Electric field simulation analysis of ICOG corona ring and study on flashover characteristics of bird droppings

In the bird-related faults of transmission lines, the bird droppings flashover fault caused by the short-circuiting of bird droppings to the corona ring is extremely significant. To decrease the flashover probability of bird droppings and improve the convenience of installation, this paper proposes a method of coating the insulating layer on the open-gap corona ring, and verifies the insulation performance of the insulation coated open-gap (ICOG) corona ring through simulation and experiment. In this paper, the feasibility of corona ring coating insulating layer is verified by finite element simulation, and the influence of ICOG corona ring structure on the surface electric field distribution of composite insulator is studied. Finally, the impact of various bird droppings parameters on the flashover of the ICOG corona ring is investigated through experiments and compared with the flashover of an ordinary corona ring. The simulation results show that when the opening distance is 50-70 mm, the opening is toward the tower side, and the thickness of the insulating layer is 5 mm, the surface field strength of the composite insulator is the smallest. The experimental results show that the flashover probability of bird droppings increases with the increase of conductivity and viscosity of bird droppings. After the open-gap corona ring is coated with the insulating layer, the area where the bird droppings flashover occurs is reduced by about 20 %, which can better play the role of anti-bird flashover and has better convenience. This paper provides a certain reference for the anti-bird control of transmission lines.