KR102010387B1 - Power converting apparatus and air conditioner including the same - Google Patents

Abstract

The present invention relates to a power converter and an air conditioner having the same. The power converter and the air conditioner including the same according to an embodiment of the present invention, a converter for converting the input AC power to a DC power source, a dc stage capacitor disposed at the output terminal of the converter to store the DC power, and a dc stage capacitor An inverter that converts the stored DC power and outputs AC power to the motor, and an active filter unit disposed at the front of the converter and performing active filtering on the input AC power, wherein the active filter unit is configured to filter the input AC power. A first capacitor portion, a first transformer for sensing current from the first capacitor portion, an amplifier for amplifying the current sensed by the first transformer, a second transformer for converting current from the amplifier, and a second transformer And a second capacitor portion for filtering the current. As a result, common mode noise can be efficiently reduced.

Description

Power converting apparatus and air conditioner having the same {Power converting apparatus and air conditioner including the same}

The present invention relates to a power converter and an air conditioner having the same. More particularly, the present invention relates to a power converter capable of efficiently reducing common mode noise and an air conditioner having the same.

The air conditioner is installed to provide a more comfortable indoor environment for humans by discharging cold air into the room to adjust the indoor temperature and purifying the indoor air to create a comfortable indoor environment. In general, an air conditioner includes an indoor unit which is configured as a heat exchanger and installed indoors, and an outdoor unit which is configured as a compressor and a heat exchanger and supplies refrigerant to the indoor unit.

On the other hand, a compressor motor driving device is used to drive the compressor of the air conditioner.

Meanwhile, according to IEC 61000, an international surge protection standard, a standard for harmonic reduction is set. Accordingly, various efforts have been made to reduce harmonics caused by input AC current in an air conditioner.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power converter capable of efficiently reducing common mode noise and an air conditioner having the same.

Power converter and an air conditioner having the same according to an embodiment of the present invention for achieving the above object, a converter for converting the input AC power to a DC power, and a dc stage capacitor disposed in the output terminal of the converter to store the DC power And an inverter for converting the DC power stored in the dc terminal capacitor and outputting the AC power to the motor, and an active filter part disposed at the front of the converter and performing active filtering on the input AC power. A first capacitor for filtering an AC power source, a first transformer for sensing current from the first capacitor, an amplifier for amplifying the current sensed in the first transformer, a second transformer for converting current from the amplifier, And a second capacitor portion for filtering the current from the second transformer.

On the other hand, a power converter and an air conditioner having the same according to another embodiment of the present invention for achieving the above object, and a converter for converting the input AC power to DC power, and disposed at the output terminal of the converter to store the DC power a dc stage capacitor, an inverter for converting DC power stored in the dc stage capacitor to output AC power to a motor, and an active filter unit disposed at the front of the converter and performing active filtering on the input AC power, and an active filter The unit includes a first transformer for detecting common mode noise of an input AC power supply, an amplifier for amplifying common mode noise detected by the first transformer, and a second transformer for converting and outputting a phase of common mode noise from the amplifier. do.

On the other hand, a power converter and an air conditioner having the same according to another embodiment of the present invention for achieving the above object, and a converter for converting the input AC power to DC power, and disposed at the output terminal of the converter to store the DC power A dc stage capacitor, an inverter for converting the DC power stored in the dc stage capacitor to output AC power to the motor, and an active filter unit disposed between the converter and the dc terminal capacitor, the active filter unit for filtering the input AC power From a first capacitor portion, a first transformer for sensing current from the first capacitor portion, an amplifier for amplifying the current sensed by the first transformer, a second transformer for converting current from the amplifier, and a second transformer It includes a second capacitor portion for filtering the current of.

According to an embodiment of the present invention, a power converter and an air conditioner having the same include: a converter for converting an input AC power into a DC power source; a dc stage capacitor disposed at an output end of the converter to store a DC power; An inverter for converting the DC power stored in the capacitor to output AC power to the motor, and an active filter part disposed at the front of the converter and performing active filtering on the input AC power, wherein the active filter part filters the input AC power. A first capacitor unit, a first transformer for sensing current from the first capacitor unit, an amplifier for amplifying the current sensed by the first transformer, a second transformer for converting current from the amplifier, and a second transformer By including the second capacitor section for filtering the current from, common mode noise can be efficiently reduced. It is.

In particular, by detecting the common mode noise using the first transformer and compensating the common mode noise using the second transformer, reliability for disturbances such as surge may be enhanced.

On the other hand, since the amplifier is operated by the voltage across the dc terminal capacitor, no separate power supply is required.

On the other hand, by outputting the common mode noise having a small level through the first capacitor unit, it is possible to simply extract the common mode noise.

On the other hand, in order to compensate for the common mode noise, a separate switch element is not required, and thus an active filter unit having a reduced manufacturing cost can be implemented.

