I. Introduction
Since the 21st century, due to the rapid improvement of science and technology in China, China has become the country with the highest voltage level and the largest power grid in the world. As a key link in grid operations, the functioning of its equipment has a direct impact on the power supply of the grid. Since the substation operates outdoors, it is affected by seasons, weather and foreign matter invasion for a long time, and the equipment is prone to rust, insulation aging and other problems, which in turn affects the safety and stability of the power grid system. Therefore, timely understanding of the operational status of substation equipment and improving the efficiency and accuracy of fault hidden danger detection is the current key work of electric power personnel.