Comparison of DC flashover performances of polluted composite post insulators in coastal areas and inland areas

作者：Gu, Yu^*; Hao, Yanpeng; Zhang, Fuzeng; Xue, Yiwei; Min, Jianfeng; Yang, Lin; Li, Licheng

来源：Power System Technology, 2014, 38(5): 1373-1378.

DOI：10.13335/j.1000-3673.pst.2014.05.038

• Coastal area
• Composite post
• ESDD
• NSDD
• Pollution flashover performance

According to the survey results of natural pollution of insulators in coastal areas, different ratios of equivalent salt deposit density (ESDD) to non-soluble deposit density (NSDD) are used to represent the accumulated pollution characteristics of composite post insulators located in coastal areas and inland areas. Firstly, the changing tendency of the upside shed surface resistances of the two sorts of specimens were measured in the fog chamber;then the DC artificial pollution tests were performed in National Engineering Laboratory for Ultra High Voltage Engineering Technology (Kunming) and the pollution flashover voltage U50% was determined by the Up-and-Down method. During the tests the partial discharge of the two sorts of specimens was observed by ultra violet camera and the statistics of ultraviolet photons was carried out, meanwhile the high-speed camera Phantom 12.1 was used to observe the partial discharge and the development of partial arcs on the insulator surfaces of the two sorts of specimens, which were assumed to be located in coastal areas or inland areas. Test results show that the surface resistances of specimens in inland areas with higher NSDD is lower than that in coastal areas;under the same ESDD the U50% of composite post insulators in coastal areas is higher than that in inland areas, and with the increase of ESDD the difference of the U50% between them is greater;on the specimens with higher NSDD for inland areas the partial arc is easy to occur and it causes the dry-bands on the surfaces of insulators, when dry-band appears, its strong water absorbability makes the dry-band moist once again immediately, and the repeated reoccurrence of this phenomena makes the insulator surface flashover and the U50% is lower than that of composite post insulators in coastal areas;with the increase of test ESDD, not only the surface resistances of the specimens decrease further, but also the arcing-bridge of sheds on inland area specimens with higher NSDD becomes more obvious, it decreases the availability of creepage distance evidently and make the greater difference between the U50% of composite post insulators in the inland areas and that in the coastal areas.

• 出版日期2014-5
• 单位华南理工大学; 南方电网科学研究院有限责任公司