New method of calculation of temperature distributions on transformer tanks

A formula that calculates the distribution temperature in the transformer tank zones close to bushings is deduced. The new formula can use analytically or numerically obtained loss distributions. The comparison of the analytically calculated temperature distribution, using proven loss distributions, with finite element simulations, that use a thermal-electromagnetic coupled problem, shows that there is a very good match between numerical and analytical results. Apart, the new formula requires much lower computational resources as compared to finite element simulations that require commercial or highly specialized software. Our formula can provide to designers a powerful tool to improve efficiency and to increase useful life of transformers.