On the other hand, according to another embodiment of the present invention, a power converter and an air conditioner having the same, a converter for converting the input AC power to a DC power source, a dc stage capacitor disposed at the output terminal of the converter to store the DC power, An inverter for converting the DC power stored in the dc terminal capacitor to output the AC power to the motor, and an active filter disposed in front of the converter, and performs an active filtering for the input AC power, the active filter unit, the input AC power Common mode noise, comprising: a first transformer for detecting common mode noise of the amplifier; an amplifier for amplifying common mode noise detected by the first transformer; and a second transformer for converting and outputting a phase of the common mode noise from the amplifier. Can be efficiently reduced.

On the other hand, according to another embodiment of the present invention, the power converter and the air conditioner having the same, a converter for converting the input AC power to a DC power source, a dc stage capacitor disposed at the output terminal of the converter and stores the DC power; and an inverter for converting the DC power stored in the dc terminal capacitor and outputting the AC power to the motor, and an active filter unit disposed between the converter and the dc terminal capacitor, wherein the active filter unit includes: a first capacitor unit for filtering the input AC power; And a first transformer for sensing current from the first capacitor portion, an amplifier for amplifying the current sensed by the first transformer, a second transformer for converting current from the amplifier, and filtering current from the second transformer. By including the second capacitor unit, common mode noise can be efficiently reduced.

1 is a diagram illustrating a configuration of an air conditioner according to an embodiment of the present invention.
2 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 1.
3 illustrates an example of an internal block diagram of a power conversion apparatus according to an embodiment of the present invention.
4A is an example of an internal circuit diagram of the power converter of FIG. 3.
4B is another example of an internal circuit diagram of the power converter of FIG. 3.
5 is an internal block diagram of the inverter controller of FIG. 4A or 4B.
6 is a diagram referred for explanation of common mode noise.
7 is an example of an internal circuit diagram of an active filter unit according to the present invention.
8 is an example of an internal circuit diagram of an active filter unit according to an embodiment of the present invention.
9 is a diagram illustrating a configuration of an air conditioner according to another embodiment of the present invention.
10 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 9.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

The suffixes "module" and "unit" for components used in the following description are merely given in consideration of ease of preparation of the present specification, and do not impart any particular meaning or role by themselves. Therefore, the "module" and "unit" may be used interchangeably.

1 is a diagram illustrating a configuration of an air conditioner according to an embodiment of the present invention.

As shown in FIG. 1, the air conditioner according to the present invention is a large air conditioner 50, and includes a plurality of indoor units 31 to 35, a plurality of outdoor units 21 and 22 connected to a plurality of indoor units, and a plurality of air conditioners. It may include a remote controller (41 to 45) connected to each of the indoor unit of, and a remote controller 10 for controlling a plurality of indoor unit and outdoor unit.

The remote controller 10 is connected to the plurality of indoor units 31 to 36 and the plurality of outdoor units 21 and 22 to monitor and control the operation thereof. At this time, the remote controller 10 may be connected to a plurality of indoor units to perform operation setting, lock setting, schedule control, group control, etc. for the indoor unit.

The air conditioner may be any one of a stand type air conditioner, a wall-mounted air conditioner, and a ceiling type air conditioner, but for convenience of description, a ceiling type air conditioner will be described as an example. The air conditioner may further include at least one of a ventilator, an air cleaner, a humidifier, and a heater, and may operate in conjunction with the operation of the indoor unit and the outdoor unit.

The outdoor units 21 and 22 are compressors (not shown) for receiving and compressing a refrigerant, an outdoor heat exchanger (not shown) for exchanging refrigerant and outdoor air, and an accumulator for extracting gas refrigerant from the supplied refrigerant and supplying the compressor to the compressor. (Not shown) and a four-way valve (not shown) for selecting a flow path of the refrigerant according to the heating operation. In addition, although a plurality of sensors, valves and oil recovery device, etc. are further included, the description of the configuration will be omitted below.

The outdoor units 21 and 22 operate the compressor and the outdoor heat exchanger provided to supply or cool the refrigerant to the indoor units 31 to 35 by compressing or exchanging the refrigerant according to a setting. The outdoor units 21 and 22 are driven by the request of the remote controller 10 or the indoor units 31 to 35, and as the air / heating capacity is changed in response to the driven indoor unit, the number of operation of the outdoor unit and the compressor installed in the outdoor unit The number of operations is variable.

In this case, the outdoor units 21 and 22 are described on the basis of supplying a refrigerant to a plurality of outdoor units, respectively, to the connected indoor units, but a plurality of outdoor units are connected to each other according to the connection structure of the outdoor unit and the indoor units, and the refrigerant to the plurality of indoor units. May be supplied.

