Solcellsdrivning av distribuerade inbyggda system

Sammanfattning: The high level of energy consumption that the industrialised countries have reached and the pollution that this brings has long been a cause for analysis and debate, development and usage of so called renewable energy sources is therefore more important than ever. The energy in the electromagnetic radiation from the sun is an interesting alternative. One way of harvesting this energy is by using solar cells, devices that generate DC current when exposed to electromagnetic radiation. The goal of this master’s thesis was to design a solar powered power supply to Syntronic AB’s Midrange 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 solar powered systems and identifying important factors needed to be taken into consideration was the objective. One of the set requirements was that the system had to be able to operate in Sweden with a maximum of 5 % down-time, using the daily solar irradiance of 2009 as a reference. The final results are two different hardware-based solutions, both using a solar module with a maximum power of 1 W, a 52 F ultracapacitor as energy storage and a circuit to both control the operation 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 approximated performance together with daily irradiance for three different locations in Sweden, the result was that both solutions met the requirement of 5 % down-time for the solar irradiance in Stockholm and Malmo, for Lulea however neither solution met the requirement.