Wireless Power and Data Transfer via a Common Inductive Link Using Frequency Division Multiplexing

TLDR

Wireless power transfer faces communication challenges across large air gaps and magnetic interference. The study proposes a method that integrates bidirectional data communication into a high‑power wireless power transfer system. The authors use a shared inductive link between coreless coils and apply power/data frequency‑division multiplexing with distinct frequency carriers, modeling the multiband system to analyze transmission gain, power delivery, crosstalk, and signal‑to‑noise ratios. A 500‑W prototype demonstrates the effectiveness of the proposed system.

Abstract

For wireless power transfer (WPT) systems, communication between the primary side and the pickup side is a challenge because of the large air gap and magnetic interferences. A novel method, which integrates bidirectional data communication into a high-power WPT system, is proposed in this paper. The power and data transfer share the same inductive link between coreless coils. Power/data frequency division multiplexing technique is applied, and the power and data are transmitted by employing different frequency carriers and controlled independently. The circuit model of the multiband system is provided to analyze the transmission gain of the communication channel, as well as the power delivery performance. The crosstalk interference between two carriers is discussed. In addition, the signal-to-noise ratios of the channels are also estimated, which gives a guideline for the design of mod/demod circuits. Finally, a 500-W WPT prototype has been built to demonstrate the effectiveness of the proposed WPT system.