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.