METHOD FOR CONTROLLING VOLTAGE WITHIN A POWERTRAIN SYSTEM

• US 20090118079A1
• Filed: 10/01/2008
• Published: 05/07/2009
• Est. Priority Date: 11/02/2007
• 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: HEAP, ANTHONY H., BRUNSSEN, WILFRIED
• Granted Patent: US 8,287,426 B2
• Time in Patent Office: Days
• US Class Current: 477/3
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 10/24 including control of energy storage means
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/085 Power
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 50/04 : Monitoring the functioning of the control system
• CPC Class Codes: F16H 2037/0866 : Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• 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: F16H 2037/106 : with switching means to provide two variator modes or ranges
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles

Abstract

A method for controlling a powertrain system includes monitoring voltage of an energy storage device. The method further includes modifying a preferred voltage limit when the voltage of the energy storage device transgresses a trigger voltage limit, and determining the power constraint of a first power actuator based on the estimated output power of the energy storage device when the voltage of the energy storage device transgresses the preferred voltage limit.

Claims

1. Method for controlling a powertrain system including a first power actuator, a second power actuator, a transmission device and an energy storage device coupled to one of the first power actuator and the second power actuator, the transmission device operative to transfer power between an output member, and the first and second power actuators, the method comprising:

monitoring voltage of the energy storage device;

providing a base voltage limit, an intermediate power constraint, a preferred voltage limit, and a trigger voltage limit for the energy storage device, said preferred voltage limit defining a preferred voltage range;

modifying the preferred voltage limit when the voltage of the energy storage device transgresses the trigger voltage limit;

monitoring a power command to the first power actuator;

estimating an output power of the energy storage device for the power command;

determining a power constraint of the first power actuator based on the intermediate power constraint when the voltage of the energy storage device is within the preferred voltage range; and

determining a power constraint of the first power actuator based on the estimated output power of the energy storage device when the voltage of the energy storage device transgresses the preferred voltage limit.

2. The method of claim 1, further comprising providing a set of base voltage limits comprising the base voltage limit, a set of intermediate power constraints comprising the intermediate power constraint, a set of preferred voltage limits comprising the preferred voltage limit, and a set of trigger voltage limits comprising the trigger voltage limit for the energy storage device.

3. The method of claim 1, further comprising:

monitoring a temperature of the energy storage device; and

determining the base voltage limit based on the temperature of the energy storage device.

4. The method of claim 1, further comprising determining the intermediate power constraint based upon an output power of the energy storage device.

5. The method of claim 1, further comprising determining the preferred voltage limit and the trigger voltage limit based on the base voltage limit.

6. The method of claim 1, further comprising:

setting the preferred voltage limit to a first voltage value based upon the base voltage limit; and

ramping the preferred voltage limit over time at a predetermined rate from the first voltage value to a second voltage value when the voltage of the energy storage device transgresses the trigger voltage limit.

7. The method of claim 6, wherein the second voltage value is equal to the base voltage limit.

8. The method of claim 1, further comprising:

monitoring a power command to an engine comprising the first power actuator;

estimating an output power of the energy storage device for the power command;

determining a power constraint of the engine based on the intermediate power constraint when the voltage is within the preferred voltage range; and

determining the power constraint of the engine based on the estimated output power of the energy storage device when the voltage of the energy storage device transgresses the preferred voltage limit.

9. The method of claim 8, wherein the power command to the engine comprises a torque command.

10. The method of claim 1, further comprising:

monitoring a power command to an electric machine comprising the first power actuator;

estimating an output power of the energy storage device for the power command;

determining a power constraint of the electric machine based on the intermediate power constraint when the voltage is within the preferred voltage range; and

determining the power constraint of the electric machine based on the estimated output battery power of the energy storage device when the voltage of the energy storage device transgresses the preferred voltage limit.

11. The method of claim 10, wherein the power command to the electric machine comprises a torque command.

12. The method of claim 1, further comprising determining the power constraint of the first power actuator based on the voltage of the energy storage device when the voltage of the energy storage device transgresses the preferred voltage limit.

13. The method of claim 12, further comprising utilizing the voltage of the energy storage device in a proportional integral control scheme when the voltage of the energy storage device transgresses the preferred voltage limit.

14. Method for controlling a powertrain system including an engine, an electric machine, a transmission device, and an energy storage device coupled to the electric machine, the transmission device operative to transfer power among an output member, the engine and the electric machine, the method comprising:

monitoring voltage of the energy storage device;

providing a base voltage limit, an intermediate power constraint, a preferred voltage limit, and a trigger voltage limit for the energy storage device, said preferred voltage limit defining a preferred voltage range;

modifying the base voltage limit when the voltage of the energy storage device transgresses the trigger voltage limit;

monitoring a power command to the engine;

estimating an output power of the energy storage device for the power command;

determining a power constraint of the engine based on the intermediate power constraint when the voltage of the energy storage device is within the preferred voltage range; and

determining the power constraint of the engine based on the estimated output power of the energy storage device when the voltage of the energy storage device transgresses the preferred voltage limit.

15. The method of claim 14, further comprising providing a set of base voltage limits comprising the base voltage limit, a set of intermediate power constraints comprising the intermediate power constraint, a set of preferred voltage limits comprising the preferred voltage limit, and a set of trigger voltage limits comprising the trigger voltage limit for the energy storage device.

16. The method of claim 14, further comprising:

setting the preferred voltage limit to a first voltage value based upon the base voltage limit; and

ramping the preferred voltage limit over time at a predetermined rate from the first voltage value to a second voltage value when the voltage of the energy storage device transgresses the trigger voltage limit, wherein the second voltage value is equal to the base voltage limit.

17. The method of claim 14, further comprising determining the power constraint of the engine based on the voltage of the energy storage device when the voltage of the energy storage voltage transgresses the preferred voltage limit, wherein the power constraint of the engine comprises a torque constraint.

18. Method for controlling a powertrain system including an engine, an electric machine, a transmission device, and an energy storage device coupled to the electric machine, the transmission device operative to transfer power among an output member, the engine and the electric machine, the method comprising:

monitoring voltage of the energy storage device;

providing a base voltage limit, an intermediate power constraint, a preferred voltage limit, and a trigger voltage limit for the energy storage device, said preferred voltage limit defining a preferred voltage range;

modifying the base voltage limit when the voltage of the energy storage device transgresses the trigger voltage limit;

monitoring a power command to the electric machine;

estimating an output power of the energy storage device for the power command;

determining a power constraint for constraining power of the electric machine based on the intermediate power constraint when the voltage of the energy storage device is within the preferred voltage range;

determining the power constraint for constraining power of the electric machine based on the estimated output power of the energy storage device when voltage of the energy storage device transgresses the preferred voltage limit.

19. The method of claim 18, further comprising:

determining an input power from the engine;

determining a constraint for constraining output power of the output member; and

constraining power of the electric machine based upon the constraint for constraining output power and the input power from the engine.

20. The method of claim 19, further comprising:

determining an input torque from the engine;

determining a constraint for constraining output torque of the output member; and

constraining torque of the electric machine based upon the constraint for constraining output torque and the input torque from the engine.