Multi-Object Charging in Room-Sized Weakly Coupled WPT System

This study introduces a new approach to power management in an inductive one-to-many wireless power transfer (WPT) system. In particular, we provide a theoretical basis for the approach based on circuit theory. The approach shows that in case of negligible direct interaction between receivers, which could be easily achieved in a weak coupling system, no additional components or power tracking is needed if the transmitter provides a stable and uniform magnetic field. In addition, the efficiency of such a system increases with the number of receivers, making it comparable with strong coupling systems despite a weak coupling coefficient. We also propose a practical realization of this approach and confirm our theoretical results by circuit and full wave finite element models. These results lead to a promising future of reliable and affordable weak coupling one-to-many WPT systems.