Motor driving apparatus and refrigerator including same

Patent metadata

Field	Value
Publication number	US-9657980-B2
Application number	US-201314783272-A
Country	US
Kind code	B2
Filing date	Apr 11, 2013
Priority date	Apr 11, 2013
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

The present invention relates to a motor driving apparatus and a refrigerator including the same. A motor driving apparatus according to an embodiment of the present invention comprises: a signal delay unit for delaying an input speed order signal; an inverter control unit for outputting an inverter switching control signal, on the basis of the speed order signal delayed by the signal delay unit; and an inverter for converting an input operation direct current power into a predetermined alternating current power, on the basis of a switching operation according to the inverter switching control signal, and driving a motor using the converted alternating current power. Therefore, it is possible to prevent starting failure and reduce noise.

First claim

The invention claimed is:

1. A motor driving apparatus comprising
a signal delay unit configured to delay an input speed command signal;
an inverter controller configured to output an inverter switching control signal based on the input speed command signal delayed by the signal delay unit; and
an inverter configured to convert an input operating direct current (DC) voltage into a predetermined alternating current (AC) voltage and driving a motor by the converted AC voltage, based on switching operation according to the inverter switching control signal,
wherein the signal delay unit includes a capacitor, and capacitance of the capacitor corresponds to a soft tart period upon initial start-up of the motor driving apparatus.

2. The motor driving apparatus according to claim 1 , wherein:
the signal delay unit delays the input speed command signal by a predetermined time in an initial start-up period of the motor driving apparatus, and
the delay time corresponds to a period until the operating DC voltage input to the inverter reaches a predetermined voltage.

3. The motor driving apparatus according to claim 1 , further comprising:
a converter controller configured to output a pulse width modulation (PWM)-based speed command signal; and
a converter configured to convert the PWM-based speed command signal into a pulse amplitude modulation (PAM)-based speed command signal and output the PAM-based speed command signal,
wherein the signal delay unit receives the PAM-based speed command signal.

4. The motor driving apparatus according to claim 3 , wherein the converter includes:
a buck switching element;
an inductor configured to store flowing current by turn-on operation of the buck switching element; and
a diode connected between the buck switching element and the inductor in parallel,
wherein the buck switching element is switched to output the PAM-based speed command signal, based on the PWM-based the speed command signal.

5. The motor driving apparatus according to claim 3 , further comprising:
a rectifier configured to rectify an input AC voltage; and
a voltage dropper configured to drop the rectified voltage and output a DC voltage, the level of which has changed,
wherein the DC voltage input to the converter and the inverter corresponds to the output voltage of the voltage dropper.

6. The method according to claim 1 , further comprising a counter electromotive force detector configured to detect counter electromotive force generated in any one of three phases of the motor,
wherein the inverter controller includes:
a speed calculator configured to calculate a rotation speed of the motor based on the detected counter electromotive force;
a current command generator configured to generate a current command based on the calculated speed and the delayed speed command signal;
a voltage command generator configured to generate a voltage command based on the generated current command; and
a switching control signal output unit configured to output the inverter switching control signal for driving the inverter based on the generated voltage command.

7. The motor driving apparatus according to claim 1 , further comprising an output current detector configured to detect output current flowing in the motor,
wherein the inverter controller includes:
a speed calculator configured to calculate rotator speed information of the motor based on the detected output current;
a current command generator configured to generate the current command based on the calculated speed information and the delayed speed command signal;
a voltage command generator configured to generate a voltage command based on the current command and the detected output current; and
a switching control signal output unit configured to output a switching control signal for driving the inverter based on the voltage command.

8. The motor driving apparatus according to claim 1 , further comprising:
a rectifier configured to rectify an input AC voltage; and
a voltage dropper configured to drop the rectified voltage and output a DC voltage, the level of which has changed,
wherein the operating DC voltage input to the inverter corresponds to the output voltage of the voltage dropper.

9. A refrigerator comprising:
a compressor;
an evaporator configured to perform heat exchange using a refrigerant compressed by the compressor;
a fan configured to deliver air subjected to heat exchange by the evaporator into the refrigerator; and
a fan drive unit configured to drive the fan,
wherein the fan drive unit includes:
a signal delay unit configured to delay an input speed command signal;
an inverter controller configured to output an inverter switching control signal based on the input speed command signal delayed by the signal delay unit; and
an inverter configured to convert an input operating direct current (DC) voltage into a predetermined alternating current (AC) voltage and driving a motor by the converted AC voltage, based on switching operation according to the inverter switching control signal,
wherein the signal delay unit includes a capacitor, and capacitance of the capacitor corresponds to a soft start period upon initial start-up of the motor driving apparatus.

10. The refrigerator according to claim 9 , wherein:
the signal delay unit delays the input speed command signal by a predetermined time in an initial start-up period of the motor driving apparatus, and
the delay time corresponds to a period until the operating DC voltage input to the inverter reaches a predetermined voltage.

11. The refrigerator driving apparatus according to claim 9 , wherein the fan drive unit further includes:
a converter controller configured to output a pulse width modulation (PWM)-based speed command signal; and
a converter configured to convert the PWM-based speed command signal into a pulse amplitude modulation (PAM)-based speed command signal and output the PAM-based speed command signal,
wherein the signal delay unit receives the PAM-based speed command signal.

12. The refrigerator according to claim 11 , wherein the converter includes:
a buck switching element;
an inductor configured to store flowing current by turn-on operation of the buck switching element; and
a diode connected between the buck switching element and the inductor in parallel,
wherein the buck switching element is switched to output the PAM-based speed command signal, based on the PWM-based the speed command signal.

13. The refrigerator according to claim 11 , wherein the fan drive unit includes:
a rectifier configured to rectify an input AC voltage; and
a voltage dropper configured to drop the rectified voltage and output a DC voltage, the level of which has changed,
wherein the DC voltage input to the converter and the inverter corresponds to the output voltage of the voltage dropper.

14. The refrigerator according to claim 9 , wherein the fan drive unit includes a counter electromotive force detector configured to detect counter electromotive force generated in any one of three phases of the motor, and
wherein the inverter controller includes:
a speed calculator configured to calculate a rotation speed of the motor based on the detected counter electromotive force;
a current command generator configured to generate a current command based on the calculated speed and the delayed speed command signal;
a voltage command generator configured to generate a voltage command based on the generated current command; and
a switching control signal output unit configured to output the inverter switching control signal for driving the inverter based on the

Assignees

• Lg Electronics Inc

Inventors

• Song hyun sook
• Son Ho Hyun
• Yoo Myung Keun

Classifications

• F25B2600/23

  Time delays · CPC title

• F25B39/02

  Evaporators · CPC title

• F25B2600/112

  of evaporator fans · CPC title

• Y02B30/741

  Cross-Sectional Technologies · mapped topic

• H02P1/04

  Means for controlling progress of starting sequence in dependence upon time or upon current, speed, or other motor parameter · CPC title