Fault Current Analysis on Distribution Feeders with High Integration of Small Scale PV Generation

Due to its easy installation, easy operation and plenty solar light, the photovoltaic (PV) generators were the ones that emerged as favourites among the other types. However, the high integration of PV generators in distribution networks may cause impacts on power system protection, mainly on overcurrent protection (OCP). This work aims to assess the variation of fault currents magnitude through the OCP relays of a distribution network with integration of small scale PV generators. The distribution feeder and the PV generator were implemented in Simulink
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/MATLAB
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and the faults were applied at two different points. As the fault moves away from substation, the positive variation of the fault current through OCP relay increases and the negative variation decreases. Moreover, the current variability for line-to-ground (LG) faults are, in average, 130.94% greater than three line-to-ground (3LG) faults. In the case where the fault is upstream from OCP relay, the average current variation was -1,443.22% for 3LG faults and -842.28% for LG faults. This can lead to miscoordination and tripping issues of OCP devices, making it necessary to evaluate the impacts on protection system reliability.