Frequency Domain Model of a Resonant LCC-S Converter for High-Frequency Wireless Power Transfer Applications Considering Switching Losses in MOSFETs Bridge

A model for a fast and reliable evaluation of the impact of MOSFETs’ switching losses in the global performances of a high-frequency wireless power converter is proposed. The frequency domain model for an LCC-S wireless resonant converter is presented. The contribution of MOSFET behavior is counted considering a trapezoidal input voltage in the converter instead of the classic square wave or Pulse Width Modulation wave to take into account MOSFETs’ rise and fall times. These times are evaluated with a simplified first-order circuit able to model the MOSFET behavior during commutations. Two commercial MOSFETs have been integrated in the converter model. The predictions of the proposed approach are compared (for validation) with results coming from Simulink environment, where the converter behavior can be reproduced in a very realistic way. An evaluation of switching losses is presented, and the consequent impact on converter performances is evaluated by comparing the converter output voltage (and output power) predicted with the proposed model and that one is achievable by the converter considering ideal switches. The analysis has been performed considering different values of input voltage and load resistance. This approach can be easily generalized to every resonant converter topology.