A control algorithm for the maximum power point tracking and the reactive power injection from grid-connected PV systems

This paper deals with the use of large-size Photovoltaic (PV) units as providers of the reactive power compensation ancillary service. To do this, a suitable control scheme has been developed, which is based on an advanced control theory, called FeedBack Linearization (FBL), widely employed in the robotics field but still not so popular in power systems engineering. This allows to regulate both the injection of reactive power and the PV voltage, which is fixed to the value corresponding to the maximum power extraction from the PV unit, thanks to the implementation of an efficient MPPT algorithm, whose main features are described in detail. Several simulations are performed in the PSCAD-EMTDC electromagnetic environment to validate the proposed approach.