Modeling of early stage partial discharge and overheating degradation of paper-oil insulation

The power transformer is one of the most important equipment in the electrical power system due to its cost and potential failure's consequences. To ensure a continuous energy supply, it is needed to assess abnormal condition such as thermal and electrical behavior. From this viewpoint, dissolved gas analysis (DGA) is very useful in detecting internal defects in oil-filled electrical equipment. A system has been developed that allows to simulate partial discharge and overheating in transformer's insulation. By using this system, we have studied on DGA under low temperature overheating in mineral oil and vegetable oil.