Charge/discharge control method for battery pack and charge/discharge control apparatus for battery pack

• US 6,828,758 B2
• Filed: 02/11/2003
• Issued: 12/07/2004
• Est. Priority Date: 02/20/2002
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ishishita, Teruo
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/361,917
• Publication Number:
  US 20030155891A1
• Time in Patent Office: 665 Days
• Field of Search: 320/132, 320/104, 320/110, 320/116, 320/118, 320/119
• US Class Current: 320/116
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 6/42 Grouping of primary cells into batteries H01M6/40 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

It is an object of the invention to provide a charge/discharge control apparatus for a battery pack which is capable of performing SOC control and reducing the SOC variation through simple processes, and a control method thereof. In order to achieve the aforementioned object, A charge/discharge control apparatus for a battery pack having a plurality of cells according to one aspect of the invention includes a voltage detection portion that measures a voltage of each set of a predetermined number of cells provided in the battery pack, a computation portion that computes a state quantity of each set of the predetermined number of cells based on the voltage measured by the voltage detection portion, and a charge/discharge control portion that performs a charge/discharge control based on a least state quantity that is a least one of the state quantities of the sets of the predetermined number of cells.

Claims

1. A charge/discharge control apparatus for a battery pack having a plurality of cells, comprising:

a voltage detection portion that measures a voltage of each set of a predetermined number of cells provided in the battery pack;

a computation portion that computes a state quantity of each set of the predetermined number of cells based on the voltage measured by the voltage detection portion; and

a charge/discharge control portion that performs a charge/discharge control based on only a least state quantity that is a least one of the state quantities of the sets of the predetermined number of cells, the charge/discharge control being performed so that only the least one of the state quantities is within a predetermined range.

2. The charge/discharge control apparatus according to claim 1,

wherein each set of the predetermined number of cells is a single cell, and

wherein the voltage detection portion measures a voltage of each single cell of the battery pack, and the computation portion computes a state quantity of each single cell.

3. The charge/discharge control apparatus according to claim 1,

wherein each set of the predetermined number of cells has an arrangement of a battery block in which a plurality of cells are connected in series, and

wherein the voltage detection portion measures a voltage of each battery block, and the computation portion computes a state quantity of each battery block.

4. The charge/discharge control apparatus according to claim 1, wherein the state quantity is a remaining capacity value of each set of the predetermined number of cells based on the voltage measured.

5. The charge/discharge control apparatus according to claim 1, wherein the state quantity is a percentage of a remaining capacity value of each set of the predetermined number of cells based on the voltage measured, with respect to a fully charged capacity value.

6. The charge/discharge control apparatus according to claim 1, further comprising an overcharge determining portion that performs an overcharge determination as to whether an overcharged state exists based on a greatest state quantity that is a greatest one of the state quantities of the sets of the predetermined number of cells.

7. The charge/discharge apparatus according to claim 6,

wherein each set of the predetermined number of cells is a single cell, and

wherein the greatest state quantity is a greatest one of the state quantities of the single cells.

8. The charge/discharge control apparatus according to claim 6,

wherein each set of the predetermined number of cells has an arrangement of a battery block in which a plurality of cells are connected in series, and

wherein the greatest state quantity is a greatest one of the state quantities of the battery blocks.

9. The charge/discharge control apparatus according to claim 6, wherein the state quantity is a remaining capacity value of each set of the predetermined number of cells based on the voltage measured.

10. The charge/discharge control apparatus according to claim 6, wherein the state quantity is a percentage of a remaining capacity value of each set of the predetermined number of cells based on the voltage measured, with respect to a fully charged capacity value.

11. A charge/discharge control method for a battery pack having a plurality of cells, comprising:

measuring a voltage of each set of a predetermined number of cells provided in the battery pack;

computing a state quantity of each set of the predetermined number of cells based on the voltage measured; and

performing a charge/discharge control based on only a least state quantity that is a least one of the state quantities of the sets of the predetermined number of cells, so that only the least state quantity is within a predetermined range.

12. The charge/discharge control method according to claim 11, wherein each set of the predetermined number of cells is a single cell, and a voltage of each single cell of the battery pack is measured, and a state quantity of each single cell is computed.

