Power Management Strategies for Vanadium Redox Flow Battery and Supercapacitors in Hybrid Energy Storage Systems
Muhammad Hamza Ali, Darío Slaifstein, Federico Martín Ibáñez, Christina Zugschwert, Mikhail Pugach
Abstract
Hybrid energy storage systems (HESS) are gaining popularity due to their flexibility to accomplish different services such as power quality, frequency regulation and load shifting. Among the various HESS schemes, the combination of vanadium redox flow battery (VRFB) and supercapacitors (SC) finds many applications in a grid, e.g., meeting the high load demand and avoiding power fluctuations. Even though VRFBs can decouple their energy and power ratings, high power cycling reduces their performance significantly. This can be overcome if they are combined with supercapacitors, which have high cyclability and outstanding power capabilities. In order to successfully combine the advantages of both devices, an Energy Management System (EMS) with a power sharing strategy is needed. This work compares different power management strategies (filtration, rule-based, and fuzzy logic technique) implemented in an active parallel topology HESS. The fuzzy logic-based technique performed better because it utilizes the SC-stack efficiently, resulting in a reduction in the number of cells in the SC stack and significant cost savings. The different strategies were validated through simulations and data gathered in physical implementations.