International Conference on Innovations in Energy Engineering & Cleaner Production IEE CP 21 1 Integration of vanadium redox battery with PV systems: Modeling and simulation of Vanadium Redox flow batteries based on MATLAB/Simulink Mohamed-Amine BABAY Industrial engineering laboratory Faculty of Science and Technologies, Sultan Moulay Slimane University Beni Mellal, Morocco mdamine.babay@gmail.com Mustapha ADAR Industrial engineering laboratory Faculty of Science and Technologies, Sultan Moulay Slimane University Beni Mellal, Morocco Adar.mustapha@gmail.com Mustapha MABROUKI Industrial engineering laboratory Faculty of Science and Technologies, Sultan Moulay Slimane University Beni Mellal, Morocco Mus_mabrouki@yahoo.com Abstract Several models have been developed and they are now providing a good understanding of how VRB works. This knowledge is very important to evaluate its performance when applied in an electrical system. This article presents a new VRB model based an electrical equivalent model of VRFB, the effect of flow rate and pump power losses has been considered in modeling the VRFB. The VRFB is connected to a resistive variable load, for discharging and a system PV for charging. A control method for State of Charge (SOC) estimation is also proposed as it plays an important role in over-charge/discharge of VRFB. An equivalent electrical model of PV system including a VRB was implemented in MATLAB/Simulink environment to analyze the operational performance of the proposed system. Keywords: Energy storage system, Vanadium Redox Flow Battery, State of Charge, Battery modeling, Solar PV, Flow rate I. INTRODUCTION Since the early 1970s, redox batteries have been extensively researched and several different redox pairs have been studied and reported in the literature. Only three of these systems have undergone some commercial development, namely the all- vanadium system (via VRB-ESS), the bromine-polysulphide system (RGN-ESS) and the zinc-bromine system (Powercell). The vanadium bromine system has a high energy density so it can replace the all-vanadium system and can be used as an energy storage system for electric vehicles. Other redox flow battery systems due to slow electrochemical kinetics of redox torque, membrane fouling, cross contamination, high cost (mainly due to the membrane and battery design low efficiency), poor sealing, loss of bypass current and low and problematic energy capacity (due to the use of aqueous electrolytes). To date, one of the main factors limiting the further development of redox batteries is the high cost associated with ion exchange membranes.[1] Alotto et al. [2]conducted a detailed study of the redox battery and described its development and future technical level. The first VRB model [3] parameterized the battery voltage, voltage loss, parasitic current loss, etc. [2]–[4]. But each of these studies is not effective in modeling the transient response, or is more complicated in the extended measurement of the parameters. D'Agostino et al [5] tried to include the operating mode and start time in their VRB model and suggested that efficient management of electrolyte pumps would minimize losses and increase efficiency. Ontiveros and Mercado [6] proposed a new stacking model for VRB, which includes stacking efficiency and mechanical model to improve the accuracy of the VRB model and understand its operation. This paper implements a simplified VRB model that includes parasitic losses and takes into account the estimated voltage and state of charge of the battery in the solar system. The future energy system must be carefully designed to ensure energy reliability and security without being affected to insure the dynamic sustainability of the grid system. Due to the intermittent nature of renewable systems, increasing permeability poses a huge challenge to the operation of the power grid. However, due to growing global awareness of pollution and ozone depletion, most countries have chosen green energy policies, forcing technology providers to seek options for using and managing renewable energy without compromising grid supply and security. The Energy Storage System (ESS) has become an indispensable partner for renewable energies, as it enables energy to be stored when it is available and supplied when the load requires it. Many forms of energy storage have been developed, but the Battery Energy Storage System (BESS) is the most mature and developed technology in decades [7]. IEECP’21, July 29-30, 2021, Silicon Valley, San Francisco, CA – USA © 2021 IEECP – SCI-INDEX DOI : https://dx.doi.org/10.6084/m9.figshare.14546805