An improved winding loss analytical model of Flyback transformer

The winding loss of Flyback transformer is difficult to calculate because the current flowing in both sides is not simultaneous, and the current phase shift at each harmonic between primary side and secondary side is not fixed at 180°. This paper proposes a novel winding loss analysis model by considering the phase shift angle of the two current and building a new magnetic field in the region between each layer. The detailed theoretical analysis for a Flyback transformer with the proposed model is presented in this paper, the transition period is analyzed in detail to explain its effect on interleaving structure. Finally the analysis results based on the proposed model is verified with both FEA simulation and experimental results.