Simulation and experiment of a composite insulator with lightning protection and icing flashover prevention

For power transmission lines in the area with atrocious environment, tripping accidents often occur resulting from the insulator flashover caused by serious lightning or icing. A novel composite insulator combining lightning protection and icing flashover prevention is proposed. The novel composite insulator with the rated voltage of 220 kV is designed and manufactured. Electric field distribution simulations are performed on the novel composite insulators under clean and icing conditions. The highest electric field strength in the simulation space is less than the air breakdown electric field strength under either clean or icing condition. The proportion of the voltage of the lightning protection part to the total voltage of the entire composite insulator changes from 10 % under clean condition to 50 % under icing condition, owing to the ice covered on the insulator. Experiments are carried out and the results are in agreement with the simulations. Lightning performance experiments show that the novel composite insulator meets the requirements of a metal oxide surge arresters for power transmission line. Icing experiments show that the novel composite insulator can prolong the ice-bridging time and can improve the icing flashover voltage effectively. The onsite application of the novel composite insulators proves the expected effect.