KR19990047873A - Phase control device of motor - Google Patents

Abstract

The present invention relates to a phase control apparatus for a motor, and in a motor for controlling a rotation speed by varying a sine wave voltage of a commercial AC power to a non-sinusoidal wave voltage, the commercial power for attenuating harmonic currents generated from the motor. A control unit for generating a switching control signal for phase control of power supplied to the motor from the zero crossing signal of the AC power for a predetermined time; and by the switching control signal from the control unit while commercial AC power is supplied to the motor. The switching means for phase-controlling the commercial AC power supplied to the motor by switching the commercial AC power supplied to the motor, the phase of the commercial AC power supplied to the motor for a predetermined time from the zero crossing signal during the driving of the motor To prevent harmonic current from occurring It is possible to prevent the operation of a power system failure in advance, as well as to comply with IEC regulations will have to be able to promote product sales.

Description

Phase control device of motor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor, and more particularly, to a phase control apparatus for a motor capable of effectively attenuating harmonic currents generated during phase control of a motor used in a cleaner or the like.

In general, the motor drive circuit in a conventional conventional cleaner is as shown in FIG.

As can be seen with reference to Figure 1, the AC power having a commercial frequency supplied from the power supply 10 is provided to the motor 30 to drive the motor 30, the internal air by the impeller rotated in conjunction with this Forced circulation causes a pressure difference between the outside and the inside of the cleaner, and cleaning is performed by inhaling contaminants such as dust from the suction port by the amount of air generated.

Here, the voltage V and the current 1 waveform of the commercial AC power supplied from the power supply 10 to the motor 40 are as shown in FIG. 2.

On the other hand, the sinusoidal voltage supplied from the power supply unit 10 is phase-controlled by the triac AC switch (TRIAC) 40 that is switched and controlled according to the gate signal, and then is converted into a non-sinusoidal voltage and then supplied to the motor 30. At this time, a harmonic current is generated near the peak of the commercial AC power supply (for example, 90 ± 10 °) during phase control.

In recent years, as the popularity of products such as cleaners increases, the total amount of harmonic currents drawn into the power system is increased, which not only causes operation failures in power capacitors, breakers, etc., but also causes breakage of transformers.

As part of the method for preventing the harmonics caused by the above-mentioned harmonic currents, the IEC (International Electrotechnical Commission) has established standards for limiting harmonic currents by combining the test periods. As shown in Fig. 3, among the various harmonic currents generated by the vacuum cleaner when the phase is adjusted near the peak of the commercial AC power supply (about 90 ± 10 °), the harmonic current that is a problem is 3rd Hamornic Current.

Therefore, various techniques have been studied in various technical fields related to cleaners for attenuation of three harmonic currents.

As described above, an object of the present invention is to provide a motor phase control apparatus capable of effectively attenuating harmonic currents generated from a motor.

In order to achieve the above object, a phase control apparatus of a motor according to the present invention includes a phase control of a sinusoidal wave voltage of a commercial AC power supply to a non-sinusoidal wave voltage to adjust a fire speed. Control unit for generating a switching control signal for phase control of the power supplied to the motor from the zero crossing signal of the commercial AC power for a predetermined time to attenuate and switching control from the controller while commercial AC power is supplied to the motor And switching means for phase controlling the commercial AC power supplied to the motor by switching the commercial AC power supplied to the motor by a signal.

1 is a view showing a motor driving circuit in a conventional conventional cleaner;

2 and 3 are views for explaining the harmonic current generated during a conventional motor drive,

4 is a circuit diagram of a phase control apparatus for a motor according to a preferred embodiment of the present invention;

5 is a waveform diagram illustrating an operation process of attenuating harmonic currents according to the present invention.

* Explanation of symbols for main parts of the drawings

10: power supply unit 30: motor

100: control unit 110: phototransistor

120: IGBT driver 122, 124: IGBT

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

4 is a circuit diagram of a phase control apparatus of a motor according to a preferred embodiment of the present invention. As can be seen with reference to the drawing, the motor crosses the motor 30 for a predetermined time T by a zero crossing signal. The control unit 100 for generating a switching control signal for controlling the phase of the commercial AC power supplied, and the phase of the commercial AC power supplied to the motor 30 is switched by the switching control signal generated from the control unit 100 It consists of switching means (110, 120) to control.

