An efficient architecture of a PV plant for ancillary service supplying

The use of Distributed Generation (DG) units for grid ancillary services, in particular for smart grid applications, has been deeply considered in the last few years. It has been demonstrated that DG units can produce not only active power, which is obviously the principal role, but also they can provide ancillary services such as: voltage control, spinning reserve, backup supply, harmonic compensation, peak shaving and others. Recently, the use of Photovoltaic (PV) DG units has been proposed for reactive power ancillary service production; the concept has been fully demonstrated, highlighting the potentiality of PV DG units as ancillary service provider. In this paper, some improvements are proposed for a PV DG unit as provider of ancillary services in terms of single components modeling and global optimization of the system. The capability of a PV plant of generating both active and reactive power is demonstrated.