Failure diagnosis techniques of grounding grid of substations and the urgent problems existing in the area

Firstly, the paper analyses overall present status of failure diagnosis of grounding grids and the latest technologies. Then it studies the commonly used methods in the area at present, including the relative method, the method according to detection the ground magnetic field and electric potential difference, the method of tabu search, the micro-disposal method etc, and compares their merits and drawbacks. At last the paper points out the urgent problems existing in the area, such as diagnosticability of grounding grid failure diagnosis, practicality of grounding grid failure diagnosis, meantime gives some countermeasures, and discusses the trend of development of failure diagnosis technology of substations, according to the situation of power system in China.