Analysis of Hot Spot Temperature of Dry-Type Transformer Based on Finite Element Method

Abstract

The service life of dry-type transformers and their operating conditions depend largely on the insulation performance of its windings, the heat generation and heat dissipation inside the dry-type transformer and its insulation performance affect each other, together determining the overall working performance of the dry-type transformer. The internal temperature distribution of dry-type transformers, especially the hot spot temperature, has become an important indicator for its stable operation. Therefore, a more accurate research of the temperature field distribution in dry-type transformers is of great significance for transformer life assessment. Based on the analysis of dry-type transformer heat generation and cooling theory, this paper establishes a three-dimensional finite element simulation model of dry-type transformer, and conducts electromagnetic and thermal coupling simulation analysis of the finite element model to obtain the internal temperature field distribution. Compared with the actual situation, the simulation results are verified to be correct, the relationship between the hot spot temperature and the surface temperature is explored based on the existing simulation results and a mew method for calculating the hot spot temperature is proposed.