Simulation and Analysis Study on Transient Temperature Rise Process of Dry-type Transformer

With the improvement of the power supply reliability requirements of China's power system and the continuous development of dry-type transformer manufacturing technology, the proportion of dry-type transformers in China has gradually increased. However, because dry-type transformers are subject to high internal electric field stress, mechanical stress and thermal stress, local overheating is more likely to occur, thereby accelerating the deterioration of insulation materials, so the temperature distribution study of dry-type transformers is increasingly important. Combined with the actual temperature rise test, studying the temperature distribution of dry-type transformers under natural convection is the key point of this simulation. Based on previous research, considering the dynamic change process of actual temperature rise, this paper obtains a new idea of temperature distribution of transformers, that is, using transient analysis of natural convective heat transfer in dry-type transformers. Firstly, the transformer model and all the conditions for the required solution (boundary, excitation, mesh) are given; Then, the distribution of the transformer heat-current field within 10h was analyzed by transient analysis, and the hot spot temperature of the dry-type transformer was obtained. Then, the axial temperature distribution of transformer windings and cores was analyzed, and the temperature distribution inside and outside of the windings was compared and analyzed, indicating the temperature distribution situation. Finally, a fixed point, that is, the endpoint on the high-voltage winding, is selected for fitting and analysis of its temperature distribution. Finally, the method proposed in this paper effectively solves the temperature distribution and transient change process of dry-type transformer, and makes innovative contributions to the research in this direction.