A Load-Independent Fission-Type Inductive Power Transfer System for 3D Reconfigurable IoT Array

Abstract

In recent years, the number of electronic devices and appliances that support wireless charging has rapidly increased, owing to the research and development breakthroughs in inductive power transfer (IPT) technology. The existing wireless charging protocols, such as Qi and AirFuel, support only a few devices to be charged simultaneously. They cannot be directly utilized to construct a complex IPT network. This article introduces a reconfigurable three-dimensional (3D) IPT system based on series-parallel (SP) compensation for wirelessly powering multiple adjacent cubic Internet of Things (IoT) devices. These cubes can be configured into different 3D array combinations according to the application demands. After the 3D cube array is formed, a self-detection mechanism runs to turn off the uncoupled coils, such that to maximize the power transmission efficiency of the entire system. These cubes serve as not only IoT loads but also wireless power relays. In this way, the number of loads is not limited by the size of a single transmission coil. In addition, it maintains a constant drive voltage to each load device, regardless of the load variations in local or adjacent cubes. The constant voltage design eases local power management. A prototyped IPT cube array is manufactured and tested to validate the proposed idea. This fission-type IPT system makes a valuable exploration of the 3D IPT technology toward future ubiquitous and reconfigurable IoT arrays.