Broadband vibration-based energy harvesting improvement through frequencyup-conversion by magnetic excitation

Abstract

Traditional vibration-based energy harvesters are designed for a specific base excitationfrequency by matching its fundamental natural frequency. This work presentsthe modeling and analysis of a nonlinear, magnetically excited energy harvesterthat exhibits efficient broadband, frequency-independent performance utilizing apassive auxiliary structure that remains stationary relative to the base motion.This system is especially effective in the regime of driving frequencies well belowits fundamental frequency, thus enabling a more compact design solution overtraditional topologies. A model based on Euler–Bernoulli beam theory is coupled to alinear circuit and a model of the nonlinear, magnetic interaction to produce adistributed parameter magneto-electromechanical system. This model is used in bothharmonic and stochastic base excitation case studies. The results of these simulationsdemonstrate multiple-order-of-magnitude power harvesting performance improvementat low driving frequencies and an insensitivity to time-varying base excitation.Furthermore, the proposed system is shown to outperform an optimally designed,standard energy harvester in the presence of broadband, random base excitation.