Design methodology of resonant inductor in a ZVS inverter

In a zero-voltage switching (ZVS) inverter, the resonant inductor is applied to realize soft-switching aimed at dynamic loss reduction. For this purpose, the loss on the resonant inductor should be low enough to ensure a distinct loss decrease for the total system. ZVS inverters usually operate at higher frequency than hard-switching inverters to allow sizing reduction of passive components. From this aspect, the resonant inductor in a relatively small dimension is required to guarantee the compactness of the whole inverter. This paper introduces a methodology incorporating new design rules for optimization and miniaturization of the resonant inductor in a ZVS inverter. High frequency winding losses as well as core loss generated by non-sinusoidal waveforms are discussed in this paper. Different winding schemes and positions are compared in order to find a design with minimized power dissipation. Finite Element Analysis (FEA) results show that the inductor designed by this method has minimum losses and optimum size.