陣列式壓電能量擷取子之寬頻設計

Design of Multiple Piezoelectric Energy Harvesters with Broadband Improvement

陳彥儒(Yen-Ju Chen)

指導教授 ： 舒貽忠

國立臺灣大學/工學院/應用力學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.01070

摘要

在壓電振動能量擷取領域中，使用之振動子會受限於共振頻率附近的輸出功率，但環境的振動變化範圍大且不穩定，因此，本論文希望透過陣列式設計，讓壓電能量擷取系統的共振頻率範圍增大，並探討陣列式系統的寬頻現象。
文中的實驗架構，透過將單一振動子模組化，讓陣列式的設計更具彈性，並以新的方法設置質量塊，以及穩定調整振動子之共振頻率，讓系統可以按照需求設定不同之頻率，已達目標之頻寬。在數值模擬方面，寬頻現象探討則以軟體分析在並聯陣列式設計下，設定每根振動子不同共振頻率，探討在何種情形下會有最佳頻寬效果。此外，透過大量數值模擬的結果，發現了其系統的最佳頻寬大小，與振動子之無因次力電耦合係數和所在共振頻率區間有關，因此提出了一套快速估算最佳頻寬大小的方法。
最後，現實情況中充滿限制，無法像軟體可以任意模擬各種情況，其中設計空間的限制和環境振源就是極大的挑戰。文中提供一套設計流程，將問題簡化為空間的幾何排列，確定可以放置的振動子總數後，再用軟體分析是否可以達到目標之輸出功率與頻寬大小，此方法可以利用軟體的模擬，準確預測結果，並節省時間與成本。

關鍵字

並聯陣列式壓電振動能量擷取系統 ； 標準整流電路 ； 寬頻效果

並列摘要

The thesis aims to develop an array of piezoelectric energy harvesters with broadband improvement. The bandwidth of a single oscillator is typically small, leading to significant power reduction at off-resonance. Instead, oscillators with slightly different resonant frequencies may enlarge the overall bandwidth. Besides, the optimal overall bandwidth is discussed here.
The thesis proposes two improvements. One is to design a module so that independent oscillators can be collected flexibly to become an array system. Second, a new design is proposed for adjusting the specific resonant frequency by rearranging the proof mass of each oscillator. In addition, a series of numerical simulations are carried out for the case of parallel connection of oscillators. The optimal wideband is simulated by adjusting the resonance of each oscillator. The result shows that the overall bandwidth of an array system is closely related to the dimensionless electromechanical coupling factor and the difference between the short and open circuit resonances. A design guideline for evaluation of optimal bandwidth is also proposed here.
Finally, the thesis discusses the restrictions imposed on the design of an array system. These restrictions include the dimensions of the device, the target power output and the bandwidth for maintaining the specific power output. The thesis provides a standard procedure by first determining the maximum number of oscillators that the space can accommodate. Second, numerical simulations are proposed for reaching the target output power and the overall bandwidth.

並列關鍵字

array of piezoelectric energy harvests connected in parallel ； standard interface ； broadband improvement

參考文獻

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