並聯與串聯電感同步切換開關介面電路應用於壓電振動能量擷取之研究

A Study of Parallel- and Series-SSHI Interfaces in Piezoelectric Energy Harvesting

徐仕銘(Shr-Ming Shiu)

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(2010年)

https://doi.org/10.6342/NTU.2010.01297

摘要

隨著積體電路製程技術的不斷進步，行動通訊設備對於功率的需求已大幅地降低，因此，將環境中所蘊含的各種型式能量轉換成電能，以提供電子設備作為驅動力來源的概念將得以實現。本論文即以壓電振動能量擷取系統之輸出功率最佳化作為研究的主軸，詳細探討近年來廣受矚目的「電感同步切換開關介面電路」(SSHI) 提升效能之機制與原理，並與傳統交流轉直流介面電路作一分析比較。實驗結果顯示，SSHI電路技術確實能有效的提升輸出功率，不僅如此，對於中力電耦合強度的壓電振動子還具有遲緩因激振頻率偏移所造成輸出功率驟降的能力，而呈現出寬頻的效果。
此外，研究中更發現SSHI能量擷取介面電路將會主動地影響振動子的機電特性，對於Parallel-SSHI介面電路而言，等效上因消除了壓電寄生電容效應而可將系統力電耦合係數放大至無限大；而Series-SSHI介面電路效果上則完全異於Parallel-SSHI介面電路，其因為採用瞬間對負載釋放能量的方式，故電容效應將被保留下來，系統的操作頻率也因此幾乎被固定在開路共振頻附近。由此可知，Parallel-SSHI與Series-SSHI兩種不同型式之能量擷取電路具有互補的特性。最後在考量電路系統損耗之情況下，多次實驗結果發現Parallel-SSHI介面電路所呈現之寬頻效果優於Series-SSHI介面電路。

關鍵字

壓電振動能量擷取系統 ； 電感同步切換開關介面電路 ； 寬頻效果

並列摘要

With the great advances in the integrated circuits, the power demand of mobile communication devices has been reduced significantly. Therefore, different forms of energy available in environment can be transformed into useful electric energy via suitable medium, and the notion of energy harvesting for producing enough power is not far fetched. The present thesis investigates the effect of the synchronized switch harvesting on inductor (SSHI) interface on power optimization in vibration-based piezoelectric energy harvesting systems. The results are also compared to those achieved based on the standard electronic interface. They show that SSHI techniques can not only boost harvested power, but also enhance the bandwidth of a power generator with medium electromechanical coupling.
Besides, it is also found that the effective electromechanical coupling of a Parallel-SSHI system increases significantly due to the elimination of parasitic piezoelectric capacitance. Different from the parallel SSHI technique operated at around the short circuit resonance, Series-SSHI is effectively operated at the open circuit resonance by releasing transient energy to electric load. As a result, the electrical response of an ideal Series-SSHI system is in conjugate with that of an ideal Parallel-SSHI system. Finally, our numerous experimental results reveal that the consideration of inevitable diode loss favors the Parallel-SSHI technique, since the frequency-insensitive feature is much more pronounced in Parallel-SSHI systems than in Series-SSHI systems.

並列關鍵字

Piezoelectric Energy Harvesting ； SSHI Interface ； Wideband Effect

參考文獻

[1] S. Meninger, J. O . Mur-Miranda, R. Amirtharajah, A. Chandrakasan and J. Lang. Vibration-to-electric energy conversion. Proceedings of the 1999 International Conference on Low Power Electronics and Design (ISLPED), p 48-53, 1999.

[2] S. Roundy, P. K. Wright and J. M. Rabaey. A study of low level vibrations as a power source for wireless sensor nodes. Computer Communications, Vol. 26, No. 11, p 1131-1144, 2003.

[3] S. Spearing. Materials issues in microelectromechanical systems (MEMS). Acta Materialia, Vol. 48, No. 1, p 179-196, 2000.

[4] C. S. Lee, J. Joo, S. Han and S. K. Koh. Multifunctional transducer using poly(vinylidene fluoride) active layer and highly conducting poly(3,4-ethylenedioxythiophene) electrode: actuator and generator. Appl. Phys. Lett., Vol. 85, p 1841-1843, 2004.

[5] C. S. Lee, J. Joo, S. Han, J. H. Lee and S. K. Koh. Poly(vinylidene fluoride) transducers with highly conducting poly(3,4-ethylenedioxythiophene) electrodes. Proc. Int. Conf. on Science and Technology of Synthetic Metals, Vol. 152, p 49-52, 2005.