Load sharing characteristic of two-phase interleaved LLC resonant converter with parallel and series input structure

Recently, the LLC series resonant converter (LLC-SRC) is widely used for many applications because it has many advantages over other power converters. To apply LLC- SRC to high current application, it is necessary to interleaved operation to reduce output current ripple. Moreover, output current should be shared equally. However, active load share technique cannot be applied to output current divide equally because LLC SRC is regulated with frequency. Therefore, design of multi-phase interleaved LLC SRC is required that load current haring can be realized automatically. In this paper, two structures for interleaved LLC SRC are suggested. In the point of load share, two structures are analyzed. In order to verify proposed analyze, the laboratory experiments are executed and discussed with a 480 W prototype.