Battery management system and driving method for cutting off and coupling battery module from/to external device

• US 7,679,325 B2
• Filed: 04/04/2006
• Issued: 03/16/2010
• Est. Priority Date: 04/07/2005
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Seo, Se-Wook
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): WILLIAMS, ARUN C
• Application Number:
  US11/396,536
• Publication Number:
  US 20060226811A1
• Time in Patent Office: 1,442 Days
• Field of Search: 320/118, 320/119, 320/122, 320/128, 320/132, 320/134, 324/427
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery management system for controlling a secondary battery module which includes a plurality of unit batteries includes a sensor, a comparator and a controller. The sensor sequentially measures respective voltages of the unit batteries. The comparator compares the respective voltages of the unit batteries to a cut-off voltage range and a recovery voltage range to determine if the voltages are within the cut-off voltage range and the recovery voltage range. The controller receives comparison results from the comparator, cuts off the secondary battery module from an external device when there is at least one unit battery within the cutoff voltage range, and couples the secondary battery module to the external device when all of the unit batteries are within the recovery voltage range.

Claims

1. A battery management system for controlling an operation of a secondary battery module comprising a plurality of unit batteries, the battery management system comprising:

sensor means for sequentially measuring respective voltages of the plurality of unit batteries;

comparator means for comparing the respective voltages of the unit batteries to a cut-off voltage range to determine whether the respective voltages are within the cut-off voltage range, and for comparing the respective voltages of the unit batteries to a recovery voltage range to determine whether the respective voltages are within the recovery voltage range; and

controller means for receiving comparison results from the comparator means, for cutting off the secondary battery module from an external device when at least one unit battery from among the plurality of unit batteries is outside the cutoff voltage range, and for coupling the secondary battery module to the external device when all of the unit batteries are within the recovery voltage range.

2. The battery management system of claim 1, further comprising:

a relay for coupling the external device to the secondary battery module; and

wherein the controller means turns off the relay when at least one unit battery among the plurality of unit batteries is outside the cut-off voltage range, and turns on the relay when all of the unit batteries are within the recovery voltage range.

3. The battery management system of claim 2, wherein:

the comparator means transmits information on a detected unit battery that is outside the cut-off voltage range to the controller means when detecting the unit battery from among the plurality of unit batteries that is outside the cut-off voltage range; and

the controller means cuts off the secondary battery module from the external device when receiving the information on the detected unit battery.

4. The battery management system of claim 3, wherein the comparator means compares the respective voltages of the unit batteries to the cut-off voltage range to determine whether the respective voltages of the unit batteries are within the cut-off voltage range, and when the respective voltages of the unit batteries are within the cut-off voltage range, the comparator means compares the respective voltages of the unit batteries to the recovery voltage range to determine whether the respective voltages of the unit batteries are within the recovery voltage range.

5. The battery management system of claim 4, wherein the controller means compares the respective voltages of the unit batteries to the recovery voltage range and counts the number of unit batteries that are within the recovery voltage range.

6. The battery management system of claim 5, wherein the secondary battery module is maintained cut off from the external device when it is not determined that all of the plurality of unit cells are within the recovery voltage range.

7. The battery management system of claim 1, wherein the comparator means compares the respective voltages of the unit batteries to the cut-off voltage range to determine whether the respective voltages of the unit batteries are within the cut-off voltage range, and when the respective voltages of the unit batteries are within the cut-off voltage range, the comparator means compares the respective voltages of the unit batteries to the recovery voltage range to determine whether the respective voltages of the unit batteries are within the recovery voltage range.

8. The battery management system of claim 7, wherein the controller means compares the respective voltages of the unit batteries to the recovery voltage range and counts the number of unit batteries that are within the recovery voltage range.

9. The battery management system of claim 8, wherein the secondary battery module is maintained cut off from the external device when it is not determined that all of the plurality of unit cells are within the recovery voltage range.

10. The battery management system of claim 1, wherein the recovery voltage range is within the cut-off voltage range.

18. The battery management system of claim 1, wherein the controller means couples the secondary battery module to the external device when all of the unit batteries are within both the cut-off voltage range and the recovery voltage range.

11. A driving method of a battery management system of a secondary battery module which includes a plurality of unit batteries, the driving method comprising the steps of:

(a) measuring respective voltages of the unit batteries;

(b) comparing the respective voltages of the unit batteries to a cut-off voltage range to determine whether the respective voltages are within the cut-off voltage range, and comparing the respective voltages of the unit batteries to a recovery voltage range to determine whether the respective voltages are within the recovery voltage range, and producing a comparison result; and

(c) according to the comparison result obtained in step (b), cutting off the secondary battery module from an external device when at least one unit battery among the plurality of unit batteries is outside the cut-off voltage range, and coupling the secondary battery module to the external device when all of the unit batteries are within the recovery voltage range.

12. The driving method of claim 11, wherein the recovery voltage range is within the cut-off voltage range.

13. The driving method of claim 11, further comprising the step, between steps (b) and (c), of counting a number of unit batteries that satisfy the recovery voltage range when the respective voltages of the unit batteries satisfy the cut-off voltage range.

14. The driving method of claim 13, further comprising the step (d) of counting a number of unit batteries that are compared to the cut-off voltage range and the recovery voltage range, determining whether the counted number is equal to the number of the unit cells in the secondary battery module, and producing a determination result.

15. The driving method of claim 14, wherein, according the determination result, when the counter number obtained in step (d) is not equal to the number of the unit batteries in the secondary module, a previous coupling state, either coupled or decoupled, between the secondary battery module and the external device is maintained.

16. The driving method of claim 11, further comprising the step (d) of counting a number of unit batteries that are compared to the cut-off voltage range and the recovery voltage range, determining whether the counted number is equal to the number of the unit cells in the secondary battery module, and producing a determination result.

17. The driving method of claim 16, wherein, according the determination result, when the counter number obtained in step (d) is not equal to the number of the unit batteries in the secondary module, a previous coupling state, either coupled or decoupled, between the secondary battery module and the external device is maintained.

19. The driving method of claim 11, wherein step (c) comprises coupling the secondary battery module to the external device when all of the unit batteries are within both the cut-off voltage range and the recovery voltage range.