Comprehensive Assessment of Fault Current Contribution in Smart Distribution Grid with Solar Photovoltaic

Abstract

The aim of this paper is to analyze the short circuit (SC) behavior and variation in fault level due to solar PV inverters in a smart distribution network. In order to investigate the issue, a generic urban distribution feeder is modeled, which supplies power to the loads of varying nature. The network is analyzed according to IEC 60909 standard and the alteration in SC current and fault level by the inverters is reported. Paper also reports that the grid strength and neutral grounding techniques significantly affect the inverter SC current. It is found that, with solar PV integration, the major change in fault level occurs due to the three phase fault then followed by double line to ground and other faults. Moreover, the varying network conditions also alter the SC current and fault level of the system. Such situation has to be managed to ensure the protection coordination and reliability of the system. The integration of more and more renewable energy sources like solar PV is expected in future power grid, therefore a proper planning study is required at the time of integration to ensure the reliable operation of the system.