Harmonic Distortion in Low Voltage Grid by Grid-Connected Photovoltaic

Power electronic devices are being introduced in low voltage (LV) grids at an increasingly rapid rate due to the growing adoption of power electronic-based home appliances in residential grid. Photovoltaic (PV) systems are considered one of the potential installed renewable energy sources in distribution power systems. This trend has led to high distortion in the supply voltage which consequently produces harmonic currents in the network and causes an inherent voltage unbalance. In this paper, a typical low voltage grid with high penetration of 3- phase and single-phase PV from southern Germany was modelled using MATLAB/Simulink environment. The characteristics of the loadside harmonic impedances were analyzed, and their harmonic contributions were evaluated for different distortion levels. The effect of the high penetration of PV on the harmonic distortion of both positive and negative sequences was also investigated