A Clamped IPT System With Adaptive Mode Switching Against Large Coupling Variations

Misalignment issue is almost inevitable in an inductive power transfer (IPT) system, leading to unstable power transfer due to the coupling variations. In order to improve the flexibility of the IPT system, the misalignment range of stable power output is desired to be as large as possible. This article proposes a clamped IPT system to improve antimisalignment ability based on the dual-mode operation. The clamped circuit is constructed with a coil and a rectifier connected to the input dc terminal of the inverter. With the effect of the clamped circuit, the operating mode of the system can be adaptively switched to match the required coupling variation region without coupling identification, output detection, or feedback communication. Then, the analysis and parametric design of the system are elaborated. Finally, a 480-W experimental setup was built to verify the feasibility of the proposed method. Experimental results show that the proposed method can maintain stable output power between 440 and 480 W with the coupling varying from 0.14 to 0.39, while the efficiency is from 83.22% to 93.55%.