METHOD AND APPARATUS FOR MANAGEMENT OF AN ELECTRIC ENERGY STORAGE DEVICE TO ACHIEVE A TARGET LIFE OBJECTIVE

• US 20080249745A1
• Filed: 06/07/2006
• Published: 10/09/2008
• Est. Priority Date: 06/07/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Heap, Anthony, Cawthorne, William, Zettel, Andrew
• Granted Patent: US 7,647,205 B2
• Time in Patent Office: Days
• US Class Current: 702/183
• CPC Class Codes: B60L 2260/56 Temperature prediction, e.g. for pre-cooling
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: B60W 2530/18 Distance travelled
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method for determining a preferred operating gradient for use in attaining a life objective for an electrical energy storage device is disclosed. A present state-of-life of the electrical energy storage device is provided and a life target for the electrical energy storage device is established as a predetermined limit in a predetermined metric at a predetermined state-of-life of the electrical energy storage device. A state-of-life gradient is then determined with respect to the predetermined metric which converges the state-of-life of the electrical energy storage device to the life target.

Claims

1. Method for determining a preferred operating gradient for use in attaining a life objective for an electrical energy storage device, comprising:

providing present state-of-life of the electrical energy storage device;

establishing a life target for the electrical energy storage device as a predetermined limit in a predetermined metric at a predetermined state-of-life of the electrical energy storage device;

determining a state-of-life gradient with respect to the predetermined metric which converges the state-of-life of the electrical energy storage device to the life target; and

,

controlling electrical energy storage device current based upon the state-of-life gradient.

2. The method of claim 1 wherein the predetermined state-of-life of the electrical energy storage device is indicative of the end of life of the electrical energy storage device.

3. The method as in claim 1 wherein the metric comprises elapsed service time of the electrical energy storage device.

4. The method as in claim 1 wherein the electrical energy storage device is a vehicular battery and the metric comprises vehicle distance traveled.

5. The method of claim 1 wherein the electrical energy storage device is a vehicular battery and the life target is based upon a respective predetermined limit in one of elapsed service time of the electrical energy storage device and vehicle distance traveled.

6. The method of claim 5 wherein the life target is normalized with respect to the one of elapsed service time of the electrical energy storage device and vehicle distance traveled upon which the life target is based.

7. Method for managing state-of-life of an electrical energy storage device, comprising:

providing a state-of-life gradient based on a present state-of-life of the electrical energy storage device and at least one predetermined limit in a predetermined metric; and

controlling electrical energy storage device current such that electrical energy storage device state-of-life substantially tracks the state-of-life gradient.

8. The method of claim 7 wherein controlling electrical energy storage device current such that electrical energy storage device state-of-life substantially tracks the state-of-life gradient comprises:

providing a plurality of predicted effects upon electrical energy storage device state-of-life based on a plurality of potential electrical energy storage device currents; and

controlling electrical energy storage device current based on the predicted effects and the state-of-life gradient.

9. Method for managing an operating state of an electrical energy storage device, comprising:

controlling power transmitted through the electrical energy storage device such that the operating state of the electrical energy storage device is less than a predetermined value when a target life objective is attained.

10. The method of claim 9, wherein the operating state of the electrical energy storage device comprises a state-of-life of the electrical energy storage device.

11. The method of claim 10, wherein the electrical energy storage device is adapted for use in a hybrid vehicular powertrain and controlling power transmitted from the electrical energy storage device such that the state-of-life is less than a predetermined value when the target life objective is attained further comprises:

calculating a life factor based upon an accumulated time and an accumulated distance of operation of the powertrain;

determining a target state-of-life gradient based upon the life factor, the state-of-life, and the target life objective; and

,

controlling electrical power between the electrical energy storage device and the powertrain based upon the target state-of-life gradient.

12. The method of claim 11, wherein controlling electrical power between the electrical energy storage device and the powertrain based upon the target state-of-life gradient further comprises:

determining potential changes in state-of-life for the electrical energy storage device based upon an array of potential electrical currents through the electrical energy storage device; and

,

selecting one of the array of potential electrical currents based upon the state-of-life gradient.

13. The method of claim 12, wherein determining potential changes in state-of-life for the electrical energy storage device based upon an array of potential electrical currents through the electrical energy storage device further comprises:

selecting the array of potential electrical currents through the electrical energy storage device; and

,

determining a corresponding array of changes in the state-of-life for the electrical energy storage device determined based upon the array of potential electrical currents through the electrical energy storage device;

wherein changes in the state-of-life for the electrical energy storage device are determined based upon;

time-based integration of the electrical currents through the electrical energy storage device, depth of discharge of the energy storage device, and, operating temperature of the electrical energy storage device.

14. The method of claim 11, wherein controlling power transmitted through the electrical energy storage device comprises controlling electrical current between the electrical energy storage device and the powertrain.

15. The method of claim 9, wherein controlling power transmitted through the electrical energy storage device such that an operating state of the electrical energy storage device is less than a predetermined value further comprises:

determining the operating state of the electrical energy storage device, comprising;

monitoring electrical current through the electrical energy storage device;

monitoring a state-of-life of the electrical energy storage device;

monitoring a temperature of the electrical energy storage device during active and quiescent periods of operation; and

,

determining a state-of-life of the electrical energy storage device, based upon the electrical energy storage device current, the state-of-life of the electrical energy storage device, and, the temperature of the electrical energy storage device during operation and during quiescent periods of operation.