盐密和灰密对110kV复合绝缘子闪络电压的影响

Effect of Both Salt and Non-soluble Deposit Densities on Flashover Voltage of 110kV Composite Insulator

合成绝缘子具有很好的防污闪特性,但也会发生污秽闪络,这与常规的人工污秽试验仅考虑盐密的影响不无关系。文中选择110kV合成绝缘子为试品,在人工雾室中研究了灰密(NSDD)和盐密(ESDD)对合成绝缘子污闪特性的影响,分析了NSDD影响的原因,并采用2种方法对试验数据进行了分析和拟合。结果表明:人工污秽试验中,合成绝缘子污闪电压Uf与ESDD和NSDD均有关,但二者的影响是彼此独立的;随着ESDD或NSDD的增加,其Uf均按幂函数规律降低;ESDD和NSDD对Uf影响的特征指数分别为0.106、0.140,即对于合成绝缘子,灰密的影响大于盐密,这与瓷绝缘子相反;灰密对污闪电压影响的原因之一是吸收更多的水分,二是破坏合成绝缘子的憎水性。

A composite insulator has better anti-pollution performance, but sometimes flashover occurs on it. It may be related with the pollution test method in which the non-soluble deposit density（NSDD） does not be included. According to the test results carried in the artificial fog chamber, this paper analyzes the effects of the equivalent salt deposit density （ESDD） and the non-soluble deposit density（NSDD） on the flashover performance of the 110kV composite insulator. The result shows that the flashover voltage Uf of the 110kV composite insulators decreases with the increase of both ESDD and NSDD by an power function with a negative index that is 0.106 for ESDD and 0.140 for NSDD. That is, the effect of NSDD is more than that of ESDD, which is opposite with a porcelain insulator. Because the non-soluble deposit can stop the hydrophbicity recovery and absorbs more water which is helpful to solution of the conductive materials, Uf decreases with the increase of NSDD.