13. The charge/discharge control method according to claim 11, wherein each set of the predetermined number of cells has an arrangement of a battery block in which a plurality of cells are connected in series, and a voltage of each battery block is measured, and a state quantity of each battery block is computed.

14. The charge/discharge control method according to claim 11, wherein the state quantity is a remaining capacity value of each set of the predetermined number of cells based on the voltage measured.

15. The charge/discharge control method according to claim 11, wherein the state quantity is a percentage of a remaining capacity value of each set of the predetermined number of cells based on the voltage measured, with respect to a fully charged capacity value.

16. The charge/discharge control method according to claim 11, further comprising performing an overcharge determination as to whether an overcharged state exists based on a greatest state quantity that is a greatest one of the state quantities of the sets of the predetermined number of cells.

17. The charge/discharge control method according to claim 16,

wherein each set of the predetermined number of cells is a single cell, and

wherein the greatest state quantity is a greatest one of the state quantities of the single cells.

18. The charge/discharge control method according to claim 16,

wherein each set of the predetermined number of cells has an arrangement of a battery block in which a plurality of cells are connected in series, and

wherein the greatest state quantity is a greatest one of the state quantities of the battery blocks.

19. The charge/discharge control method according to claim 16, wherein the state quantity is a remaining capacity value of each set of the predetermined number of cells based on the voltage measured.

20. The charge/discharge control method according to claim 16, wherein the state quantity is a percentage of a remaining capacity value of each set of the predetermined number of cells based on the voltage measured, with respect to a fully charged capacity value.

21. A charge/discharge control apparatus for a battery pack having a plurality of cells, comprising:

a voltage detection portion that measures a voltage of each set of a predetermined number of cells provided in the battery pack;

a computation portion that computes a state quantity of each set of the predetermined number of cells based on the voltage measured by the voltage detection portion;

a charge/discharge control portion that performs a charge/discharge control based on a least state quantity that is a least one of the state quantities of the sets of the predetermined number of cells; and

an overcharge determining portion that performs an overcharge determination as to whether an overcharged state exists based on a greatest state quantity that is a greatest one of the state quantities of the sets of the predetermined number of cells.

22. The charge/discharge control apparatus according to claim 21,

wherein each set of the predetermined number of cells is a single cell, and

wherein the greatest state quantity is a greatest one of the state quantities of the single cells.

23. The charge/discharge control apparatus according to claim 21,

wherein each set of the predetermined number of cells has an arrangement of a battery block in which a plurality of cells are connected in series, and

wherein the greatest state quantity is a greatest one of the state quantities of the battery blocks.

24. The charge/discharge control apparatus according to claim 21, wherein the state quantity is a remaining capacity value of each set of the predetermined number of cells based on the voltage measured.

25. The charge/discharge control apparatus according to claim 21, wherein the state quantity is a percentage of a remaining capacity value of each set of the predetermined number of cells based on the voltage measured, with respect to a fully charged capacity value.

26. A charge/discharge control method for a battery pack having a plurality of cells, comprising:

measuring a voltage of each set of a predetermined number of cells provided in the battery pack;

computing a state quantity of each set of the predetermined number of cells based on the voltage measured;

performing a charge/discharge control based on a least state quantity that is a least one of the state quantities of the sets of the predetermined number of cells; and

performing an overcharge determination as to whether an overcharged state exists based on a greatest state quantity that is a greatest one of the state quantities of the sets of the predetermined number of cells.

27. The charge/discharge control method according to claim 26,

wherein each set of the predetermined number of cells is a single cell, and

wherein the greatest state quantity is a greatest one of the state quantities of the single cells.

28. The charge/discharge control method according to claim 26,

wherein each set of the predetermined number of cells has an arrangement of a battery block in which a plurality of cells are connected in series, and

wherein the greatest state quantity is a greatest one of the state quantities of the battery blocks.

29. The charge/discharge control method according to claim 26, wherein the state quantity is a remaining capacity value of each set of the predetermined number of cells based on the voltage measured.

30. The charge/discharge control method according to claim 26, wherein the state quantity is a percentage of a remaining capacity value of each set of the predetermined number of cells based on the voltage measured, with respect to a fully charged capacity value.