Design of an Unbalanced High Power Three-Winding Planar Transformer for Electric Vehicle Application

This paper presents the study of a three-winding planar transformer usually required for Three-port Active Bridge converters. The transformer operates at high switching frequency under unbalanced power flow conditions and contains parallel layers to handle high current. The main difficulty is to integrate high and low voltages respecting the insulation exigencies and keeping a small number of PCB's with reduced thickness. Furthermore, the current sharing between parallel-connected layers is evaluated by using a new modified analytic method. This method is applied to different winding configurations and the results are validated by FEA (Finite Element Analysis) simulation.