振动能量回收技术能够将环境中的机械振动能转换成电能,进而为微功耗装置供电,具有良好的应用前景.设计了一种利用压电材料的新型振动能量收集器,该机电耦合结构由一对非对称压电悬臂梁组成,悬臂梁末端固定有永磁体,利用永磁体产生的非线性力,实现了悬臂梁共振频率与外界激振频率的匹配调节.提出了该结构的理论模型,借助Matlab/Simulink数值分析软件对理论模型进行了仿真分析,并通过实验进行了验证.实验结果表明外界激励加速度幅值为3 rn/s2的时,结构即能实现较大频带范围内的频率匹配调节,频带范围不低于6.5 Hz,最大回收功率不低于2 mW.%Vibration energy harvesting technology can convert ambient mechanical vibration energy into electrical energy and then powers micro-power consumption devices,it is an attractive technology for practical application.Here,a novel vibration energy harvesting device was designed based on piezoelectric materials,its electro-mechanical coupled structure was composed of a pair of asymmetric cantilevers,their free ends were glued with magnets.Fortunately,a nonlinear magnetic force caused by magnets was adopted to realize the matching adjustment between the resonance frequency of the cantilever and external excitation frequency.The theoretical model of the device's structure was proposed.The model was simulated with MATLAB/Simulinke and verified with tests.The results showed that when the external excitation acceleration amplitude is 3 m/s2,the device can be used to realize the frequency matching adjustment within a wider frequency band range,the frequency band range is higher than 6.5 Hz and the maximum harvesting power is higher than 2 mW.
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