LLC Resonant Converter With Reconfigurable Secondary-Side for Output Voltage Regulation

This brief proposes a reconfigurable LLC resonant converter that enables the regulation of a tailored portion of the output voltage through a novel adaptive transformer turns ratio scheme implemented on the secondary rectifier. The converter employs a center-tapped transformer and a switch to reconfigure the secondary rectifier and adjust the effective turns ratio. Using the proposed concept, voltage regulation is achieved with a reduced number of switches and devices in the current’s path, no modification to the primary side, and fixed-frequency operation. A laboratory prototype rated at 4 kW with a 1 kV input voltage is implemented and tested to validate the feasibility and performance of the proposed converter.