KR100258433B1 - Apparatus for reducing harmonic current in motor - Google Patents

Abstract

PURPOSE: A high tone wave current attenuator of a motor is provided to prevent an operation obstacle of a power system by attenuating 3 high tone wave current generated when a phase of a sine wave voltage is controlled using an inductor set in a coil. CONSTITUTION: A power supply(10) supplies a sine wave voltage. The reactor(20) includes an E shape core, a coil wound around the E shape core, and an I shape core. The coil has an inductance of 10 mH. A reactor(20) delays a phase of a sine wave voltage supplied to a motor(30) to attenuate 3 high tone wave current by the inductance of 10 mH. The E shape core and the I shape core each includes an air gap which is formed between three projections of the E shape core and the I shape core. The coil includes two terminals which are connected to a power supply current of a motor. A motor(30) drives according to an alternating current voltage from the power supply(10). A triac(40) is switched according to a gate signal and controls a phase of the sine wave voltage.

Description

Harmonic Current Attenuation Device for Motors {APPARATUS FOR REDUCING HARMONIC CURRENT IN 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 attenuating harmonic currents generated when driving a cleaner motor.

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 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 40 are as shown in FIG.

On the other hand, the sinusoidal voltage supplied from the power supply unit 10 is phase-controlled by a triac AC switch (TRIAC) 40 that is switched and controlled according to the gate signal, and is then changed to a non-sinusoidal voltage and then supplied to the motor 30. Because of this, harmonic currents are generated.

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

In order to prevent the harmonics caused by the harmonic currents described above, the IEC (International Electrotechnical Commission) has established standards for limiting harmonic currents in association with test laboratories. As shown, among the various harmonic currents generated by the cleaner when adjusted at 90 ° phase, the harmonic current in question is 3rd Hamornic Current.

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

On the other hand, an object of the present invention is to provide a harmonic current attenuation apparatus for a motor capable of attenuating harmonic currents by setting the inductance of the coil wound on the reactor as described above to a predetermined value.

In order to achieve the above object, a harmonic current attenuation apparatus of a motor according to the present invention includes an E-core, an I-core and Reactors wound around the coil having an inductance of a predetermined value set in the E-shaped core is characterized in that the configuration is further included.

1 shows a motor driving circuit in a conventional conventional cleaner;

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

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

5 is a view showing the structure of a reactor according to the present invention;

6 and 7 are diagrams for explaining harmonic currents generated when the motor is driven with a reactor;

Explanation of symbols on the main parts of the drawings

10: power supply 20: reactor

22: E-core 24: Coil

26: I-core 30: motor

40: triac

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

4 is a harmonic current attenuation apparatus of a motor according to a preferred embodiment of the present invention, which is composed of a power supply unit 10, a reactor 20, a motor 30, and a triac 40, and a conventional motor driving circuit. As can be seen by comparison, the harmonic current attenuation apparatus of the motor according to the present invention is configured to further include a reactor 20.

In FIG. 4, the reactor 20 attenuates three harmonic currents by phase-delaying the sine wave voltage supplied from the power supply unit 10. As shown in the structural diagram shown in FIG. 22) and a coil 24 wound around the E-core 22 and an I-core 26.

Here, the harmonic current can be effectively attenuated by setting the inductance of the coil 24 wound on the E-shaped core 22 to a predetermined value (preferably, about 10 mH).

An operation process of the harmonic current attenuation apparatus of the motor according to the present invention configured as described above will be described with reference to FIGS. 4 to 7.

First, the AC power from the power supply unit 10 is supplied to the motor 30 through the reactor 20 to drive the motor 30, and the internal air is driven by an impeller rotated in conjunction with the rotation 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.

At this time, the sine wave voltage is phase-controlled by the triac 40 which is switched and controlled in accordance with the gate signal, so that the sine wave voltage is changed to a non-sinusoidal wave voltage and supplied to the motor 30. Three harmonic currents are attenuated through the reactor 20 composed of the coil 24 wound on the 22 and the I-core 26.

Specifically, the three harmonic currents are attenuated by the inductance set in the E-shaped core 22 to a predetermined value (preferably, about 10 mH).

FIG. 6 shows the voltage V and the current I in the motor driving circuit equipped with the reactor 20 as described above, and FIG. 7 shows the three harmonic currents attenuated accordingly as experimental data. As can be seen with reference to Figs. 6 and 7, the three harmonic currents generated during the phase control of the sine wave voltage are attenuated through the reactor 20.

As described above, by using the present invention, since the three harmonic currents generated during the phase control of the sinusoidal voltage are effectively attenuated by the inductance set in the coil in the reactor, not only the IEC regulations but also the operation disturbances of the power system are prevented. It can be prevented in advance, and has an excellent effect of promoting product sales.

Claims (2)

(delete) In a motor in which a reactor is installed to control a phase of an input voltage to adjust a rotational speed and attenuate harmonic currents generated during phase control. The reactor is a harmonic current attenuation device of the motor, characterized in that consisting of a coil having an inductance of 10mH wound around the E-shaped core and the I-shaped core and the E-shaped core.

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