Photovoltaic plant with reduced output current harmonics using generation-side active power conditioner

This study presents a study on a scheme to reduce the current harmonics from a photovoltaic (PV) plant. The scheme uses a power conditioner unit, which is placed parallel with the plant and works in feed-forward mode, and behaves to compensate the PV plant's output current distortion, so that the total current flows to the grid is sinusoidal. In addition, this scheme includes an effective control structure, which combines a simple sine-wave generation for synchronisation, as well as a distortion current's components extraction, and a conditioner current control. In this study, the control system was implemented to a voltage source inverter with LCL output filter as conditioner power circuit. The workability of the scheme and the power quality improvement achieved were evaluated by using a TMS320F28335 DSP-based control conditioner proto-type; using real signal from PV plant operation. Then, the effect on the conditioner installation to the power quality improvement for different power operation of PV-inverter was analysed. Finally, the improvement on the utilisation factor of PV-inverter and plant was analysed and described.