Energy harvesting from electric power lines employing the Halbach arrays

Abstract

This paper proposes non-invasive energy harvesters to scavenge alternating magnetic field energy from electric power lines. The core body of a non-invasive energy harvester is a linear Halbach array, which is mounted on the free end of a piezoelectric cantilever beam. The Halbach array augments the magnetic flux density on the side of the array where the power line is placed and significantly lowers the magnetic field on the other side. Consequently, the magnetic coupling strength is enhanced and more alternating magnetic field energy from the current-carrying power line is converted into electrical energy. An analytical model is developed and the theoretical results verify the experimental results. A power of 566 μW across a 196 kΩ resistor is generated from a single wire, and a power of 897 μW across a 212 kΩ resistor is produced from a two-wire power cord carrying opposite currents at 10 A. The harvesters employing Halbach arrays for a single wire and a two-wire power cord, respectively, exhibit 3.9 and 3.2 times higher power densities than those of the harvesters employing conventional layouts of magnets. The proposed devices with strong response to the alternating currents are promising to be applied to electricity end-use environment in electric power systems.

Large Power Amplification in Magneto‐Mechano‐Electric Harvesters through Distributed Forcing

“…The use of low‐loss piezoelectric material is found to provide 32% higher electrical output as compared to traditional piezoelectric material . A Halbach array of magnets have been shown to provide 390% improvement in power density as compared to the conventional layout of magnets on piezoelectric beam . This architecture is only suitable for a two‐wire power cord carrying opposite currents.…”

A Noncontact Magnetoelectric Generator for Energy Harvesting From Power Lines

“…The harvester consists of a piezoelectric cantilever beam and NdFeB magnets, and is excited by the force acting on the magnets [16]. Recently, piezoelectric cantilever beam generators for energy harvesting from power lines were presented [17], [18], which use modified Manuscript magnetic structures to improve the power output. However, sharp vibrations of a piezoelectric cantilever beam might cause piezoelectric fracture as the layers of the beam are adhesively bonded.…”

Semi-Analytical Modeling and Analysis of Halbach Array

“…Nevertheless, the cost of an electric machine could be increased when HA is used due to the manufacturing difficulties of HA arising from factors such as the bonding difficulties of PMs, which are magnetized in different directions, etc. However, as there are many merits of HA, it is widely used for diverse kinds of electric machines, such as, motor [9][10][11][12][13][14][15], maglev [16,17], eddy current brake [18][19][20][21][22], actuator [23,24], magnetic bearing [25][26][27], energy harvester [28][29][30][31], etc.…”

“…The above methods are not applicable if the device contains no ferromagnetic core and has wide airgap. However, in some cases, the HA can be placed in open space and most of the magnetic flux can pass through a long distance in air such as when it is used in energy harvester around the transmission line [30,31].…”