Battery Energy Storage System (BESS) are expected to play a key-role in reaching the EU objectives concerning the reduction of carbon emissions. In fact, BESS would contribute to ensure resilient and reliable low-carbon power networks, which will be ever more characterized by intermittent and variable Renewable Energy Sources (RES). Nonetheless, the growing penetration of inverter-connected RES in power systems may potentially affect the grid stability, especially during frequency events caused by a sudden large infeed loss. BESS would alleviate this issue by rapidly varying the power output in response to frequency changes. In addition, BESS can arbitrage with energy market prices, contributing to flatten the energy consumption curve, and thus facilitating the integration of RES. The combination of BESS with other electrochemical storage system such as supercapacitor into Hybrid Energy Storage System (HESS) can also provide additional flexibility and ultra-fast services. Recently, Grid Forming (GFM) converters – as interface between the BESS and the main network – gained significant interest over traditional configurations, since they would grant extremely fast response from BESS, which is proportional to the system frequency evolution (i.e. damping response) and its rate of change (i.e. inertial response). The deployment of BESS equipped with GFM converters may positively re-design the pathway towards the implementation of a true low-carbon power network. Nonetheless, at the moment, the research and development and regulatory preparedness in this field is limited. Although asset-level pilot projects are being carried out, the proper assessment of the operation and control of a power system dominated by a BESS with GMF converters remains unclear. In this context, the fundamental objectives of this Ph.D. project are listed below and included in three major work-packages: WP1: Unlocking BESS flexibility at system-level: The first objective of this research is to develop a system-level scheduling model which accounts for the BESS’ ability to provide inertial and damping response and support system-level frequency response transient dynamics. Moreover, the proposed model shall provide insights on the actual competition between BESS (short-duration and long-duration types, including redox flow batteries) or HESS and other sources of ancillary services (e.g. pumped-hydro storage, synchronous compensators, demand response, conventional units etc.). Hence, the objective is to optimize system-level requirements of services to ensure safe rate of change of frequency, frequency nadirs and quasi-steady state levels, avoiding unnecessary overscheduling of the BESS headroom. Moreover, the model will explicitly consider the effect of the energy recovery after delivering long term services so that its deliverability from storage assets is always guaranteed.

This PhD opportunity is a collaboration between Fondazione Bruno Kessler and the University of Trento. For more information on this call and how to apply, please visit the website of the University of Trento (https://www.unitn.it/en/phd/civil-environmental-and-mechanical-engineering).