Dc Voltage Micro Grid in the Distributed Generation

One of the EU energy policy goals is development of utilization of renewable and small loacal power sources. Local balancing of power production and consumtion is aimed due to power transmission loses minimazation. In other words all energy consumed in separated small area (cottage, town, commune) should be produced within this area. Research it has been done so far shows that it is very hard, in particular using unstable renewable power based on solar and wind energy, to reach the aim with keeping very high quality factors, high effciency and low costs. One of the solutions could be local microgrid connected or not to power system. The microgrids can be realized as AC or DC current. There is DC current microgrid idea presented in the paper. In authors opinion such microgrid using power electronics converters and advanced control systems allows easier effective connection of different power sources as AC microgrid. In particular there are no problems like reactive power control, voltage and current distortion, reactive loses etc.