Research on dual‐frequency modulation strategy of wireless power transfer system

Abstract

AbstractCompared with traditional wired power transmission, wireless power transfer(WPT) has fully exhibited its key advantages of better safety and convenience, stronger reliability and electrical isolation, and less maintenance. Although the phase‐shift modulation strategy has been widely used in various WPT applications, it has certain limitations in terms of high‐frequency hard‐switching, which increases the power loss of the WPT system during voltage regulation. To achieve efficient operation over a wide range of load power, this paper proposes a dual‐frequency modulation strategy for the WPT system. The advantages of the dual‐frequency modulation strategy are the simple modulation logic and the lower switching loss. It maintains the optimal load impedance during constant voltage output and improves the overall efficiency of the system. For validation, we designed the control circuit and wrote the control program and built the experimental prototype of the WPT system to carry out the phase‐shift modulation experiment and the dual‐frequency modulation experiment, respectively. The experimental results show that the soft switching range and efficiency of the WPT system under the dual‐frequency modulation strategy are better. At the rated output power, the efficiency of the WPT system under dual‐frequency modulation strategy is 89.75%. The feasibility of the dual‐frequency modulation strategy has been confirmed.