Hybrid Modulation PWM-Controlled Multifrequency and Multiload WPT System Based on Variable Resonant Network

In order to reduce the reactive power of the existing hybrid modulation pulsewidth modulation (HM-PWM)-controlled multifrequency and multiload wireless power transfer (MFML WPT) system without a resonant network, a design idea of a variable resonant network is proposed, accordingly, an HM-PWM-controlled MFML WPT system based on a variable resonant network is studied. According to the variation in load frequency, the output frequency of the inverter and the frequency of the variable resonant network can change accordingly. First, the structure and working principle of the MFML WPT system based on a variable resonant network are introduced. Second, taking a dual-frequency variable resonant network as an example, the control method and range of frequency adjustment are studied by modeling. Third, the MFML WPT system based on a variable resonant network is mathematically modeled, the output power and efficiency are analyzed. Finally, the feasibility of the design idea of the variable resonant network is proved by experiments. The results show that in the range of 20–90 kHz, the variable resonant network can realize stable switching of any two frequencies, and the power factor of the system can reach 0.99. So, the MFML WPT system can realize high-efficiency WPT for loads with different frequencies.