劣化复合绝缘子闪络特性研究

复合绝缘子由于其质量轻体积小、机械性能好、抗污能力强、安装方便的特点而被大范围使用，但由于复合绝缘子伞裙和芯棒材料在使用中容易产生劣化，劣化后的复合绝缘子电气性能将会降低，其自然闪络及污秽闪络特性有待研究。选取的样品为运行5~7年的220 kV复合绝缘子，进行了劣化复合绝缘子的自然状态污闪试验和人工污秽闪络试验。研究发现，不同劣化程度的复合绝缘子在自然状态下的闪络特性差距较大，且随着劣化程度的降低，闪络电压呈现增加的趋势。闪络电压最高的样品为最低样品闪络电压的3.956 7倍。对于6支绝缘子试品，其低压端试验样品污闪电压明显低于高压端试验样品，低33%~64%。对于不同劣化程度的复合绝缘子，其闪络电压均随着SDD的增加而降低，且污秽对轻度劣化绝缘子闪络电压影响较大。劣化复合绝缘子闪络电压和SDD之间依然满足负幂函数关系，且随着劣化程度的降低，其幂函数常数a逐渐增加。研究结果对外绝缘劣化复合绝缘子防污工作具有指导和借鉴意义。

Study on flashover characteristics of degraded composite insulators

Composite insulators are widely used due to their light weight,small size,good mechanical properties,strong anti-fouling ability,and easy installation.The electrical performance of the deteriorated composite insulator will be reduced,and its natural flashover and contamination flashover characteristics need to be studied.The selected samples were 220 kV composite insulators with an operating life of 5 to 7 years,and the natural state pollution flashover test and artificial pollution flashover test of the deteriorated composite insulator were carried out.It was found that the flashover characteristics of composite insulators with different deterioration degrees were quite different in the natural state.And with the decrease of the deterioration degree,the flashover voltage showed an increasing trend.The sample with the highest flashover voltage was 3.956 7 times the flashover voltage of the lowest sample.For the 6 insulator samples,the pollution flashover voltage of the low-voltage end test samples was significantly lower than that of the high-voltage end test samples,33%~64% lower.For composite insulators with different degrees of deterioration,the flashover voltage decreased with the increase of SDD,and contamination had a greater impact on the flashover voltage of mildly deteriorated insulators.The relationship between the flashover voltage of the deteriorated composite insulator and SDD still satisfied the negative power function,and the power function constant a increased gradually with the decrease of the deterioration degree.The research results had guiding and reference significance for the anti-fouling work of composite insulators with external insulation deterioration.