DEVELOPMENT AND IMPLEMENTATION OF FUZZY LOGIC METHOD FOR EFFECTIVE SCHEDULING IN SELECTIVE BATTERY BALANCING SYSTEM

• Main Author: Iris Paramesti, Kirana
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/77390
• Institution: Institut Teknologi Bandung

BESS (Battery Energy Storage System) is an energy storage technology that generally uses Li-ion batteries. Li-ion battery cells are connected in series to increase the voltage that will be applied to the BESS. Imbalance can occur even if the batteries have the same capacity. The BESS balancing system of the TF ITB Energy Management Laboratory currently uses the constant period method which causes the status of the battery target cell switches selected by the balancing system based on relatively low voltage values to change too frequently. The fuzzy logic method was developed and implemented to obtain an effective schedule on a selective battery balancing system prototype. Voltage and SoC (State of Charge) of the battery are used as input variables with the parameters voltage difference, SoC difference, and average SoC, and balancing time as the output variable of the fuzzy logic system. The fuzzy inference system uses the Mamdani type with centroid defuzzification. The balancing time uses MF (membership function) which is selected based on the response time of charging or discharging the LFP battery. The fuzzy logic mechanism has an influence on the battery balancing time during battery discharge, charge and steady state conditions, even though there is an error in selecting the target cell and battery degradation. Under discharge and steady state battery conditions with the first output MF model produces a balancing time of 2 hours. In the condition of charging the battery with the second output MF model, a balancing time of 29-30 minutes is produced which can equalize the voltage and SoC values of the lowest cell with the value of the closest cell. In the discharge and steady state of the battery with the second output MF model, a balancing time of 29 minutes is produced to equalize the voltage and SoC values of the lowest cell with the value of the closest cell.