Energy Harvesting From Two-Wire Power Cords Using Magnetoelectric Transduction

This paper presents an energy harvester using a Terfenol-D/PMNT/Terfenol-D magnetoelectric (ME) transducer for scavenging ac magnetic field energy from two-wire power cords connected to household and commercial appliances. The harvester uses a magnetic circuit consisting of six NdFeB magnets mounted on the free end of a cantilever beam. The magnets produce concentrated flux gradient on the ME transducer, and the vertical Ampere forces acting on the two conductors of the power cord are superimposed. An enhanced movement is then induced on the magnetic circuit. The ME transducer undergoes magnetic field variations and generates power output. A prototype is fabricated and tested. Because of the high magnetomechanical coupling effect of the magnetostrictive material and the large flux gradient on the ME transducer, the harvester can generate a maximum power of 671.2 Ω W with a matching load resistance of 991 kΩ at 6 A. The results demonstrate the potential of the proposed device applied to electricity end-use environment in electric power systems.