DuraCap: 具有最大功率追蹤與冷啟動功能之能源採集系統

• Main Authors: Chen, Chien-Ying, 陳建穎
• Other Authors: Chou, Pai H.
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/69569586504342209888

碩士 === 國立清華大學 === 資訊工程學系 === 97 === DuraCap is a solar-powered energy harvesting system that stores harvested energy in supercapacitors and is volage compatible with lithium-ion batteries. The use of supercapacitors instead of batteries enables DuraCap to extend the operational life time from tens of months to tens of years. DuraCap addresses two additional problems with micro-solar systems, namely cold booting and maximum power point tracking (MPPT). Cold booting is when the system starts running from the state of total exhaustion of stored energy, and it can be inefficient due to the long charging time of supercapacitors. We solve this problem by dedicating a smaller supercapacitor to this stage before handing over to the array of larger-value supercapacitors. To enable accurate and efficient MPPT, we propose and evaluate a bound-control circuit for PFM regulator switching. The DuraCap also contains an I-V tracer to obtain the I-V curve and P-V curve of the solar panel to enable self-configuring to match solar panels of different types and sizes. Two types of enhanced switch for power path switching are designed for low voltage control that reduces the power consumption. Experimental results show the DuraCap’s bound-control MPPT circuit, enhanced switch, and supercapacitor array achieve the highest conversion efficiency, thereby enabling low power consumption and long operational life time.