適用於壓電能量擷取系統之使用壓電震盪器的同步切換能量擷取整流器

Synchronized Switch Harvesting Using Piezoelectric Oscillators for Piezoelectric Energy Harvesting System

洪聖瑋(Sheng-Wei Hung)

指導教授 ： 吳文中

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201903531

摘要

為取代傳統電池，能量擷取系統廣受關注，其中，微型壓電能量擷取器擷取環境中振動能因擁有較高能量密度且高穩定度，因此成了熱門研究之一。壓電能量擷取系統包含壓電元件、介面電路與負載裝置。其中介面電路包含整流器與降壓器，而整流器部分通常以全橋整流器實現，但傳統全橋整流因功率因子較低，且二極體的順向跨壓將產生巨大能量損失，因此，傳統全橋整流器可改使用具有非線性之同步切換技術之整流器，以提升擷取效能。另外，現今壓電能量整流電路大多使用電感來提升電路效率，然而電感屬於磁性元件，不免產生電磁波，亦可能產生電磁干擾，且電感有體積過大的缺點，因此本論文提出一全新架構-使用壓電震盪器之同步切換電路(Syncronized Switch Harvesting using Piezoelectric Oscillators, SSHO)取代電感，其中同步切換技術實現電壓反轉，使電壓振幅增加進而提升輸出功率。
本論文以TSMC 0.25 μm CMOS製程實現SSHO整流器晶片，根據佈局後模擬結果，在壓電元件等效電流源為25 μA、寄生電容15 nF、振動頻率為125 Hz情況下，電路具有475%的輸出增益。

關鍵字

壓電能量擷取 ； 交流-直流轉換器 ； 同步切換介面電路 ； 無電感整流器

並列摘要

In order to replace the traditional battery, the concept of energy harvesting has been proposed and attracted widespread attention. Using the micro-piezoelectric transducer for extracting ambient energy is now a popular research topic. The piezoelectric energy harvesting system consists of a piezoelectric transducer, a load device, and interface circuits, which usually includes a rectifier and a DC/DC converter. In general, a full-bridge rectifier is used to convert AC source into DC voltage because it is easy to implement. However, the it has low power efficiency since its low power factor and forward voltage of the diodes consume large amounts of energy. As a result, more and more rectifiers with nonlinear synchronous switch harvesting techniques are proposed to improve the efficiency. Majority of which use inductors extract more energy by realizing voltage inversion and load independent; however, the inductor which is magnetic a component would generate electromagnetic waves and induce the electromagnetic interference. Therefore, this thesis proposes a new architecture-Synchronized Switch Harvesting using Piezoelectric Oscillators (SSHO) for solving these problem. Without bulky external inductors SSHO achieves voltage inversion which increases the voltage amplitude and then the output power.
In this thesis, the SSHO rectifier fabricated in TSMC 0.25 μm HV-CMOS process has executed and tape-out. According to the post-layout simulation results, the circuit can boost the output power up to 475% when the equivalent current source of the piezoelectric source is 25 μA, the parasitic capacitance is 15 nF, and the vibration frequency is 125 Hz.

並列關鍵字

Piezoelectric energy harvesting ； AC/DC Converter ； Synchronized Switching Interface Circuit ； Inductor-less Rectifier

參考文獻

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