Temperature based electric machine control

• US 9,352,656 B2
• Filed: 08/31/2012
• Issued: 05/31/2016
• 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: Rao, Balakrishna, Isayeva, Rimma, Luedtke, Daniel
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US13/600,964
• Publication Number:
  US 20140062184A1
• Time in Patent Office: 1,369 Days
• Field of Search: 307/9.1
• US Class Current: 1/1
• CPC Class Codes: B60K 2001/006 the electric motors
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/425 Temperature
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 3/0038 relating to sensors
• CPC Class Codes: B60L 3/06 Limiting the traction current under mechanical overload conditions
• CPC Class Codes: H02K 1/2766 having a flux concentration effect
• CPC Class Codes: H02K 11/25 Devices for sensing temperature, or actuated thereby
• CPC Class Codes: H02K 15/00 Methods or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines
• CPC Class Codes: H02P 29/68 based on the temperature of a drive component or a semiconductor component
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A vehicle having at least one electric machine capable of propelling the vehicle is provided. An oil circulation path is provided that circulates oil through the electric machines. A controller commands the electric machines to fulfill torque demands. The controller utilizes the oil temperature in the oil circulation path in order to control the commanded torque output by the electric machines. In the event of a failure or fault in the oil temperature sensors, the controller estimates the oil temperature from the temperature of coils within the electric machine. The estimated oil temperature is utilized instead of the sensed oil temperature to control the torque outputs to maintain torque demands.

Claims

1. A vehicle comprising:

a first electric machine (EM) including windings;

a windings temperature sensor;

a second electric machine (EM) including coils;

an oil line for providing oil to the first EM;

an oil-temperature sensor; and

a controller configured to

alter a current provided to the first EM based on oil temperature such that torque output by the first EM is maintained in accordance with a requested torque as the oil temperature changes, and

in response to a fault in the oil-temperature sensor, alter the current based on windings temperature of the first EM and coil temperature of the second EM such that torque output by the first EM is maintained in accordance with the requested torque.

2. The vehicle of claim 1, wherein altering a current provided to the first electric machine includes increasing the current as the windings temperature increases.

3. The vehicle of claim 1, wherein altering a current provided to the first electric machine includes decreasing the current as the windings temperature decreases.

4. The vehicle of claim 1, wherein altering a current provided to the first electric machine includes altering a phase of the current.