PV based distributed generation power system protection: A review

This review paper is focused on common protection challenges related to the integration of distributed generation (DG) into medium voltage (MV) distribution power systems. Protection challenges, as indicated by the general scientific community, are explained and discussed. Based on these challenges, several alternative centralized and decentralized protection alternatives are explained and critically evaluated. Photovoltaic (PV) based distributed generators are connected to the utility grid through inverters, which are able to control active and reactive parts of their output and also limit their fault current contribution. Research is proposed to quantify the risks to protection in conventional power systems with increasing presence of distributed generation. Since the positive, negative and zero sequence current output from PV inverters can be controlled, conventional overcurrent protection using negative and zero sequence current is proposed to increase the protection reliability and maintain coordination in the presence of distributed generators.