Parametric Study of Low Frequency Broadband Rectilinear-to-Rotary Vibrational Energy Harvesting

摘要

A parametric study of a high-power-density dual resonator for achieving low frequency broadband electro-magnetic energy harvesting is reported.The dual resonator consists of a rectilinear oscillator(RLO)performing magnetic levitation and a rotary oscillator(RTO)performing electromagnetic coupling through a stator and a rotor. Both oscillators,coupled by magnetic forces generated by a set of arc permanent magnets,radially magnetized and centro-symmetrically fixed onto the RLO and the rotor of the RTO achieve the reciprocating-to-rotary motion con-version and frequency up-conversion.Specifically,the dual resonator is able to convert stochastic reciprocating mo-tion into controllable rotation,provide intrinsic frequency up-conversion,use non-contact magnetic coupling to pro-vide near loss-free energy transfer and be configured into specific applications to obtain and maintain high-energy orbits of multi-stable energy harvesting.While solely focusing on developing a dual resonator provides substantial benefits,its dynamic behavior is unclear,thus electromagnetic-dynamic governing equations are derived,and a curve fitting model of restoring torque of RTO under different repulsive magnets configurations are developed to predict key characteristics and to improve performance of the electromechanical system.Power analysis is carried out for providing a quantitative guidance of customizing the harvester to achieve an optimal power density.