基于污闪电压的自然积污绝缘子外绝缘状态评价

External Insulation Condition Evaluation of Naturally Polluted Insulators Based on Pollution Flashover Voltage

以浙江电网挂网运行的不同结构型式自然积污绝缘子为研究对象,在人工雾室进行污闪试验得到其污闪电压,并对其外绝缘状态进行评价,分析各种型式自然积污绝缘子的污秽度安全区域。结果表明:部分取样自然积污绝缘子的绝缘裕度较低,应及时采取防污闪措施。绝缘子上、下表面的污秽分布越不均匀,污秽不均匀度K值越小,绝缘子安全运行的允许ESDD值越大。总体上,钟罩型绝缘子的污秽度安全区域最大,双伞型绝缘子次之,普通型绝缘子的安全区域最小。

Taking different types of naturally polluted insulators on overhead transmission lines in Zhejiang power grid as research objects, pollution flashover tests were conducted in the artificial fog chamber and the pollution flashover voltage was obtained. On this basis, the external insulation condition was evaluated. The contamination safety zone of naturally polluted insulators was analyzed. The results show that the insulation margin of some sampled naturally polluted insulators was very low. It is necessary to take some timely measures for prevention from pollution flashover. The unevener the pollution distribution of upper and lower surfaces of polluted insulators is, the smaller the unevenness degree is, the larger the allowed equivalent salt deposit density（ESDD） value for safe operation is. On the whole, the safety zone of bell jar insulators is the largest, followed by the double-shed insulators and the safety zone of the common type insulators is the smallest.