Reconfigurable Topology Design on the Secondary Side of Rotary WPT Systems for Ensuring Stable Power Transmission over Large Coupling Variation

Under rotating conditions, Wireless Power Transfer (WPT) technology offers distinct advantages over wired power transmission as it is free from the constraints of cables. Nevertheless, variations in coupling are inevitable during practical applications, and the intricate external environment and high-speed rotation of the equipment introduce vibration and misalignment in the coupling structure, resulting in fluctuations in the transmission power of the rotating WPT system. This study investigates the design of a reconfigurable topology network on the secondary side of the rotary WPT system, with a focus on achieving constant power output. Initially, a three-layer helical coil structure is devised to ensure stable coupling coefficient despite misalignment conditions. Subsequently, a rotary WPT system with reconfigurable topology on the secondary side is proposed to tackle significant changes in coupling coefficient and maintain consistent transmission power. Lastly, an experimental prototype capable of delivering a constant power output of 200 W is constructed and validated through experiments. The experimental results illustrate that the variation in transmission power of the WPT system remains below 10% when the coupling coil experiences a 15 mm misalignment, demonstrating the system’s power stability.