复合绝缘子污闪与冰闪特性及临界闪络电流研究

绝缘子的电气特性是进行输电线路外绝缘设计的关键参数之一，其临界闪络电流对绝缘子的状态评估和闪络预警有着重要的作用。以FXBW-110/100型复合绝缘子为试品，在人工气候室对该绝缘子进行了人工污秽试验和人工覆冰试验。试验结果表明：复合绝缘子污闪和冰闪电压随着绝缘子表面盐密的增加而降低，冰闪和污闪电压与盐密均满足负幂指数关系，覆冰条件下的污秽特征指数与污秽无覆冰状态下的特征指数相差不大，可将覆冰视为一种特殊形式的污秽；在相同污秽条件下覆冰复合绝缘子的闪络电压比未覆冰的闪络电压低，随着覆冰厚度的增加，绝缘子闪络电压进一步降低；复合绝缘子污闪和冰闪的临界闪络电流与盐密满足幂指数关系，污闪和冰闪的临界闪络电流均随着绝缘子表面的盐密的增加而增加，在相同污秽条件下覆冰绝缘子的临界闪络电流比未覆冰的临界闪络电流更大。

Study on Icing and Contamination Flashover Characteristics and Critical Flashover Current of Composite Insulators

The electrical characteristics of the insulators are one of the key parameters for the design of the external insulation of the transmission lines. Insulator critical flashover current plays an important role in condition assessment and flashover warning for insulators. In this paper, the artificial pollution test and artificial icing test of the FXBW-110/100 composite insulators are carried out in the artificial climate chamber. The test results show that the contamination flashover voltage and icing flashover voltage of composite insulator decrease with the increase of salt density on the surface of the insulator, which can be fitted as the exponential expression. The fitting parameters of the exponential expression under contamination condition with and without ice are almost same. Therefore, the icing condition can be considered as a special form of pollution condition. The flashover voltage of the insulators with icing is lower than that of the insulators without icing under the same pollution conditions. The flashover voltage decreases with the increasing of the thickness of icing layer on the insulator. The critical flashover current of icing and contamination composite insulators increases with the increase of SDD. The relationship can be fitted as exponential expression under the same pollution conditions, the critical flashover current(Ic) of ice covered insulators is larger than that without icing.