Research on temperature rise characteristics of interturn short circuit in transformer based on multi-physics coupling

In the operation of the power system, the reliable work of the power transformer is the basis of the safe and economic operation of the power system, the failure of the transformer will not only cause the transformer to stop operation, but even damage, thus affecting the normal operation of the power system. In this paper, based on multi-physics coupling, interturn short-circuit fault is set in COMSOL software to simulate the interturn short-circuit operation of transformer and its temperature distribution is obtained. It is determined that the change of normal winding current is not obvious when the early turn to turn fault occurs in the high voltage winding. However, the current and heat production of the faulty coil increased significantly, resulting in an increase in the temperature of the top oil and tank casing. Therefore, thermal characteristics such as the top oil temperature winding current can be used to detect inter-turn faults in the early stage.