Prva dva poglavlja rada bave se mrežnim pravilima elektroenergetskog sustava te osnovnim principima rada nadstrujne zaštite. Navedena poglavlja stvaraju podlogu za bolje razumijevanje istraživanja. Glavni dio istraživanja je treće poglavlje koje se bavi utjecajem distribuiranih izvora na elektroenergetsku mrežu gdje je proučena i objašnjena problematika velikog prodora distribuiranih izvora. Nakon toga su u četvrtom poglavlju proučene razne metode za poboljšanje sustava kroz smanjivanje negativnih utjecaja distribuiranih izvora na mrežu te su analitički prikazane prednosti i nedostaci svake od metoda Zaključeno je da mnoga predložena rješenja ne mogu biti generalizirana za svaku mrežu te da je potrebno svaku mrežu proučiti posebno, no da i tada neće biti idealnog rješenja ili zbog tehničkih uvjeta ili zbog problema isplativosti. The first two chapters of the thesis deal with the network rules of the electric power system and the basic principles of overcurrent protection. The mentioned chapters create a basis for a better understanding of the research. The main part of the research is the third chapter, which deals with the impact of distributed sources on the power grid, where the problem of the large penetration of distributed sources is studied and explained. After that, in the fourth chapter, various methods for improving the system by reducing the negative impact of distributed sources on the network were studied, and the advantages and disadvantages of each method were analytically presented. It was concluded that many of the proposed solutions cannot be generalized for every network and that it is necessary to study each network separately, but even then there will not be an ideal solution either due to technical conditions or due to profitability problems.