Impact of PV systems on microgrids under different levels of penetration and operational scenarios

The insertion of photovoltaic (PV) systems on the small-scale low voltage (LV) networks can result in operational instability conditions due to the PV undispatched behavior and current harmonic injection. This paper presents a study of the impact evaluation of PV systems with different penetration levels and operational scenarios in a LV network. The conducted studies evaluate the effects verified at the point of common coupling (PCC) when PV system injects power with different penetration levels. For evaluating these effects, the internal impedance of the PCC is estimated based on a injection signal scheme. The network impacts evaluation uses standards for small-scale grid-connected PV systems in which reactive power compensation is rarely implemented. Experimental results demonstrate the impact of PV by analysing the variables: voltage fluctuation, harmonic distortion, and unbalanced level. Based on this, it is possible to evaluate the impact of the PV on the LV networks, which provides a strategic information for determining the proper penetration level for insertion small-scale PVs LV microgrids.