Quantification of primary frequency control provision from battery energy storage systems connected to active distribution networks

In this paper, we consider the provision of primary frequency control by using battery energy storage systems (BESSs). In particular, we use a standard droop-based frequency control for a BESS where the control action (i.e. the BESS power output) consists in the contribution of two additive terms: the regulating power, proportional to the frequency deviations, and an offset term computed to manage the BESS State-of-Energy (SOE). In the context of such a control scheme, we propose a method to forecast the BESS energy for regulation needs and we show that the inclusion of such a forecast can increase the regulating power provision. Finally, we demonstrate the performance of the proposed approach by means of a real-scale experimental setup composed by a grid-connected 720 kVA/560 kWh BESS installed at the EPFL campus in Lausanne, Switzerland.