A Noncontact Magnetoelectric Generator for Energy Harvesting From Power Lines

A noncontact energy harvester employing a Terfenol-D/PZT/Terfenol-D magnetoelectric transducer for scavenging ac magnetic field energy from a power line is proposed. The harvester uses a Halbach array and a magnetic circuit mounted on the free end of a cantilever beam. The Halbach array produces augmented magnetic field on the side where the power line is placed, and the magnetic circuit generates concentrated flux gradient on the magnetoelectric transducer. When the power line is energized, the harvester experiences an enhanced magnetic force which induces a bending movement of the beam. Due to the enhanced exciting force and the large magnetic field the magnetoelectric transducer undergoes, the response of the harvester to the ac can be potentially strengthened. Experimental study has been conducted. The results show that, at the current of 5 A, the harvester can produce a power of 523 μW across an 896 kQ resistor under the resonant frequency of 50 Hz.