The indoor units 31 to 35 are connected to any one of the plurality of outdoor units 21 and 22, and receive coolant to discharge cold air. The indoor units 31 to 35 include an indoor heat exchanger (not shown), an indoor unit fan (not shown), an expansion valve (not shown) for expanding the supplied refrigerant, and a plurality of sensors (not shown).

At this time, the outdoor unit (21, 22) and the indoor unit (31 to 35) are connected by a communication line to transmit and receive data, and the outdoor unit and the indoor unit is connected to the remote controller 10 by a separate communication line to control the remote controller (10). It works accordingly.

The remote controllers 41 to 45 may be connected to the indoor units, respectively, to input a user's control command to the indoor unit, and receive and display state information of the indoor unit. In this case, the remote controller communicates by wire or wirelessly according to the connection type with the indoor unit. In some cases, one remote controller is connected to the plurality of indoor units, and the setting of the plurality of indoor units may be changed through one remote controller input.

In addition, the remote controller 41 to 45 may include a temperature sensor therein.

2 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 1.

Referring to the drawings, the air conditioner 50 is largely divided into an indoor unit 31 and an outdoor unit 21.

The outdoor unit 21 includes a compressor 102 that serves to compress the refrigerant, a compressor electric motor 102b that drives the compressor, an outdoor side heat exchanger 104 that serves to radiate the compressed refrigerant, and an outdoor unit. An outdoor blower 105 disposed at one side of the heat exchanger 104 and configured to expand the condensed refrigerant by an outdoor blower 105 including an outdoor fan 105a for promoting heat dissipation of the refrigerant and an electric motor 105b for rotating the outdoor fan 105a. A mechanism 106, a cooling / heating switching valve 110 for changing a flow path of a compressed refrigerant, and an accumulator 103 for temporarily storing a gasified refrigerant to remove moisture and foreign matter and then supplying a refrigerant having a constant pressure to the compressor. And the like.

The indoor unit 31 is an indoor heat exchanger 109 disposed indoors to perform a cooling / heating function, and an indoor fan 109a disposed at one side of the indoor heat exchanger 109 to promote heat dissipation of the refrigerant, and an indoor unit. And an indoor blower 109 composed of an electric motor 109b for rotating the fan 109a.

At least one indoor side heat exchanger 109 may be installed. The compressor 102 may be at least one of an inverter compressor and a constant speed compressor.

In addition, the air conditioner 50 may be configured as a cooler for cooling the room, or may be configured as a heat pump for cooling or heating the room.

Meanwhile, although one indoor unit 31 and one outdoor unit 21 are shown in FIG. 2, the driving device of the air conditioner according to the embodiment of the present invention is not limited thereto, and the multi-type unit includes a plurality of indoor units and outdoor units. Applicable to the air conditioner, an air conditioner having a single indoor unit and a plurality of outdoor units, of course.

The compressor 102 in the outdoor unit 21 of FIG. 1 may be driven by the motor driving device 200 for the compressor shaft driving the compressor motor 250.

3 illustrates an example of an internal block diagram of a power converter according to an embodiment of the present invention, and FIG. 4A is an example of an internal circuit diagram of the power converter of FIG. 3.

Referring to the drawings, the power converter 220 according to an embodiment of the present invention, for driving the motor in a sensorless manner, may be referred to as a motor driving device.

Power converter 220 according to an embodiment of the present invention, the active filter 450, converter 410, inverter 420, inverter controller 430, dc terminal voltage detector (B), smoothing capacitor (C) ), An output current detector E may be included. In addition, the power converter 220 may further include an input current detector A or the like.

On the other hand, the power conversion device 220 according to an embodiment of the present invention, it is possible to detect the phase current by using one dc-stage resistor element disposed between the dc-stage capacitor and the inverter.

In this case, the inverter controller 430 controls the switching device in the inverter 420 by controlling the variable width of the pulse vector based on the space vector.

To this end, the inverter controller 430 receives phase current information sequentially detected by using one dc stage resistance element, and based on this, in the inverter 420, by controlling a variable width of a pulse vector based on a space vector. The switching element can be controlled.

On the other hand, by using a single dc resistor unit (Rdc), by time-division, by detecting the phase current, the manufacturing cost is reduced, there is an advantage that the installation is easy.

Hereinafter, the operation of each component unit in the power converter 220 of FIGS. 3 and 4A will be described.

The input current detector A can detect the input current i _s input from the commercial AC power supply 405. To this end, a CT (current trnasformer), a shunt resistor, or the like may be used as the input current detector A. FIG. The detected input current i _s may be input to the inverter controller 430 as a discrete signal in the form of a pulse.

The converter 410 converts the commercial AC power supply 405 which passed through the reactor L into DC power, and outputs it. Although the commercial AC power supply 405 is shown as a single phase AC power supply in the figure, it may be a three phase AC power supply. The internal structure of the converter 410 also varies according to the type of the commercial AC power source 405.

