A Comprehensive Study on Composite Resonant Circuit-Based Wireless Power Transfer Systems

In the magnetic resonant wireless power transfer (WPT) technology, system topology is the main factor that determines the WPT characteristics of the system, and recently, various system topologies based on various composite resonant circuits are being applied in WPT applications. This paper groups the composite resonant circuit-based WPT systems into one family and conducts a comprehensive investigation on their topologies and characteristics. First, characteristics of the composite resonant circuits, which are the fundamental circuits of transmitter and receiver of these systems, are investigated; in the process, a calculation method of resonant frequency, current ratio, and quality factor of these circuits are presented and the characteristics of these parameters are clarified. Second, based on that, the composite resonant circuit-based WPT systems are investigated. Possible topologies of these systems are explored and an equivalent system model of these systems is proposed. Based on that, characteristics evaluation expressions of these systems are derived and the optimal design guide of these systems is discussed. Finally, experimental prototypes are constructed and the proposed theory is verified by experiment results.