Interactions of Rooftop Solar Photovoltaic Systems with Symmetrical and Unsymmetrical Faults in Distribution Feeders

In this paper, the response of a single-phase rooftop solar photovoltaic (PV) system has been studied with the occurrence of symmetrical and unsymmetrical faults. From the results obtained, it was observed that the behavior of solar photovoltaic systems to faults depend largely on the control scheme used for the power electronic converter which connects it to the grid. It has been shown through simulations that the solar PV system shuts down its operation when a fault occurs between line conductors and the ground whereas it is able to ride through the fault when it does not have a ground path. Overcurrents and overvoltages were observed in the system immediately after the fault is cleared due to electromagnetic transients. These results are helpful in understanding fault behavior of solar PV systems and can be utilized to design better controllers for power electronic converters and suitable protection schemes for hybrid power systems.