T01.9 - An Optimization Method for Planar Transformer Winding Losses in GaN Based Multi-Output Flyback Converter

This article introduces a new winding structure design approach to suppress stray flux in the magnetic core window of planar transformers and reduce high-frequency winding losses. The method utilizes the eddy current effect of a good conductor and is easy to implement without incurring additional costs. Finite element simulations show that the proposed methodology is highly effective in multi-output flyback planar transformers. The design was used in a 78W TV power supply study, where the improved winding structure resulted in a 1.2% increase in overall efficiency and a significant decrease in the temperature of the planar transformer compared to traditional winding structures.