Three-Dimensional Methodology for the Overheating Hazard Assessment on Transformer Covers

In this paper, a 3-D methodology for the overheating hazard assessment on transformer covers based on electromagnetic analytical formulation linked with thermal finite element method is presented. The objective is to offer a practical tool to compute the temperature distribution and to localize the hot spots on transformer covers due to electromagnetic induction. The proposed methodology is carefully focused on those cases where the electromagnetic wave penetration depth compared to the big machine dimensions is a key issue. The accuracy of obtained results is ensured by means of the identification of proper electromagnetic and thermal parameters involved in the computation. An experimental work is presented, and measurements are compared with simulation results using different finite element models.