Evaluation of Eddy Losses Due to High Current Leads in Transformers Using a Subproblem Method

A subproblem finite element method is developed for evaluating the eddy losses due to high current leads in transformers. The structural component of the transformer is modeled with classical volumetric elements or more efficiently with a thin shell model (surface impedance technique). Tools are then developed to correct the inaccuracies near edges and corners inherent to thin shell models for magnetodynamic problems. Improvements of local fields make possible accurate calculations of eddy losses and of temperature rise.