A novel approach for minimizing high frequency transformer copper losses

As power supply frequencies approach the megahertz level, skin and proximity effects become significant factors to consider when calculating copper losses in transformers. Using electromagnetic theory and mmf diagrams in both space and time, a method that provides insight into the mechanism of skin and proximity effect losses and also yields quantitative results is proposed. Using this method several winding geometries for various topologies are covered. The analysis and optimization process is experimentally verified using an interleaved flyback transformer.