A Mistuning-Tolerant and Controllable Power Supply for Roadway Wireless Power Systems

Inductive power transfer power supplies for electric vehicle charging in dynamic applications need to tolerate large variations in coupling and tuning with varying loads. This paper investigates the use of a buck converter to regulate the input voltage to a fixed frequency unidirectional switch push-pull converter to meet the requirements of dynamic charging. The presented circuit is optimized to remove some of the additional components introduced. A mathematical model is presented that shows the circuit is capable of operating while extremely mistuned in both the inductive and capacitive regions while maintaining sinusoidal currents. A controller design is also presented allowing constant primary current operation, safe start up, and operation under no load conditions. A 5-kW prototype was built and validated when operated with a dynamic load under severely mistuned conditions.