KR101911262B1 - Power transforming apparatus having noise reduction function and air conditioner including the same - Google Patents

Abstract

The present invention relates to a power conversion apparatus, and more particularly, to a power conversion apparatus having a noise reduction function capable of reducing noise in a switching frequency region and an air conditioner including the same. The present invention relates to a rectifying unit for rectifying AC power; A power factor control unit connected to the rectifying unit and including a switching element to perform a power factor improving operation on a signal output from the rectifying unit; A converter driver for driving the switching elements; A noise reduction unit positioned between the converter driving unit and the switching device to modulate a resistance value of the driving signal of the switching device; And a control unit for controlling the converter driving unit and the noise reduction unit so that a resistance value of the driving signal of the switching device is modulated.

Description

TECHNICAL FIELD The present invention relates to a power conversion apparatus having a noise reduction function and an air conditioner including the power conversion apparatus.

The present invention relates to a power conversion apparatus, and more particularly, to a power conversion apparatus having a noise reduction function capable of reducing noise in a switching frequency region and an air conditioner including the same.

Generally, a compressor of an air conditioner uses a motor as a driving source. These motors are supplied with AC power from a power conversion device.

It is generally known that such a power conversion apparatus mainly constitutes a rectification section, a power factor control section, and an inverter type power conversion section.

First, the commercial voltage of the AC output from the commercial power source is rectified by the rectifying part. The voltage rectified in this rectifying part is supplied to a power converting part such as an inverter. At this time, the power converting unit generates AC power for driving the motor by using the voltage output from the rectifying unit.

In some cases, a DC-DC converter for improving the power factor may be provided between the rectification part and the inverter.

DC-DC converters and inverters convert power using switching devices that switch at high speed, and electromagnetic interference (EMI) noise may occur in this process.

Also, as electrical appliances evolve to include more and more smart functions, EMI noise due to high-speed switching is getting worse and standby power is also getting worse.

To reduce such EMI noise, a noise filter core may be used or a circuit for frequency modulation phase delay may be used.

However, when only the noise filter core is used, such noise reduction performance is degraded, and a circuit for frequency modulation phase delay requires a complicated circuit configuration.

Therefore, there is a demand for a method capable of improving EMI noise reduction performance without complicated circuit configuration.

The present invention provides a power conversion apparatus having a noise reduction function capable of improving EMI characteristics while minimizing at least one of additional areas for additional cost / circuit modification / circuit construction, and an air conditioner including the same. .

According to a first aspect of the present invention, there is provided a plasma processing apparatus comprising: a rectifying section for rectifying an AC power source; A power factor control unit connected to the rectifying unit and including a switching element to perform a power factor improving operation on a signal output from the rectifying unit; A converter driver for driving the switching elements; A noise reduction unit positioned between the converter driving unit and the switching device to modulate a resistance value of the driving signal of the switching device; And a control unit for controlling the converter driving unit and the noise reduction unit so that a resistance value of the driving signal of the switching device is modulated.

Here, the noise reduction unit may modulate a driving signal applied to a gate terminal of the switching device.

At this time, the noise reduction unit may be located between the converter driving unit and the gate end of the switching device, and may modulate the resistance value of the gate end.

The noise reduction unit may further include: a first resistor located between the gate of the converter driving unit and the switching element; A second resistor connected in parallel with the first resistor; And a switch connected in series with the second resistor and controlled by the control unit.

At this time, the switch may be periodically driven.

The period of the switch may be more than twice the period of the switching element.

As a second aspect of the present invention, the present invention can provide an air conditioner including the power conversion device described above.

According to the present invention, by modulating the driving signal applied to the gate terminal of the switching element, the energy for the corresponding frequency is dispersed and the noise can be reduced. That is, electromagnetic interference (EMI) characteristics can be improved.

1 is a block diagram showing an example of a power conversion apparatus.
2 is a circuit diagram showing an example of a power conversion apparatus.
3 and 4 are circuit diagrams showing a power conversion apparatus having a noise reduction function according to an embodiment of the present invention.
5 is a signal diagram showing signals of a switching device and a switch according to an embodiment of the present invention.
6 and 7 are signal diagrams showing voltage and current signals according to ON / OFF states of a switching device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, such elements, components, regions, layers and / And should not be limited by these terms.

Fig. 1 is a block diagram showing an example of a power conversion apparatus, and Fig. 2 is a circuit diagram showing an example of a power conversion apparatus.

