Microgrid energy management control with a vanadium redox flow and a lithium-ion hybrid battery system for PV integration

Hybrid energy storage systems combine multiple energy storage technologies, to improve the overall storage’s performance and lifetime expectancy, compared to a single storage unit. This work proposes an online power/energy sharing management control of a hybrid energy storage system and a simulation tool developed by the authors. The hybridized system is composed of two PV installations (3.6 kWp and 6.7 kWp), a vanadium redox flow battery (VRFB) (5.0 kW /60 kWh) and a lithium-ion battery (LIB) (3.3 kW useful /9.8 kWh). The software simulation architecture is designed using MATLAB, where three hypothetical operation scenarios are simulated, with the aim of optimizing the energy usage according to its technical characteristics, current state operation and PV generation, with a 1-year time frame. The system’s overall performance is evaluated through three technical key-performance indicators. The combination of different energy storage technologies is a feasible solution that depends on the application goals and on the assurance of the accuracy and reliability of the system and its control strategy.The authors would like to thank the support of this work, developed under the European POCITYF project, financed by 2020 Horizon under grant agreement no. 864400. This work was also supported by the PhD. Scholarship (author Ana Foles) of FCT – Fundação para a Ciência e Tecnologia –, Portugal, with the reference SFRH/BD/147087/2019