MOTOR CONTROL MECHANISM FOR ELECTRIC VEHICLES

• US 20100181949A1
• Filed: 01/16/2009
• Published: 07/22/2010
• Est. Priority Date: 01/16/2009
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: BATES, Allen Keith, BUI, Nhan Xuan, WINARSKI, Daniel James, HANCOCK, Reed Alan, IMAINO, Wayne Isami
• Granted Patent: US 8,288,979 B2
• Time in Patent Office: Days
• US Class Current: 318/400.90
• CPC Class Codes: H02P 1/04 Means for controlling progress of starting sequence in dependence upon time or upon current, speed, or other motor parameter
• CPC Class Codes: H02P 3/12 by short-circuit or resistive braking

Abstract

An apparatus for controlling a wheel motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the wheel motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the wheel motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

Claims

1. An apparatus for controlling a wheel motor of a vehicle, comprising:

a plurality of switches for controlling a direction of current through motor coils of the wheel motor; and

a brushless motor control circuit connected to each of the plurality of switches, wherein responsive to a request to adjust one of an angular velocity and an angular acceleration of the wheel motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

2. The apparatus of claim 1, wherein the request to adjust one of an angular velocity and an angular acceleration of the wheel motor is a request to increase the angular velocity, and the predetermined configuration connects the motor coils in a parallel configuration to reduce the total back EMF from the motor coils and allow for greater angular velocity.

3. The apparatus of claim 1, wherein the request to adjust one of an angular velocity and an angular acceleration of the wheel motor is a request to increase the angular velocity, and the predetermined configuration bypasses an electrical connection to at least one of the motor coils to provide a minimum back EMF and maximize angular velocity.

4. The apparatus of claim 1, wherein the request to adjust one of an angular velocity and an angular acceleration of the wheel motor is a request to one of increase or decrease the angular acceleration, and the predetermined configuration is a serial configuration to maximize torque.

5. The apparatus of claim 1, wherein responsive to a request to stop the wheel motor, the plurality of switches are activated to short the motor coils, providing for dynamic braking.

6. The apparatus of claim 1, wherein the wheel motor is configured with at least two of the motor coils per electric phase.

7. A system for controlling a vehicle wheel motor, comprising:

one of a battery and a capacitor;

a controller connected to the one of the battery and the capacitor; and

a plurality of switches selectively activated by the controller for controlling a direction of current through motor coils of the wheel motor, wherein;

during a first mode of operation, the plurality of switches are activated by the controller to place the motor coils in a serial configuration to maximize wheel motor torque, and

during a second mode of operation, the plurality of switches are activated by the controller to place the motor coils in a parallel configuration to reduce a total back electromotive force (BEMF) from the motor coils and increase angular velocity.

8. The system of claim 7, wherein during a third mode of operation, the plurality of switches are activated by the controller to place the motor coils in a bypass configuration to reduce a total back electromotive force (BEMF) from the motor coils and maximize angular velocity.

9. The system of claim 7, wherein during a third mode of operation, the plurality of switches are activated by the controller to short the motor coils, providing dynamic braking and recharging the one of the battery and the capacitor.

10. The system of claim 7, further including a power inverter connected between the one of the battery and the capacitor and the controller.

11. A method for controlling a wheel motor of a vehicle, comprising:

receiving a request to adjust one of an angular velocity and an angular acceleration of the wheel motor; and

activating a plurality of switches for controlling a direction of current through motor coils of the wheel motor, the plurality of switches activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

12. The method of claim 11, wherein the request to adjust one of an angular velocity and an angular acceleration of the wheel motor is a request to increase the angular velocity, and the plurality of switches are activated to connect the motor coils in a parallel configuration to reduce the total back EMF from the motor coils and allow for greater angular velocity.

13. The method of claim 11, wherein the request to adjust one of an angular velocity and an angular acceleration of the wheel motor is a request to increase the angular velocity, and the plurality of switches are activated bypass an electrical connection to at least one of the motor coils to provide a minimum back EMF and allow for greater angular velocity.

14. The method of claim 11, wherein the request to adjust one of an angular velocity and an angular acceleration of the wheel motor is a request to one of increase or decrease the angular acceleration, and the plurality of switches are activated to connect the motor coils in a serial configuration to maximize torque.

15. The method of claim 11, wherein responsive to a request to stop the wheel motor, the plurality of switches are activated to short the motor coils, providing for dynamic braking.

16. The method of claim 11, further including selectively activating a plurality of motor coils for each electrical phase of the wheel motor to further increase angular velocity.

17. A method of manufacturing a system for controlling a vehicle wheel motor, comprising:

providing one of a battery and a capacitor;

providing a controller connected to the one of the battery and the capacitor; and

providing a plurality of switches adapted to be selectively activated by the controller for controlling a direction of current through motor coils of the wheel motor, wherein during a first mode of operation, the plurality of switches place the motor coils in a serial configuration to maximize wheel motor torque.

18. The method of manufacture of claim 17, wherein the plurality of switches are further adapted to be activated by the controller during a second mode of operation to place the motor coils in a parallel configuration to reduce a total back electromotive force (BEMF) from the motor coils and increase angular velocity.

19. The method of manufacture of claim 17, wherein the plurality of switches are further adapted to be activated by the controller during a second mode of operation to place the motor coils in a bypass configuration to reduce a total back electromotive force (BEMF) from the motor coils and maximize angular velocity.

20. The method of manufacture of claim 17, wherein the plurality of switches are further adapted to be activated by the controller during a second mode of operation to short the motor coils, providing dynamic braking and recharge the one of the battery and the capacitor.