Bifilar Winding of a Center-Tapped Transformer Including Integrated Resonant Inductance for LLC Resonant Converters

A bifilar winding method is proposed for the center-tapped transformer which includes integrated resonant inductance in an LLC resonant converter in order to improve the balance of its resonant network and power conversion efficiency. This method can reduce resonance imbalance and transformer inefficiency caused by leakage inductance imbalance in the secondary side of the transformer. As a result, the proposed bifilar winding method employed in the center-tapped transformer maintains the balance of rectifying current and reduces conduction losses in the converter.