A novel control strategy for wireless charging in electric vehicle based on class E amplifier

Class E amplifier is a high frequency power supply for the magnetic resonance wireless power transmission (WPT) system for electric vehicles, and its efficiency is an important index to evaluate the performance of the system. In view of the efficiency and voltage stress in the switch device of class E amplifier are verified dramatically with the load change, this paper proposed an active control strategy to realize ZVS condition of class E amplifier by capacitor and inductor arrays, load estimation in primary side, and an optimization algorithm together. A set of experiment of 1000W and efficiency of inverter part is over 95% in an air gap of 20 centimeter was carried out to verify the effectiveness of the proposed strategy.