压电-电磁复合动能采集器无量纲参数建模与分析

A study on the dimensionless parameter model of a piezoelectric-electromagnetic hybrid vibration energy harvester

针对压电-电磁复合动能采集器的物理参数模型难以提供统一的性能比较标准,以及最大输出功率及最优负载直接求解困难等问题。通过引入无量纲参数建立了采集器的无量纲参数模型,理论推导了归一化输出功率,并采用遗传算法求解了最大输出功率及最优负载;数值分析了无量纲参数对采集器性能的影响,并实验验证了模型和遗传算法求解的正确性。结果表明:(1)减小线圈负载可提升性能;(2)增大机械品质因子将提高频率选择能力;(3)当压电和电磁均为弱耦合作用时,性能受二者共同影响,且在二者匹配时获得最优;(4)当电磁为强耦合作用时,性能基本只受电磁端影响,且随其增强而不断趋近最优;(5)压电-电磁双耦合机制可增大采集器的最优负载范围。

In order to establish a unified p e r f o r m a n c e c o m p a r i s o n standard a n d obtain the m a x i m u m output p o w e r and the corresponding optimal loads for a piezoelectric-electromagnetic hybrid vibration energy harvester, a generalized dimensionless parameter model was introduced to address this p r o b l e m. T h e expression of the theoretical normalized output power was derived, and the maximum value a n d the optimal loads w e r e obtained b a s e d o n a genetic algorithm; the relationships between the dimensionless parameters a n d the p e r f o r m a n c e of the harvester w e r e analyzed b y numerical simulations, and the feasibility of the m o d e l a n d genetic algorithm for this topic w e r e verified b y a n e x p e r i m e n t. T h e results show ： （ 1 ） reducing coil resistance c a n i m p r o v e the p e r f o r m a n c e; （2） i m p r o v i n g m e c h a n i c a l quality factor c a n increase the frequency selectivity; （3） the p e r f o r m a n c e is c o - d etermined b y piezoelectric a n d electromagnetic factors w h e n the two effects are weak coupling, and the best p e r f o r m a n c e is obtained at their m a t c h i n g p o int; （4） the p e r f o r m a n c e is almost determined by the electromagnetic factor when it is strong c o u p l i n g, a n d it increases to the ultimate p e r f o r m ance with the electromagnetic effect; ？ the optimal load range is increased b y using the piezoelectric-electromagnetic dual-coupling mechanisms.