双端磁耦合式压电振动俘能器结构设计

现有的非线性压电俘能器的输出功率提升主要通过改变俘能器的结构或引入非线性元素,但这些方法在提高俘能结构的输出功率,拓宽俘能器的俘能频带方面能力受限。该文设计了一种双端磁耦合式悬臂梁结构压电俘能结构,在利用永磁体引入非线性元素的基础上优化俘能结构,进一步提高系统的输出电压,拓宽俘能频带。通过将悬臂梁俘能结构等效为复杂边界条件的悬臂梁,推导磁耦合式悬臂梁结构的工作状态方程,并得到磁耦合式悬臂梁俘能结构的输出电压与永磁铁间距的关系,并通过实验测试进行验证。结果表明,在永磁体间距为5mm时,压电俘能结构获得最大的输出功率,在最佳的永磁铁间距和负载电阻下,双端压电磁耦合式悬臂梁的输出功率可达传统悬臂梁式压电俘能结构的1.5倍,谐振频率下降约7Hz。

Structure Design of Piezomagnetoelastic Energy Harvester Based on Double Cantilever Vibration

The improvement of the output power of the existing nonlinear piezoelectric energy harvesters is mainly realized by changing the structure or introducing into the nonlinear elements. However, these methods have limited ability to improve the output power of the devices and broaden the harvesting bandwidth. In this paper, a double cantilever piezomagnetoelastic structure is designed to optimize the harvester. In addition, by setting permanent magnets, the output voltage can be further improved, and the bandwidth can be broadened. The double cantilever structure is equivalent to a cantilever with complex boundary conditions. The working state equations of the piezomagnatoelastic energy harvester are deduced and the relationship between the output voltage and the space of the permanent magnet is obtained and verified by experimental. The experiment results show that the maximum output power is obtained when the distance between permanent magnets is 5 mm. Under the optimal permanent magnet distance and load resistance, the output power of the double cantilever piezomagnetoelastic energy harvester is 1.5 times as much as that of the conventional cantilever energy harvester and resonance frequency decreases about 7 Hz.