Three-phase CLLLC Resonant Converters

A three-phase resonant converter allows high-density operations than a one-phase resonant converter. These one-phase converters, such as LLC and CLLLC, have already been investigated and optimized by many authors. These papers study the different topologies and connections that a three-phase CLLLC resonant converter can present. Two main topologies are considered in this paper. They both exhibit a three-phase bridge as input and a three-phase transformer that integrates each phase's resonant tank. The difference between both topologies emerges from the output rectifier. One topology uses a three-phase bridge as a rectifier, whereas the other uses three one-phase full-bridge. The three-phase bridge rectifier and a delta connection on both sides of the transformer allow a faster response while reducing the RMS current through the transformer. In addition, a better PCB integration can be acquired.