DC GRID TECHNOLOGY FOR DISTRIBUTED GENERATION

Abstract

Soon after renewable sources, photovoltaic system and fuel cell in particular, become more economical they plays larger role in the distribution system. Also due to the environmental concerns the use of the renewable sources becomes more pronounced. This gives rise to terms like microgrid. It was easy to install a photovoltaic system and a fuel cell in a local premise. Although it was costlier earlier but now with the more producers in market the price of photovoltaic system is affordable. It not only helps the user to reduce the electricity bill but also the main distributor since there will be less demand which can be easily fuffilled. But the efficiency of photovoltaic system is still a huge challenge. Even if there is improvement in that, in future, there will still be losses due to conversions from dc to ac as photovoltaic system and fuel cell mainly produces dc. And then again many loads uses dc so there is a conversion from ac to dc for few loads. Is there any chance that these losses can be ignored, surely not because the present distribution system is ac and hence there is a need of conversion, but what if there exist another distribution system in parallel with present ac system, a dc distribution system, which only caters dc loads. Surely the losses due to conversion at load will be reduced also if a photovoltaic system is connected to that dc distribution system, DC grid, losses at the source side will also be reduced. There will be a huge cost indulge in the development of such grid. Hence it is advisable to have a voltage profile and system characteristic in advance if such system is installed. In this thesis system voltage profile and losses are calculated for a hybrid AC and DC grid.