KR19990059544A - Harmonic Current Attenuation Device of Motor - Google Patents

Abstract

The present invention relates to a harmonic current attenuation apparatus of a motor, the apparatus for driving the motor by filtering the AC power supplied from the power supply unit to phase control through the phase control unit, and then supplied to the motor, the alternating current supplied to the motor Harmonic transformer for attenuating the harmonic current included in the power supply, and the resistance value is switched by the user's operation to change the resistance value, the harmonic current is attenuated through the harmonic transformer to adjust the intensity of the power supplied to the motor step by step On the other hand, it is composed of a switching means for directly supplying the phase-controlled AC power through the phase control unit to the motor, through the slide switch to attenuate the harmonic current while phase-controlling the motor to avoid the unused band, as well as the phase By supplying controlled AC power directly to the motor through the switching terminal , It is one to improve the output of the motor.

Description

Harmonic Current Attenuation Device of Motor

The present invention relates to a harmonic current attenuation apparatus of a motor, and more particularly, to a harmonic current attenuation apparatus of a motor capable of raising the output of the motor as well as attenuating the harmonic current generated when the cleaner motor is driven.

In general, the motor driving circuit in a conventional vacuum cleaner, as shown in Figure 1, the power supply unit 10 for supplying an AC power having a commercial frequency and the noise of the AC power supplied from the power supply unit 10 Phase for switching the triac 40 to control the phase of the motor 30 and the motor 30 driven by the AC power supplied from the power supply 10, The first switch for switching the AC power supplied to the motor 30 by switching the control unit 32, the slide switch 34 for adjusting the speed of the motor by the user's operation, and the phase control unit 32 Consists of an evil 40.

In detail, in FIG. 1, the phase controller 32 includes a capacitor C, a resistor R, and a diode AC switch (DIAC), and at a predetermined predetermined voltage (preferably, about 40V). AC power supplied from the power supply unit 10 by switching of the phase control unit 32 is switched through the first triac Triode AC (TRIACI) 40, whereby the phase of the motor 30 is controlled. Will be.

A motor operation process of a conventional conventional cleaner configured as described above will be described with reference to FIG. 1.

First, when the user manipulates the slide switch 34, the contacts (a, b) of the switch (SW) is switched to the on state, the AC power is supplied to the motor 30, the AC power supplied to the motor 30 at this time The noise included in the filter is filtered through the filtering unit 12.

Then, the diac DIAC in the phase control unit 32 is turned on and off by the AC power filtered through the filtering unit 12, and thus is supplied to the motor 30 through the first triac TriAC1. By switching the AC power, the phase is controlled while the motor 30 is driven.

At this time, the motor 30 is driven by the AC power supplied from the power supply unit 10 while being switched through the first triac TRIAC1, and the internal air is driven by an impeller rotated in conjunction with the driving of the motor 30. The cleaning is performed by sucking the contaminants such as dust from the suction port due to the forced circulation and the amount of air generated by the pressure difference between the outside and the inside of the cleaner.

Here, the waveforms of the voltage V and the current I supplied to the motor 30 are as shown in FIG.

On the other hand, the triac 40 is switched by the on-off of the diac (DIAC) in the phase control unit 32, wherein the sinusoidal voltage of the commercial frequency supplied from the power supply unit 10 is phase-controlled to vary the non-sine plate voltage Harmonic current is generated since it is supplied to the motor 30.

Recently, as the spread of products such as cleaners that control the phase of the motor 30 is increased, harmonic currents introduced into the power system are increasing. Such harmonic currents may cause operation disturbances in power capacitors, breakers, and the like. In addition, the transformer may be destroyed.

In order to prevent the harm caused by harmonic currents, IEC (International Electrotechnical Commission) has established standards for limiting harmonic currents in association with test laboratories. When the phase of the motor is adjusted around 90 ° ± 10 °, various high frequency currents are generated. Among them, the harmonic current that is a problem is 3rd Hamornic Current, as shown in FIG.

Therefore, there is an urgent need to attenuate the 3 harmonic currents to match the 3 harmonic currents, and various researches have been conducted on the attenuation technology of the 3 harmonic currents in various technical fields related to the cleaner.

As a technology for attenuating the above-mentioned three harmonic currents, there is a "harmonic current attenuation device for a motor" filed with the Korean Intellectual Property Office on August 25, 1997. According to this device, a commercial frequency supplied from a power supply unit is provided. The AC power supply with is switched by the triac and phase controlled by the voltage of the non-sinusoidal wave and then supplied to the motor. At this time, the harmonic current generated by the phase control of the AC power supplied to the motor near 90 ± 10 ° is constant. By attenuating by a reactor acting as a resistive component (also referred to as "harmonic transformer", hereinafter referred to as "harmonic transformer"), the three harmonic currents can be effectively attenuated.

