Dynamical Characterization of Grid-Scale Energy Storage Assets

The advent of affordable grid-scale electrochemical energy storage units is radically changing modern electrical grids: the availability of fast-responding devices is opening new regulation paradigms for power networks and contributing to the system optimization. In this perspective, the characterization of the dynamical performance of the available commercial devices represents a crucial step in the assessment of the regulation capabilities of these technologies. In this paper, a 240 kVA lithium-ion storage device is considered: the aim is to develop a rigorous characterization procedure which enables the realization of a reliable dynamical model of the system, starting from the available experimental measurements. The resulting dynamical model has a maximum error of 5% when compared to the equivalent experimental data.