Wireless Power Transmission with Electromagnetic Inductive Coupling

Period of Performance: 10/25/2007 - 06/20/2008


Phase 1 SBIR

Recipient Firm

Geophex Ltd.
605 Mercury Street
Raleigh, NC 27603
Principal Investigator


This project addresses the problem of the wireless transfer of power between a source and nearby mobile platform such as a robotic vehicle. The primary objective of this research will be to design and evaluate, by analysis and computer modeling, an inductively-coupled system consisting of an optimally-designed configuration of transmitting coils to maximize the coupling efficiency though a target receiving coil. In particular, the concept of inductive focusing or flux focusing will be explored. Briefly, this is the idea of controlling the currents in a set of concentric transmitting coils to concentrate the magnetic flux through a receiver coil. That is, the transmitter is designed to maximize the flux linkage through the receiving coil while minimizing the flux elsewhere. This can be done by selecting the currents in the coils to reinforce the field linking the receiving coil while simultaneously canceling the fields outside of this coil. This can be formulated as a constrained optimization problem. The advantage of this approach is that minimal power is wasted due to the induction of currents in conducting material outside the target coil.