In order to extract as much energy as possible from ambient vibrations, many vibration-based energy harvesters (VEHs) are designed to resonate at a specific base excitation frequency. Unfortunately, many vibration energy sources are low frequency (0.5 Hz–100 Hz), intermittent, and broadband. Thus, resonant VEHs would not be excited continuously and would require a large mass or size to tune to such a low frequency. This work presents the modeling, analysis, and experimental application of a nonlinear, magnetically excited energy harvester that exhibits efficient broadband, frequency-independent performance. This design utilizes a passive auxiliary structure that remains stationary relative to the base motion of the VEH. This device is especially effective for driving frequencies well below its fundamental frequency, thus enabling a more compact design compared to traditional resonant topologies. A mechanical model based on Euler-Bernoulli beam theory is coupled to a linear circuit and a model of the nonlinear, magnetic interaction to produce a distributed parameter magneto-electromechanical system. The results of both harmonic and broadband, stochastic simulations demonstrate multiple-order-of-magnitude power harvesting performance improvement at low driving frequencies and an insensitivity to time-varying base excitation frequency content. Furthermore, the proposed system is shown to enable more practical designs than a resonant energy harvester for the specific example of harvesting energy from walking motion.
- Aerospace Division
Broadband and Low Frequency Vibration-Based Energy Harvesting Improvement Through Magnetically Induced Frequency Up-Conversion
Wickenheiser, AM. "Broadband and Low Frequency Vibration-Based Energy Harvesting Improvement Through Magnetically Induced Frequency Up-Conversion." Proceedings of the ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Volume 1. Philadelphia, Pennsylvania, USA. September 28–October 1, 2010. pp. 611-618. ASME. https://doi.org/10.1115/SMASIS2010-3821
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