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 multi-output flyback planar transformers and reduce high-frequency winding losses. The method utilizes the eddy current effect of copper and it is easy to implement without incurring additional cost. Finite element simulations show that the proposed methodology is highly effective in multi-output flyback planar transformers. The design was used in a 78W GaN based TV power supply, 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 winding structure by traditional approach.