Wireless power transmission to an electromechanical receiver using low-frequency magnetic fields

• Published in: Smart materials and structures Vol. 21; no. 11; pp. 115017 - 1-11
• Main Authors: Challa, Vinod R, Mur-Miranda, Jose Oscar, Arnold, David P
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.2012; Institute of Physics
• Subjects: Coiling; Electric power generation; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Magnetic fields; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; Orientation; Physics; Receivers; Torque; Transmitters; Wireless power transmission; Coils; Power supplies; Output power; Resonance frequency; Energy conversion; Magnetic field effects; Ferromagnetic materials; Wireless network; Modelling; Performance; Electromechanical system
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/21/11/115017

A near-field, electrodynamically coupled wireless power transmission system is presented that delivers electrical power from a transmitter coil to a compact electromechanical receiver. The system integrates electromechanical energy conversion and mechanical resonance to deliver power over a range of distances using low-amplitude, low-frequency magnetic fields. Two different receiver orientations are investigated that rely on either the force or the torque induced on the receiver magnet at separation distances ranging from 2.2 to 10.2 cm. Theoretical models for each mode compare the predicted performance with the experimental results. For a 7.1 mApk sinusoidal current supplied to a transmitter coil with a 100 cm diameter, the torque mode receiver orientation has a maximum power transfer of 150 μW (efficiency of 12%) at 2.2 cm at its resonance frequency of 38.4 Hz. For the same input current to the transmitter, the force mode receiver orientation has a maximum power transfer of 37 μW (efficiency of 4.1%) at 3.1 cm at its resonance frequency of 38.9 Hz.