Electric Field Simulation and Experimental Investigation of an Anti-ice-flashover Composite Insulator with Lightning Protection
|Keywords||lightning protection anti-ice-flashover finite element|
Ice flashover and lightning disasters greatly influence the security of power grid,which have always been the main reason of trip-out of transmission line. The design ofa new anti-ice-flashover composite insulator with the function of lightning protection wasproposed in this paper, and simulative and experimental methods to study thecharacteristics of flashover characteristics to verify the feasibility of the insulator wasused.On the basis of comprehensive analysis about research results of home and abroad,the finite element analysis software ANSYS to build the models of the electric fielddistribution of composite insulators under clean conditions was used in this paper. Theresults show that the insulation part of the insulator withstands most of the entire voltagewhile the lightning protection part withstands very low voltage under clean conditions.The basic, electric and mechanical performance tests were performed, and all the resultsmeet the standard requirements.While under icing condition, the simulation results show that the insulation partwithstands almost50%the entire voltage because of the influence of ice resistance, andthe potential distribution changes self-adaptively, as ensures the ability of anti-ice-flashover of the insulator. Through icing experiments, it was found that the ice bridgingwas postponed and the ice-flashover voltage was improved due to the protection of thebig sheds to the middle and small sheds.The electric field distribution of the insulator under pollution condition wassimulated. Because of the effect of pollution resistance, the voltage drop of the insulationpart is near to the lightning-protection part. As enlarged sheds increase creepage distanceof the insulator, the pollution experiments show that the flashover voltage of the newinsulator is higher than that of an ordinary one.According to the above, the sheds have little influence on the electric fielddistribution in clean condition. The sheds can prevent the insulation from connected byice in icing condition. Increasing the size of sheds can increase creepage distance of aninsulator, thus increase the flash voltage. The electrical characteristics of the newinsulator can meet the practical engineering requirements.