分段线性压电能量收集器机电耦合建模

摘要

In this study, we propose an electromechanical coupling model to reduce the errors between the theoreti⁃cal and experiment values of the pure mechanical model of the present piecewise⁃linear piezoelectric energy harvest⁃er. The amplitude⁃frequency response equation of voltage is provided on the basis of the electromechanical coupling model. The experiment results on the generating performance of the piecewise⁃linear piezoelectric energy harvester are obtained by processing the experimental unit and constructing the experiment platform. The comparison between the experimental and theoretical values of the pure mechanical model and the theoretical value of the electromechan⁃ical coupling model shows that the electromechanical coupling model can effectively reduce the errors between the experimental and theoretical values in comparison with the pure mechanical model. The relative errors of the voltage peak value decreased from 15.8% to 12.72% with an external excitation acceleration of 2 m/s2 and the impact dis⁃tance of 1 mm. Accordingly, the relative errors of the frequency bandwidth reduced from 24.42% to 4.41%. Moreo⁃ver, the investigations on different excitation accelerations and strike intervals show that the proposed electrome⁃chanical coupling model is more applicable to further research on the parameter optimization of the piecewise⁃linear piezoelectric energy harvester.%为了减小现有分段线性压电能量收集器的纯机械模型理论值与实验值之间的误差，提出了装置的机电耦合模型，基于该模型给出了装置发电电压的幅频响应关系式，通过加工实验装置及搭建实验平台得到分段线性压电能量收集器发电性能实验结果。实验值与纯机械模型理论值、机电耦合模型理论值的对比表明：所提出的机电耦合模型相对于纯机械模型能够有效减小理论值与实验值之间的误差。在外部激振加速度为2 m／s2，撞击间距为1 mm条件下，装置发电最大电压值相对误差由15．81％减小到12．72％，工作频率宽度的相对误差由24．42％减小到4．41％。同时，对不同激振加速度及不同撞击间距的研究表明，所提出机电耦合模型更适用于分段线性压电能量收集器的进一步参数优化研究。