Piezoelectromagnetic synergy design and performance analysis for wind galloping energy harvester

Abstract

To improve the performance of the wind galloping energy harvester, the piezoelectromagnetic synergy design is proposed. Hamilton's principle and Euler–Bernoulli beam assumptions, quasi-steady hypothesis, Gauss law and Faraday's law are adopted to establish an electromechanical coupled distributed parameter model for the hybrid energy harvesting system. Using the harmonic balance method, the approximate analytical solutions of the dynamic response and electric output are derived. Wind tunnel experiments validate the nonlinear results of the proposed model including the Hopf bifurcation and unsteady response. The load resistances are optimized via finding the extreme of the power binary function. For the wind speed smaller than the critical wind speed, the piezoelectric module works with switched-off electromagnetic module. For the wind speed larger than the critical wind speed, piezoelectric and electromagnetic modules work concurrently to realize the synergistic effect. The piezoelectromagnetic galloping energy harvester is demonstrated to be superior than the piezoelectric galloping energy harvester and the electromagnetic energy harvester for higher harvested power from smaller galloping oscillations.