High Frequency Fed Unity Power Factor AC-DC Converter For Wireless Power Transfer Applications

Abstract: Wireless power transfer over near to midrange distances have been receiving much attention owing to their potential applications such as biomedical implants, charging pad platforms for mobile devices and electric vehicle recharging. The newest technologies mostly depend on inductive coupling techniques to transmit power between transmitting and receiving coils. Wireless power transfer (WPT) receivers are devices that can transmit power to electrical devices without any wired connections. But there is a lack of research targeting the optimal design of the power converter at the receiver side. The novel scheme presents a power converter and its control circuit for high frequency fed AC to DC conversion for wireless power transfer. Wireless power transfer is achieved via resonant inductive coupling between the transmitting and receiving coils. Based on the resonant technique, the input current is shaped to be sinusoidal and is forced to follow the high-frequency sinusoidal input voltage so as to achieve unity power factor. A control scheme is also proposed for the converter which can be realized by simple operational amplifiers and digital logic gates. The distinctive features of this converter are favourable for future high-frequency AC power transfer system operating in the range from a few hundred kHz to the MHz range.

Keywords: Wireless Power Transfer (WPT), magnetic resonant coupling, Power Factor (PF) correction, High frequency converter.