Battery Capacity Estimation Based on Open-Loop And Closed-Loop Models

• US 20170259688A1
• Filed: 03/09/2016
• Published: 09/14/2017
• Est. Priority Date: 03/09/2016
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lee, Tae-Kyung
• Granted Patent: US 10,118,500 B2
• Time in Patent Office: Days
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2260/52 drive range estimation, e.g. of estimation of available travel distance
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A vehicle power system may include a controller programmed to output an electric only range indicator based on a change in capacity of a traction battery derived from open-loop and closed-loop estimates of change in state of charge of the traction battery. The change in capacity may be proportional to a ratio of the open-loop estimate to the closed-loop estimate. The closed-loop estimate may contain information indicative of the change in capacity. The open-loop estimate may contain information indicative of an initial capacity of the traction battery.

Claims

1. A vehicle power system comprising:

a controller programmed to output an electric only range indicator based on a change in capacity of a traction battery derived from open-loop and closed-loop estimates of change in state of charge of the traction battery.

2. The system of claim 1, wherein the change in capacity is proportional to a ratio of the open-loop estimate to the closed-loop estimate.

3. The system of claim 1, wherein the closed-loop estimate contains information indicative of the change in capacity.

4. The system of claim 1, wherein the open-loop estimate contains information indicative of an initial capacity of the traction battery.

5. The system of claim 1, wherein the change in capacity is an average of a plurality of changes in capacity each associated with a change in state of charge event.

6. A vehicle comprising:

a traction battery; and

a controller programmed to alter maximum charge and discharge current limits of the traction battery based on a change in capacity of the traction battery derived from open-loop and closed-loop estimates of change in state of charge of the traction battery.

7. The vehicle of claim 6, wherein the change in capacity is proportional to a ratio of the open-loop estimate to the closed-loop estimate.

8. The vehicle of claim 6, wherein the closed-loop estimate contains information indicative of the change in capacity.

9. The vehicle of claim 6, wherein the open-loop estimate contains information indicative of an initial capacity of the traction battery.

10. The vehicle of claim 6, wherein the change in capacity is an average of a plurality of changes in capacity each associated with a change in state of charge event.

11. A traction battery management method comprising:

altering by a controller maximum charge and discharge power limits of a traction battery based on a change in capacity of the traction battery derived from open-loop and closed-loop estimates of change in state of charge of the traction battery.

12. The method of claim 11, wherein the change in capacity is proportional to a ratio of the open-loop estimate to the closed-loop estimate.

13. The method of claim 11, wherein the closed-loop estimate contains information indicative of the change in capacity.

14. The method of claim 11, wherein the open-loop estimate contains information indicative of an initial capacity of the traction battery.

15. The method of claim 11, wherein the change in capacity is an average of a plurality of changes in capacity each associated with a change in state of charge event.