1 and 2, the power inverter 100 includes a rectifier 110 for rectifying an AC power source 10, a converter 120 for controlling the power factor of the DC voltage rectified by the rectifier 110, A converter control unit 130 for controlling the converter 120, an inverter 140 for outputting a three-phase AC current, an inverter control unit 150 for controlling the inverter 140 and a converter 120 and an inverter 140, And a DC-side capacitor C between the first and second capacitors.

This inverter 140 outputs a three-phase alternating current, and this output current is supplied to the motor 200. Here, the motor 200 may be a compressor motor for driving the air conditioner. Hereinafter, the motor 200 is a compressor motor that drives the air conditioner, and the power inverter 100 is a motor driving device that drives such a compressor motor.

However, the motor 200 is not limited to a compressor motor and can be used in various applications using frequency-varying alternating voltages, for example, AC motors such as refrigerators, washing machines, electric trains, automobiles, and vacuum cleaners.

The motor driving apparatus 100 may further include a DC voltage detection unit B, an input voltage detection unit A, an input current detection unit D, and an output current detection unit E.

The motor drive apparatus 100 receives the AC power from the system, converts the power, and supplies the converted power to the motor 200.

The converter 120 converts the input AC power supply 10 into a DC power supply. The converter 120 may use a DC-DC converter operating as a power factor control (PFC) unit. In addition, such a DC-DC converter can use a boost converter. Optionally, the converter 120 may be a concept that includes the rectifier 110. Hereinafter, the converter 120 will be described by way of example using a step-up converter.

The rectifying unit 110 receives and rectifies the single-phase AC power supply 10 and outputs the rectified power to the converter 120 side. For this purpose, the rectifying part 110 can use a full-wave rectifying circuit using a bridge diode.

In this way, the converter 120 can perform the power factor improving operation in the process of stepping up and smoothing the voltage rectified by the rectifier 110.

The converter 120 includes an inductor L1 connected to the rectifying section 110, a switching device Q1 connected to the inductor L1, a capacitor C connected in parallel with the switching device Q1, And a diode D1 connected between the switching element Q1 and the capacitor C. [

The boost converter 120 is a converter that can obtain an output voltage higher than the input voltage. When the switching device Q1 is turned on, energy is stored in the inductor L1 while the diode D1 is shut off, And the output voltage is generated at the output terminal while the charge is discharged.

Further, when the switching element Q1 is interrupted, the energy stored in the inductor L1 at the time of the switching element Q1 is added and is transferred to the output terminal.

Here, the switching device Q1 may perform a switching operation by a separate pulse width modulation (PWM) signal. That is, the PWM signal transmitted from the converter control unit 130 is connected to the base (or gate) terminal of the switching element Q1, and the switching operation can be performed by the PWM signal.

The switching element Q1 may use a power transistor, for example, an insulated gate bipolar mode transistor (IGBT).

The IGBT is a switching device having a structure of a metal oxide semi-conductor field effect transistor (MOSFET) and a bipolar transistor. The IGBT is a device capable of small driving power, high speed switching, high voltage conversion and high current density.

In this manner, the converter control unit 130 can control the turn-on timing of the switching element Q1 in the converter 120. [ Thus, the converter control signal Sc for the turn-on timing of the switching element Q1 can be output.

The converter control unit 130 may receive the input voltage Vs and the input current Is from the input voltage detection unit A and the input current detection unit B, respectively.

Optionally, such converter 120 and converter control 130 may be omitted. That is, the output voltage passing through the rectifying unit 110 can be charged to the DC stage capacitor C or the inverter 140 can be driven.

The input voltage detecting section A can detect the input voltage Vs from the input AC power supply 10. [ For example, at the front end of the rectifying part 110. [

The input voltage detecting section A may include a resistance element, an OP AMP, or the like for voltage detection. The detected input voltage Vs can be applied to the converter control unit 130 to generate a converter control signal Sc as a discrete signal in the form of a pulse.

Next, the input current detection unit D can detect the input current Is from the input AC power supply 10. [ Specifically, it may be located at the front end of the rectifying section 110. [

The input current detection unit D may include a current sensor, a current transformer (CT), a shunt resistor, or the like, for current detection. The detected input voltage Is may be applied to the converter control unit 130 to generate the converter control signal Sc as a discrete signal in the form of a pulse.

The DC voltage detecting section B detects the pulsating voltage Vdc of the DC stage capacitor C. For such power detection, a resistance element, OP AMP, or the like can be used. The detected voltage Vdc of the DC stage capacitor C may be applied to the inverter controller 150 as a discrete signal in the form of a pulse and may be applied to the DC voltage Vdc of the DC stage capacitor C The inverter control signal Si can be generated based on the inverter control signal Si.

