Analysis and Design of a Three-Coil HF-IPT System

This work illustrates and assesses the operating principles of multi-coil inductive power transfer systems, with particular emphasis on the benefits arising from the possibility of steering the power flow between multiple transceivers. This enables new classes of applications that are focused on smart re-configurable systems that operate as cooperative networks for power management. In this work we present both a general the-oretical formulation of the problem, together with experimental results for a symmetrical system driven by class EF transceivers operating at 13.56 MHz, in which the three coils have the same inductance (1.18
$\mu \mathrm{H})$
and the same coupling coefficient with each other (4.4 %). The experimental results show that by controlling the relative phase between the transceivers it is possible to steer the power flow in the system in three possible ways: from one-to-two, from two-to-one and zero power flow.