室內用光伏能源接收電路使用多模式以及時域最大功率點追蹤

Indoor Photovoltaic Energy Harvesters Using Multi-Mode and Time-Based MPPT

張銘家(Ming-Chia Chang)

指導教授 ： 劉深淵

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201904375

摘要

隨著物聯網、穿戴式裝置與可植入式醫療元件的發展，光能功率傳輸受到相當大的關注。在相關應用中，透過光伏元件所轉換出的能量，經由能量接收器傳遞後，能夠在能量接收器上產生直流電壓。在傳統光伏能源傳輸系統中，能量接收器無具備最大功率點追蹤功能，因此，光伏元件無法對能量接收器傳輸最大輸出功率，進而導致功率轉換效率大幅下降。最近，具備最大功率點追蹤器的能量接收器被提出。透過切換電容式直流轉換器傳輸功率到負載，最大功率點追蹤器達成了能量接收器以及光伏元件的阻抗匹配。因此，改善了能量接收器的功率轉換效率。本論文針對直流-直流轉換器，提出兩個提高功率轉換效率的方法。在第二章中，提出輸入功率介於500奈米瓦-50微瓦搭載多重模式最大功率點追蹤器的室內用光伏能源接收器。三種不同開關尺寸以及電容大小的切換電容直流對直流轉換器。多種模式的最大功率點追蹤器調整電壓轉換率以及切換電容直流轉換器的切換頻率。除此之外，此多種模式的最大功率點追蹤器也透過可調整式的切換電容直流轉換器達成涵蓋500奈米瓦-50微瓦的輸入功率範圍。此室內用光伏能量接收器實現於0.18微米CMOS製程，有效面積1.15平方毫米。量測的最高功率傳輸效率為64.4%。在第三章中，提出了一個使用時域最大功率點追蹤及CMOS光伏元件的室內光伏能源接收電路。時域的最大功率點追蹤器電路選擇三種不同開關尺寸以及電容大小的切換電容直流對直流轉換器的其中一種，以及調整切換頻率達成最大功率點追蹤。當時域的最大功率點追蹤電路鎖定時，一個控制工作週期的技術被使用在時域的最大功率點追蹤電路上，達成降低時域的最大功率點追蹤電路所造成的功率耗損。此室內用光伏能量接收器實現於0.18微米CMOS製程，有效面積2.89平方毫米，其中光伏元件的面積為1.436平方毫米。量測的最高功率傳輸效率為68.3%。此能量接受器涵蓋5微瓦-500微瓦的輸入功率範圍，以及當輸入功率在10微瓦-500微瓦時，保持功率轉換效率大於50%以上。

關鍵字

室內用光伏 ； 獵能 ； 最大功率點追蹤

並列摘要

For the development of the Internet of Things (IoT), wearable devices, and implantable medical devices, the light energy transmission is receiving significant attention. In these applications, the light energy is received by Photovoltaic (PV) Cell, and a DC voltage will be received in an energy harvester. In the traditional light power transfer systems, photovoltaic cell transfer power through energy harvester to the load, the power conversion efficiency is significantly decreased by the DC-DC conversion systems without the maximum power point tracking systems. Recently, including the maximum power point tracking energy harvesters are presented. By transferring power to the load with switched capacitor DC converter, the maximum power point tracking systems accomplish energy harvester and Photovoltaic Cell impedance matching. Therefore, the energy harvester power conversion efficiency is improved.This thesis presents two DC-DC converters to increase their PCSs. In chapter 2, a 500nW-50µW indoor photovoltaic energy harvester is presented with a multi-mode maximum power point tracking (MPPT) circuit. Three switched-capacitor DC-DC converters (SCDCs) with different switch sizes and flying capacitors are realized. A multi-mode MPPT circuit is presented to tune the voltage conversion ratios and the switching frequency of the SCDCs. In addition, this multi-mode MPPT circuit also utilizes three reconfigurable SCDCs to cover the input power range of 500nW~50µW. This indoor photovoltaic energy harvester is realized in a 0.18μm CMOS process and its active area is 1.15mm2. The measured peak power conversion efficiency is 64.4%. In chapter 3, an indoor photovoltaic energy harvester using a time-based maximum power point tracking (TBMPPT) circuit and CMOS PV cell is presented. The TBMPPT circuit selects one of three switched-capacitor DC-DC converters and adjusts the switching frequency to achieve the maximum power. This TBMPPT circuit can also track the light intensity variations. When the TBMPPT circuit is locked, a duty-cycle control technique is used to lower the power. This indoor PV energy harvester is realized in a 0.18μm CMOS process. Its total active area is 2.89mm2 wherein the area of the PV cell is 1.436mm2. The measured peak power conversion efficiency (PCE) is 68.3%. This energy harvester can cover the wide input power range of 5μW-500μW and maintain the PCE>50% over the input power range of 10μW-500μW.

並列關鍵字

Indoor Photovoltaic ； Energy Harvesters ； MPPT

參考文獻

Reference

[1] G. Chen, H. Ghaed, R. Haque, M. Wieckowski, Y. Kim, G. Kim, D. Fick, D. Kim, M. Seok, K. Wise, D. blaauw, and D. Sylvester, “A cubic-millimeter energy-autonomous wireless intraocular pressure monitor,” in IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers (ISSCC), Feb. 2011, pp. 310–312.

[2] S. Bandyopadhyay, P. P. Mercier, A. C. Lysaght, K. M. Stankovic, and A. P. Chandrakasan, “A 1.1nW energy-harvesting system with 544 pW quiescent power for next-generation implants,” IEEE Journal of Solid-State Circuits, vol. 49, no. 12, pp. 2812–2824, Dec. 2014.

[3] J. Kim, J. Kim, and C. Kim, “A regulated charge pump with a low-power integrated optimum power point tracking algorithm for indoor solar energy harvesting,” IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 58, no. 12, pp. 802–806, Dec. 2011.

[4] I. Lee, W. Lim, A. Teran, J. Phillips, D. Sylvester, and D. Blaauw, “A >78%-efficient light harvester over 100-to 100klux with reconfigurable PV-cell network and MPPT circuit,” in IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers (ISSCC), Feb. 2016, pp. 370-371.