On the other hand, unlike the drawing, the detected DC voltage is applied to the converter control unit 130 and may be used for generating the converter control signal Sc.

The inverter 140 includes a plurality of inverter switching elements Qa, Qb, Qc, Qa ', Qb' and Qc ', and supplies the smoothed DC power source Vdc to a predetermined frequency Phase AC power supply of the three-phase motor 200, and outputs the three-phase AC power to the three-phase motor 200.

Specifically, the inverter 140 is a pair of the upper arm switching elements Qa, Qb, and Qc and the lower arm switching elements Qa ', Qb', and Qc 'connected in series to each other, The devices can be connected in parallel with each other.

As with the converter 120, the switching elements Qa, Qb, Qc, Qa ', Qb', Qc 'of the inverter can use power transistors, for example, an insulated gate bipolar mode transistor ; IGBT) can be used.

The inverter control unit 150 can output the inverter control signal Si to the inverter 140 in order to control the switching operation of the inverter 140. [ The inverter control signal Si is generated based on the output current io flowing to the motor 200 and the DC short voltage Vdc across the DC short capacitor C as a switching control signal of the pulse width modulation method And output. The output current io at this time can be detected from the output current detection unit E and the DC short voltage Vdc can be detected from the DC voltage detection unit B. [

The output current detection section E can detect the output current io flowing between the inverter 140 and the motor 200. [ That is, the current flowing in the motor 200 is detected. The output current detection unit E can detect all of the output currents ia, ib, ic of each phase or can detect the output currents of two phases using the three-phase balance.

The output current detection unit E may be located between the inverter 140 and the motor 200. For current detection, a current transformer (CT), a shunt resistor, or the like may be used.

3 and 4 are circuit diagrams showing a power conversion apparatus having a noise reduction function according to an embodiment of the present invention.

3 and 4 mainly show the configuration of a DC-DC converter 120 that operates as a power factor control (PFC) part of a power converter. That is, the converter 120 may be referred to as a power factor control unit. 3 and 4, the rectifier 110 (see FIG. 2) may be located at the front end of the converter 120. [

That is, the converter 120 includes an inductor L1 connected to the rectifying unit 110, a switching device Q1 connected to the inductor L1, a capacitor C connected in parallel with the switching device Q1, And a diode D1 connected between the switching element Q1 and the capacitor C. [

As described above, the converter 120 can perform the power factor improving operation in the process of stepping up and smoothing the voltage rectified by the rectifier 110.

Here, the switching device Q1 may perform a switching operation by a pulse width modulation (PWM) signal transmitted from the converter driving unit 130. [ That is, the PWM signal transmitted from the converter driving unit 131 is connected to the gate terminal of the switching element Q1, and the switching operation can be performed by the PWM signal.

Here, an example in which the converter controller 130 described with reference to FIG. 1 and FIG. 2 includes the converter driver 131 and the controller 160 will be described. That is, the converter control unit 130 of FIGS. 1 and 2 may include the converter driving unit 131 and the control unit 160 described herein.

The inverter 140 shown in FIG. 1 and FIG. 2 may be positioned at the lower end of the DC stage capacitor C.

Referring again to FIGS. 3 and 4, the resistance value of the driving signal of the switching element Q1 is modulated between the converter driving part 131 for driving the switching element Q1 of the converter 120 and the switching element Q1 A noise reduction unit 170 is provided.

The control unit 160 controls the converter driving unit 131 and the noise reduction unit 170 so that the resistance value of the driving signal of the switching device Q1 is modulated.

Here, the noise reduction unit 170 may modulate the drive signal applied to the gate terminal of the switching element Q1 under the control of the control unit 160. [

At this time, the noise reduction section 170 is located between the gate drive stage of the converter drive section 131 and the switching element Q1, and can modulate the resistance value of the gate stage.

The noise reduction unit 170 includes a first resistor R1 positioned between the converter driving unit 131 and the gate terminal of the switching device Q1, a second resistor R1 connected in parallel with the first resistor R1, And a switch Q2 connected in series with the second resistor R2 and controlled by the control unit 160. [

Such a switch Q2 may be a semiconductor device such as a field effect transistor (FET). Also, an IGBT element used as the switching element Q1 may be used.

3, in a state in which the switch Q2 is off, the driving signal of the converter driving unit 131 is applied to the gate terminal of the switching element Q1 through the first resistor R1. 4, in a state in which the switch Q2 is turned on, the driving signals of the converter driving unit 131 are supplied to the switching elements Q1 through the first resistor R1 and the second resistor R2, which are connected in parallel to each other, As shown in FIG.