However, the harmonic current attenuator of such a motor supplies AC power to the motor through a harmonic transformer to attenuate the harmonic current generated during phase control of the motor, but is supplied to the motor by a harmonic transformer acting as a resistance component. Since the AC voltage is a voltage drop, the motor output is reduced, there is a problem that the suction power is weak.

Accordingly, the present invention has been made to solve the above problems, to provide a harmonic current attenuation apparatus of the motor that can improve the output of the motor by reducing the resistance component in the section in which harmonic current is not generated. The purpose is.

In order to achieve the above object, a harmonic current attenuation apparatus of a motor according to the present invention includes a device for driving a motor by filtering an AC power supplied from a power supply and controlling the phase through a phase controller and then supplying the motor to the motor. Harmonic transformer for attenuating the harmonic current included in the AC power supplied to the motor, and the resistance value is switched by the user's operation to change the resistance value, the harmonic current is attenuated through the harmonic transformer to the power of the power supplied to the motor While controlling the intensity step by step, it is characterized in that it is composed of a switching means for supplying the phase-controlled AC power directly to the motor through the phase control unit.

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

2 and 3 are views for explaining a high frequency current generated at the time of driving a conventional motor,

4 is a circuit diagram of a harmonic current attenuator of a motor according to a preferred embodiment of the present invention;

5 is a view showing the power consumption of the motor according to the present invention.

* Explanation of symbols for main parts of the drawings

10: power supply unit 12: filtering unit

20: harmonic transformer 30: motor

32: phase control unit 34, 36: slide switch

40: triac

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention. On the other hand, the same reference numerals are attached to the same parts as in the conventional configuration, and operation description thereof will be omitted to avoid duplicate descriptions.

Figure 4 is a circuit diagram of a harmonic current attenuator of the motor according to a preferred embodiment of the present invention, the harmonic current attenuator of the motor according to the present invention shown in Figure 4 is different from the prior art is supplied from the power supply 10 While the AC power is supplied to the motor 30 through the harmonic transformer 20, the fixed terminal a and the variable terminals b and c of the sliding switch 36 are selectively connected by a user's operation, thereby providing resistance. While the value decreases step by step, when the switching terminals d and e in the sliding switch 36 are connected, the AC power supplied from the power supply unit 10 is directly supplied to the motor 30 without passing through the harmonic transformer 20. Is that.

An operation process of the harmonic current attenuation 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, in the initial state, the switching terminals d and e in the slide switch 36 are set to the off state.

Next, when the user turns on the slide switch 36, the fixed terminal a and the variable terminal b in the slide switch 36 are connected, and noise contained in the AC power supplied from the power supply unit 10 is reduced. After filtering through the filtering unit 12, the filtered AC power is supplied to the phase control unit 32.

In addition, the AC power filtered through the filtering unit 12 switches the triac triac according to ON / OFF of the DIAC in the phase control unit 32, so that the phase of the AC power supplied to the motor 30 is changed. The harmonic current generated during phase control is attenuated while passing through the harmonic transformer 20, and then supplied to the motor 30 to drive the motor 30. At this time, the resistance value in the slide switch 36 is set to the variable resistor R1 so that the power consumption of the motor 30 is limited to about 800W.

On the other hand, when the user continuously operates the slide switch 36 to connect the fixed terminal a and the variable terminal c in the slide switch 36 (time point t in FIG. 5), the resistance in the slide switch 36 The value is reduced by the variable resistor R2 so that the power consumption of the motor 30 jumps to about 1200W. After that, the harmonic current is attenuated through the harmonic transformer 20 and then supplied to the motor 30 so that the motor 30 ) Is driven.

At this time, the power consumption of the motor 30 is adjusted within 1200W ~ 1600W, 800W ~ 1200W of the power consumption of the motor 30 is the unused band (T1 in Fig. 5).

On the other hand, when the user continuously operates the variable section t3 of the slide switch 36 so that the switching terminals d and e are connected, the switching terminals d and e are not passed through. Since it is directly supplied to the motor 30 through, the AC power is not dropped by the harmonic transformer 20 acting as a resistance component, the power consumption of the motor 30 is increased to about 1800W as shown in FIG. T6 of FIG. 5). In FIG. 5, the T2 section 800W to 1200W is an unused band.

As described above, according to the present invention, the harmonic current is attenuated while the phase control of the motor is avoided through the slide switch, and the phase controlled AC power is directly supplied to the motor through the switching terminal. It has the effect of improving the output.

Claims (1)

In the device for filtering the AC power supplied from the power supply to control the phase through the phase control unit, and then supply to the motor to drive the motor, A harmonic transformer for attenuating harmonic currents included in the AC power supplied to the motor; By switching by the user's operation to change the resistance value, the harmonic current is attenuated through the harmonic transformer to adjust the strength of the power supplied to the motor step by step, while the phase control unit to control the AC power Harmonic current attenuation apparatus of the motor, characterized in that it is composed of a switching means for supplying directly to the motor.