Abstract:As substations shift from manned to unmanned, operators use cameras and robots to capture equipment images to understand the operation of the equipment. However, under foggy conditions, the images collected by the substation have issues of low visibility and unclear clarity, resulting in ineffective remote monitoring and operation, and increasing the safety risk of power grid operation. This article focuses on the study of images of substations in foggy weather. Firstly, the current types of image defogging algorithms and their applications in power systems were reviewed. At the same time, the characteristics of the substation foggy image image were summarized, including the composition of meters, switches, and other equipment, and the background colors of the image were mainly gray, yellow, black, white, and other colors. Then, the principles of several defogging algorithms based on image restoration and image enhancement techniques were analyzed and introduced. And select the actual collected substation foggy images, starting from subjective and objective evaluation, comprehensively compare and analyze the advantages and disadvantages of several defogging algorithms in the defogging ability of substation foggy images. Finally, based on the characteristics of foggy images in substations and the development trend of image defogging technology, several future development directions are proposed.