Decoupling Control of Double-Side Frequency Tuning for LCC/S WPT System

Abstract

The parameter fluctuations will lead to the frequency detuning problem of the wireless power transfer (WPT) system, thus affecting the transmission efficiency and output stability. The traditional primary-side frequency tuning method cannot realize the full compensation of the secondary-side resonance parameters, and the double-side frequency tuning method with data communication still exists a coupling problem. Therefore, this paper proposes a decoupling control of double-side frequency tuning for LCC/S wireless power transfer (LCC/S WPT) system, which has the advantages of avoiding information exchange and circuit simplicity. Firstly, based on the circuit model, the influence mechanism of frequency detuning on the transmission efficiency and voltage gain are deeply studied. On this basis, a zero phase angle (ZPA) control method based on optimal efficiency tracking and a two-step perturb and observe method with maximum current search are proposed to adjust the primary and secondary resonance parameters respectively. Finally, a 200W experimental prototype was built to verify the effectiveness of the proposed frequency tuning strategy. It is strong robustness to the parameter fluctuations, and double-side can well maintain the resonance state, which can improve the transmission efficiency and stability of the LCC/S WPT system.