| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply system capable of determining whether a short-circuit failure has occurred in a switching element or in a battery cell, in an equalization circuit.SOLUTION: A power supply system comprises: discharge resistors R1, R5 connected to each battery cell BC1 of a battery pack; a switching element FET1 for switching conduction and interception between the battery cell and the resistors; a first voltage sensor 20 for measuring a voltage across the switching element; a second voltage sensor 22 for measuring a voltage of the battery cell from the positive electrode side of the discharge resistor R1; and a control unit 18 for performing on/off control of the switching element while acquiring a voltage measurement value. The control unit determines that the battery cell is short-circuited, when a difference between voltage measurement values of the first and second voltage sensors is smaller than a threshold and both voltage measurement values decrease with time, during off-control of the switching element; and that the switching element is short-circuited, when the difference between voltage measurement values of the first and second voltage sensors is equal to or larger than the threshold, during the off-control of the switching element.SELECTED DRAWING: Figure 2 |
