KR102010388B1 - Power converting apparatus and air conditioner including the same - Google Patents

Abstract

The present invention relates to a motor drive device and an air conditioner having the same. The motor drive apparatus 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, an input voltage detector for detecting the input voltage of the front end of the converter, and the pulsation voltage from the converter A dc terminal capacitor, a dc terminal voltage detection unit detecting a voltage across the dc terminal capacitor, an inverter converting DC power stored in the dc terminal capacitor to output AC power to the motor, and a controller for controlling the inverter. The control unit controls to compensate the harmonic components of the input voltage from the input voltage detector, and controls to compensate for the delay of the dc terminal voltage based on the dc terminal voltage from the dc terminal voltage detector. This makes it possible to reduce harmonics of the input current in the motor driving apparatus using the capacitor having a low capacitance.

Description

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

The present invention relates to a motor driving apparatus and an air conditioner having the same, and more particularly, in a motor driving apparatus using a capacitor having a low capacitance, a motor driving apparatus capable of reducing harmonics of an input current and an air conditioning including the same. It is about the flag.

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 motor driving apparatus capable of reducing harmonics of an input current and an air conditioner having the same in a motor driving apparatus using a capacitor having a low capacitance.

Motor driving apparatus 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 source, an input voltage detector for detecting the input voltage of the front end of the converter, converter DC stage capacitor to store pulsating voltage from DC stage, DC stage voltage detector to detect voltage across dc stage capacitor, inverter to convert DC power stored in dc stage capacitor to output AC power to motor, and inverter And a control unit to compensate for the harmonic components of the input voltage from the input voltage detector, and to compensate for the delay of the dc terminal voltage based on the dc terminal voltage from the dc terminal voltage detector.

According to an embodiment of the present invention, a motor drive device and an air conditioner including the same include: a converter for converting an input AC power source into a DC power source; an input voltage detector for detecting an input voltage in front of the converter; and a pulsation voltage from the converter. It includes a dc terminal capacitor for storing a, a dc terminal voltage detection unit for detecting a voltage across the dc terminal capacitor, an inverter for converting the DC power stored in the dc terminal capacitor to output AC power to the motor, and a control unit for controlling the inverter The control unit controls to compensate the harmonic components of the input voltage from the input voltage detector, and controls to compensate for the delay of the dc terminal voltage based on the dc terminal voltage from the dc terminal voltage detector, thereby using a capacitor having a low capacitance. In the motor drive device, harmonics of the input current can be reduced.

In particular, when a capacitor having a low capacitance is used, the voltage across the dc terminal capacitor pulsates, thereby compensating for the delay of the dc terminal voltage and compensating for the harmonic component of the input voltage, thereby reducing the harmonics of the input current in the motor driving device. It becomes possible.

On the other hand, only by the compensation of the delay of the dc terminal voltage, harmonic reduction of the input current cannot be smoothly performed according to the magnitude of the input current, but after compensating the harmonic components of the input voltage and performing the delay compensation of the dc terminal voltage, Regardless, the harmonics of the input current can be stably reduced.

On the other hand, by compensating for the harmonic components of the input voltage and performing delay compensation of the dc terminal voltage, it is possible to quickly reduce the harmonics of the input current.

On the other hand, as the ripple of the pulsating voltage is increased, the delay compensation value of the dc terminal voltage is controlled to be larger, so that harmonics of the input current can be stably reduced even when a capacitor having a low capacitance is used.

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 motor driving apparatus according to an embodiment of the present invention.
4 is an example of an internal circuit diagram of a motor driving apparatus according to the present invention.
FIG. 5 is a waveform diagram in the motor driving device of FIG. 4.
6 is an example of an internal block diagram of an inverter controller according to an exemplary embodiment of the present invention.
7A to 7B are waveform diagrams in the motor driving apparatus controlled by the inverter controller in FIG. 6.
8 is a circuit diagram of a motor driving apparatus according to an embodiment of the present invention.
9 to 10 are views referring to the operation of the motor driving apparatus of FIG. 8.
11 is a flowchart illustrating a method of operating a motor driving apparatus according to an exemplary embodiment of the present invention.
12 to 13B are views referred to for describing the operating method of FIG. 11.
14 is a diagram illustrating a configuration of an air conditioner according to another embodiment of the present invention.
15 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 14.

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 motor driving apparatus according to an embodiment of the present invention.

Referring to the drawings, the motor driving apparatus 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 apparatus.

The motor driving apparatus 220 according to the embodiment of the present invention is a capacitorless type motor driving apparatus including a low capacitance dc terminal capacitor C, and may be referred to as a motor driving unit.