When the switching means is switched by the switching control signal from the control unit 100 to the motor 30 by the phototransistor 110 for switching the driving power and the driving power supplied through the phototransistor 110 It is composed of an IGBF driver 120 for controlling the phase of the commercial AC power supply by switching the commercial AC power supplied.

Here, the IGBT driver 120 includes a first IGBT 122, a second IGBT 124, a first diode D1, and a second diode D2. On the other hand, since the triac TRIAC cannot be turned off while the current is being supplied from the power supply 10 to the motor 30, the current is supplied from the power supply 10 to the motor 30 as in the present invention. In order to control the phase of a commercial AC power supply, a special switching device is required. For this, the present invention uses an IGBT device.

An operation process of the phase control apparatus of the motor according to the present invention configured as described above will be described in detail with reference to FIGS. 4 and 5.

First, the commercial AC power supplied to the motor 30 is as shown in FIG.

On the other hand, when controlling the phase of the commercial AC power supplied to the motor 30, the control unit 100 generates a zero crossing signal ZCS (ZCS) generated by zero crossing of the commercial AC power shown in FIG. (C) generates a switching control signal for controlling the phase of the commercial AC power supplied to the motor 30 for a predetermined time T.

That is, the control unit 100 is 0 to 80 degrees, 180 to 260 degrees, 360 to 440 degrees to prevent harmonic currents from occurring near the peak of the commercial AC power supplied from the power supply unit 10 to the motor 30. Generates a switching control signal for controlling the phase of the commercial AC power supplied from the power supply unit 10 to the motor 30 for a predetermined time T such as 540 to 620 °, ... All)).

Then, the phototransistor 110 is switched by the switching control signal generated from the control unit 100 so that the driving power supplied to the IGBT driver 120 is switched, and the power supply unit 10 is supplied through the IGBT driver 120. The phase of the commercial AC power supplied from) is phase controlled as shown in FIG. 5 (d) and supplied to the motor 30.

Specifically, when the commercial AC power supply from the power supply unit 10 is supplied to the motor 30 in the C1 direction, a closed circuit is configured through the first IGBT 122 and the second diode D2 so that the motor 30 In this case, since the first IGBT 122 is switched by the driving power supplied through the photodiode 110 by the switching control signal shown in FIG. The phase of the commercial AC power supplied from the supply unit 10 to the motor 30 is controlled as shown in FIG.

In addition, when the commercial AC power from the power supply unit 10 is supplied to the motor 30 in the C2 direction, a closed circuit is configured through the second IGBT 124 and the first diode D1 to drive the motor 30. In this case, since the second IGBT 124 is switched by the driving power supplied through the photodiode 110 by the switching control signal generated in FIG. 5 (c) generated from the controller 100, the power supply unit ( The phase of the commercial AC power supplied from the 10 to the motor 30 is controlled as shown in FIG.

As described above, according to the present invention, the driving power is switched and supplied to the IGBT driving unit through the phototransistor by the switching control signal generated from the control unit, and accordingly, from the zero crossing signal to the motor for a predetermined time while driving the motor. The phase-controlled commercial AC power supply prevents harmonic currents from being generated from the motor, thus preventing operational disturbances in the power system, and complying with the IEC regulations. There is.

Claims (4)

A motor for controlling a rotation speed by varying a sine wave voltage of a commercial AC power to a non-sinusoidal voltage, wherein the motor is operated for a predetermined time from a zero crossing signal of the commercial AC power to attenuate harmonic currents generated from the motor. The control unit for generating a switching control signal for controlling the phase of the power supplied to the motor and the commercial alternating current power supplied to the motor by the switching control signal from the control unit while the commercial AC power is supplied to the motor A phase control apparatus for a motor, characterized by comprising a switching means for phase controlling a commercial AC power supplied. The switching device of claim 1, wherein the switching means is supplied to the motor by first switching means for switching driving power by a switching control signal from the controller, and driving power supplied while being switched through the first switching means. A phase control apparatus for a motor, comprising a second switching means for controlling a phase of a commercial AC power supply. 3. A phase control apparatus for a motor according to claim 2, wherein said first switching means is a phototransistor. The method of claim 2 or 3, wherein the second switching means comprises a first IGBT, a second IGBT, a first diode, and a second diode, and is supplied through the first switching means while commercial AC power is supplied to the motor. The phase control device of the motor, characterized in that for controlling the phase of the commercial AC power supplied to the motor by the drive power.