Maximum efficiency control of wireless power transfer systems with Half Active Rectifier based on primary current measurement

Applying wireless power transfer (WPT) to transportation applications is one of the best solutions to overcome drawbacks of a limited energy souse in electric vehicles (EVs). Although dynamic charging of EVs can extend their driving distance, control techniques have to be further developed to maintain maximum transmitting efficiency because of parameters variation, e.g. distance change and load change. This paper proposes an efficiency maximization method based on the primary current change with power control on the secondary side using Half Active Rectifier (HAR). The reference value of the primary voltage is calculated based on the measured primary current. The simulation and experiment results demonstrate that the reference voltage can be obtained with satisfactory accuracy and the transmitting efficiency can be maximized by primary voltage control without communication between the primary side and the secondary side of the system.