双梁磁力压电振动能量采集器的实验和仿真

摘要

基于非线性技术改善能量采集器的能量采集效果作用,本文研究了非线性磁力耦合的双悬臂梁压电振动能量采集器,该采集器由两条不同的固有频率悬臂梁与永磁体组成.本文给出双梁磁力耦合压电能量采集器模型并建立了动力学方程式,通过实验测试获取相关参数与拟合磁力公式,数值仿真分析了双梁固有频率比1∶1.2与1∶1.5和永磁体初始间距40mm与30mm的4种结构能量采集器的电压输出性能与频率特征.根据数值分析设计实验:外激励加速度3m/s2作用下,双梁磁力结构能量采集器比单梁线性结构多一个电压共振峰;双梁固有频率比为1∶1.5比双梁固有频率比1∶1.2的电压响应带宽宽;初始磁距30mm共振峰值分别为(12Hz,39.4V)与(18Hz,13.4V)比初始磁距40mm两电压共振峰高且电压共振峰峰之间的电压输出比其他组合结构高.%As nonlinear technology can improve the energy harvest effect of energy harvest system,this paper studies a vibration Piezoelectric Energy Harvester(PEH) with double cantilever beams under a nonlinear magnetic coupling.The harvester consists of two cantilevers with different natural frequencies and one permanent magnet.In this paper,the numerical model of the energy harvester is proposed,and the dynamic equations are established.The relevant parameters and fitting magnetic formula are firstly obtained through experiment.Numerical simulation is then carried out on studying the voltage output ability and frequency characteristic of four different structure energy harvesters with the double-beam natural frequency ratio of 1∶ 1.2 and 1 ∶ 1.5 and the permanent magnet initial spacing of 40 mm and 30 mm.The experimental results show that under external excitation acceleration of 3 m/s2,the double-beam magnetic PEH experiences two output voltage resonance peaks,but singlebeam PEH only has one voltage resonance peak.Meanwhile,the voltage response frequency bandwidth of the PEH with natural frequency ratio of 1 ∶ 1.5 is wider than that with the natural frequency ratio of 1 ∶ 1.2.It is also found that the output voltage resonance peaks of the PEH with the initial magnetic spacing of 30 mm are (12Hz,39.4V) and (18Hz,13.4V),which are higher than that for the case with the initial magnetic spacing of 40 mm,and the voltage output between two voltage resonance peaks are also higher than that of the other nonlinear PEHs.