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

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.