The Influence of Wind Speed on Wall Bushing Surface Charge Transition

The outdoor side of the wall bushing runs in the natural environment for a long time and is blown by different wind speeds in nature. The influence of wind speed on the bushing surface charge is not clear. Based on the measurement of electric field, the surface potential transition of the true type ±100k V bushing under different wind speed conditions are measured. The results show that the transition process of surface potential with time is accelerated with the increase of wind speed. This is because the wind brings more ions from space, make the concentration and mobility of ions in the air higher. In the windward direction, the superposition of the wind and the original electric field makes the ions in the air migrate faster, forming a stronger air current density, resulting in faster charge accumulation on interface between air and sheds. In the measurement of axial surface potential, it is found that the heteropolar charge is mainly concentrated in the middle of the bushing, which causes the change of the measured surface potential trend. Non-uniform charge distribution along the axis will distort the axial electric field distribution of the bushing, which will increase the flashover probability along the surface of the bushing and affect the operation reliability of the bushing. The research in this paper can provide reference for bushing operation in actual windy conditions.