Research on Constant Current and Constant Voltage Charging Control Method for a Three-Phase Reconfigurable Battery Wireless Charger

To accommodate the constant current output (CCO) and constant voltage output (CVO) charging profile of lithium-ion batteries and avoid overcharging or undercharging, a three-phase resonant wireless charging system with self-tunable CCO–CVO output characteristics is proposed. The system eliminates complex control schemes such as phase-shifting or frequency modulation. Output mode switching is achieved merely by controlling two switches to reconfigure the topology, and the system can automatically shift into a low-power state upon completion of charging. First, a novel three-phase hybrid topology based on double-sided LCC/LCC-S compensation is proposed, and its output characteristics and zero-phase angle (ZPA) performance are analyzed using the equivalent mutual-inductance circuit model of each single topology. Second, a systematic parameter design method is presented under theoretical derivations and the maximum safe current constraint, which provides a theoretical basis for component optimization. Third, the effects of load resistance at the switching point and no-load operation on output stability, as well as special operating conditions including open-circuit load and load removal after full charge, are investigated to verify the stability and safety of the system. Finally, simulation and experimental prototypes are established. The system achieves stable CCO–CVO output with smooth mode switching and a peak efficiency of 93.6% under the full-bridge drive, which validates the effectiveness and correctness of the proposed strategy.