Multiple output of dual half bridge LLC resonant converter using PFM-PD control

This paper proposes the multiple output of dual half bridge LLC resonant converter using PFM-PD control. For the main output, dual half bridge LLC resonant converter controlled by pulse frequency modulation (PFM) is used. For the sub output, multiple outputs scheme is configured and operated by phase delay (PD) control. Since the control variables, PFM and PD, have little mutual effect, the sub output voltage can be regulated for a wide input and load range. All MOSFETs achieved ZVS and all rectifier diodes attained ZCS for the whole load range. The modes of operation are investigated and then steady state characteristics of the proposed converter are analyzed. A 320 V-400 V input, 24 V/20 A, 5 V/16 A hardware prototype is realized with dsPIC33FJ16GS502 and tested to verify the performances of the proposed multiple output converters.