Design and modelling of inductive chargers for electric vehicle charging using primary side control

This paper derives analytical models for designing inductive chargers for electric vehicles intended to be charged with only primary side charger control. Designs with series or parallel resonant capacitors on the output of the secondary winding are compared. A design optimization methodology is given for component selection and maximizing converter efficiency for a range of parameters. Analysis of the power output for varying frequency show that the series secondary topology has lower secondary current for the same power rating and will be easier to tune and control the output power. The parallel topology offers a possible better overall efficiency but is more difficult to design and control. Simulation and test results show excellent correspondence between the analytical models and an example design.