Self-oscillating Closed-loop Control Strategy Based on Contactless Hysteresis Regulator and Dynamic Reference Modulation

Abstract

This paper proposes a self-oscillating closed-loop control strategy based on the contactless hysteresis regulator and dynamic reference modulation, to achieve automatic and quick response to variations of the load parameter and the coupling mechanism in an inductive wireless power transfer system, and realize the precise output voltage control. First, the self-oscillating control strategy based on the dynamic reference modulation for the inductive wireless power transmission system with series/series compensation is proposed. Then, the phase shift time parameter is introduced to describe the variation of the dynamic reference, and the influence of the dynamic reference on the self-oscillating frequency and the output voltage gain characteristic is analyzed in detail. The monotonic interval of the output voltage regulation and the limitation of the adjustable output voltage are presented. Furthermore, this paper proposes an implementation scheme of the contactless hysteresis regulator based on the information feedback of the overvoltage/undervoltage status. By combining the proposed contactless hysteresis regulator with the self-oscillating control based on the dynamic reference modulation, the closed-loop regulation of the output voltage is realized. Finally, an 80 W experimental prototype is built to verify the correctness of the theoretical analysis and the superiority of the proposed control strategy.