IP Library › Granted Patent US 10,333,448
Granted Patent B2
US 10,333,448 · App. 15/482,935 · Granted Jun 25, 2019

Method for torque control systems and methods based on rotor temperature

Inventors: Anno Yoo (Rochester Hills, MI); Yo Chan Son (Rochester Hills, MI); Sangyeop Kwak (Orion Charter Township, MI)
Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
H02P21/24B60L11/1803H02P21/14H02P21/22H02P21/26H02P27/08H02P29/66B60L2240/423B60L2260/56Y02T10/642Y02T10/7005Y02T10/7241Y02T10/7275
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Quick Facts
Patent No.
US 10,333,448
App. No.
15/482,935
Granted
Jun 25, 2019
Kind
B2
Abstract

An electric motor control system of a vehicle includes a current command module configured to, based on a motor torque request for an electric motor of the vehicle, generate a first d-axis current command for the electric motor and a first q-axis current command for the electric motor. An adjustment module is configured to, based on a speed of a rotor of the electric motor and the motor torque request, selectively determine at least one of a d-axis current adjustment and a q-axis current adjustment based on a temperature of the rotor of the electric motor. An adjusting module is configured to produce a second d-axis current command for the electric motor by adjusting the first d-axis current command based on the d-axis current adjustment and to produce a second q-axis current command for the electric motor by adjusting the first q-axis current command based on the q-axis current adjustment.

Claims (88)

1. An electric motor control system of a vehicle, comprising:

a current command module configured to, based on a motor torque request for an electric motor of the vehicle, generate a first d-axis current command for the electric motor and a first q-axis current command for the electric motor;

an adjustment module configured to, based on a speed of a rotor of the electric motor and the motor torque request, selectively determine at least one of a d-axis current adjustment and a q-axis current adjustment based on a temperature of the rotor of the electric motor;

an adjusting module configured to produce a second d-axis current command for the electric motor by adjusting the first d-axis current command based on the d-axis current adjustment and to produce a second q-axis current command for the electric motor by adjusting the first q-axis current command based on the q-axis current adjustment; and

a switching control module configured to, based on the second d-axis current command and the second q-axis current command, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device,

wherein:

the adjustment module is configured to:

when the speed is greater than a predetermined speed, set both the d-axis current adjustment and the q-axis current adjustment to a predetermined value; and

when the speed is less than the predetermined speed, based on whether the motor torque request is greater than a predetermined torque, selectively determine one of the d-axis current adjustment and the q-axis current adjustment based on the temperature of the rotor of the electric motor; and

the adjusting module is configured to:

based on the d-axis current adjustment being equal to the predetermined value, set the second d-axis current command equal to the first d-axis current command; and

based on the q-axis current adjustment being equal to the predetermined value, set the second q-axis current command equal to the first q-axis current command,

wherein the adjusting module is configured to:

one of:

set the second d-axis current command equal to the first d-axis current command plus the d-axis current adjustment; and

set the second d-axis current command equal to the first d-axis current command multiplied by the d-axis current adjustment; and

one of:

set the second q-axis current command equal to the first q-axis current command plus the q-axis current adjustment; and

set the second d-axis current command equal to the first q-axis current command multiplied by the q-axis current adjustment.

2. The electric motor control system of claim 1 wherein the adjustment module is configured to:

when the speed is less than the predetermined speed and the motor torque request is greater than the predetermined torque, determine the d-axis current adjustment based on the temperature of the rotor of the electric motor; and

when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque, determine the q-axis current adjustment based on the temperature of the rotor of the electric motor.

3. The electric motor control system of claim 2 wherein the adjustment module is further configured to, when the speed is less than the predetermined speed and the motor torque request is greater than the predetermined torque, set the q-axis current adjustment to the predetermined value.

4. The electric motor control system of claim 2 wherein the adjustment module is further configured to, when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque, set the d-axis current adjustment to the predetermined value.

5. The electric motor control system of claim 2 wherein the adjustment module is further configured to, when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque, determine the d-axis current adjustment based on the first d-axis current command, a d-axis inductance of the electric motor, a q-axis inductance of the electric motor, and a predetermined gain.

6. The electric motor control system of claim 2 wherein the adjustment module is configured to, when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque:

determine a magnetic flux linkage of the electric motor based on the temperature of the rotor;

determine a variation in the magnetic flux linkage based on the temperature of the rotor; and

determine the q-axis current adjustment based on the magnetic flux linkage and the variation in the magnetic flux linkage.

7. The electric motor control system of claim 2 wherein the adjustment module is configured to, when the speed is less than the predetermined speed and the motor torque request is greater than the predetermined torque:

determine a variation in magnetic flux linkage of the electric motor based on the temperature of the rotor; and

determine the d-axis current adjustment based on the variation in the magnetic flux linkage, a d-axis inductance of the electric motor, and a q-axis inductance of the electric motor.

8. An electric motor control method for a vehicle, comprising:

based on a motor torque request for an electric motor of the vehicle, generating a first d-axis current command for an electric motor of the vehicle and a first q-axis current command for the electric motor;

based on a speed of a rotor of the electric motor and the motor torque request, selectively determining at least one of a d-axis current adjustment and a q-axis current adjustment based on a temperature of the rotor of the electric motor;

producing a second d-axis current command for the electric motor by adjusting the first d-axis current command based on the d-axis current adjustment;

producing a second q-axis current command for the electric motor by adjusting the first q-axis current command based on the q-axis current adjustment; and

based on the second d-axis current command and the second q-axis current command, controlling switching of an inverter module and applying power to stator windings of the electric motor from an energy storage device,

wherein:

selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes:

when the speed is greater than a predetermined speed, setting both the d-axis current adjustment and the q-axis current adjustment to a predetermined value; and

