基于复合梁结构的压电-电磁能量收集器研究

Research on Piezoelectric-Electromagnetic Energy Harvester Based on Composite Beam Structure

能量收集器是解决复杂环境下为无线传感器网络节点供能问题的有效方法之一。针对传统收集器的共振频率高、频带窄等缺陷,设计了一种基于复合梁结构的压电-电磁式能量收集器,并进行了动力学分析与实验研究。首先对该结构进行理论模型建模,建立动力学方程,验证了其结构合理性。之后将该结构与其他传统压电结构进行对比研究,分析了收集器的动力学特性以及发电性能,优化结构参数,并进行了实验验证。研究发现通过复合梁与电磁单元的引入,收集器的工作频带得到了拓宽,改善了其发电性能,有效地使得该结构的一阶与二阶共振频率靠近。实验结果表明:负载电阻为10 kΩ、磁铁线圈间距为7 mm时,该复合梁压电电磁结构收集器具有最优的输出特性,其最大输出功率为20.17 mW,有效工作带宽约为13.40 Hz。

Energy harvester is one of the effective methods to solve the problem of supplying energy to wireless sensor network nodes in complex environments.To aboid the defects of traditional collectors such as high resonance frequency and narrow frequency band,a piezoelectric-electromagnetic energy harvester based on composite beam structure is designed,and the dynamics analysis and experimental research are carried out.The structure is first modelled theoretically,and the kinetic equations are established to verify its structural rationality.After that,the structure is compared with other conventional piezoelectric structures,the kinetic characteristics of the harvester and power generation performance are analyzed,and the structural parameters are optimized for experimental verification.It is found that the operating band of the harvester is broadened by introducing of the composite beam and the electromagnetic unit,which improve the power generation performance and effectively fultill the approach of the first-and second-order resonant frequencies of the structure.The results show that the harvester with the composite beam piezoelectromagnetic structure has the optimal output characteristics of a maximum output power of 20.17 mW and an effective operating bandwidth of about 13.40 Hz at a load resistance of 10 kΩand a magnet coil spacing of 7 mm.