Multifrequency and Multiload WPT System Based on Cascade H-bridge Multilevel Inverter

Abstract

To address the issues of limited output power and harmonic interference in existing multifrequency and multiload magnetic coupling resonant wireless power transfer (MFML MCR-WPT) systems, this paper proposes a MFML-MCR-WPT system based on a cascaded H-bridge multilevel inverter(CHB MLI). The system utilizes the phase disposition multifrequency modulation technique, achieving arbitrary frequency and quantity power output and control through the design of modulation wave quantity, frequency, and amplitude. Firstly, the structure of the CHB-MLI-based MFML-MCR-WPT system is proposed, and the working principle of the multifrequency modulation method is analyzed. Subsequently, a five-level dual frequency and dual-load system is taken as an example to establish the mathematical model. Then, System parameter optimization is conducted to suppress cross-coupling and inter frequency interference. Furthermore, to address the power and loss imbalance among H-bridge units under multifrequency low modulation indices, a carrier reconstruction method is adopted to balance power distribution and switching losses. Finally, an experimental platform is constructed to validate the proposed theory. Simulation and experimental results demonstrate that the system achieves multilevel multifrequency power output with continuous power and frequency control, maintains minimal inter-channel interference, and achieves H-bridge unit balancing ratios of 1:1.19, while exhibiting excellent system compatibility and controllability.