The Temperature Variation Characteristic Analysis Based on the Electromagnetic-Thermal Coupled Method for the Dry-type Transformer

In order to obtain the temperature variation characteristic and overload capability of the dry-type transformers in the ocean oil-extracting power system, an electromagnetic-thermal coupled method is proposed in this paper. Firstly, the heat generation and dissipation mechanism of the dry-type transformer are analyzed, and the uniform equations of electromagnetic and thermal analysis are established through the electric power losses. Then, a 3D finite element model is established to describe the electromagnetic-thermal coupling characteristics for the dry-type transformer. And considered the effects of temperature on electrical conductivity. Finally, the power losses and temperature rise of the dry-type transformer components are calculated, and the relationship among the load factor, losses and temperature variation are analyzed in detail. In addition, the allowable overload capability are considered based on the temperature limit.