磁力非线性耦合的I-L组合压电梁俘能器发电性能试验研究

Experimental test for power generation performance of I-L composite piezoelectric beam energy harvester with magnetic nonlinear coupling

针对线性的压电振动俘能器俘能频带过窄,输出较低等问题,提出了一种磁力非线性耦合的I-L组合压电梁俘能器。俘能器由带永磁铁的I型压电梁和L型压电梁组成,可通过调节两永磁铁间的水平距离,得到不同的非线性磁力耦合效应。试验结果表明:存在最优电阻使压电俘能系统的输出功率最大;对比无磁力系统,磁力耦合的I-L组合压电梁俘能器共振频率发生了明显的偏移:I型压电梁向左偏移,L型压电梁向右偏移,拓宽了系统的俘能频带;当激励加速度为0.2 g水平距离为20 mm、激振频率为18.4 Hz时,俘能器最大可得到1.2 mW的输出功率。

Here,aiming at problems of narrower energy capture frequency band and lower output of linear piezoelectric vibration energy harvester,an I-L composite piezoelectric beam energy harvester with magnetic nonlinear coupling was proposed.The energy harvester was composed of I-shaped piezoelectric beam with permanent magnet and L-shaped one.Different nonlinear magnetic coupling effects could be obtained by adjusting horizontal distance between the two permanent magnets.The test results showed that there is an optimal resistance to maximize output power of the piezoelectric energy harvesting(PEH)system;compared with the non-magnetic system,the resonance frequency of the proposed energy harvester has an obvious shift with I-type piezoelectric beam shifting to the left and L-type one shifting to the right to widen the energy capture frequency band of the system;when the excitation acceleration is 0.2 g,the horizontal distance is 20 mm and the excitation frequency is 18.4 Hz,the proposed energy harvester can obtain the maximum output power of 1.2 mW.