Analysis of an Internal Fault of Main Transformer

In recent years, with a large number of photovoltaic and other new energy connected to the grid, higher requirements have been put forward for the safety and stability of the power grid. The on-load tap changer of the main transformer plays a vital role. According to the light gas alarm and heavy gas trip of the main transformer body caused by the gear adjustment, this paper first carried out the on-site inspection of the main transformer body, especially the gear indication, and then judged the fault position through the oil chromatogram data and electrical test of the body and the oil chamber of the change-over switch. The fault position and cause was determined through the on-site core lifting and internal oil discharge inspection, and the treatment suggestions and measures of the same type of on load tap changer are given.