GENERATING MOTOR CONTROL REFERENCE SIGNAL WITH CONTROL VOLTAGE BUDGET

• US 20150222210A1
• Filed: 02/04/2015
• Published: 08/06/2015
• Est. Priority Date: 02/06/2014
• Status: Active Grant

• Current Assignee: Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Original Assignee: Steering Solutions IP Holding Corporation (Nexteer Automotive Group Ltd.)
• Inventors: Kleinau, Julie A., Ballal, Siddharth
• Granted Patent: US 10,389,289 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02P 21/22 Current control, e.g. using a current control loop
• CPC Class Codes: H02P 6/00 Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor vector control H02P21/00
• CPC Class Codes: H02P 7/00 Arrangements for regulating or controlling the speed or torque of electric DC motors

Abstract

A method of controlling a motor in a motor control system is provided. The method determines a control voltage budget value based on an operating region of the motor. The method adjusts a supply voltage signal based on the control voltage budget value. The method determines a motor voltage command based on the adjusted supply voltage signal. The method applies a voltage corresponding to the motor voltage command to the motor in order to generate a desired motor torque.

Claims

1. A method of controlling a motor in a motor control system, the method comprising:

determining a control voltage budget value based on an operating region of the motor;

adjusting a supply voltage signal based on the control voltage budget value;

determining a motor voltage command based on the adjusted supply voltage signal; and

applying a voltage corresponding to the motor voltage command to the motor in order to generate a desired motor torque.

2. The method of claim 1, wherein the adjusting the supply voltage signal comprises subtracting the control voltage budget value from the supply voltage signal.

3. The method of claim 1, wherein the operating region of the motor comprises at least one of a motor quadrant, a motor velocity, and a motor load.

4. The method of claim 3, wherein determining the control voltage budget value comprises using a lookup table in which different control voltage budget values are indexed by different motor quadrant values and different motor velocity values.

5. The method of claim 4, wherein the control voltage budget values in the lookup table are predetermined through analysis as a function of at least one of a control loop bandwidth and dynamic response characteristics.

6. The method of claim 4, wherein the control voltage budget values in the lookup table are predetermined to be zeros for motor velocity values that are within a threshold difference from a zero motor velocity and to be gradually larger values as the motor velocity increases and control loop voltage requirements approach a supply voltage limit.

7. The method of claim 3, wherein determining the control voltage budget value comprises calculating the control voltage budget value as a function of the motor quadrant and the motor velocity.

8. The method of claim 3, further comprising determining the motor quadrant based on signs of the motor torque command and the motor velocity.

9. The method of claim 1, wherein the control voltage budget value for a particular motor torque command value and a particular motor velocity value is larger when the motor torque command and the motor velocity are in a same rotational direction of the motor than the control voltage budget value is when the motor torque command and the motor velocity are in different rotational directions of the motor.

10. The method of claim 1, wherein the motor is a DC (direct current) brush motor, wherein the determining the control voltage budget value comprises setting the control voltage budget value to a constant regardless of the operating region of the motor.

11. A motor control system, comprising:

a motor;

a control module configured to;

determine a control voltage budget value based on an operating region of the motor;

adjust a supply voltage signal based on the control voltage budget value;

determine a motor voltage command based on the adjusted supply voltage signal; and

apply a voltage corresponding to the motor voltage command to the motor in order to generate a desired motor torque.

12. The system of claim 11, wherein the control module is configured to adjust the supply voltage signal by subtracting the control voltage budget value from the supply voltage signal.

13. The system of claim 11, wherein the operating region of the motor comprises at least one of a motor quadrant, a motor velocity, and a motor load.

14. The system of claim 13, wherein the control module is configured to determine the control voltage budget value by using a lookup table in which different control voltage budget values are indexed by different motor quadrant values and different motor velocity values.

15. The system of claim 14, wherein the control voltage budget values in the lookup table are predetermined through analysis as a function of at least one of a control loop bandwidth and dynamic response characteristics.

16. The system of claim 14, wherein the control voltage budget values in the lookup table are predetermined to be zeros for motor velocity values that are within a threshold difference from a zero motor velocity and to be gradually larger values as the motor velocity increases and control loop voltage requirements approach a supply voltage limit.

17. The system of claim 13, wherein the control module is further configured to determine the motor quadrant based on signs of the motor torque command and the motor velocity.

18. The system of claim 11, wherein the control voltage budget value for a particular motor torque command value and a particular motor velocity value is larger when the motor torque command and the motor velocity are in a same rotational direction of the motor than the control voltage budget value is when the motor torque command and the motor velocity are in different rotational directions of the motor.

19. The system of claim 11, wherein the motor is a DC (direct current) brush motor, wherein the determining the control voltage budget value comprises setting the control voltage budget value to a constant regardless of the operating region of the motor.

20. The system of claim 11, wherein the control module is further configured to scale the supply voltage signal with a scale factor prior to adjusting the supply voltage signal in order to account for inverter switching dead time.