BATTERY MANAGEMENT SYSTEM, AND METHOD OF BALANCING BATTERY CELL IN BATTERY MODULE USING THE SAME

摘要

A method for balancing cells of a battery module is provided to balance voltages of at least two battery cells included in a battery module by a battery management system (BMS). The method for balancing cells of a battery module includes the steps of: (a) measuring, by a measuring unit included in a BMS, an open circuit voltage (OCV) which is a charge voltage of each of battery cells; (b) setting, by a control unit of the BMS, a voltage included among the measured OCVs as a balancing voltage; (c) controlling, by the control unit of BMS, the respective battery cells having the measured OCVs which are higher than the balancing voltage to be balanced to have the balancing voltage by discharging currents to resistance based on the set balancing voltage by controlling a switch circuit which is included in a cell balancing unit of the BMS and is electrically connected to the resistance; and (d) controlling, by the control unit of the BMS, the respective battery cells having the measured OCVs which are lower than the balancing voltage to be balanced to have the balancing voltage by injecting currents of a current source into the respective battery cells having the measured OCVs which are lower than the balancing voltage by controlling the switch circuit which is included in the cell balancing unit and is electrically connected to the current source.