Broadband energy harvesting by nonlinear magnetic rolling pendulum with subharmonic resonance
Broadband energy harvesting by nonlinear magnetic rolling pendulum with subharmonic resonance
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DOI：
10.1016/j.apenergy.2019.113822
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发表时间：
2019-12-01
期刊：
影响因子：
11.2
通讯作者：
Zhu, Meiling
中科院分区：
文献类型：
--
作者：
Kuang, Yang;Hide, Rosalie;Zhu, Meiling
非线性系统可能表现出二次共振，这可以为能量收集提供额外的并且因此加宽的带宽。然而，文献中报道的非线性能量采集器的二次共振受到低功率输出和有限带宽的影响。提出了一种新型的磁滚摆（MRP），具有大带宽和高功率输出的能量收集的初级和次级共振。MRP采用具有最小机械阻尼的磁悬浮永磁体的滚动运动。制造了一个原型并进行了表征。建立了与有限元分析相结合的分析模型，并通过实验进行了验证。实验和仿真结果均表明，MRP的线性谐振频率为4.6Hz，峰值功率为3.7mW。它表现出强烈的非线性行为和宽带特性，在主共振中激励振幅低至2 m/s（2）。当激励振幅大于5 m/s（2）时，激发二次共振（1/2阶次谐波）。MRP在次谐波共振下的响应在位移和功率输出方面与主共振的形式相同。这有助于次谐波谐振产生与主谐振相同的功率水平，但具有更大的带宽。当以14 m/s（2）激励时，MRP显示出9.7 Hz的1 mW带宽，其中2/3归因于次谐波共振。
Nonlinear systems may exhibit secondary resonances, which can provide an additional and thus broadened bandwidth for energy harvesting. However, the secondary resonances of nonlinear energy harvesters reported in the literature suffer from low-power output and limited bandwidth. This work proposes a novel magnetic rolling pendulum (MRP) with a large bandwidth and high power output in both primary and secondary resonances for energy harvesting. The MRP employs the rolling motion of a magnetically levitated permanent magnet with minimal mechanical damping. A prototype was fabricated and characterised. An analytical model combined with finite element analysis was developed and validated by experiment. Both experiment and simulation show that the MRP has a linear resonance frequency of 4.6 Hz and peak power of 3.7 mW. It exhibits strong nonlinear behaviours and broadband characteristics with excitation amplitude as low as 2 m/s(2) in the primary resonance. As the excitation amplitude is larger than 5 m/s(2), the secondary resonance (1/2 order subharmonics) is excited. The responses of the MRP at the subharmonic resonance take the same form as the primary resonance in terms of displacement and power outputs. This helps the subharmonic resonance to produce the same power level as the primary resonance but with a larger bandwidth. When excited at 14 m/s(2), the MRP shows 1-mW-bandwidth of 9.7 Hz, 2/3 of which is attributed to the subharmonic resonance.