Design and Multiobjective Optimization of an Auxiliary Wireless Power Transfer Converter in Medium-Voltage Modular Conversion Systems

This article proposes an optimized design for a wireless power transfer converter serving as an auxiliary power supply in a medium-voltage, high
$\mathrm{d}v/\mathrm{d}t$
modular conversion system. A
CLLC-CL
circuit topology is implemented to generate a load-independent output voltage with a coupling-coefficient-independent resonant frequency. The output voltage of the circuit can be tuned by changing one pair of resonant
LC
parameters, which decouples the circuit gain from the coil design. Essential parameters of coil and magnet are extracted analytically or numerically to avoid time-consuming 3-D finite element analysis simulations for the subsequent optimization. After the design of the circuit and coil, a multiobjective optimization is carried out with objectives being efficiency, isolation capacitance, and insulation rating of the converter. Finally, experiments demonstrate a 48- to 48-V dc–dc converter with 100 W output power, 92.78% efficiency, 2.78 pF isolation capacitance, and 27 kV insulation rating to validate the optimization result.