Meanwhile, the converter 410 may be formed of a diode or the like without a switching element, and may perform rectification without a separate switching operation.

For example, in the case of single phase AC power, four diodes may be used in the form of a bridge, and in the case of three phase AC power, six diodes may be used in the form of a bridge.

On the other hand, the converter 410, for example, a half-bridge type converter that is connected to two switching elements and four diodes may be used, and in the case of a three-phase AC power supply, six switching elements and six diodes may be used. .

When the converter 410 includes a switching element, the boosting operation, the power factor improvement, and the DC power conversion may be performed by the switching operation of the switching element.

The smoothing capacitor C smoothes and stores the input power. In the figure, one element is illustrated as the smoothing capacitor C, but a plurality of elements may be provided to ensure device stability.

On the other hand, in the drawing, but is illustrated as being connected to the output terminal of the converter 410, not limited to this, a direct current power may be input directly, for example, a direct current power from a solar cell is supplied to the smoothing capacitor (C). It may be input directly or DC / DC converted. Hereinafter, the parts illustrated in the drawings will be mainly described.

On the other hand, since the DC power is stored at both ends of the smoothing capacitor C, this may be referred to as a dc terminal or a dc link terminal.

The dc end voltage detector B may detect a dc end voltage Vdc that is both ends of the smoothing capacitor C. To this end, the dc terminal voltage detector B may include a resistor, an amplifier, and the like. The detected dc terminal voltage Vdc may be input to the inverter controller 430 as a discrete signal in the form of a pulse.

The inverter 420 includes a plurality of inverter switching elements, converts the smoothed DC power supply Vdc into three-phase AC power supplies va, vb and vc of a predetermined frequency by turning on / off an operation of the switching device, It may output to the synchronous motor 230.

Inverter 420 is a pair of upper arm switching elements Sa, Sb, Sc and lower arm switching elements S'a, S'b, S'c, which are connected in series with each other, and a total of three pairs of upper and lower arms The switching elements are connected in parallel with each other (Sa & S'a, Sb & S'b, Sc & S'c). Diodes are connected in anti-parallel to each of the switching elements Sa, S'a, Sb, S'b, Sc, and S'c.

The switching elements in the inverter 420 perform on / off operations of the respective switching elements based on the inverter switching control signal Sic from the inverter controller 430. As a result, the three-phase AC power supply having the predetermined frequency is output to the three-phase synchronous motor 230.

The inverter controller 430 may control a switching operation of the inverter 420 based on a sensorless method. To this end, the inverter controller 430 may receive an output current i _o detected by the output current detector E. FIG.

The inverter controller 430 outputs an inverter switching control signal Sic to the inverter 420 to control the switching operation of the inverter 420. The inverter switching control signal Sic is a switching control signal of the pulse width modulation method PWM, and is generated and output based on the output current i _o detected by the output current detector E. FIG. A detailed operation of the output of the inverter switching control signal Sic in the inverter controller 430 will be described later with reference to FIG. 5.

The output current detector E detects the output current i _o flowing between the inverter 420 and the three-phase motor 230. That is, the current flowing through the motor 230 is detected. The output current detector E may detect all of the output currents ia, ib, and ic of each phase, or may detect the output currents of the two phases by using three-phase equilibrium.

The output current detector E may be located between the inverter 420 and the motor 230, and a current trnasformer (CT), a shunt resistor, or the like may be used for current detection.

When a shunt resistor is used, three shunt resistors are located between the inverter 420 and the synchronous motor 230 or the three lower arm switching elements S'a, S'b, S'c of the inverter 420. It is possible to connect one end to each). On the other hand, it is also possible to use two shunt resistors using three-phase equilibrium. On the other hand, when one shunt resistor is used, the corresponding shunt resistor may be disposed between the above-described capacitor C and the inverter 420.

The detected output current i _o , as a discrete signal in the form of a pulse, may be applied to the inverter controller 430, and the inverter switching control signal Sic based on the detected output current i _o . Is generated. Hereinafter, the detected output current i _o may be described in parallel as the three-phase output currents ia, ib and ic.

On the other hand, the three-phase motor 230 is provided with a stator and a rotor, each phase AC power of a predetermined frequency is applied to the coil of the stator of each phase (a, b, c phase), the rotor rotates Will be

Such a motor 230 may be, for example, a Surface-Mounted Permanent-Magnet Synchronous Motor (SMPMSM), an Interior Permanent Magnet Synchronous Motor (IPMSM), and a synchronous clock. Synchronous Reluctance Motor (Synrm) and the like. Of these, SMPMSM and IPMSM are permanent magnet synchronous motors (PMSMs) with permanent magnets, and synrms have no permanent magnets.

