ELECTRIC VEHICLE (EV) DRIVING MODE OPTIMIZATION FOR A PARALLEL HYBRID ELECTRIC VEHICLE

• US 20090287366A1
• Filed: 05/15/2008
• Published: 11/19/2009
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Zou, Zhanjiang, Davis, Scott W., Nellums, Richard A., Connolly, Tom
• Granted Patent: US 8,566,013 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• 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 20/20 Control strategies involving selection of hybrid configuration, e.g. selection between series or parallel configuration
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method of operating a parallel hybrid electric drive train may include manually selecting a first mode by a user. The first mode include an electric mode that provides for propelling a vehicle using only an electric motor. The method may also include propelling the vehicle in the electric mode, limiting an allowed vehicle acceleration below a predetermined acceleration value, detecting a battery state of charge, and preventing an engine start during operation in the electric mode.

Claims

1. A method of operating a hybrid electric drive train, the drive train comprising an electric motor and an internal combustion engine, each capable of propelling a vehicle, the method comprising:

providing a manually selectable first mode, wherein the first mode includes an electric mode that includes propelling the vehicle using only the electric motor;

propelling the vehicle in the electric mode;

limiting an allowed vehicle acceleration to below a predetermined acceleration value;

detecting a battery state of charge; and

preventing an engine start during operation in the electric mode.

2. The method of claim 1, wherein the first mode further includes increasing an amount of charge in a battery portion prior to the propelling a vehicle using only an electric motor.

3. The method of claim 2, wherein increasing the amount of charge includes operating an internal combustion engine to drive the electric motor and operating the electric motor as a generator to charge the battery portion.

4. The method of claim 3, further comprising a notifying when a state of charge is below a predetermined value.

5. The method of claim 1, further comprising notifying a user of an estimated vehicle availability value, the vehicle availability value including at least one of:

a distance available for operation in electric mode, a time remaining in electric mode, and a maximum acceleration rate available in electric mode.

6. The method of claim 1, wherein the predetermined acceleration value may be selectively adjusted during operation in electric mode.

7. The method of claim 1, further comprising at least partially recharging a battery portion with a regenerative brake.

8. The method of claim 1, wherein detecting the battery state of charge includes estimating available battery power based upon an estimated discharge rate and battery state of charge.

9. The method of claim 1, further comprising discharging the battery below an approximately thirty percent state of charge while in electric mode.

10. The method of claim 9, further comprising preventing a discharging of the battery below an approximately forty percent state of charge while in a hybrid mode, wherein the engine will automatically start to charge the battery during operation in the hybrid mode.

11. A method of operating a hybrid electric drive train comprising:

manually selecting a first mode by a user, wherein the first mode includes an electric mode that includes propelling a vehicle using only an electric motor;

propelling the vehicle in the electric mode;

detecting a battery state of charge; and

preventing an engine start during operation in the electric mode while propelling a vehicle using only an electric motor; and

permitting a user override for permitting an engine start while propelling a vehicle using only an electric motor.

12. The method of claim 11, further comprising preventing the engine from exceeding a rotational speed of approximately one-thousand revolutions per minute.

13. The method of claim 11, further comprising preventing a discharge of the battery below an approximately forty percent state of charge while in a hybrid mode, wherein the engine will automatically start to charge the battery during operation in the hybrid mode.

14. The method of claim 11, further comprising limiting an allowed vehicle acceleration below a predetermined acceleration value.

15. The method of claim 14, wherein limiting the allowed acceleration includes limiting the rotational speed of the motor when in the electric only mode to a value below a speed permitted in a hybrid mode, wherein the electric motor and the engine are permitted to propel the vehicle during the hybrid mode.

16. The method of claim 11, further comprising notifying the user of an estimated vehicle availability value, wherein the vehicle availability value includes at least one of:

distance available for operation in electric mode, time remaining in electric mode, and maximum acceleration rate available in electric mode.

17. The method of claim 11, wherein the first mode further includes increasing an amount of charge in a battery portion prior to the propelling a vehicle using only an electric motor.

18. The method of claim 17, wherein increasing the amount of charge includes operating an internal combustion engine to drive the electric motor and operating the electric motor as a generator to charge the battery portion.

19. The method of claim 18, further comprising notifying the user when a state of charge is below a predetermined value.

20. The method of claim 11, further comprising shutting down the motor when a state of charge of the battery portion is below a predetermined value.