Fuzzy logic in battery energy storage system (BESS)

Abstract

The battery energy storage system (BESS) is a portable device that consists of batteries, controllers, sensors, relays, and other elements that are vital for battery charging and electricity supply operations. A BESS can be used in on or off grid applications to supply electricity as the main source or a back-up source of energy, and to eliminate power factor surcharge by utility companies. This research seeks to design, apply, and validate the use of fuzzy logic controller as a battery management system to regulate the simultaneous charging and discharging processes of batteries. In this project, BESS hardware is constructed to include two 24V battery sets, an electrical load, proper electrical connections, switches, relays, current sensors, voltage measurements, LED indicators, and a microcontroller. Fuzzy logic controllers, one for each battery set, are designed, simulated, and analyzed in MATLAB before implemented in the actual BESS hardware. The experiment involves repeatedly running the BESS for several hours, through a number of charging and discharging cycles, and analyzing current and voltage measurements. By comparing the performances of the fuzzy logic controllers and that of a conventional sequential algorithm, it can be concluded that the fuzzy logic controller can be applied as a safe and efficient battery management system and may improve the battery life in a BESS.