On the other hand, the power conversion device 220 according to an embodiment of the present invention, proposes a method for efficiently reducing harmonics, in particular common mode noise generated by the input AC power source.

To this end, the power conversion device 220 according to an embodiment of the present invention, the converter 410 for converting the input AC power (Vs) to a DC power source, and is disposed at the output terminal of the converter 410 to store the DC power Inverter 420 for converting the dc terminal capacitor (C), the DC power stored in the dc terminal capacitor (C) to output AC power to the motor, and is disposed in front of the converter 410, the input AC power (Vs) And an active filter unit 450 for performing active filtering on the first filter unit 450. The active filter unit 450 includes a first capacitor unit 451 and a first capacitor unit 451 for filtering an input AC power supply Vs. A first transformer 452 for sensing a current from the amplifier, an amplifier 455 for amplifying the current sensed by the first transformer 452, a second transformer 458 for converting a current from the amplifier 455, and And a second capacitor portion 456 that filters the current from the second transformer 458. As a result, common mode noise can be efficiently reduced. This will be described in detail later with reference to FIG. 8.

4B is another example of an internal circuit diagram of the power converter of FIG. 3.

Referring to FIG. 4B, the power converter 220b according to another embodiment of the present invention is similar to FIG. 4A, but the position of the active filter unit 450 is an output terminal of the converter 410. There is a difference between the arrangement between the 410 and the dc terminal capacitor (C).

4A and 4B will be described in detail later with reference to FIG. 8.

5 is an internal block diagram of the inverter controller of FIG. 4A or 4B.

Referring to FIG. 5, the inverter controller 430 may include an axis converter 310, a speed calculator 320, a current command generator 330, a voltage command generator 340, an axis converter 350, and The switching control signal output unit 360 may be included.

The axis conversion unit 310 receives the three-phase output currents (ia, ib, ic) detected by the output current detection unit E, and converts the two-phase currents i α and i β of the stationary coordinate system.

On the other hand, the axis conversion unit 310 can convert the two-phase current (iα, iβ) of the stationary coordinate system into a two-phase current (id, iq) of the rotary coordinate system.

)와 연산된 속도(

)를 출력할 수 있다.The speed calculator 320 calculates the calculated position (based on the two-phase currents iα and iβ of the stationary coordinate system axially changed by the axis converter 310.

) And computed speed (

) Can be printed.

)와 속도 지령치(ω^* _r)에 기초하여, 전류 지령치(i^* _q)를 생성한다. 예를 들어, 전류 지령 생성부(330)는, 연산 속도(

)와 속도 지령치(ω^* _r)의 차이에 기초하여, PI 제어기(335)에서 PI 제어를 수행하며, 전류 지령치(i^* _q)를 생성할 수 있다. 도면에서는, 전류 지령치로, q축 전류 지령치(i^* _q)를 예시하나, 도면과 달리, d축 전류 지령치(i^* _d)를 함께 생성하는 것도 가능하다. 한편, d축 전류 지령치(i^* _d)의 값은 0으로 설정될 수도 있다. On the other hand, the current command generation unit 330 has a calculation speed (

) And the current command value i ^* _q based on the speed command value ω ^* _r . For example, the current command generation unit 330 has a calculation speed (

) Based on the difference between the speed command value ω ^* _r and the PI controller 335, the PI control may be performed, and the current command value i ^* _q may be generated. In the drawing, although the q-axis current command value i ^* _q is illustrated as a current command value, it is also possible to generate | generate a d-axis current command value i ^* _d unlike a figure. On the other hand, the value of the d-axis current command value i ^* _d may be set to zero.

On the other hand, the current command generation unit 330 may further include a limiter (not shown) for restricting the level so that the current command value i ^* _q does not exceed the allowable range.

Next, the voltage command generation unit 340 includes the d-axis and q-axis currents i _d and i _q which are axis-converted in the two-phase rotational coordinate system by the axis conversion unit, and the current command value (such as the current command generation unit 330). Based on i ^* _d , i ^* _q ), the d-axis and q-axis voltage command values v ^* _d and v ^* _q are generated. For example, the voltage command generation unit 340 performs the PI control in the PI controller 344 based on the difference between the q-axis current i _q and the q-axis current command value i ^* _q , and q The axial voltage setpoint v ^* _q can be generated. In addition, the voltage command generation unit 340 performs the PI control in the PI controller 348 based on the difference between the d-axis current i _d and the d-axis current command value i ^* _d , and the d-axis voltage. The setpoint (v ^* _d ) can be generated. On the other hand, the voltage command generation unit 340 may further include a limiter (not shown) for restricting the level so that the d-axis and q-axis voltage command values (v ^* _d , v ^* _q ) do not exceed the allowable range. .

On the other hand, the generated d-axis and q-axis voltage command values v ^* _d and v ^* _q are input to the axis conversion unit 350.

