Design and Control of a Decoupled Multi-channel Wireless Power Transfer System Based on Multilevel Inverters

Traditional multi-channel wireless power transfer (WPT) systems suffer from the complex system structure and cross-interference among receivers. To solve such problems, this article presents the design and control methods of a decoupled multi-channel WPT system based on multilevel inverters. A single-phase multilevel inverter is utilized to drive the transmitter circuit with a voltage waveform consisting of multiple components. Particularly, these components are independent in the frequency spectrum, and their amplitudes can be controlled independently. Moreover, primary compensation is used to offer multiple frequencies for the primary circuit. And additional damping filters are used in the secondary circuits to reduce the cross-interference between the receivers. In addition, the features of the system topology are analyzed, and an exact parameter design method is presented. Furthermore, combined with the neutral point (NP) voltage balance strategy, a simple vector-based control method is proposed to regulate the transmitted power in each power channel. As a result, the power can be transferred to loads through the designed power channels simultaneously without mutual interference. Finally, both simulation and experiment of a 1kW experimental prototype with SIC-MOSFET are given to verify the feasibility of the proposed multi-channel WPT system and the control strategy.