Charge condition adjusting apparatus

• US 20070247115A1
• Filed: 04/02/2007
• Published: 10/25/2007
• Est. Priority Date: 04/12/2006
• Status: Active Grant

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Ishikawa, Satoshi, Saigo, Tsutomu
• Granted Patent: US 7,508,166 B2
• Time in Patent Office: Days
• US Class Current: 320/119
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Providing a charge condition adjusting apparatus, which can shorten a time for equalization of each charge in unit cells, a low-voltage CPU selects each smallest unit cell in the each cell block, which has each smallest voltage between the both electrodes, from among plural unit cells structuring the cell blocks. The low-voltage CPU controls ON/OFF of a block-discharging switch to connect the both electrodes of each cell block and each block-discharging resistor for discharging the each cell block until the each voltage between the both electrodes of the selected smallest unit cell reaches the target voltage. Successively, the low-voltage CPU controls ON/OFF of a selecting switches and a cell-discharging switch to connect the both electrodes of each unit cell and each cell-discharging resistor to discharge the each unit cell until the each voltage between the both electrodes of the unit cells reaches the target voltage.

Claims

1. A charge condition adjusting apparatus comprising:

a voltage detecting device detecting each voltage between both ends of plural unit cells structured by connecting secondary batteries to each other;

a discharging resistor for discharging the unit cell; and

an equalizing device controlling discharge through the discharging resistor of the plural unit cells based on the voltages between the both ends of the respective unit cells detected by the voltage detecting device so as to equalize the voltages between both electrodes of the plural unit cells,

wherein the plural unit cells are segmented to plural cell blocks,

wherein the equalizing device comprises;

a first equalizing unit selecting a smallest unit cell in the cell block, which has a smallest voltage between the both ends thereof among the plural unit cells of the cell block, and discharging each cell block by connecting both ends of the cell block and the discharging resistor until the voltage between the both ends of the smallest unit cell in the cell block reaches a target voltage, and

a second equalizing unit discharging each unit cell by connecting the both ends of the each unit cell and the discharging resistor until the each voltage between the both ends of the plural unit cells in each cell block reaches the target voltage after discharging by the first equalizing unit is completed.

2. The charge condition adjusting apparatus according to claim 1, wherein the target voltage is defined by the smallest value among the voltages between the both ends of the each unit cells detected by the voltage detecting device.

3. The charge condition adjusting apparatus according to claim 1, wherein the first equalizing unit comprises:

a first discharging unit discharging the each cell block in a first predetermined period; and

a first discharge-control unit detecting the voltage between the both ends of the smallest unit cell in the cell block by the voltage detecting device whenever the first discharging unit discharges the each cell block completely, and making the first discharging unit repeat discharging the cell block until the detected voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage.

4. The charge condition adjusting apparatus according to claim 1, wherein the second equalizing unit comprises:

a second discharging unit discharging the unit cell in a second predetermined period; and

a second discharge-control unit detecting the voltage between the both ends of the unit cell by the voltage detecting device whenever the second discharging unit discharges the unit cell completely, and making the second discharging unit repeat discharging the unit cell until the detected voltage between the both ends of the unit cell reaches the target voltage.

5. The charge condition adjusting apparatus according to claim 1, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.

6. The charge condition adjusting apparatus according to claim 2, wherein the first equalizing unit comprises:

a first discharging unit discharging the each cell block in a first predetermined period; and

a first discharge-control unit detecting the voltage between the both ends of the smallest unit cell in the cell block by the voltage detecting device whenever the first discharging unit discharges the each cell block completely, and making the first discharging unit repeat discharging the cell block until the detected voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage.

7. The charge condition adjusting apparatus according to claim 2, wherein the second equalizing unit comprises:

a second discharging unit discharging the unit cell in a second predetermined period; and

a second discharge-control unit detecting the voltage between the both ends of the unit cell by the voltage detecting device whenever the second discharging unit discharges the unit cell completely, and making the second discharging unit repeat discharging the unit cell until the detected voltage between the both ends of the unit cell reaches the target voltage.

8. The charge condition adjusting apparatus according to claim 3, wherein the second equalizing unit comprises:

a second discharging unit discharging the unit cell in a second predetermined period; and

a second discharge-control unit detecting the voltage between the both ends of the unit cell by the voltage detecting device whenever the second discharging unit discharges the unit cell completely, and making the second discharging unit repeat discharging the unit cell until the detected voltage between the both ends of the unit cell reaches the target voltage.

9. The charge condition adjusting apparatus according to claim 6, wherein the second equalizing unit comprises:

a second discharging unit discharging the unit cell in a second predetermined period; and

a second discharge-control unit detecting the voltage between the both ends of the unit cell by the voltage detecting device whenever the second discharging unit discharges the unit cell completely, and making the second discharging unit repeat discharging the unit cell until the detected voltage between the both ends of the unit cell reaches the target voltage.

10. The charge condition adjusting apparatus according to claim 2, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.

11. The charge condition adjusting apparatus according to claim 3, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.

12. The charge condition adjusting apparatus according to claim 4, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.

13. The charge condition adjusting apparatus according to claim 6, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.

14. The charge condition adjusting apparatus according to claim 7, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.

15. The charge condition adjusting apparatus according to claim 8, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.

16. The charge condition adjusting apparatus according to claim 9, wherein the first equalizing unit judges that the voltage between the both ends of the smallest unit cell in the cell block reaches the target voltage when a difference between the voltage between the both ends of the smallest unit cell in the cell block and the target voltage becomes an allowable voltage tolerance or less, wherein the second equalizing unit judges that the voltage between the both ends of the unit cell reaches the target voltage when a difference between the voltage between the both ends of the unit cell and the target voltage becomes an allowable voltage tolerance or less.