Storage application for ancillary service support to the main grid

Nowadays, the high penetration of Dispersed Generation (DG) introduces new issues in the stability and safety of the electrical system due to the intermittent and not deterministic behavior of Renewable Energy Sources (RESs). The paper proposes an extension of the ancillary services, usually provided only by conventional power plants, to the DG units, in order to improve the power quality of electrical networks and to enhance their capability to host RESs through the integration of Energy Storage Systems (ESSs). Three main services have been analyzed: primary voltage regulation, primary frequency regulation and exchange profiles adjustment to increase RESs programmability. First, a numerical analysis of the three services has been carried out by exploiting numerical models, and then an experimental application is presented.