Hybrid Energy Storage Systems for Electric Vehicles and Stationary Applications

High performance storage systems, such as Hybrid and Battery Energy Storage Systems, are required in stationary and automotive application fields to lead the electrification of the road transport sector as well as the integration of renewable energy sources in the power system. However, the development of pure and hybrid battery packs require effective Battery Management Systems (BMSs) to ensure performance exploitation and safe operating conditions. On the other hand, high efficiency and fast dynamic response are required from the integrated power electronic converters to effectively interconnect the whole power system. This dissertation has focused on the development of an advanced BMS for automotive battery pack application as well as stationary hybrid energy storage systems. In particular, the State of Charge (SoC) estimation has been investigated to develop accurate and reliable solutions for state estimation both at cell and pack level. Subsequently, the hybridization of energy storage systems has been investigated and the SoC estimation functionality has been implemented for HESSs considering a battery and supercapacitor integration. The main contribution has concerned the development of accurate models for both supercapacitors and battery systems as well as the design of advanced and reliable model-based state estimation algorithms to improve the system performances. Subsequently, DC-DC power converters for smooth integration of different storage technologies and their interconnection in power systems have been investigated. A design methodology for Dual-Active-Bridge converters has been defined by taking into account main system requirements. Moreover, advanced modulation techniques and control strategies have been investigated and a real prototype has been implemented for experimental validation.