Improved Multiphase Interleaved LLC Resonant Converter With Virtual Controllable Voltage Sources

In this article, a simplified virtual controllable voltage sources (SVCVSs) structure for multiphase ( $n \ge3$ ) interleaved LLC resonant converter has been proposed. The SVCVS in each phase is constructed by single auxiliary winding of transformer of the nearby as the phase number is $\ge 3$ , hence printed circuit board (PCB) layout of the improved multiphase interleaved LLC resonant converter becomes much simpler. The feasibility of the multiphase interleaved LLC resonant converter with SVCVSs has been illustrated by vector diagrams, and a family of topologies has been derived. Finally, the 12-V/60-A three-phase interleaved LLC converter with VCVSs/SVCVSs has been tested based on a laboratory built-up prototype. Experimental results show that the three-phase converter with SVCVSs can achieve close output current ripple but higher efficiency than the converter with VCVSs.