Short circuit calculations in medium voltage networks with distributed energy sources

U ovom diplomskom radu se obraĊivala tema proraĉun struje kratkog spoja u srednjenaponskim mreţama sa obnovljivih izvorima energije. Kratki spoj je nepovoljno stanje u mreţi koje moţe dovesti do trajnih oštećenja elemenata mreţe, ali i uzrokovati ţivotnu opasnost za ljude. Ovim radom su takoĊer opisani obnovljivi izvori energije, te njihova upotreba u današnje vrijeme. U radu je opisana i primjenjena metoda superpozicije koja se koristi za proraĉun struje kratkog spoja. Proraĉun struje kratkog spoja na distributivnoj mreţi, metodom superpozicije je odraĊen u tri sluĉaja. Prvi sluĉaj je sluĉaj u kojemu na mreţu nisu spojene elektrane na obnovljive izvore. U drugom sluĉaju na mreţu je spojena elektrana na biomasu, a u trećem sluĉaju na mreţu je osim elektrane na biomasu spojena i fotonponska elektrana. This master's thesis deals with calculation of short circuit current in distribution power grid with renewable energy sources. Short circuit is a failure in power grid that can cause permament damage of power grid elements and life-threatening danger fo people. This master's thesis describes renewable energy sources and their use nowadays. Method of superpostion is also described in this master's thesis. Calculation of short circuit current in distribution power grid has been done for three cases, in all three cases method of superposition was used for calculation. First case of calculation consists only of distribution power grid. The second case of calculation consists of distribution power gird with biomass power plant. The third case of calculation consists of distribution power grid with biomass power plant and photovoltaic power plant.