Design and Analysis of Automatic Modulation and Demodulation Strategy in Wireless Power and Drive Transfer System

This article presents an innovative wireless power and drive transfer (WPDT) system with inherent modulation and demodulation functionality. For high-frequency alternating input voltage, which is conventionally used in wireless power transfer (WPT) systems, the high-order harmonic components are usually regarded as interferences to the system. However, this proposed WPDT solution, instead of filtering the high-order harmonics, uses it as the combined source for simultaneous power and driving signal transmission. Thus, it is possible to design the system for two resonance frequency channels with arbitrary primary currents for control. As a result, the transmission currents for the main power and driving signals can be automatically modulated on the primary side, while demodulated for the two channels on the secondary side. All the control can be completed through only one full-bridge converter. The experimental prototype successfully demonstrates that the system can be flexibly shifted between two modes for 1/0 driving signal transmission while maintaining the stability of the output power with high efficiency.