Multifrequency and Multiload MCR-WPT System Based on Hysteresis Current Control

Aiming at the problems that existing multifrequency and multiload (MFML) magnetic coupling resonant wireless power transfer (MCR-WPT) systems either the output power frequencies are limited or a large amount of reactive power in them leads to decreased power factor (PF). This article proposes an MFML MCR-WPT system based on hysteresis current control, which controls multifrequency current superposition output and has equivalent current source characteristics. The system outputs multifrequency current by tracking the command current, which consists of subcommand currents designed according to load frequency and power requirements and raises PF without affecting power transfer quality by adding power compensating capacitor (
C
_P
) with lower cost and design complexity than existing technologies. First, the system structure and working principle are introduced. Then, the criterion of equivalent current source is deduced, based on which the system model is established, and its characteristics are analyzed. After that, the system parameter design methods are given. Finally, an experimental platform is built to verify the proposed theory. The simulation and experimental results show that the proposed system can output multifrequency power, switch the frequency freely, and raise PF by adding
C
p without affecting power transfer.