Method for determining and/or predicting the maximum power capacity of a battery

• US 8,718,988 B2
• Filed: 04/13/2012
• Issued: 05/06/2014
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Roscher, Michael, Bohlen, Oliver
• Primary Examiner(s): Saxena, Akash
• Application Number:
  US13/446,544
• Publication Number:
  US 20120215517A1
• Time in Patent Office: 753 Days
• Field of Search: 320/127, 320/132, 320/148, 320/137, 702/63, 703/4
• US Class Current: 703/4
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method determines and/or predicts a maximum power capacity of a battery by using a model of the battery based on an electric equivalent circuit diagram that predicts the maximum power capacity of the battery. The maximum power of the battery is prognosticated for a defined prognosis period and for the different operating modes with respect to the charging or discharging operation, considering the maximum allowable operating voltage and the maximum allowable operating current.

Claims

1. A method for predicting a maximum power capacity of a battery, the method comprising the acts of:

using a model of the battery, which is based on an electric equivalent circuit diagram, to predict the maximum power capacity of the battery, wherein;

the maximum power of the battery is prognosticated for a defined prognosis period and for different operating modes with respect to charging or discharging operation, the prognosticating for the defined prognosis period taking into consideration a maximum allowable operating voltage and a maximum allowable operating current,

the operating modes comprise charging with voltage limitation, charging with current limitation, discharging with voltage limitation, and discharging with current limitation, and

the model comprises a current response that is an exponential function of time at a fixed voltage.

2. The method according to claim 1, wherein the power capacity of the battery for the charging or discharging operation is equal to a value, in terms of amount, that is the lesser of:

(a) simultaneously determined maximum power values for the maximum allowable charging or discharging current, and (b) the maximum allowable charging or discharging voltage.

3. The method according to claim 2, further comprising the act of considering a load prehistory of the battery using a calculated bias value.

4. The method according to claim 2, further comprising the act of providing parameters for the model of the battery via a parameter estimating unit.

5. The method according to claim 2, further comprising the act of obtaining parameters for the model of the battery from a stored parameter map.

6. The method according to claim 1, further comprising the act of considering a load prehistory of the battery using a calculated bias value.

7. The method according to claim 6, further comprising the act of providing parameters for the model of the battery via a parameter estimating unit.

8. The method according to claim 6, further comprising the act of obtaining parameters for the model of the battery from a stored parameter map.

9. The method according to claim 1, further comprising the act of providing parameters for the model of the battery via a parameter estimating unit.

10. The method according to claim 1, further comprising the act of obtaining parameters for the model of the battery from a stored parameter map.

11. The method according to claim 1, wherein the model further comprises a voltage response that is a function of time at a fixed current.