Battery energy storage systems: Power electronics interface and grid integration

One of the fundamentals of a sustainable society is the production of electricity from renewable sources. Many countries and institutions are investing heavily for reaching this objective. However, the non-controllable nature of most renewable sources brings new challenges to the existing electrical networks. Energy storage systems can help the electrical network to increase its renewable energy hosting capacity, and, among them, battery-based storage systems are particularly suitable for supporting the grid due to their fast response and flexible operation. Nonetheless, the wide adoption of Battery Energy Storage Systems (BESSs) is nowadays limited by the high initial investments and the not always clear business case. Therefore, this thesis investigates how to reduce the investments and operating costs by optimizing the power electronics interface, and how to enhance the system revenues by combining multiple functionalities and enabling new ones, to make the deployment of BESS more financially viable.