Power quality impact of distributed energy resources in low voltage distribution grids

The amount of power electronic-based distributed energy resource connected to low voltage grids is increasing at a fast rate. These interfaces can create power quality issues and consequently, affect the system's equipment and the quality of supply. In this study, the focus is on analysing the harmonic distortion impact of photovoltaic connected through a two-level voltage source inverter with a pulse-width modulation control and electric vehicle connected by a six-pulse rectifier in an existing low voltage grid. The converters are modelled by their Norton equivalent. Moreover, passive filtering is used to mitigate the high amount of harmonic distortion that the selected converters inject into the grid. The results show that the increase in photovoltaic and electric vehicle penetration increases the harmonic distortion at the point of coupling and that the photovoltaics act as an active filter by filtering out the electric vehicle harmonics.