The purpose of our thesis is to introduce the concept of virtual power plants and their energy impact on medium electricity grid. When speaking of smart grids, a virtual power plant constitutes a part of a smart grid which is in itself a response to a change in conditions, caused by an unpredicted occurrence. Virtual power plants came to being as a consequence of obligations concerning shares of renewable sources in energy consumption, reduction of CO2 emissions, other improvements in energy efficiency and development of new technology . Our thesis presents a solution in case of a blackout or a failure in power supply. In the grid chosen for our research, power cuts occur frequently, which lead us to choose a power source with an output of 1 MVA. In our case, it was a diesel-powered generator. It is connected to the distribution network upon a partial or total failure in power supply.
Focussed on operation of virtual power plants, the paper set about installation and documentation necessary to put the power plant in operation. In the analysis part we have calculated the voltage drops and choke points or current within the distribution network. We come to a conclusion that the generator’s energy impact on the chosen electricity system at different loads (50 % and 100 % load) is significant, since voltage drops are decreased. Regarding operation, we noticed output power decrease and voltage stabilization at the transformer stations, as well as the observed medium voltage outlet.
At the full and half load on the medium voltage power outlet, a 30 % load decrease of the transformer station cell is noted. Also notable is generator’s influence on power losses at the mv power outlet. The power losses are reduced to half, the reason for this lying in the lower current throughout the grid. These calculations have been conducted in ideal conditions, but it is uncertain, how these calculations would vary in reality.