Method and apparatus for controlling power flow in a hybrid powertrain system

• US 20080243346A1
• Filed: 03/29/2007
• Published: 10/02/2008
• Est. Priority Date: 03/29/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Huseman, Steven C.
• Granted Patent: US 7,865,287 B2
• Time in Patent Office: Days
• US Class Current: 701/53
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/11 using model predictive control [MPC] strategies, i.e. control methods based on models predicting performance utilising navigation and traffic information in the control strategy B60W20/12
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: F16H 2037/102 the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/104 Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

There is described hybrid powertrain operation and control. Preferred power flows from an engine to an electromechanical transmission and from an energy storage system to an electric machine are determined based upon an operator torque request. Operation of the engine, the electric machine, and the electromechanical transmission are controlled to substantially meet the operator torque request. Actual power flow from the energy storage device is monitored. The power flow from the engine is adjusted based upon a difference between the actual and preferred power flows from the energy storage device.

Claims

1. Article of manufacture, comprising a storage medium having a machine-executable program encoded therein adapted to operate a hybrid powertrain, the powertrain comprising an internal combustion engine, an energy storage system, an electric machine, and an electromechanical transmission, the energy storage system and electric machine electrically-operatively coupled for power flow therebetween;

and, the engine, electric machine, and the electromechanical transmission mechanically-operatively coupled to transmit power therebetween to generate a power flow to an output, the program comprising;

code to determine an operator torque request;

code to determine a preferred power flow from the engine to the electro-mechanical transmission and a preferred power flow from the energy storage system to the electric machine based upon the operator torque request;

code to control operation of the engine, the electric machine, and the electro-mechanical transmission to substantially meet the operator torque request;

code to monitor actual power flow from the energy storage device during the operation; and

,

code to control the power flow from the engine based upon a difference between the actual and preferred power flows from the energy storage device.

2. The article of claim 1, wherein the code to determine the preferred power flow from the engine to the electromechanical transmission and the preferred power flow from the energy storage system to the electric machine based upon the operator torque request further comprises:

code to determine an optimum power flow from the engine to the transmission, and, determining the power flow from the energy storage system to the electric machine based upon the optimum power flow from the engine to the transmission.

3. The article of claim 2, wherein code to determine the optimum power flow from the engine to the transmission comprises code to determine an engine torque command and an engine speed command which minimize power loss of the powertrain system.

4. The article of claim 2, wherein the code to control operation of the engine, the electric machine, and the electromechanical transmission to substantially meet the operator torque request comprises code to control the engine to generate the optimum power flow to the transmission, and, code to control the power flow from the energy storage system to the electric machine to meet the operator torque request based upon the optimum power flow from the engine to the transmission.

5. The article of claim 1, wherein the code to monitor the actual power flow from the energy storage device comprises code to monitor electric current flowing therefrom.

6. The article of claim 1, wherein the code to control the power flow from the engine based upon a difference between the actual and preferred power flows from the energy storage device comprises code to execute a closed loop control scheme to selectively adjust an engine torque command and an engine speed command based upon engine operation and the difference between the actual and preferred power flows from the energy storage device.

7. The article of claim 6, further comprising code to execute the closed loop control scheme to selectively adjust the engine torque command when the engine torque output is substantially less than a maximum engine torque output.

8. The article of claim 6, further comprising code to execute the closed loop control scheme to adjust the engine speed and the engine torque commands when the engine torque output approaches a maximum engine torque output.

9. The article of claim 6, further comprising code to execute the closed loop control scheme to selectively adjust the engine speed command when the engine torque output is substantially at a maximum engine torque output.

10. The article of claim 6, further comprising code to reduce the power flow to the output when the engine torque command exceeds a maximum engine torque output.

11. The article of claim 1, further comprising:

code to selectively reduce the power flow to the driveline when the difference between the actual and preferred power flows from the energy storage device exceeds a predetermined threshold.

12. Article of manufacture, comprising a storage medium having machine-executable program encoded therein adapted to operate a hybrid powertrain, the powertrain comprising an internal combustion engine, an energy storage system, an electric machine, and an electromechanical transmission, the energy storage system and electric machine electrically-operatively coupled for power flow therebetween;

the engine, electric machine, and the electro-mechanical transmission mechanically-operatively coupled to transmit power therebetween to generate a power flow to an output;

the engine output power exceeding the input power to the transmission by an amount;

the program comprising;

code to determine an operator torque request;

code to determine a preferred input power from the engine to the electro-mechanical transmission and a preferred power flow from the energy storage system to the electric machine based upon the operator torque request;

code to control the engine, the electric machine, and the electro-mechanical transmission to substantially meet the operator torque request;

code to monitor actual power flow from the energy storage device; and

,

code to determine the amount the engine output power exceeds the input power to the transmission based upon a difference between the preferred power flow from the energy storage system to the electric machine and the actual power flow from then energy storage device; and

,

code to adjust the output power from the engine based upon the amount the engine output power exceeds the input power to the transmission.

13. The article of claim 12, wherein the engine output power exceeds the input power to the transmission by an amount based upon at least one of power consumed by accessory loads, ambient temperature, operating temperature, altitude, fuel quality, component faults, and, component deterioration.

14. The article of claim 12, wherein the code to determine the preferred power flow from the engine to the electromechanical transmission and the preferred power flow from the energy storage system to the electric machine based upon the operator torque request further comprises:

code to determine an optimum power flow from the engine to the transmission, and, determining the power flow from the energy storage system to the electric machine based upon the optimum power flow from the engine to the transmission.

15. The article of claim 14, wherein code to determine the optimum power flow from the engine to the transmission comprises code to determine an engine torque command and an engine speed command which minimize power loss of the powertrain system.

16. The article of claim 12, wherein the code to adjust the output power from the engine based upon the amount the engine output power exceeds the input power to the transmission comprises code to execute a closed loop control scheme to selectively adjust an engine torque command and an engine speed command based upon engine operation and the difference between the actual and preferred power flows from the energy storage device.

17. The article of claim 16, further comprising code to execute the closed loop control scheme to selectively adjust the engine torque command when the engine torque output is substantially less than a maximum engine torque output.

18. The article of claim 17, further comprising code to execute the closed loop control scheme to selectively adjust the engine speed command when the engine torque output is substantially at a maximum engine torque output.

19. The article of claim 18, further comprising code to reduce the power flow to the output when the engine torque command output exceeds a maximum engine torque output.

20. Article of manufacture, comprising a storage medium having machine-executable program encoded therein adapted to operate a hybrid powertrain, the powertrain comprising an internal combustion engine, an energy storage system, two electric machines, and an electro-mechanical transmission, the energy storage system and the electric machines electrically-operatively coupled for power flow therebetween;

and, the engine, electric machines, and the electro-mechanical transmission mechanically-operatively coupled to transmit power therebetween to generate a power flow to an output, the program comprising;

code to determine an operator torque request;

code to determine a preferred power flow from the engine to the electro-mechanical transmission and a preferred power flow from the energy storage system to the electric machines based upon the operator torque request;

code to control power flow from the engine to the preferred power flow and control power flow from the electric energy storage device to the electric machines to substantially meet the operator torque request;

code to monitor power flow from the energy storage device to the electric machines; and

,

code to adjust the preferred power flow from the engine to reduce a difference between the monitored power flow and the preferred power flow from the energy storage system to the electric machines.