Computation of temperature distributions in transformer covers due to high crossing currents in bushing regions

Abstract Analytical formulae are widely applied in transformer design due to their easy implementation and low demand of computational resources. One of the great challenges in the field of transformer design is the acquisition of closed-form formulae for calculating temperature distributions in transformer tanks, taking account of different types of surrounding media. The presence of these media results in a variety of boundary conditions when solving the heat equation. In this research, a new rigorous analytical formula for calculating temperature profiles in bushing regions of transformer tank walls is obtained by solving the heat equation, with boundary conditions that properly model the heat interchange between different surrounding media. The heat source is modeled using a formula taken from a previously published investigation performed by the authors. Several study cases are performed, where analytical results are compared with finite element simulations for different boundary conditions. Analytical and numerical results show a good match, demonstrating high precision of our developed analytical method. Thus, this method provides a powerful tool for calculating temperature distributions in transformer tanks, which can be employed for optimization purposes during transformer design stages.