when the speed is less than the predetermined speed, based on whether the motor torque request is greater than a predetermined torque, selectively determining one of the d-axis current adjustment and the q-axis current adjustment based on the temperature of the rotor of the electric motor; and

producing the second d-axis current command includes, based on the d-axis current adjustment being equal to the predetermined value, setting the second d-axis current command equal to the first d-axis current command; and

producing the second q-axis current command includes, based on the q-axis current adjustment being equal to the predetermined value, setting the second q-axis current command equal to the first q-axis current command, and

wherein:

one of:

producing the second d-axis current command includes setting the second d-axis current command equal to the first d-axis current command plus the d-axis current adjustment; and

producing the second d-axis current command includes setting the second d-axis current command equal to the first d-axis current command multiplied by the d-axis current adjustment; and

one of:

producing the second q-axis current command includes setting the second q-axis current command equal to the first q-axis current command plus the q-axis current adjustment; and

producing the second q-axis current command includes setting the second d-axis current command equal to the first q-axis current command multiplied by the q-axis current adjustment.

9. The electric motor control method of claim 8 wherein selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes:

when the speed is less than the predetermined speed and the motor torque request is greater than the predetermined torque, determining the d-axis current adjustment based on the temperature of the rotor of the electric motor; and

when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque, determining the q-axis current adjustment based on the temperature of the rotor of the electric motor.

10. The electric motor control method of claim 9 selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes, when the speed is less than the predetermined speed and the motor torque request is greater than the predetermined torque, setting the q-axis current adjustment to the predetermined value.

11. The electric motor control method of claim 9 wherein selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes, when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque, setting the d-axis current adjustment to the predetermined value.

12. The electric motor control method of claim 9 wherein selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes, when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque, determining the d-axis current adjustment based on the first d-axis current command, a d-axis inductance of the electric motor, a q-axis inductance of the electric motor, and a predetermined gain.

13. The electric motor control method of claim 9 wherein selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes, when the speed is less than the predetermined speed and the motor torque request is less than the predetermined torque:

determining a magnetic flux linkage of the electric motor based on the temperature of the rotor;

determining a variation in the magnetic flux linkage based on the temperature of the rotor; and

determining the q-axis current adjustment based on the magnetic flux linkage and the variation in the magnetic flux linkage.

14. The electric motor control method of claim 9 wherein selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes, when the speed is less than the predetermined speed and the motor torque request is greater than the predetermined torque:

determining a variation in magnetic flux linkage of the electric motor based on the temperature of the rotor; and

determining the d-axis current adjustment based on the variation in the magnetic flux linkage, a d-axis inductance of the electric motor, and a q-axis inductance of the electric motor.

15. An electric motor control system of a vehicle, comprising:

a current command module configured to, based on a motor torque request for an electric motor of the vehicle, generate a first d-axis current command for the electric motor and a first q-axis current command for the electric motor;

an adjustment module configured to, based on a speed of a rotor of the electric motor and the motor torque request, selectively determine at least one of a d-axis current adjustment and a q-axis current adjustment based on a temperature of the rotor of the electric motor;

an adjusting module configured to produce a second d-axis current command for the electric motor by adjusting the first d-axis current command based on the d-axis current adjustment and to produce a second q-axis current command for the electric motor by adjusting the first q-axis current command based on the q-axis current adjustment; and

a switching control module configured to, based on the second d-axis current command and the second q-axis current command, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device,

wherein:

the adjustment module is configured to:

when the speed is greater than a predetermined speed, set both the d-axis current adjustment and the q-axis current adjustment to a predetermined value; and

when the speed is less than the predetermined speed, based on whether the motor torque request is greater than a predetermined torque, selectively determine one of the d-axis current adjustment and the q-axis current adjustment based on the temperature of the rotor of the electric motor; and

the adjusting module is configured to:

based on the d-axis current adjustment being equal to the predetermined value, set the second d-axis current command equal to the first d-axis current command; and

based on the q-axis current adjustment being equal to the predetermined value, set the second q-axis current command equal to the first q-axis current command.

16. An electric motor control method for a vehicle, comprising:

based on a motor torque request for an electric motor of the vehicle, generating a first d-axis current command for an electric motor of the vehicle and a first q-axis current command for the electric motor;

based on a speed of a rotor of the electric motor and the motor torque request, selectively determining at least one of a d-axis current adjustment and a q-axis current adjustment based on a temperature of the rotor of the electric motor;

producing a second d-axis current command for the electric motor by adjusting the first d-axis current command based on the d-axis current adjustment;

producing a second q-axis current command for the electric motor by adjusting the first q-axis current command based on the q-axis current adjustment; and

based on the second d-axis current command and the second q-axis current command, controlling switching of an inverter module and applying power to stator windings of the electric motor from an energy storage device,

wherein:

selectively determining at least one of the d-axis current adjustment and the q-axis current adjustment includes:

when the speed is greater than a predetermined speed, setting both the d-axis current adjustment and the q-axis current adjustment to a predetermined value; and

when the speed is less than the predetermined speed, based on whether the motor torque request is greater than a predetermined torque, selectively determining one of the d-axis current adjustment and the q-axis current adjustment based on the temperature of the rotor of the electric motor; and

producing the second d-axis current command includes, based on the d-axis current adjustment being equal to the predetermined value, setting the second d-axis current command equal to the first d-axis current command; and

producing the second q-axis current command includes, based on the q-axis current adjustment being equal to the predetermined value, setting the second q-axis current command equal to the first q-axis current command.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 10, 2017
From: YOO, ANNO; SON, YO CHAN; KWAK, SANGYEOP
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 041937/0294 →
Continuity (1)
Related Publication 20180294756A1 · Oct 11, 2018
Cited By (1)
US 12,345,269