CONTROLLED SHUTDOWN OF AN ELECTRIC VEHICLE

• US 20130226377A1
• Filed: 02/24/2012
• Published: 08/29/2013
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Stanek, Joseph, Grimes, Jeffery R., Treharne, William David, Skaff, Ryan, Gillespey, Brian
• Granted Patent: US 8,831,808 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 7/16 for vehicles comprising converters between the power source and the motor
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• 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

A vehicle is provided with a motor that is configured to provide drive torque and to facilitate regenerative braking. The vehicle also includes a controller that is configured to receive input that is indicative of a vehicle speed and a battery state of charge (BSOC), and to disable the drive torque when the BSOC is less than a maximum discharge limit. The controller is also configured to activate regenerative braking when the BSOC is less than the maximum discharge limit and the vehicle speed is greater than a predetermined speed.

Claims

1. A vehicle comprising:

a motor configured to provide drive torque and to facilitate regenerative braking; and

a controller configured to;

receive input indicative of a vehicle speed and a battery state of charge (BSOC),

disable the drive torque when the BSOC is less than a maximum discharge limit, and

activate regenerative braking when the BSOC is less than the maximum discharge limit and the vehicle speed is greater than a predetermined speed.

2. The vehicle of claim 1 further comprising:

an electric braking actuator for assisting a friction braking system; and

an electric steering actuator for assisting a steering system;

wherein the controller is further configured to disable the electric braking actuator and the electric steering actuator when the BSOC is less than the maximum discharge limit and the vehicle speed is less than the predetermined speed.

3. The vehicle of claim 2 further comprising:

a climate control system; and

a battery for providing electrical energy to the motor, the climate control system, the electric braking actuator and the electric steering actuator;

wherein the controller is further configured to disable the climate control system when the BSOC is less than the maximum discharge limit.

4. The vehicle of claim 1 wherein the maximum discharge limit is between 6% and 3% BSOC and the predetermined speed is between 5 and 0 kph.

5. The vehicle of claim 1 further comprising:

an interface communicating with the controller and configured to display a warning message when the BSOC is less than the maximum discharge limit.

6. A vehicle system comprising:

a controller configured to;

receive input indicative of a vehicle speed and a battery state of charge (BSOC),

disable drive torque when the BSOC is less than a maximum discharge limit, and

disable electric braking assistance and electric steering assistance when the BSOC is less than the maximum discharge limit and the vehicle speed is less than a predetermined speed.

7. The vehicle system of claim 6 wherein the controller is further configured to disable drive torque by decreasing an available battery power limit to 0 KW at a controlled ramp rate.

8. The vehicle system of claim 6 wherein the controller is further configured to:

activate regenerative braking when the BSOC is less than the maximum discharge limit and the vehicle speed is greater than the predetermined speed.

9. The vehicle system of claim 6 wherein the controller is further configured to:

disable a climate control system when the BSOC is less than the maximum discharge limit.

10. The vehicle system of claim 6 further comprising:

an interface communicating with the controller and configured to display a vehicle shutdown message when the BSOC is less than the maximum discharge limit.

11. The vehicle system of claim 6 wherein the controller is further configured to:

receive input indicative of a gear selection and a key position; and

electrically disconnect a battery from a motor in response to at least one of a gear selection of park and a key position of off.

12. A method for controlled shutdown of an electric vehicle, the method comprising:

receiving input indicative of a vehicle speed and a battery state of charge (BSOC);

disabling drive torque when the BSOC is less than a first discharge limit; and

activating regenerative braking when the BSOC is less than the first discharge limit and the vehicle speed is greater than a predetermined speed.

13. The method of claim 12 further comprising:

supplying energy generated during regenerative braking to an electric braking actuator for providing braking assistance.

14. The method of claim 12 further comprising:

supplying energy generated during regenerative braking to an electric steering actuator for providing steering assistance.

15. The method of claim 12 further comprising:

disabling an electric brake actuator and an electric steering actuator when the BSOC is less than the first discharge limit and the vehicle speed is less than a predetermined speed.

16. The method of claim 12 further comprising:

disabling a climate control system when the BSOC is less than the first discharge limit.

17. The method of claim 12 further comprising:

displaying a vehicle shutdown message when the BSOC is less than the first discharge limit.

18. The method of claim 12 further comprising:

receiving input indicative of a gear selection; and

electrically disconnecting a battery from at least one of a motor and a climate control system in response to a gear selection of park.

19. The method of claim 12 further comprising:

receiving input indicative of a key position; and

electrically disconnecting a battery from a motor in response to a key position of off.

20. The method of claim 19 further comprising:

upon electrically disconnecting the battery, electrically reconnecting the battery to the motor when the BSOC increases above a second discharge limit to allow vehicle restart, the second discharge limit being greater than the first discharge limit.