)와, d축, q축 전압 지령치(v^* _d,v^* _q)를 입력받아, 축변환을 수행한다.The axis conversion unit 350 may be a position calculated by the speed calculating unit 320 (

), And the d-axis and q-axis voltage command values (v ^* _d , v ^* _q ) are input, and axis conversion is performed.

)가 사용될 수 있다.First, the axis conversion unit 350 converts from a two-phase rotation coordinate system to a two-phase stop coordinate system. At this time, the position calculated by the speed calculating unit 320 (

) Can be used.

In addition, the axis conversion unit 350 performs a transformation from the two-phase stop coordinate system to the three-phase stop coordinate system. Through this conversion, the axis conversion unit 1050 outputs the three-phase output voltage command values v ^* a, v ^* b, v ^* c.

The switching control signal output unit 360 generates the switching control signal Sic for the inverter based on the pulse width modulation (PWM) method based on the three-phase output voltage command values (v ^* a, v ^* b, v ^* c). To print.

The output inverter switching control signal Sic may be converted into a gate driving signal by a gate driver (not shown) and input to the gate of each switching element in the inverter 420. As a result, each of the switching elements Sa, S'a, Sb, S'b, Sc, and S'c in the inverter 420 performs a switching operation.

On the other hand, as described above, the motor drive device 100, through the control of the inverter 420, in order to perform vector control for driving the motor 230, the output current (io) flowing through the motor (motor) In particular, it is essential to detect phase current.

The inverter controller 430 may control the motor 230 at a desired speed and torque by using the current command generator 330 and the voltage command generator 340 by using the sensed phase current. Will be.

6 is a diagram referred for explanation of common mode noise.

Referring to the drawings, the input AC power source Vsa as shown in the drawing may be input to the active filter unit 450 of FIG. 4A.

According to a switching operation of the inverter 430 or the like in the power converters 220 and 220b of FIG. 4A or 4B, a harmonic component may be included in the input AC power supply Vsa, and in particular, common noise noise. May occur.

Due to the common noise noise, the durability of the internal circuit elements may be weakened, and the power conversion efficiency may be lowered.

7 is an example of an internal circuit diagram of an active filter unit according to the present invention.

Referring to the drawings, the active filter unit 450x for reducing the common mode noise described in the description of FIG. 6 includes a transformer 710 for sensing an input AC power and amplifying the sensed current. An amplifier 720 and capacitors Cm, Cn, and Co may be provided.

According to the active filter unit 450x of FIG. 7, when a transformer for detecting current of the input AC power supply Vsa is used in order to reduce common mode noise, the transformer may be turned on due to a high level of AC power. There is a limitation in the characteristics, in particular, there is a disadvantage in that there is a limit in the frequency range to compensate.

Accordingly, the present invention proposes a method for efficiently and simply reducing such common mode noise. This will be described with reference to FIG. 8 or below.

8 is an example of an internal circuit diagram of an active filter unit according to an embodiment of the present invention.

Referring to the drawings, the active filter 420 according to the embodiment of the present invention includes a common mode noise detector 453, a common mode noise compensator 459, and a common mode noise detector 453 and a common mode. A transformer 454 may be provided to insulate the noise compensator 459.

In detail, the transformer 454 may be disposed between the first capacitor portion 451 and the second capacitor portion 456.

The common mode noise detector 453 may include a first capacitor unit 451 and a first transformer 452.

The first capacitor unit 451 may filter the input AC power supply Vs. To this end, the first capacitor unit 451 may include capacitors Ca and Ca, which are connected to both ends (a to b) of the input terminal, respectively. In this case, the capacitors Caa and Cab may be connected to the input terminal in a Y shape, and thus may be referred to as Y capacitors.

For example, the first capacitor unit 451 may perform high pass filtering to cut off low frequency input AC power and output high frequency common mode noise in.

Accordingly, the first capacitor unit 451 can output common mode noise in of the input AC power supply Vs.

On the other hand, by outputting common mode noise having a small level through the first capacitor unit 451, it is possible to simply extract common mode noise.

The first transformer 452 may detect the current ina from the first capacitor unit 451.

In detail, the first transformer 452 may detect common mode noise of the input AC power supply Vs.

The first transformer 452 may be a small transformer.

On the other hand, it is preferable that the magnitude of the current input to the first transformer 452 is smaller than the magnitude of the current input to the active filter unit 450. That is, unlike FIG. 7, a small level of common mode noise may be input to the first transformer 452.

The amplifier 455 may amplify the current sensed by the first transformer 452.

In detail, the amplifier 455 may amplify common mode noise detected by the first transformer 452.

On the other hand, the amplifier 455 may operate based on the voltage at both ends of the dc terminal capacitor (C). According to this, there is an advantage that a separate power supply for the amplifier 455 is unnecessary.

