Winding Strategy Analysis and Optimization for High-Current Matrix Transformer

Matrix transformer exhibits characteristic that can create low winding loss in high current application. This paper outlines the modeling, analysis, and optimization of winding strategy in the proposed matrix transformer structure. The impact of multiple interleaving structure, the number of winding layers, and copper volume to loss are analyzed. From 2D FEM analysis, the interleaving structure with the lowest AC resistance ratio is found. However, the 3D FEM analysis shows an increased AC resistance, due to the not captured proximity effect in part of the winding window. This fact is often overlooked in matrix transformer design and can change the design result. The analysis is verified in a DCX prototype achieving 91.3% efficiency and 488A output current capability.