低气压下三种直流绝缘子覆冰闪络特性及其比较

ICE FLASHOVER PERFORMANCE AND COMPARISON ON THREE TYPES OF DC INSULATORS AT LOW ATMOSPHERIC PRESSURE

根据人工气候室模拟覆冰条件所进行的直流闪络试验结果,分析了气压和覆冰水电导率对二种超高压直流绝缘子(XZP-160、LXZP-210、XZWP-160)覆冰负极性闪络电压的影响。试验结果表明:直流绝缘子覆冰负极性闪络电压与气压、覆冰水电导率等呈非线性关系;覆冰水电导率对负极性闪络电压的影响在覆冰期比在融冰期更严重;不同结构绝缘子的冰闪电压有着明显的差异,三伞型 XZWP-160绝缘子受气压和污秽的影响比钟罩犁XZP-160和LXZP-210绝缘子严重。由此,建议住高海拔覆冰地区要慎重选择直流绝缘子。同时对三种不同类型的绝缘子在覆冰期的闪络电压进行校正,这对我国西电东送工程中直流输电外绝缘的设计有着重要的参考价值。

Based on the investigations carried out in the artificial climate chamber on three types of DC iced insulators (XZP-160, LXZP-210, XZWP-160), this paper analyzes the effects of the atmospheric pressure and the freezing water conductivity on the -DC flashover voltage of the iced insulators. The test results show that the -DC flashover voltage of the iced insulators is a non-linear relation with the air pressure and the freezing water conductivity, and that the effect of freezing water conductivity on the -DC flashover voltage of the iced insulators is much more severe during the freezing than during the melting; The effects of the air pressure and pollution on the -DC flashover voltage of the XZWP-160 which is with three sheds are much more serious than that of the other two insulators. So this paper suggests that it is not suitable to use XZWP-160 insulators at high altitude and icing districts. And it puts forward a correction method of the -DC flash-over voltage for the three type insulators. The results obtained here could be used as a reference to design the external insulation of DC transmission on the west-to- east power transmission.