H5-Bridge-Based Single-Input–Dual-Output <i>LLC</i> Converter With Wide Output Voltage Range
Liang Wang, Haoyu Wang, Bo Xue, Mingde Zhou
Abstract
In this article, a novel single-input–dual-output <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i> 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 semiactive 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 zero voltage switching turning- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and all the diodes can achieve zero current switching turning- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> over a wide output voltage and load ranges. To verify this concept, a 1.6-kW rated prototype is designed to convert 390-V input into two decoupled 100–400 V outputs. The designed prototype exhibits 97.72% peak efficiency and good decoupled voltage regulation performances. The experimental results agree well with the theoretical analysis.