ABSTRACT
This chapter presents an algorithm named directional tuning/detuning control for power flow regulation of wireless power transfer (WPT) systems. Despite the fact that controlling the primary side can minimize the physical size and heat generation of the pickup which is desirable in applications such as biomedical implantable devices, it is only suited to single-pickup situations. The center frequency drift is used here as an example to illustrate how the secondary output power gets affected by the parameter variations under different Q values. Circuit parameter variations such as load change, magnetic coupling variations between the primary and secondary coils, and the system operating frequency drift can all cause the output voltage of wireless power pickups to deviate from the desired operating condition and fail to meet the load demand where a constant and stable output voltage is required. Shorting control is a most commonly used PFC method due to its simplicity.
