PACK-TO-MULTICELL EQUALIZATION OF LITHIUM BATTERY STRING BASED ON SERIES-PARALLEL TOPOLOGY OF SWITCHED-CAPACITOR CIRCUIT

• Main Author: Lawrence, Paul
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68339
• Institution: Institut Teknologi Bandung

Balance in the battery system is very important for better system operation. Because without a balancing system, each battery cell will occur excessive deviation. The total capacity of the pack will also experience a reduction during operation, causing the work system to fail. Active cell balancing is the most preferred balancing to be applied which requires maximum utility at the available capacity. Active cell balancing topology can be categorized into four different types according to the charge transfer topology such as pack-to-cell topology, cell-to-pack topology, cell-to-cell topology, and cell-to-pack-to-cell topology This study proposes a pack-to-multicell topology to balance the voltage distribution of lithium batteries. This topology uses a pack as a storage place for the voltage collected from each capacitor and increases the voltage that is reduced in the process of sending from the battery through the capacitor. On the other hand, this topology transfers energy simultaneously from the pack to each cell. The distribution of voltage throughout the cell makes the balancing process work optimally. It is hoped that the use of this new topology can be used as a new breakthrough in overcoming battery imbalances. Experimental testing of the proposed system has been carried out. This topology test uses four 3000 mAh lithium batteries connected in series, with the initial battery voltage (3.30, 3.35, 3.40, 3.45 V). At this voltage, the battery voltage balance is obtained at 70000 s. Battery voltage balancing can be affected along with the given value of different frequency variations.