According to this configuration, the switch Q2 performs the on / off operation under the control of the controller 160, so that the resistance value between the converter driving unit 131 and the switching element Q1 is 1 resistor R1 or a parallel resistance value between the first resistor R1 and the second resistor R2. Therefore, the resistance value of the gate terminal of the switching element Q1 can be modulated by the value of the first resistor R1 and the value of the parallel resistance of the first resistor R1 and the second resistor R2.

5 is a signal diagram showing signals of a switching device and a switch according to an embodiment of the present invention. 5 shows the gate signal of the switching element IGBT Q1 and the driving signal (switch signal) of the switch Q2, and the resistance value (Gate input resistance) of the noise reduction section 170 corresponding thereto Respectively.

The gate signal of the switching element IGBT Q1 represents a PWM signal for driving the converter 120, and the signal of the switch Q2 may correspond thereto.

That is, the switch Q2 may be periodically driven according to the PWM signal. That is, the controller 160 may periodically drive the switch Q2 by applying a periodic driving signal to the switch Q2.

At this time, the period of the switch Q2 may be more than twice the period of the switching element Q1. FIG. 5 shows a case where the period of the switch Q2 is twice the period of the switching element Q1. However, the present invention is not limited thereto.

The switch Q2 of the noise reduction unit 170 may be in a switch on state or a switch off state when the signal of the switching element Q1 of one period advances.

Referring to FIG. 5, during the first driving period of the switching device Q1, the switch Q2 is in the on state and during the second driving period of the switching device Q1 the switch Q2 is in the off state ) State.

At this time, the resistance value (Gate input resistance) of the noise reduction section 170 is a periodic value between the value of the first resistor R1 or the combined resistance value of the first resistor R1 and the second resistor R2 I have.

6 and 7 are signal diagrams showing voltage and current signals according to ON / OFF states of a switching device according to an embodiment of the present invention.

6 shows the voltage and current signals of the switching element Q1 when the switching element Q1 is in an on state.

As soon as the switching element Q1 is turned on, the voltage Vce at the collector-emitter end decreases and the current Ic flows through the collector-emitter terminal. At this time, it can be seen that the peak of the current Ic is made at the point t1.

The peak positions of the voltage Vce and the current Ic are different from each other when the resistance value of the gate terminal is R1 and R2. Here, R1 may be a resistance value by the first resistor R1, and R2 may be a parallel resistance value between the first resistor R1 and the second resistor R2.

7 shows the voltage and current signals of the switching element Q1 when the switching element Q1 is off.

At the moment when the switching element Q1 is turned off, the voltage Vce at the collector-emitter end increases, and the current Ic through the collector-emitter end is stopped. At this time, it can be seen that the peak of the voltage Vce occurs at the point t2.

As described above, it can be seen that the peak positions of the voltage Vce and the current Ic are different from each other when the resistance value of the gate terminal is R1 and R2. Here, R1 may be a resistance value by the first resistor R1, and R2 may be a parallel resistance value between the first resistor R1 and the second resistor R2.

Therefore, the energy for the frequency is dispersed, and the noise can be reduced. That is, electromagnetic interference (EMI) characteristics can be improved.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: power converter 110: rectifying part
120: converter 130: converter control unit
131: converter driving unit 160:
170: Noise Reduction Unit

Claims (7)

A rectifying part for rectifying AC power;
A power factor control unit connected to the rectifying unit and including a switching element to perform a power factor improving operation on a signal output from the rectifying unit;
A converter driver for driving the switching elements;
A noise reduction unit positioned between the converter driving unit and the switching device to modulate a resistance value of the driving signal of the switching device; And
And a controller for controlling the converter driving unit and the noise reduction unit so that a resistance value of the driving signal of the switching device is modulated,
Wherein the noise reduction unit includes a first resistor located between the converter driving unit and the gate terminal of the switching element, a second resistor connected in parallel with the first resistor, and a first resistor connected directly to the second resistor, And a switch directly connected to the first resistor between the converter driving unit and the first resistor and controlled by the control unit,
Wherein the noise reduction unit modulates a driving signal applied to a gate terminal of the switching element, wherein a resistance value between the converter driving unit and the switching element is a value obtained by the first resistance or a parallel resistance value between the first resistance and the second resistance Lt; RTI ID = 0.0 > periodically < / RTI &
Wherein the switch is periodically driven, and the period of the switch is at least twice the period of the switching element. delete delete delete The power conversion apparatus according to claim 1, wherein the period of the switch is twice the period of the switching element. delete An air conditioner comprising the power conversion device according to any one of claims 1 to 5.

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