Method for detecting a triggering of a security device

Patent metadata

Field	Value
Publication number	US-9520621-B2
Application number	US-201214124379-A
Country	US
Kind code	B2
Filing date	Jun 4, 2012
Priority date	Jun 9, 2011
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

The disclosure relates to a method for detecting a triggering of a security device. The security device is associated with a battery cell and is triggered if a security-critical situation is present in the battery cell. Initially an actual time path of a parameter of the battery cell is detected. At the same time, an expected time path of the parameter is determined, in particular using a model. Then, the actual time path is compared to the expected time path of the parameter. Finally, based on the comparison, it is determined whether to trigger the security device or not.

First claim

The invention claimed is:

1. A method for identifying triggering of a safety device, wherein the safety device is associated with a battery cell and is triggered when there is a safety-critical situation in the battery cell, comprising:
detecting an actual time profile of a voltage of the battery cell;
determining an expected time profile of the voltage using a model;
comparing the actual time profile of the voltage with the expected time profile of the voltage by comparing an actual change in the voltage over time with an expected change in the voltage over time; and
making a decision, on the basis of the comparison, as to whether the safety device has been triggered, the decision being made that the safety device has been triggered when the actual change in the voltage over time deviates by more than a predefined amount from the expected change in the voltage over time.

2. The method as claimed in claim 1 , further comprising:
moving a battery system, which includes the battery cell, to a safe state when triggering of the safety device has been identified.

3. The method as claimed in claim 1 , wherein:
the safety device short-circuits the battery cell in the safety-critical situation, and
the safety-critical situation includes at least one of (i) an elevated internal pressure in the battery cell and (ii) a mechanical deformation of the battery cell.

4. The method as claimed in claim 1 , wherein:
the safety device bridges the battery cell in the safety-critical situation, and
the safety-critical situation includes an elevated internal pressure in the battery cell.

5. The method as claimed in claim 1 , wherein the expected change in the voltage of the battery cell over time is determined using a battery module configured to take into consideration at least one of (i) a battery current which flows through the battery cell and (ii) a temperature of the battery cell.

6. The method as claimed in claim 5 , wherein:
the battery module is configured as an observer system, and
the actual time profile of the voltage is supplied to the battery model.

7. The method as claimed in claim 1 , wherein a battery management unit is configured to execute the method.

8. A battery comprising:
at least one battery cell;
at least one safety device which is associated with the at least one battery cell and is configured to be triggered when there is a safety-critical situation in the at least one battery cell; and
a battery management unit configured to identify the triggering of the at least one safety device by (i) detecting an actual time profile of a voltage of the at least one battery cell, (ii) determining an expected time profile of the voltage using a model, (iii) comparing the actual time profile of the voltage with the expected time profile of the voltage by comparing an actual change in the voltage over time with an expected change in the voltage over time, and (iv) making a decision, on the basis of the comparison, as to whether the at least one safety device has been triggered, the decision being made that the safety device has been triggered when the actual change in the voltage over time deviates considerably from the expected change in the voltage over time.

9. An electric motor vehicle, comprising:
a battery including at least one battery cell, at least one safety device, and a battery management unit, the at least one safety device is associated with the at least one battery cell and is configured to be triggered when there is a safety-critical situation in the at least one battery cell, the battery management unit is configured to identify the triggering of the at least one safety device by (i) detecting an actual time profile of a voltage of the at least one battery cell, (ii) determining an expected time profile of the voltage using a model, (iii) comparing the actual time profile of the voltage with the expected time profile of the voltage by comparing an actual change in a voltage over time with an expected change in the voltage over time, and (iv) making a decision, on the basis of the comparison, as to whether the at least one safety device has been triggered, the decision being made that the safety device has been triggered when the actual change in the voltage over time deviates considerably from the expected change in the voltage over time.

Assignees

• Fink Holger
• Bosch Gmbh Robert
• Samsung Sdi Co Ltd

Inventors

• Fink Holger

Classifications

• H01M10/486

  for measuring temperature · CPC title

• H01M10/48

  Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte (constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569) · CPC title

• H01M50/574

  Devices or arrangements for the interruption of current · CPC title

• H01M10/44

  Methods for charging or discharging (circuits for charging H02J7/00) · CPC title

• G01R31/385

  Arrangements for measuring battery or accumulator variables (for monitoring G01R31/382) · CPC title