Motor driving apparatus and laundry treatment machine including the same

Patent metadata

Field	Value
Publication number	US-9708744-B2
Application number	US-201414535595-A
Country	US
Kind code	B2
Filing date	Nov 7, 2014
Priority date	Nov 8, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

The laundry treatment machine includes an inverter to convert direct current (DC) voltage into alternating current (AC) voltage and to output the AC voltage to a motor. The laundry treatment machine includes an inverter controller to control the inverter to supply current corresponding to a direction opposite to back electromotive force generated from the motor to the motor so as to align the motor during a starting operation of the motor. It is feasible to rapidly align a rotor of the motor during the starting operation of the motor.

First claim

What is claimed is:

1. A laundry treatment machine comprising:
a washing tub;
a motor to rotate the washing tub; and
a driving circuitry to control at least one of voltage and current provided to the motor, wherein the driving circuitry includes:
an inverter to convert direct current (DC) voltage into alternating current (AC) voltage and to output the AC voltage to the motor; and
an inverter controller to continuously output a pulse width modulation (PWM) switching control signal to the inverter, and to control the inverter to supply current corresponding to a direction opposite to back electromotive force generated from the motor to the motor so as to align the motor during a starting operation of the motor,
wherein the inverter controller controls the inverter to supply only flux voltage to the motor so as to align the motor during the starting operation of the motor, and
wherein the inverter controller controls the inverter to supply the flux voltage and torque voltage to the motor so as to drive the motor during a normal operation after the starting operation.

2. The laundry treatment machine according to claim 1 , wherein the inverter controller generates a voltage command value to rotate the motor during the normal operation of the motor and controls the inverter in response to the generated voltage command value.

3. The laundry treatment machine according to claim 1 , further comprising:
an output voltage detector to detect output voltage applied to the motor; and
an output current detector to detect output current flowing in the motor,
wherein the inverter controller estimates a rotor position of the motor based on the detected output current and a PWM-based output voltage detected by the output voltage detector and outputs an inverter switching control signal for controlling the inverter based on the estimated rotor position of the motor.

4. The laundry treatment machine according to claim 1 , further comprising:
an output voltage detector to detect output voltage applied to the motor; and
an output current detector to detect output current flowing in the motor, wherein the inverter controller includes:
an estimation circuitry to estimate a rotor position and speed of the motor based on the detected output current and PWM-based output voltage detected by the output voltage detector;
a current command generation circuitry to generate a current command value based on the estimated speed of the motor and a speed command value;
a voltage command generation circuitry to generate a voltage command value based on the current command value and the detected output current; and
a switching control signal output circuitry to output a switching control signal for driving the inverter based on the voltage command value.

5. The laundry treatment machine according to claim 4 , wherein the voltage command generation circuitry comprises:
a d-axis voltage command generation circuitry to generate the flux voltage command value; and
a q-axis voltage command generation circuitry to generate the torque voltage command value, and
wherein the q-axis voltage command generation circuitry sets a q-axis voltage command to 0 so as to align the motor during the starting operation of the motor.

6. The laundry treatment machine according to claim 4 , wherein the estimation circuitry comprises:
a back electromotive force estimation circuitry to estimate back electromotive force generated from the motor based on the detected output current and the detected PWM-based output voltage; and
a speed estimation circuitry to estimate the rotor position and speed of the motor based on the estimated back electromotive force.

7. The laundry treatment machine according to claim 1 , wherein
the inverter controller comprises a limiter to limit a level of the flux voltage and supplied to the motor so as to align the motor during the starting operation of the motor.

8. The laundry treatment machine according to claim 7 , wherein in a case in which the switching control signal is generated using a space vector method, the limiter limits a level of the flux voltage supplied to the motor such that a voltage vector during the starting operation of the motor is located at the same sector selected from among a plurality of space vector sectors so as to align the motor during the starting operation of the motor.

9. A motor driving apparatus comprising:
an inverter to convert DC voltage into AC voltage and to output the AC voltage to a motor; and
an inverter controller to continuously output a pulse width modulation (PWM) switching control signal to the inverter, and to control the inverter to supply current corresponding to a direction opposite to back electromotive force generated from the motor to the motor so as to align the motor during a starting operation of the motor,
wherein the inverter controller controls the inverter to supply only flux voltage to the motor so as to align the motor during the starting operation of the motor, and
wherein the inverter controller controls the inverter to supply flux voltage and torque voltage to the motor so as to drive the motor during a normal operation after the starting operation.

10. The motor driving apparatus according to claim 9 , wherein the inverter controller generates a voltage command value to rotate the motor during the normal operation of the motor and controls the inverter in response to the generated voltage command value.

11. The motor driving apparatus according to claim 9 , further comprising:
an output voltage detector to detect output voltage applied to the motor; and
an output current detector to detect output current flowing in the motor, wherein
the inverter controller estimates a rotor position of the motor based on the detected output current and a PWM-based output voltage detected by the output voltage detector and outputs an inverter switching control signal for controlling the inverter based on the estimated rotor position of the motor.

12. The motor driving apparatus according to claim 9 , further comprising:
an output voltage detector to detect output voltage applied to the motor; and
an output current detector to detect output current flowing in the motor, wherein
the inverter controller includes: an estimation circuitry to estimate a rotor position and speed of the motor based on the detected output current and PWM-based output voltage detected by the output voltage detector;
a current command generation circuitry to generate a current command value based on the estimated speed of the motor and a speed command value;
a voltage command generation circuitry to generate a voltage command value based on the current command value and the detected output current; and
a switching control signal output module to output a switching control signal for driving the inverter based on the voltage command value.

13. The motor driving apparatus according to claim 12 , wherein the voltage command generation circuitry comprises:
a d-axis voltage command generator to generate the flux voltage command value; and
a q-axis voltage command generator to generate the torque voltage command value, and wherein
the q-axis voltage command generator sets a q-axis voltage command to 0 so as to align the motor during the starting operation of the motor.

14. The motor driving apparatus according to claim 12 , wherein the estimation circuitry comprises:
a back electromotive force estimation circuitry to estimate back electromotive force generated from the motor based on the detected output current and the detected PWM-based output voltage; and
a speed estimation circuitry to estimate

Assignees

• Lg Electronics Inc

Inventors

• Jung Hansu
• Koo Jain
• Lee Soongkeun

Classifications

• H02P6/182 Primary

  using back-emf in windings · CPC title

• H02P6/21

  Open loop start · CPC title

• H02P21/34

  Arrangements for starting · CPC title

• D06F33/02

  Textiles & Paper · mapped topic

• D06F37/304 Primary

  Arrangements or adaptations of electric motors · CPC title