Solcellsdrivning av distribuerade inbyggda system
The high level of energy consumption that the industrialised countries have reached and thepollution that this brings has long been a cause for analysis and debate, development and usageof so called renewable energy sources is therefore more important than ever. The energy in theelectromagnetic radiation from the sun is an interesting alternative. One way of harvesting thisenergy is by using solar cells, devices that generate DC current when exposed to electromagneticradiation.The goal of this master?s thesis was to design a solar powered power supply to Syntronic AB?sMidrange platform. The envisioned application is a stand-alone distributed embedded system,for example a node-based temperature monitoring system. Creating a tool for design of solarpowered systems and identifying important factors needed to be taken into consideration wasthe objective. One of the set requirements was that the system had to be able to operate inSweden with a maximum of 5 % down-time, using the daily solar irradiance of 2009 as areference.The final results are two different hardware-based solutions, both using a solar module with amaximum power of 1 W, a 52 F ultracapacitor as energy storage and a circuit to both control theoperation of the solar module and to provide the Midrange platform with a 3 V supply voltage.The systems were implemented to evaluate their performance. With the approximatedperformance together with daily irradiance for three different locations in Sweden, the resultwas that both solutions met the requirement of 5 % down-time for the solar irradiance inStockholm and Malmo, for Lulea however neither solution met the requirement.