Visualization of surface discharge area in SF6 based on infrared trap

Abstract

A method for visualization of surface discharge area in SF6 based on infrared trap is proposed in this study. The infrared images of a heated insulator with a surface defect under different applied voltages were studied, and the infrared trap phenomenon was observed in the infrared image. When partial discharge occurs on the heated insulator surface, a spindle shaped infrared trap will be formed at the end of the defect. In the infrared trap area, the apparent temperature measured using the infrared camera decreases compared to that without discharge. The infrared trap area corresponds to surface discharge area. With the increase in the applied voltage, the discharge becomes more severe, the infrared trap area gradually expands, and the trap depth also increases. This infrared trap phenomenon found in this study can serve as a method to visualize the surface discharge area in SF6 gas.