Open AccessLarge air gap misalignment tolerable multi‐coil inductive power transfer for wireless sensors
Author(s) -
Kallel Bilel,
Kanoun Olfa,
Trabelsi Hafedh
Publication year - 2016
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2015.0800
Subject(s) - electromagnetic coil , air gap (plumbing) , inductance , wireless power transfer , maximum power transfer theorem , power (physics) , power transmission , inductive coupling , transmission (telecommunications) , coupling (piping) , resonant inductive coupling , electrical engineering , electric power transmission , energy (signal processing) , excitation , acoustics , electronic engineering , computer science , engineering , physics , energy transfer , materials science , mechanical engineering , voltage , quantum mechanics , composite material , engineering physics
The efficiency of wireless power transmission via electromagnetic induction is strongly dependent on the distance and the lateral misalignment between the sending and the receiving coils. In this study, the authors propose to adopt a multiple‐input–single‐output (MISO) coil system to increase the efficiency of energy transmission in case of large air gap misalignment between coils. The sending part consists of a matrix of air‐core coils, in which only the four coils under the receiving coil, supplied with the same current, contribute to energy transmission. To orientate the magnetic field and to reduce the energy losses, they propose to power the two nearest neighbour coils with low, out‐of‐phase, excitation current. A simplified analytic model of the multi‐coil system configuration is developed, whereas the mutual inductance and the coupling factor are determined by numerical simulations. To validate the analytical and simulation results, an experimental setup was built. Both simulation and experimental results at a distance of 83% of the receiving coil diameter show that the proposed MISO coil system improves the received power and reaches at the same time a much better efficiency than that of two‐coil systems.