Analysis and design of two-phase interleaved LLC resonant converter considering load sharing

Recently, the LLC series resonant converter (LLC-SRC) is widely used for many applications because it has many advantages over other power converters. However, it is difficult to apply this topology to high current applications because the current ripple stress on the output capacitor becomes severely high. Nevertheless, it is possible to reduce the output current ripple drastically as employing the interleaved technique. However, to ensure output current sharing, multiphase interleaved LLC-SRC causes design difficulty of resonant tanks, which consists of magnetizing inductance (LM), resonant inductance (LR), and resonant capacitance (CR). In this paper, design consideration to ensure output current sharing of multiphase interleaved LLC-SRC is proposed. In order to verify proposed design consideration, the laboratory experiments are executed and discussed with a 480 W prototype.