Motor driving appartus and home appliance including the same

Patent metadata

Field	Value
Publication number	US-10050571-B2
Application number	US-201615160313-A
Country	US
Kind code	B2
Filing date	May 20, 2016
Priority date	May 21, 2015
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

A motor driving apparatus includes an inverter to convert a direct current (DC) voltage into an alternating current (AC) voltage through a switching operation and to output the AC voltage to a motor, an output current detector to detect an output current flowing in the motor, and a controller to control the inverter, wherein, at the time of starting the motor, the controller controls a first current, including a DC component and a high-frequency component, to be supplied to the motor during a first period for alignment of the motor, and controls a second current, including a DC component and a high-frequency component, to be supplied to the motor during a second period for alignment of the motor, and the controller calculates the stator resistance and inductance of the motor based on the first current and the second current. Consequently, it is possible to easily calculate the stator resistance and inductance of the motor during the alignment of the motor.

First claim

What is claimed is:

1. A motor driving apparatus comprising:
an inverter to convert a direct current (DC) voltage into an alternating current (AC) voltage through a switching operation and to output the AC voltage to a motor;
an output current detector to detect an output current flowing in the motor; and
a controller to control the inverter, wherein a first current having a first DC component and a high-frequency component current is supplied to the motor during a first period for alignment of the motor, and a second current having a second DC component and a second high-frequency component is supplied to the motor during a second period after the first period for alignment of the motor, and wherein a stator resistance and inductance of the motor based on the first current and the second current is determined,
wherein the stator resistance of the motor is calculated based on values obtained by removing the first and second high-frequency components from the first current and the second current, and the inductance of the motor is calculated based on values obtained by removing the first and second DC components from the first current and the second current.

2. The motor driving apparatus according to claim 1 , wherein the stator resistance and the inductance are determined during an initial start of the motor.

3. The motor driving apparatus according to claim 1 , wherein the first current, including a first flux current having the first DC component and a third high-frequency component based on a stationary coordinate system, and a first torque current, having a forth high-frequency component based on the stationary coordinate system is supplied to the motor during the first period, and the second current, including a second flux current having the second DC component and a fifth high-frequency component based on the stationary coordinate system, and a second torque current having a sixth high-frequency component based on the stationary coordinate system is supplied to the motor during the second period,
wherein the first high-frequency component includes the third high-frequency component and the fourth high-frequency component,
wherein the second high-frequency component includes the fifth high-frequency component and the sixth high-frequency component.

4. The motor driving apparatus according to claim 3 , wherein a magnitude of the second flux current is higher than a magnitude of the first flux current by an integer ratio, and a magnitude of the second torque current is higher than a magnitude of the first torque current by an integer ratio.

5. The motor driving apparatus according to claim 1 , wherein the stator resistance of the motor is calculated based on a current reference value and a voltage reference value of the first current and a current reference value and a voltage reference value of the second current based on a stationary coordinate system, and the inductance of the motor is calculated based on a current reference value and a voltage reference value of the first current and a current reference value and a voltage reference value of the second current based on a rotating coordinate system.

6. The motor driving apparatus according to claim 1 , further including:
a converter to convert the AC voltage into the DC voltage;
a capacitor to store a DC terminal voltage applied between output terminals of the converter; and
a DC terminal voltage detector to detect the DC terminal voltage.

7. The motor driving apparatus according to claim 1 , wherein the controller accelerates the motor after alignment of the motor, and varies the speed of the motor after acceleration of the motor.

8. The motor driving apparatus according to claim 1 , wherein a magnitude of a load is calculated based on the stator resistance of the motor during a normal operation of the motor after starting of the motor, and a speed reference value is generated based on the calculated magnitude of the load.

9. The motor driving apparatus according to claim 8 , wherein the controller includes:
a speed calculator to calculate a rotor speed of the motor based on the detected output current;
a current reference generator to generate a current reference value based on the calculated rotor speed of the motor and the speed reference value;
a voltage reference generator to generate a voltage reference value based on the current reference value and the detected output current; and
a switching control signal output device to output a switching control signal for driving the inverter based on the voltage reference value.

10. A home appliance comprising:
a motor;
an inverter to convert a DC voltage into an AC voltage through a switching operation and to output the AC voltage to the motor;
an output current detector to detect an output current flowing in the motor; and
a controller to control the inverter, wherein during a time of starting the motor, a first current including a first DC component and a first high-frequency component is supplied to the motor during a first period for alignment of the motor, and a second current including a second DC component and a second high-frequency component is supplied to the motor during a second period after the first period for alignment of the motor, and wherein a stator resistance and inductance of the motor based on the first current and the second current is determined,
wherein the stator resistance of the motor is calculated based on values obtained by removing the first and second high-frequency components from the first current and the second current, and the inductance of the motor is calculated based on values obtained by removing the first and second DC component from the first current and the second current.

11. The home appliance according to claim 10 , wherein the first current, including a first flux current having the first DC component and a third high-frequency component based on a stationary coordinate system, and a first torque current having a fourth high-frequency component based on the stationary coordinate system is supplied to the motor during the first period, and the second current, including a second flux current having the second DC component and a fifth high-frequency component based on the stationary coordinate system, and a second torque current having a sixth high-frequency component based on the stationary coordinate system is supplied to the motor during the second period,
wherein the first high-frequency component includes the third high-frequency component and the fourth high-frequency component,
wherein the second high-frequency component includes the fifth high-frequency component and the sixth high-frequency component.

12. The home appliance according to claim 11 , wherein a magnitude of the second flux current is higher than a magnitude of the first flux current by an integer ratio, and a magnitude of the second torque current is higher than a magnitude of the first torque current by an integer ratio.

13. The home appliance according to claim 10 , wherein the stator resistance of the motor is calculated based on a current reference value and a voltage reference value of the first current and a current reference value and a voltage reference value of the second current based on a stationary coordinate system, and the inductance of the motor is calculated based on a current reference value and a voltage reference value of the first current and a current reference value and a voltage reference value of the second current based on a rotating coordinate system.

14. The home appliance according to claim 10 , further including:
a converter to convert the AC voltage into the DC voltage;

Assignees

• Lg Electronics Inc

Inventors

• Jang Minho

Classifications

• H02P6/18

  without separate position detecting elements · CPC title

• H02P21/14

  Estimation or adaptation of machine parameters, e.g. flux, current or voltage · CPC title

• D06F37/304 Primary

  Arrangements or adaptations of electric motors · CPC title

• H02P6/20 Primary

  Arrangements for starting (H02P6/08 takes precedence) · CPC title

• D06F34/10

  Power supply arrangements, e.g. stand-by circuits · CPC title