Next, the common mode noise compensation unit 459 may include a second transformer 458 and a second capacitor unit 455.

The second transformer 458 can convert the current from the amplifier 455.

In particular, the second transformer 458 can convert the current from the amplifier 455 so that the phase of the current applied to the first transformer 452 and the current output from the second transformer 458 are reversed. have.

In detail, the second transformer 458 may convert the phase of the common mode noise from the amplifier 455 and output the compensation signal inb having the opposite phase.

The second capacitor unit 456 may filter and output the current from the second transformer 458.

To this end, the second capacitor unit 456 may include capacitors Cba and Cbb connected to both ends (c-d) of the output terminal of the active filter unit 450, respectively. In this case, the capacitors Cba and Cbb may be connected to an output terminal in a Y shape, and thus may be referred to as Y capacitors.

For example, the second capacitor unit 456 may perform high pass filtering to block low frequency currents and output a compensation signal inb having a phase opposite to that of the high frequency common mode noise in. .

Accordingly, the common mode noise (ina) included in the input AC power supply Vs can be effectively removed by the compensation signal inb outputted at both ends of the output terminal of the active filter unit 450. do. In particular, common mode noise in a wide frequency band can be reduced.

As described above, by detecting the common mode noise using the first transformer 452 and compensating the common mode noise using the second transformer 458, reliability of disturbance such as surge may be enhanced.

On the other hand, in order to compensate for the common mode noise, a separate switch element is not required, and thus an active filter unit having a reduced manufacturing cost can be implemented.

The active filter unit 450 of FIG. 8 may be applied to the above-described FIG. 4A or 4B.

Meanwhile, the power converter 220 according to the embodiment of the present invention described with reference to FIGS. 3 to 8 may be applied to various home appliances in addition to the air conditioner 100 of FIG. 1. For example, the present invention can be applied to various fields such as laundry treatment equipment (washing machine, dryer, etc.), refrigerator, water purifier, and robot cleaner.

9 is a diagram illustrating a configuration of an air conditioner according to another embodiment of the present invention.

Referring to the drawings, the air conditioner 100b of FIG. 9 differs from the system type air conditioner of FIG. 1 in that it includes one outdoor unit 31b.

As shown in FIG. 9, the air conditioner 100b according to the present invention may include an indoor unit 31b and an outdoor unit 21b connected to the indoor unit 31b.

The indoor unit 31b of the air conditioner may be any of a stand type air conditioner, a wall-mounted air conditioner, and a ceiling type air conditioner, but the drawing illustrates the stand type indoor unit 31b.

Meanwhile, the air conditioner 100b may further include at least one of a ventilation device, an air cleaning device, a humidifier, and a heater, and may operate in conjunction with the operation of the indoor unit and the outdoor unit.

The outdoor unit 21b includes a compressor (not shown) for receiving and compressing a refrigerant, an outdoor heat exchanger (not shown) for exchanging refrigerant and outdoor air, and an accumulator for extracting a gas refrigerant from the supplied refrigerant and supplying it to the compressor (not shown). And a four-way valve (not shown) for selecting a flow path of the refrigerant according to the heating operation. In addition, although a plurality of sensors, valves and oil recovery device, etc. are further included, the description of the configuration will be omitted below.

The outdoor unit 21b operates the compressor and the outdoor heat exchanger, and compresses or heat exchanges the refrigerant according to a setting to supply the refrigerant to the indoor unit 31b. The outdoor unit 21b may be driven by the demand of the remote controller (not shown) or the indoor unit 31b. In this case, as the cooling / heating capacity is changed corresponding to the indoor unit being driven, the number of operation of the outdoor unit and the number of operation of the compressor installed in the outdoor unit may be changed.

At this time, the outdoor unit 21b supplies the compressed refrigerant to the connected indoor unit 310b.

The indoor unit 31b receives a coolant from the outdoor unit 21b and discharges cold air into the room. The indoor unit 31b includes an indoor heat exchanger (not shown), an indoor fan (not shown), an expansion valve (not shown) in which the refrigerant supplied is expanded, and a plurality of sensors (not shown).

At this time, the outdoor unit 21b and the indoor unit 31b are connected by a communication line to transmit and receive data, and the outdoor unit and the indoor unit are connected to a remote controller (not shown) by wire or wirelessly and operate under the control of a remote controller (not shown). can do.

The remote controller (not shown) may be connected to the indoor unit 31b to input a user's control command to the indoor unit, and receive and display state information of the indoor unit. At this time, the remote control may communicate by wire or wirelessly according to the connection form with the indoor unit.

10 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 9.

Referring to the drawings, the air conditioner 100b is largely divided into an indoor unit 31b and an outdoor unit 21b.

