Design and Control of a Series-Series Resonant Boost Converter for Wireless Power Applications in Electrical Vehicles

The wireless transfer concept (WPT) is becoming attractive for static and dynamic charging of batteries onboard electric vehicles (EVs). This process requires the proper alignment between primary and secondary coils in order to keep constant voltage while the efficiency remains high. However, coil misalignment is commonly presented in EV applications, affecting the charging process. This paper proposes a PI controller operating on a high-frequency dc-dc converter with boost capability used to guarantee constant voltage. This facilitates the power transfer process regardless of the alignment between coils. In addition, a method to design the transmitter coil
$(Tx)$
and the receiver coil
$(Rx)$
is illustrated considering conduction and switching losses. Time-domain simulations are initially carried out in order to test the controller. Furthermore, a low-scale prototype is built and tested in order to validate the feasibility of the controller. Results show that the output voltage remains constant for the transferred Dower. considermo chanves in the distance between coils.