Short Circuit Analysis of 11kV/400V Connected 415kW Solar Grid - Part I

This work presents the analysis of short-circuit at solar power plant along with calculations,in three part series. The solar power plant is privately owned with rated capacity of 415 kW capable to produce minimum of 880 kWh , providing electricity to six consumers hospital, market/business center, industrial facility, two sectors comprising 400 households and to the Govt. owned 1 MVA, 11kV/400V, Dyn11 distribution transformer. In this study, twelve faults at certain conditions which bypass protectionary switch gear and trigger short circuit in the plant, as per electrical NEC standards is modeled with practical real-world operating conditions, has been analyzed. The failure of protectionary circuit from faults resulting in complete destruction of the solar plant but the successful protection of the DISCOM substation has been analyzed and presented with parameters. In this study, all the faults excluding the faults due to faulty battery management has been collectively presented which trigger uncontrolled short-circuit. The faults have been deliberately induced in the normal operating conditions and twelve such faults at consumer and grid site have been analyzed.