Method and apparatus for controlling vehicle battery charging

• US 7,834,582 B2
• Filed: 05/11/2006
• Issued: 11/16/2010
• Est. Priority Date: 05/11/2006
• 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: Luan, Yunfei, Lo, Chihsiung, Frisch, Damon R., Tamai, Goro
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US11/432,456
• Publication Number:
  US 20070262749A1
• Time in Patent Office: 1,650 Days
• Field of Search: 320/104, 320/132, 320/149, 701/22, 180/65.1, 180/65.21, 903/904, 903/905, 903/907
• US Class Current: 320/104
• CPC Class Codes: H02J 7/1492 by means of controlling devices between the generator output and the battery
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

An electrical charging strategy and system for a high voltage electrical energy storage system able to supply electrical energy to a hybrid vehicle is disclosed. The system charges the electrical energy storage system so state-of-charge at the end of a trip is substantially unchanged. The strategy and system employs opportunity charging to achieve maximum energy efficiency of the hybrid system, thus minimizing fuel consumption and maximizing fuel economy. The charging system operation is controlled, based upon: the state-of-charge of the electrical energy storage system, and, the operating efficiency of the internal combustion engine. Battery life is likewise extended through use of this strategy.

Claims

1. Control system for a charging system operable to supply electrical energy to an electrical energy storage system of a vehicle having a hybrid propulsion system including an internal combustion engine, operable to provide propulsion torque to a driveline of the vehicle, and operable to provide charging torque to the charging system, comprising:

the control system, operable to;

determine a state-of-charge of the electrical energy storage system;

determine operating efficiency of the internal combustion engine; and

,

control operation of the charging system, based upon;

the state-of-charge of the electrical energy storage system, and, the operating efficiency of the internal combustion engine.

2. The system of claim 1, further comprising the control system operable to:

determine speed of the vehicle; and

,

control operation of the charging system, based upon;

the state-of-charge of the electrical energy storage system, the operating efficiency of the internal combustion engine, and, the speed of the vehicle.

3. The system of claim 1, further comprising the control system operable to:

determine an operating point of the internal combustion engine; and

,

control operation of the electrical charging system, based upon;

the state-of-charge of the electrical energy storage system, the operating efficiency of the internal combustion engine, and, the engine operating point.

4. The system of claim 3, wherein the control system operable to control operation of the electrical charging system based upon the operating efficiency of the internal combustion engine comprises:

the control system operable to selectively operate the electrical charging system when a change in the operating efficiency due to operation of the electrical charging system exceeds a predetermined value.

5. The system of claim 3, wherein the control system operable to control operation of the electrical charging system based upon the state-of-charge of the electrical energy storage system comprises:

the control system operable to increase range of engine operation at which the electrical charging system operates based upon a decrease in the state-of-charge.

6. The system of claim 5, further comprising the control system operable to limit range of engine operation at which the electrical charging system operates based upon an increase in the state-of-charge.

7. The system of claim 6, further comprising the control system operable to discontinue operation of the electrical charging system when the state-of-charge exceeds a maximum value.

8. The system of claim 1, wherein the electrical charging system comprises a high voltage electrical energy charging system.

9. The system of claim 1, wherein the control system operable to control operation of the charging system comprises:

the charging system operable to transform kinetic energy of the internal combustion engine into potential electrical energy based upon a control signal from the control system.

10. The system of claim 1, wherein the control system operable to control operation of the charging system, based upon the state-of-charge of the electrical energy storage system comprises:

the control system operable to maintain the state-of-charge of the electrical energy storage system between predetermined limits.

11. The system of claim 1, wherein the control system operable to determine operating efficiency of the internal combustion engine comprises:

the control system operable to determine a specific fuel consumption of the engine.

12. Method to control operation of a charging system for an electrical energy storage system of a vehicle having a hybrid propulsion system comprising:

an internal combustion engine, and, an electric generator operably coupled to the engine and having an electrical output to an electrical energy storage system, comprising;

determining a state-of-charge of the electrical energy storage system;

determining operating efficiency of the internal combustion engine; and

,

controlling operation of the charging system, based upon;

the state-of-charge of the electrical energy storage system, and, the operating efficiency of the internal combustion engine.

13. The method of claim 12, comprising:

determining speed of the vehicle; and

,

controlling operation of the charging system, based upon;

the state-of-charge of the electrical energy storage system, the operating efficiency of the internal combustion engine, and, the speed of the vehicle.

14. The method of claim 12, comprising:

determining an operating point of the internal combustion engine; and

,

controlling operation of the electrical charging system, based upon;

the state-of-charge of the electrical energy storage system, the operating efficiency of the internal combustion engine, and, the engine operating point.

15. The method of claim 14, wherein controlling operation of the electrical charging system, based upon the operating efficiency of the internal combustion engine comprises:

selectively operating the electrical charging system when a change in the operating efficiency due to operation of the electrical charging system exceeds a predetermined value.

16. Method to optimize life of an electrical energy storage system, comprising:

determining a state-of-charge of the electrical energy storage system;

determining operating efficiency of the internal combustion engine;

determining an operating point of the internal combustion engine;

controlling operation of the electrical charging system, based upon;

the state-of-charge of the electrical energy storage system, the operating efficiency of the internal combustion engine, and, the engine operating point;

selectively operating the electrical charging system when a change in the operating efficiency due to operation of the electrical charging system exceeds a predetermined value;

increasing range of engine operation at which the electrical charging system operates, based upon a decrease in the state-of-charge;

limiting range of engine operation at which the electrical charging system operates, based upon an increase in the state-of-charge, and,

discontinuing operation of the electrical charging system when the state-of-charge exceeds a maximum value.

17. The method of claim 16, wherein the electrical energy storage system comprises a vehicle having a hybrid propulsion system including an internal combustion engine, and, an electric generator operably coupled to the engine and having an electrical output to the electrical energy storage system.

18. Method to control operation of a charging system for an electrical energy storage system of a vehicle having a hybrid propulsion system including an internal combustion engine and an electric generator operably coupled to the engine and having an electrical output to an electrical energy storage system, comprising:

controlling operation of the charging system to bias charging of the energy storage system during periods of engine operation whereat charging induced increases in engine loads result in relatively greater operating efficiency of the internal combustion engine.

19. The method to control operation of a charging system for an electrical energy storage system of a vehicle as claimed in claim 18, further comprising:

at relatively high energy storage system states of charge, limiting energy storage system charging to periods of engine operation whereat operating efficiency of the internal combustion engine is relatively low.