A Magnetically Controlled <i>CLLC</i> -DCX Converter With Output Regulation Capability

The CLLC resonant converter operating in DC transformer (DCX) mode has excellent features such as fixed switching frequency, load-independent voltage gain, full zero voltage switching (ZVS) operation, and simple synchronous rectifier control, but the output voltage cannot be adjusted. To address this issue, this letter proposes a magnetically controlled CLLC-DCX converter based on variable resonant inductors. The proposed control method adjusting resonant inductors to change the equivalent transformer turns ratio n<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</sub> while keeping the resonant frequency fixed. Finally, an experimental prototype is built to validate the proposed magnetically control method.