Research on Control Method and Variable Topology Design of Wireless Power Transmission System with Coil Offset

Abstract

Aiming at the coil offset of magnetic coupling wireless power transmission (WPT) system with the Series–Series (SS) resonance structure, in order to stabilize the transmission efficiency above 80% according to SAE J2954, Control method and variable topology design with the maximum lateral offset of 20 cm are researched on. In this paper, the mutual inductance theory is adopted to establish an equivalent circuit model of the system. The expressions of the transmission characteristics with coil offset are derived and the influence of coil offset on transmission characteristics is analyzed. According to the difference offsets, a bilateral control method with phase‐shift control on primary side and double closed‐loop control on secondary side for small offset (0, 10 cm) for constant voltage output at 200 V is adopted. In addition, a double‐sided LCC topology structure is developed for larger offset (10, 20 cm) with the maximum efficiency transmission method by parameter configuration. The simulation platform and the experiment platform are developed and the output characteristic experiments with different loads and different coupling coefficients under different offsets are finished to verify the results and provide a reference for the anti‐offset research of the system. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.