Discharging a battery module, having at least two battery cells, of a battery having at least two battery modules

Patent metadata

Field	Value
Publication number	US-11289741-B2
Application number	US-201716465734-A
Country	US
Kind code	B2
Filing date	Nov 16, 2017
Priority date	Dec 2, 2016
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A method for discharging a battery module, having at least two battery cells, of a battery having at least two battery modules, wherein the battery cells of each of the battery modules are arranged next to one another and are mechanically and electrically connected to one another, wherein, in each of the battery modules, the respective battery cells are individually activated and deactivated in terms of an energy storage function by a cell switch unit, wherein the battery cells of the battery module to be discharged are selectively electrically coupled successively to a discharge device by the cell switch unit and starting from one predefined battery cell, in order to individually successively electrically discharge the battery cells in order to discharge the battery module.

First claim

The invention claimed is:

1. A method for discharging of a battery module during failure of the battery module, comprising:
providing a battery with a plurality of battery modules, each of the plurality of battery modules comprising a plurality of battery cells which are arranged adjacent to one another and mechanically and electrically connected together,
wherein, in each of the plurality of battery modules, the plurality of battery cells are each individually activated by a cell switch unit in a first switching state to enable an energy storage function and each individually deactivated by the cell switch unit in a second switching state to disable the energy storage function,
wherein, during a failure of at least one of the plurality of battery modules, the plurality of battery cells contained within those battery modules which have failed are coupled to a discharge device by way of the cell switch unit, and the discharge device individually discharges each of the plurality of battery cells according to a sequence which starts with a predefined battery cell, and
wherein the discharge device comprises a resistor.

2. The method according to claim 1 , wherein, during the failure, the plurality of battery cells contained within those battery modules which have failed are deactivated by the cell switch unit before being coupled to the discharge device.

3. The method according to claim 1 , further comprising:
detecting a state value for each of the plurality of battery cells, and
evaluating whether each of the state values fall within a predefined value range,
wherein, when one of the state values is outside of the predefined value range, the corresponding battery cell is designated as the predefined battery cell.

4. The method according to claim 3 , wherein designation of the predefined battery cell signals the failure of the at least one of the plurality of battery modules.

5. The method according to claim 1 , wherein the sequence is determined according a cell's spatial distance from the predefined battery cell.

6. The method according to claim 3 , wherein the sequence is determined according to the state value of each of the plurality of battery cells.

7. The method according to claim 1 , wherein the discharge device is common to the plurality of battery modules and connected to terminals of the battery, and
wherein, during the failure, those battery modules which have failed are likewise individually and sequentially coupled to the discharge device such that only a single battery cell is discharged by the discharge device at a time.

8. The method according to claim 1 , wherein discharging a respective battery cell via the discharge device reduces the respective battery cell to a predefined lower state of charge which is greater than a completely discharged state.

9. A battery comprising two battery terminals and a plurality of battery modules,
wherein each of the plurality of battery modules comprise a plurality of battery cells which are arranged adjacent to one another and mechanically and electrically connected together,
wherein each of the plurality of battery modules further comprise a cell switch unit, controllable by means of a control unit, and the cell switch unit is configured to, in a first switching state, individually activate each of the plurality of battery cells to enable an energy storage function and to, in a second switching sate, individually deactivate each of the plurality of battery cells to disable the energy storage function,
wherein, during a failure of at least one of the plurality of battery modules, the control unit is configured to couple the plurality of battery cells contained within those battery modules which have failed to a discharge device by way of the cell switch unit, and the discharge device individually discharges each of the plurality of battery cells according to a sequence which starts with a predefined battery cell, and
wherein the discharge device comprises a resistor.

10. The method according to claim 2 , further comprising:
detecting a state value for each of the plurality of battery cells, and
evaluating whether each of the state values fall within a predefined value range,
wherein, when one of the state values is outside of the predefined value range, the corresponding battery cell is designated as the predefined battery cell.

11. The method according to claim 2 , wherein the sequence is determined according a cell's spatial distance from the predefined battery cell.

12. The method according to claim 3 , wherein the sequence is determined according a cell's spatial distance from the predefined battery cell.

13. The method according to claim 4 , wherein the sequence is determined according a cell's spatial distance from the predefined battery cell.

14. The method according to claim 2 , wherein the discharge device is common to the plurality of battery modules and connected to terminals of the battery, and
wherein, during the failure, those battery modules which have failed are likewise individually and sequentially coupled to the discharge device such that only a single battery cell is discharged by the discharge device at a time.

15. The method according to claim 3 , wherein the discharge device is common to the plurality of battery modules and connected to terminals of the battery, and
wherein, during the failure, those battery modules which have failed are likewise individually and sequentially coupled to the discharge device such that only a single battery cell is discharged by the discharge device at a time.

16. The method according to claim 4 , wherein the discharge device is common to the plurality of battery modules and connected to terminals of the battery, and
wherein, during the failure, those battery modules which have failed are likewise individually and sequentially coupled to the discharge device such that only a single battery cell is discharged by the discharge device at a time.

17. The method according to claim 5 , wherein the discharge device is common to the plurality of battery modules and connected to terminals of the battery, and
wherein, during the failure, those battery modules which have failed are likewise individually and sequentially coupled to the discharge device such that only a single battery cell is discharged by the discharge device at a time.

18. The method according to claim 6 , wherein the discharge device is common to the plurality of battery modules and connected to terminals of the battery, and
wherein, during the failure, those battery modules which have failed are likewise individually and sequentially coupled to the discharge device such that only a single battery cell is discharged by the discharge device at a time.

19. The method according to claim 2 , wherein discharging a respective battery cell via the discharge device reduces the respective battery cell to a predefined lower state of charge which is greater than a completely discharged state.

20. The method according to claim 1 , wherein each of the plurality of battery modules are provided with a dedicated discharge device for discharging the plurality of battery cells contained therein.

Assignees

• Audi Ag

Inventors

• Hinterberger Michael
• Hellenthal Berthold
• Vassen Heinz-Willi
• Pilgram Peter

Classifications

• H02J7/933 Primary

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/585

  Sequential battery discharge in systems with a plurality of batteries · CPC title

• H01M50/519

  comprising printed circuit boards [PCB] · CPC title

• H01M50/509

  characterised by the type of connection, e.g. mixed connections · CPC title

• H01M50/507

  comprising an arrangement of two or more busbars within a container structure, e.g. busbar modules · CPC title