参数激励变势能函数压电俘能器的特性研究

Study on the Characteristics of Piezoelectric Energy Harvester with Variable Potential Energy Function Under Parametric Excitation

提出了一种具有变势能函数的二自由度压电俘能器结构。利用拓展哈密顿原理推导了俘能器的机电耦合模型,并对系统进行了运动及动力学仿真分析。研究表明,在系统发生共振时,随着外部磁铁的运动,系统中的磁力和磁势能均发生变化,系统的磁势能穿越了形状不同的磁势能曲线,产生了较大的磁势能变化,其中的大部分能量转化为梁的弹性势能,且通过对系统俘能特性的研究表明,俘能器的工作带宽与输出电压均方根峰值均得到较大提升,从而提高了俘能器的性能。

In this paper,a two degrees of freedom energy harvester with variable potential energy function is proposed.Hamiltonian principle is employed to establish the dynamic model of the energy harvester,and kinematics and dynamics of the system is conducted.The results reveal that under the circumstance of resonance,the motion of the outer magnet causes both magnetic force and potential energy to be varied,the magnetic potential energy of the system will traverse a serial magnetic potential energy curves with different shapes,this will result in a greater variation of magnetic potential energy,most of which will change into the elastic potential energy of the beam,and through the study of the energy harvesting characteristics of the system,it is shown that the working bandwidth and the peak rms voltage have been greatly increased,as a consequence,improved the performance of the piezoelectric energy harvester.