the SF6 gas analysis failed to correctly reflect the discharge fault during the first trip in the analysis of the fault of DC voltage divider. After the disintegration of the DC voltage divider, it is found that the SF6 decomposition generated in the capacitor internal discharge could not be detected through the gas test tap of DC voltage divide due to internal condenser gas chamber for individual seal design, and it leads to failure to correctly judge the health status of the device. It is suggested that the SF6 decomposition components test must be made to understand the internal gas path composition of the equipment, and the scheme of fault diagnosis of DC voltage divider in operation. Improvement suggestions are put forward for the internal design of the DC voltage divider.