Effects of Air Humidity and Hanging Angle on Accumulation Characteristics of Pollution Particles on Anti-icing Polymer Insulators

Abstract

Pollution flashover accident is one of the main faults in various high voltage transmission lines, which affects stability and safety of electrical power systems. The accumulation of pollution particles on the insulator surface is the premise of pollution flashover accidents. In this paper, based on the actual operating conditions of polymer insulators, suspension patterns of the insulator, movement trajectory of pollution particles and the air humidity were considered to investigate the accumulation characteristics of pollution particles by using FLUENT software. Firstly, according to the actual dimension of 500 kV anti-icing polymer insulators, the insulator simulation model and air flow field were established at a ratio of 1:1. Secondly, considering the influences of gravity and fluid drag force, pollution particles were added to the air flow field to analyze the motion characteristics of particles. Thirdly, the different hanging angles of “V” type insulator (15°, 30°, 45°, 60°, −15°, −30°, −45°, −60°) and air humidity (0.01%, 0.04%, 0.07%, 0.1%) were set to study the collision rate of pollution particles. The pressure contour around the insulator, movement trajectory of pollution particles and collision rate were obtained with variation of air humidity and suspension patterns of the insulator. The obtained results show that with increasing the hanging angle of insulator, the collision rate of particles shows the increasing tendency from 0°∼30°, but shows the decreasing tendency when the angle is higher than 30°. When the hanging angle is from 0° to −60°, the changing trends of collision rate is the same with that from 0° to 60°, but the maximum collision rate is smaller than that from 0° to 60°. As the humidity increases, the water vapor in the air prevents the movement of pollution particles, resulting in the decrease in the collision rate.