Airfoil-based electromagnetic energy harvester containing parallel array motion between moving coil and multi-pole magnets towards enhanced power density

In this letter, the airfoil-based electromagneticenergy harvester containing parallel arraymotion between movingcoil and trajectory matching multi-polemagnets was investigated. Themagnets were aligned in an alternativelymagnetized formation of 6magnets to explore enhanced power density. In particular, themagnet array was positioned in parallel to the trajectory of the tipcoil within its tip deflection span. The finite element simulations of themagnetic flux density and induced voltages at an open circuit condition were studied to find the maximum number of alternativelymagnetizedmagnets that was required for the proposedenergy harvester. Experimental results showed that theenergy harvester with a pair of 6 alternativelymagnetized linearmagnet arrays was able to generate an induced voltage (Vo) of 20 V, with an open circuit condition, and 475 mW, under a 30 Ω optimalresistance load operating with the wind speed (U) at 7 m/s and a natural bending frequency of 3.54 Hz. Compared to the traditional electromagneticenergy harvester with a singlemagnet moving through acoil, the proposedenergy harvester, containing multi-polemagnets and parallel arraymotion, enables the movingcoil to accumulate a strongermagnetic flux in each period of the swingingmotion. In addition to the comparison made with the airfoil-basedpiezoelectricenergy harvester of the same size, our proposed electromagneticenergy harvester generates 11 times more power output, which is more suitable for high-power-densit...
Source: Review of Scientific Instruments - Category: Physics Authors: Source Type: research