Study on the influence of wind and sand erosion on the audible noise of corona discharge at the terminal ball of pipe-shaped busbars in 750kV substations

In order to effectively achieve corona control and precise noise reduction in various 750kV substations in the northwest region, this paper studied the influence of wind and sand erosion on the audible noise of corona discharge at the terminal ball of the tubular busbar in 750kV substations. Using the outdoor test field of the Power Equipment Quality Inspection and Testing Center of Wuhan Branch of China Electric Power Research Institute as the test platform, the surface of the terminal ball of the tubular busbar was polished with sandpaper of different particle sizes to simulate the surface damage state of the ring under wind and sand erosion. Obtained the starting and extinguishing voltages of corona discharge at the terminal ball of tubular busbar caused by wind erosion, as well as the distribution pattern of audible noise. The research results indicate that after polishing the surface of the terminal ball of the tubular busbar with sandpaper of different particle sizes, the complete halo noise on its surface increases with the increase of roughness. After surface chiseling, the corona noise value is significantly higher than that before polishing, with a difference of about 3-6dB in noise variation. The research results can provide sufficient experimental basis for the selection of terminal balls for tubular busbars in substations in wind erosion areas, and have good practical value.