Control Strategy for Grid-tied Solar Photovoltaic Multifunctional Inverter Under Balanced and Unbalanced Loads

In this paper, a two-level grid-tied solar photovoltaic system operating under balanced and unbalanced loading conditions is discussed. The proportional resonant (PR) current controller developed in a stationary reference (αβ) frame is used to control the inverter to operate in multifunctional mode to make the source current sinusoidal under balanced/unbalanced loads. Inverter rated capacity at any given time is fully utilized for variations in solar irradiance by providing ancillary services such as reactive power compensation and reduction of source current harmonics. The simulation and experimental results show that the effectiveness of the proposed control technique under balanced and unbalanced loads.