Wireless Power Transfer for Variable Load, Distance, and Power Division Ratio in a Loosely-Coupled Multiple-Receiver Relay System

This article proposes a wireless power transfer (WPT) system for variant receiver (Rx) configuration, power distribution ratio, load, and distance with multiple relays, each of which is connected to a resistive load. Each Rx relay transfers power to an adjacent Rx and acts as a relay while its local load consumes power. We develop a methodology for the design of WPT resonators that achieve optimum efficiency for multiple receivers with power distribution ratios, loads, and distances. The WPT configuration is extended to a general m×n, two-dimensional grid for a large area coverage. A mathematical model of the proposed WPT system is provided, and a multiple-Rx wireless power network using a power inverter serves as a proof-of-concept. Following the design guidelines provided in this article, experimental examples with variable parameters while delivering a total power of 100 W are discussed. To illustrate the practical applicability of this approach, a demonstration on a consumer display and speaker device is performed.