Motor control device and method therefor

Patent metadata

Field	Value
Publication number	US-12244257-B2
Application number	US-202118266131-A
Country	US
Kind code	B2
Filing date	Dec 9, 2021
Priority date	Dec 17, 2020
Publication date	Mar 4, 2025
Grant date	Mar 4, 2025

Abstract

A motor control method according to an embodiment of a present invention comprises the steps of: performing three-phase commutation in a first range section of a motor rotational speed in a brake mode of a motor; performing two-phase commutation in a second range section of the motor rotational speed performing one-phase commutation in a first range section of the motor rotational speed; and turning off commutation when the motor rotational speed is less than or equal to the first range section.

First claim

The invention claimed is:

1. A motor control method comprising the steps of:
performing three-phase commutation in a first range section of a motor rotation speed in a brake mode of a motor;
performing two-phase commutation in a second range section of the motor rotation speed;
performing one-phase commutation in a third range section of the motor rotation speed; and
turning off commutation when the motor rotation speed is less than or equal to the first range section.

2. The motor control method according to claim 1 , wherein the first range section is set above three-phase commutation sustaining speed being calculated from the motor rotation speed at start of the brake mode and the three-phase commutation sustaining speed ratio,
wherein the second range section is set above two-phase commutation sustaining speed being calculated from the motor rotation speed at the start of the brake mode, the three-phase commutation sustaining speed ratio, and the two-phase commutation sustaining speed ratio, and
wherein the third range section can be set above one-phase commutation sustaining speed calculated from the motor rotation speed at the start of the brake mode, the three-phase commutation sustaining speed ratio, the two-phase commutation sustaining speed ratio, and the one-phase commutation sustaining speed ratio.

3. The motor control method according to claim 2 , wherein the three-phase commutation sustaining speed ratio is greater than the two-phase commutation sustaining speed ratio, and the two-phase commutation sustaining speed ratio is greater than the one-phase commutation sustaining speed ratio.

4. The motor control method according to claim 1 , wherein the brake mode comprises a normal brake mode and an emergency brake mode.

5. The motor control method according to claim 4 , wherein a first range section in the emergency break mode is larger than a first range section in the normal break mode.

6. The motor control method according to claim 4 , wherein the emergency brake mode is performed by detecting any one of DC current abnormality, motor current abnormality, PWM failure, function failure, motor rotation abnormality, and signal reception of a host control unit.

7. The motor control method according to claim 1 , wherein during the three-phase commutation, all three MOSFETs are commutated,
wherein during the two-phase commutation, two MOSFETs that generate a reverse torque opposite to a rotational direction of a motor are commutated, and
wherein during the one-phase commutation, one MOSFET generating reverse torque opposite to a rotation direction of a motor is commutated.

8. A motor control device comprising:
a three-phase bridge unit comprising three MOSFETs operating in different phases so that the motor operates in three-phase; and
a control unit for controlling the three MOSFETs,
wherein during a brake mode of a motor, the control unit performs three-phase commutation in a first range section of a motor rotation speed, performs two-phase commutation in a second range section of the motor rotation speed, performs one-phase commutation in a third range section of the motor rotation speed, and turns off commutation when the motor rotation speed is less than or equal to the third range section.

9. The motor control device according to claim 8 , wherein the control unit sets the first range section to be greater than or equal to a three-phase commutation sustaining speed calculated from a motor rotation speed at start of a brake mode and a three-phase commutation sustaining speed ratio,
wherein the control unit sets the second range section to be greater than or equal to the two-phase commutation sustaining speed calculated from the motor rotation speed at the start of the brake mode, the three-phase commutation sustaining speed ratio, and the two-phase commutation sustaining speed ratio, and
wherein the control unit sets the third range section to be greater than or equal to one-phase commutation sustaining speed calculated from the motor rotation speed at the start of the brake mode, the three-phase commutation sustaining speed ratio, the two-phase commutation sustaining speed ratio, and the one-phase commutation sustaining speed ratio.

10. The motor control device according to claim 8 , wherein the break mode comprises a normal break mode and an emergency break mode, and
wherein a first range section in the emergency break mode is larger than a first range section in the normal break mode.

11. The motor control device according to claim 8 , wherein the control unit performs an emergency brake mode by detecting any one of a DC current abnormality, a motor current abnormality, a PWM failure, a function failure, a motor rotation abnormality, and a signal reception of a host control unit.

12. The motor control device according to claim 8 , comprising:
a motor position measuring unit comprising a first sensor and a second sensor for measuring the motor position;
a motor driving unit configured to receive a control signal from the control unit and output a PWM signal to the three-phase bridge unit;
a power supply unit configured to supply power to the control unit, receive a first motor rotation position signal from the first sensor, and transmit the first motor rotation position signal to the control unit; and
an input terminal protection unit configured to block voltage supplied to the motor or detect overcurrent.

13. The motor control device according to claim 12 , wherein the control unit receives a second motor rotation position signal from the second sensor and determines a functional failure by comparing it with the first motor rotation position signal received from the power supply unit.

14. The motor control device according to claim 12 , wherein the control unit perform an emergency brake mode when detecting an abnormal DC current from the input terminal protection unit.

15. The motor control device according to claim 12 , wherein the control unit perform an emergency brake mode when detecting motor current abnormality from the three MOSFETs.

16. The motor control device according to claim 12 , wherein the control unit perform an emergency brake mode when detecting a PWM failure from the motor driving unit.

17. The motor control device according to claim 12 , wherein the control unit perform an emergency brake mode when detecting a motor rotation abnormality from the power supply unit.

18. The motor control device according to claim 8 , wherein during the three-phase commutation, all three MOSFETs are commutated.

19. The motor control device according to claim 8 , wherein during the two-phase commutation, two MOSFETs that generate a reverse torque opposite to a rotational direction of a motor are commutated.

20. The motor control device according to claim 8 , wherein during the one-phase commutation, one MOSFET generating reverse torque opposite to a rotation direction of a motor is commutated.

Assignees

• Lg Innotek Co Ltd

Inventors

• Kim Jang Hoon
• Kim Won Kyu

Classifications

• H02P29/024

  Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load · CPC title

• H02P25/086

  Commutation · CPC title

• H02P23/14

  Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage · CPC title

• H02P23/24

  Controlling the direction, e.g. clockwise or counterclockwise · CPC title

• H02H7/09

  against over-voltage; against reduction of voltage; against phase interruption · CPC title