CONTROL STRATEGY FOR AN ELECTRIC MACHINE IN A VEHICLE

• US 20140062349A1
• Filed: 11/30/2012
• Published: 03/06/2014
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Isayeva, Rimma, Gabriel, David Crist, Degner, Michael W., Tang, Yuqing, Wu, Hongjie
• Granted Patent: US 9,130,487 B2
• Time in Patent Office: Days
• US Class Current: 318/139
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• 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 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: G05B 9/02 electric
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A hybrid-electric vehicle and method of controlling a hybrid-vehicle is provided. The vehicle includes a traction battery, at least one electric-machine, and a controller. The controller is configured to alter a voltage between the battery and the electric-machine based on a measured voltage of the battery or the high voltage bus. In response to an indication that the measured voltage is faulty during a drive cycle, the controller instead alters the voltage between the battery and the electric machine based on a substituted battery voltage signal such that the electric-machine remains operable for the drive cycle.

Claims

7. A vehicle comprising:

a fraction battery;

a high voltage bus to provide high voltage to least one electric-machine; and

a controller configured to;

alter a voltage between the battery and the electric-machine based on a measured voltage signal of the high voltage bus; and

in response to an indication that the measured voltage signal is faulty, alter the voltage between the battery and the electric machine based on a substituted battery voltage signal such that the electric-machine remains operable for a drive cycle.

1. A vehicle comprising:

a fraction battery;

at least one electric-machine; and

a controller configured to;

alter a voltage between the battery and the electric-machine based on a measured voltage signal of the battery; and

in response to an indication that the measured voltage signal is faulty, alter the voltage between the battery and the electric machine based on a substituted battery voltage signal such that the electric-machine remains operable for a drive cycle.

2. The vehicle of claim 1 wherein the controller comprises a variable voltage converter.

3. The vehicle of claim 2 wherein the measured voltage is faulty when the measured voltage exceeds a threshold range.

4. The vehicle of claim 1 further comprising at least one sensor for providing the measured voltage signal of the battery voltage.

5. The vehicle of claim 1 wherein in response to the faulty measured voltage signal of the battery, the substitute battery voltage signal is provided by a battery control unit.

6. The vehicle of claim 5 wherein the substitute battery voltage signal is provided from the battery control unit through a vehicle control area network (CAN).

8. The vehicle of claim 7 wherein the controller comprises a variable voltage converter.

9. The vehicle of claim 8 wherein in response to the faulty measured voltage signal of the high voltage bus, the variable voltage converter is set to a mode that prevents providing a boost voltage to the at least one electric machine.

10. The vehicle of claim 7 wherein the measured voltage is faulty when the measured voltage exceeds a threshold range.

11. The vehicle of claim 7 further comprising at least one sensor for providing the measured voltage signal of the high voltage bus.

9-1. The vehicle of claim 7 wherein the substituted battery voltage signal is equal to a measured battery voltage signal.

12. A method of controlling comprising:

varying a voltage between a traction battery and an electric-machine based on a measured voltage signal;

in response to an indication that the measured voltage signal is faulty during a drive cycle, substituting an alternate voltage signal; and

varying the voltage between the battery and the electric machine based on the alternate voltage signal such that the electric-machine remains operable for the drive cycle.

13. The method of claim 12 wherein if the measured voltage signal is based on a battery voltage, substituting an alternate battery voltage signal provided by a battery control unit.

14. The method of claim 13 wherein the alternate battery voltage signal is provided from the battery control unit through a vehicle control area network (CAN).

15. The method of claim 12, wherein if the measured voltage signal is based on a high voltage bus voltage, substituting an alternate high voltage signal set equal to a battery voltage signal;

and

setting a variable voltage controller to a mode that prevents providing a boost voltage to at least one of the electric machines.