A Collaborative Tuning Control Strategy for Adaptive Tracking of Minimum Turn-off Current Under ZVS in Dynamic WPT Systems With Parameter Variations

Conventional methods for achieving zero-voltage switching (ZVS) with minimized reactive power under phase-shift (PS) modulation overlook the inevitable changes in coupling coefficient and load during the practical charging process. Analyzing ZVS operation only from a static perspective. To fill the research gap, this article develops a time-domain model that takes into account variations of bilateral detuning factors, mutual inductance, and load. Their impact on ZVS and the system characteristics are analyzed. Furthermore, a collaborative tuning control strategy with switch-controlled capacitors (SCC) is proposed for adaptive tracking of the minimum turn-off current under ZVS and wide output voltage regulation in dynamic scenarios with parameter variations. In addition, complex mathematical calculation is not required to implement control. Finally, a 960 W experimental prototype was established, and the results showed that the ZVS current remained the minimum across a wide voltage gain range of 0.5-1.2 and loads of 110-960 W. The maximum efficiency after tuning reached 94.7%.