A photovoltaic grid-connected converter operating with reactive power and current harmonic compensation functions

The capacity of a single-phase photovoltaic (PV) grid-connected converter to perform ancillary functions for power quality improvement is studied in this research work. The importance of the nominal value of the dc bus voltage on the capacity of the converter to compensate current harmonics is demonstrated from the analysis carried out to design a control system based on hysteresis. With the proposed control scheme, the converter can inject the active power generated to the grid, compensate the reactive power and harmonics demand of a nonlinear load, and simultaneously inject reactive power as a grid-support function. It can operate exchanging reactive power with the grid or act as an active power filter even under the absence of solar energy.