Enabling a flexible exchange of energy of a photovoltaic plant with the grid by means of a controlled storage system

Abstract

In this paper, we describe a control strategy for a photovoltaic (PV) power plant equipped with an energy storage system (ESS), based on lithium-ion battery. The plant consists of the following units: the PV generator, the energy storage system, the DC-bus and the inverter. The control, organised in a hierarchical manner, maximises the self-consumption of the local load unit. In particular, the ESS action performs power balance in case of low solar radiation or surplus of PV generation, thus managing the power exchange variability at the plant with the grid. The implemented control strategy is under testing in RSE pilot test facility in Milan, Italy.

Keywords:

• solar energy
• photovoltaic generator
• energy storage
• smart grid
• control design

Acknowledgement

The authors are grateful to Silvia M. Canevese and Antonio Gatti for their helpful comments to the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work has been financed by the Research Fund for the Italian Electrical System under the Contract Agreement between RSE S.p.A. and the Ministry of Economic Development – General Directorate for Nuclear Energy, Renewable Energy and Energy Efficiency in compliance with the Decree of 8 March 2006. Paper supported by the MIUR national project ‘Identification and adaptive control of industrial systems’ and by CNR – IEEIT.