The outdoor unit 21b includes a compressor 102b that serves to compress the refrigerant, a compressor electric motor 102bb that drives the compressor, an outdoor side heat exchanger 104b that serves to radiate the compressed refrigerant, and an outdoor unit. An outdoor blower 105b disposed at one side of the heat exchanger 104b and including an outdoor fan 105ab for promoting heat dissipation of the refrigerant and an electric motor 105bb for rotating the outdoor fan 105ab, and an expansion for expanding the condensed refrigerant; The mechanism 106b, the cooling / heating switching valve 110b for changing the flow path of the compressed refrigerant, and the accumulator 103b for temporarily storing the gasified refrigerant to remove moisture and foreign matter and then supplying a refrigerant of a constant pressure to the compressor. And the like.

The indoor unit 31b is an indoor side heat exchanger 109b disposed indoors to perform a cooling / heating function, and an indoor fan 109ab and an indoor side disposed on one side of the indoor side heat exchanger 109b to promote heat dissipation of the refrigerant. The indoor blower 109b etc. which consist of the electric motor 109bb which rotates the fan 109ab are included.

At least one indoor side heat exchanger 109b may be installed. The compressor 102b may be at least one of an inverter compressor and a constant speed compressor.

In addition, the air conditioner 100b may be configured as a cooler for cooling the room, or may be configured as a heat pump for cooling or heating the room.

The compressor 102b in the outdoor unit 21b of FIG. 9 may be driven by a power converter 220, such as FIG. 3, which drives the compressor motor 250b.

Alternatively, the indoor fan 109ab or the outdoor fan 105ab may be driven by the power converter 220, as shown in FIG. 3, which drives the indoor fan motor 109bb and the outdoor fan motor 150bb, respectively. .

On the other hand, the operating method of the power converter or air conditioner of the present invention, it is possible to implement as a processor readable code on a processor-readable recording medium provided in the power converter or air conditioner. The processor-readable recording medium includes all kinds of recording devices that store data that can be read by the processor. Examples of the processor-readable recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like, and may also be implemented in the form of a carrier wave such as transmission over the Internet. . The processor-readable recording medium can also be distributed over network coupled computer systems so that the processor-readable code is stored and executed in a distributed fashion.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (13)

A converter for converting input AC power into DC power;
A dc terminal capacitor disposed at an output terminal of the converter to store the DC power;
An inverter for converting DC power stored in the dc terminal capacitor and outputting AC power to a motor;
An active filter unit disposed at a front end of the converter and performing active filtering on the input AC power source;
The active filter unit,
A first capacitor unit filtering the input AC power;
A first transformer for sensing current from the first capacitor unit;
An amplifier for amplifying the current sensed by the first transformer;
A second transformer for converting current from the amplifier;
And a second capacitor unit for filtering current from the second transformer. The method of claim 1,
And the phase of the current applied to the first transformer and the current output from the second transformer are opposite. The method of claim 1,
The first capacitor unit,
And a common mode noise of the input AC power. The method of claim 1,
The amplifier,
And a power conversion device operating based on voltages at both ends of the dc terminal capacitor. The method of claim 1,
And a magnitude of a current input to the first transformer is smaller than a magnitude of a current input to the active filter unit. The method of claim 1,
The active filter unit,
And a third transformer disposed between the first capacitor portion and the second capacitor portion. The method of claim 1,
And an inverter controller for controlling the inverter. A converter for converting input AC power into DC power;
A dc terminal capacitor disposed at an output terminal of the converter to store the DC power;
An inverter for converting DC power stored in the dc terminal capacitor and outputting AC power to a motor;
An active filter unit disposed at a front end of the converter and performing active filtering on the input AC power source;
The active filter unit,
A first transformer for detecting common mode noise of the input AC power;
An amplifier for amplifying the common mode noise detected by the first transformer;
And a second transformer for converting and outputting a phase of the common mode noise from the amplifier. A converter for converting input AC power into DC power;
A dc terminal capacitor disposed at an output terminal of the converter to store the DC power;
An inverter for converting DC power stored in the dc terminal capacitor and outputting AC power to a motor;
And an active filter unit disposed between the converter and the dc terminal capacitor.
The active filter unit,
A first capacitor unit filtering the input AC power;
A first transformer for sensing current from the first capacitor unit;
An amplifier for amplifying the current sensed by the first transformer;
A second transformer for converting current from the amplifier;
And a second capacitor unit for filtering current from the second transformer. The method of claim 9,
And the phase of the current applied to the first transformer and the current output from the second transformer are opposite. The method of claim 9,
The first capacitor unit,
And a common mode noise of the input AC power. The method of claim 9,
The amplifier,
And a power conversion device operating based on voltages at both ends of the dc terminal capacitor. 13. The air conditioner of claim 1, further comprising a power converter of any one of claims 12.

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