Composite Control Method for Maximum Efficiency and Constant Voltage in Wireless Charging

ABSTRACT

In response to the challenge that transmission efficiency in wireless power transfer (WPT) systems is highly susceptible to variations in coupling coil mutual inductance and load conditions, this study puts forward a hybrid control strategy integrating impedance adaptation with phase shift regulation, aiming to concurrently fulfill the dual control objectives of maximizing transmission efficiency and maintaining constant output voltage. Specifically, the research commences with a theoretical exploration of transmission efficiency under the LCC/S‐type resonant topology. On the receiver side, a buck‐boost DC‐DC converter is incorporated to dynamically modulate the equivalent input impedance, thereby enabling real‐time impedance matching for efficiency optimization. On the transmitter side, a closed‐loop control scheme—anchored in phase‐shift PI regulation and enhanced via an improved Random Initialization Multi‐Explorer (RIME) algorithm—is adopted to ensure voltage output stability. Moreover, this work proposes a mutual inductance estimation technique grounded in system operating parameters, which is subsequently refined through linear regression correction to bolster the precision of parameter identification. The proposed methodology is ultimately validated through the construction and testing of an experimental platform, demonstrating its practical efficacy.