三稳态压电能量采集器的动态特性与实验

Dynamic Characteristics and Experimental Analysis of Tri-stable Piezoelectric Energy Harvester

为了探究三稳态压电振动能量采集器的动力学特性,以磁-机-压电耦合型三稳态压电振动能量采集器(tristable piezoelectric vibration energy harvester,简称TPVEH)为研究对象,利用磁荷法、力平衡和基尔霍夫定律分别建立了采集器末端磁铁与外部磁铁之间的非线性磁力模型和系统集总参数动力学模型。仿真分析了磁铁间距、激励加速度幅值和频率等参数对采集器动力学特性和采集电压的影响。研制了三稳态压电振动能量采集器原理样机,搭建了实验测试平台,实验验证了仿真结果的正确性。研究结果表明,随着激励加速度幅值增大,能量采集器依次经历单稳态、双稳态和三稳态3种运动状态,且三稳态运动时的工作频带和输出性能(位移、速度和采集电压)比双稳态和单稳态时要高。

n order to investigate the dynamics of the tri-stable piezoelectric vibration energy harvester(TPVEH),a TPVEH composed of a piezoelectric cantilevered beam with a tip magnet and two external magnets is presented.The magnetic coupling model is established to calculate the nonlinear pulse force between the tip magnet and the two external magnets with the magnetic point dipole model,and then the lumped-parameter dynamics model of the TPVEH is consequently established with force balance principle and Kichihoff current method.The influences of the distances between the tip magnet and the external magnets,the exciting amplitude and frequency on the dynamic characteristics of the TPVEH are analyzed respectively.Finally,aprototype TPVEH is developed and an experimental platform was setup to validate the simulation results.The research results show that the TPVEH will exhibit mono-,bi-and tri-stable motion with the increasing of the exciting amplitude,and the frequency-band,the output performances of the TPVEH obtained from the tri-stable motion are larger than those of the mono-and bi-stable motions.