Battery capacity estimation based on open-loop and closed-loop models

• US 10,118,500 B2
• Filed: 03/09/2016
• Issued: 11/06/2018
• 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
• Primary Examiner(s): Kik, Phallaka
• Application Number:
  US15/064,639
• Publication Number:
  US 20170259688A1
• Time in Patent Office: 972 Days
• Field of Search: 320109, 320104, 320112, 320132
• 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 maximum capacity of a traction battery derived from open-loop and closed-loop estimates of change in state of charge of the traction battery, and operate the traction battery according to maximum charge and discharge current limits 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 maximum capacity of the traction battery derived from open-loop and closed-loop estimates of change in state of charge of the traction battery, and operate the traction battery according to the limits.

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 maximum capacity of the traction battery derived from open-loop and closed-loop estimates of change in state of charge of the traction battery, and operate the traction battery according to the limits.

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.