H5-Bridge-Based Single-Input–Dual-Output LLC Converter With Wide Output Voltage Range

In this manuscript, a novel single-input-dual-output (SIDO) LLC converter is proposed for wide output voltage applications. An H5-bridge is utilized on the primary side and linked with two separate resonant tanks. By morphing the H5 bridge, the input of each resonant tank can be configured as either full bridge, half bridge, or idle. On the secondary side, two semi-active rectifiers provide two control degrees-of-freedoms. The circuit operation is always tuned at the optimal resonant frequency and the output voltages are modulated by the secondary side pulsewidth. It exhibits good voltage regulation performance with two fully decoupled output ports. Both output ports can achieve wide voltage ranges. All MOSFETs can achieve ZVS turning-ON and all the diodes can achieve ZCS turning-OFF over a wide output voltage and load ranges. To verify this concept, a 1.4-kW rated prototype is designed to convert 390V input into two decoupled 100-400V outputs. The designed prototype exhibits 97.72% peak efficiency and good decoupled voltage regulation performances. The experimental results agree well with the theoretical analysis.