CREATION AND DEPLETION OF SHORT TERM POWER CAPABILITY IN A HYBRID ELECTRIC VEHICLE

• US 20090118877A1
• Filed: 09/18/2008
• Published: 05/07/2009
• Est. Priority Date: 11/03/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: BMW AG (Bayerische Motoren Werke AG), Daimler AG (Mercedes-Benz Group AG), GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust), Chrysler LLC (Stellantis NV)
• Inventors: Cawthorne, William R., Center, Marc B.
• Granted Patent: US 8,224,514 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2260/26 Transition between different drive modes
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: B60L 7/08 : Controlling the braking effect B60L7/04, B60L7/06 take precedence
• CPC Class Codes: B60W 10/06 : including control of combustion engines
• CPC Class Codes: B60W 10/10 : including control of change-speed gearings
• 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 20/13 : in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: H01M 10/44 : Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

Short term power limits of an electrical energy storage device are progressively tightened toward long term power limits in accordance with net energy flow or magnitude or duration metrics.

Claims

1. A method for controlling operation of a hybrid powertrain system based upon electric power limits for an electric energy storage device, comprising:

providing long term power limits of the electric energy storage device;

determining short term power limits of the electric energy storage device based upon the long term power limits; and

controlling power output of the hybrid powertrain system based upon the short term power limits of the electric energy storage device during an electrical energy storage device power excursion outside of the long term power limits.

2. The method of claim 1, further comprising:

determining an energy area metric based upon the long term power limits, an elapsed time, and an electrical energy storage device power flow; and

converging the short term power limits to the long term power limits when the monitored energy area metric reaches a first predetermined threshold.

3. The method of claim 2, further comprising:

calculating a difference between electric energy storage device power flow and the long term power limits; and

determining the energy area metric by integrating said difference over the elapsed time.

4. The method of claim 2, further comprising:

establishing the short term power limits to a predetermined level in excess of the long term power limits when the energy area metric is reduced to a second predetermined threshold.

5. The method of claim 1, wherein the short term power limits comprise one of a predetermined magnitude over the long term power limits and a predetermined percentage over the long term power limits.

6. The method of claim 1, further comprising:

determining electric energy storage device power flow;

monitoring an elapsed time wherein electric energy storage device power flow exceeds the long term power limits;

incrementing the monitored elapsed time when the actual power output exceeds the long term power limits;

decrementing the monitored elapsed time when the actual power output is less than the long term power limits; and

converging the short term power limits to the long term power limits when the monitored elapsed time reaches a first predetermined threshold.

7. The method of claim 6, further comprising:

establishing the short term power limits to a predetermined level greater than the long term power limits when the monitored elapsed time reaches a second predetermined threshold.

8. The method of claim 1, wherein the power excursion results from hybrid powertrain system operation effecting one of clutch plate synchronization, engine starting, and regenerative braking.

9. The method of claim 1, wherein the short term power limits comprise a maximum short term power limit comprising a maximum discharge power limit of the electric energy storage device.

10. The method of claim 1, wherein the short term power limits comprise a minimum short term power limit comprising a maximum charge power limit of the electric energy storage device.

11. The method of claim 1, wherein the long term power limits comprise a maximum long term power limit comprising a maximum discharge power limit of the electric energy storage device over an extended time period.

12. The method of claim 1, wherein the long term power limits comprise a minimum long term power limit comprising a maximum charge power limit of the electric energy storage device over an extended time period.

13. A method for operating a hybrid powertrain system including an electro-mechanical transmission connected to an energy storage device, comprising;

monitoring electric power flow between the electric energy storage device and the electro-mechanical transmission;

determining a net energy change in the electric energy storage device based upon the electric power flow between the electric energy storage device and the electro-mechanical transmission and predetermined long term power limits;

determining short term power limits of the electric energy storage device based upon the long term power limits and the net energy change; and

controlling power output of the hybrid powertrain system based upon the short term power limits of the electric energy storage device.

14. The method of claim 13, further comprising:

converging the short term power limits to the long term power limits when the net energy change reaches a first predetermined threshold; and

controlling the short term power limits to a predetermined level greater than the long term power limits when the net energy change reaches a second predetermined threshold.

15. A method for operating of a hybrid powertrain system including an electro-mechanical transmission connected to an energy storage device, comprising;

monitoring electric power flow between the electric energy storage device and the electro-mechanical transmission;

determining a net elapsed time based upon the electric power flow between the electric energy storage device and the electro-mechanical transmission and predetermined long term power limits;

determining short term power limits of the electric energy storage device based upon the long term power limits and the net elapsed time; and

controlling power output of the hybrid powertrain system based upon the short term power limits of the electric energy storage device.

16. The method of claim 15, wherein determining a net elapsed time comprises:

incrementing the net elapsed time when the power flow exceeds the long term power limits;

decrementing the net elapsed time when the power output is less than the long term power limits.

17. The method of claim 16, wherein determining short term power limits comprises:

converging the short term power limits to the long term power limits when the net elapsed time reaches a first predetermined threshold; and

controlling the short term power limits to a predetermined level greater than the long term power limits when the net elapsed time reaches a second predetermined threshold.