Motor driving device 220 according to an embodiment of the present invention, the converter 410, the inverter 420, the inverter control unit 430, the dc terminal voltage detector (B), the dc terminal capacitor (C), the output current detector ( E), an input voltage detector A and a dc stage reactor L may be included.

On the other hand, when using a low-capacity dc terminal capacitor (C), it is possible to use a film capacitor rather than an electrolytic capacitor, thus, the size of the motor drive device 200 can be reduced, the manufacturing cost is reduced have.

On the other hand, in the case of using the low-capacity dc stage capacitor C, the dc stage voltage is pulsated, and accordingly, the change or magnitude of the ripple of the dc stage voltage becomes large. The greater the pulsation of the dc stage voltage, the greater the harmonic content of the input current.

In the present invention, in relation to the harmonic quality regulation, in the motor drive device 220 using a low-capacity dc stage capacitor (C), it proposes a method for reducing the harmonics of the input current. This will be described with reference to FIG. 6 or below.

4 is an example of an internal circuit diagram of a motor driving apparatus according to the present invention.

Referring to the drawings, the motor driving apparatus 220x of FIG. 4 includes a rectifier 410x, a dc stage reactor L, a dc stage capacitor C, and an inverter 420x that rectify the input AC power supply 201x. can do.

In order to reduce harmonics of the input current, the motor driving device 220x of FIG. 4 detects voltages at both ends of the dc stage reactor L connected between the rectifier 410x and the dc stage capacitor C. (101x).

The harmonics of the input current can be reduced by performing control based on the voltage detected by the voltage detector 101x and the voltage at both ends of the dc terminal capacitor C. FIG.

However, on the basis of the voltage detected by the voltage detector 101x and the voltage at both ends of the dc terminal capacitor C, even if harmonics of the input current are reduced through PI control, the improvement of the input current waveform is not effective. There are disadvantages. That is, there is a disadvantage that the harmonic reduction of the input current is not performed stably.

FIG. 5 is a waveform diagram in the motor driving device of FIG. 4.

According to the motor driving device 220x of FIG. 4, as shown in FIG. 5B, harmonics are present in the input current waveform isism. As shown in FIG. 5A, an output flowing through the motor 230x is shown. The dc component of the current (Vdcm) becomes unstable.

Accordingly, the present invention proposes a method of stably reducing harmonics of input current.

On the other hand, in the case of using the low-capacity dc stage capacitor C, the dc stage voltage is pulsated, and accordingly, the change or magnitude of the ripple of the dc stage voltage becomes large. The greater the pulsation of the dc stage voltage, the greater the harmonic content of the input current.

Therefore, in the present invention, in the motor drive device 220 using a low-capacity dc terminal capacitor (C) with respect to the harmonic quality regulation, a method for stably reducing the harmonics of the input current. This will be described with reference to FIG. 6 or below.

6 is an example of an internal block diagram of an inverter controller according to an exemplary embodiment of the present invention.

Referring to FIG. 6, 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 input voltage compensator 380, The dc stage voltage delay compensator 390, the 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 input voltage compensator 380.

The input voltage compensator 380 may extract harmonic components of the input voltage Vs from the input voltage detector A, and perform control on the extracted harmonic components. The output of the input voltage compensator 380 is input to the dc stage voltage delay compensator 390.

The dc stage voltage delay compensator 390 compensates for the delay of the dc stage voltage based on the dc stage voltage Vdc from the dc stage voltage detector B after the harmonic component compensation of the input voltage Vs.

On the other hand, the dc stage voltage delay compensator 390 may control the delay compensation value of the dc stage voltage to increase as the pulsation voltage, that is, the ripple of the dc stage voltage Vdc increases.

The output of the dc stage voltage delay compensator 390 may be a d-axis or q-axis voltage command value (v ^* _d , v ^* _q ), and may be input to the axis conversion unit 350, respectively.

)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.

7A to 7B are waveform diagrams in the motor driving apparatus controlled by the inverter controller in FIG. 6.

First, FIG. 7A illustrates that the dc terminal voltage Vdc is stably pulsated under the control of the inverter controller in FIG. 6, and FIG. 7B illustrates that harmonics are reduced in the input voltage waveform Vsa.

8 is a circuit diagram of a motor driving apparatus according to an embodiment of the present invention, and FIGS. 9 to 10 are views referred to for describing the operation of the motor driving apparatus of FIG. 8.

First, referring to FIGS. 8 and 9, the motor driving apparatus 220 according to an embodiment of the present invention may include a converter 410, an inverter 420, an inverter controller 430, a dc terminal voltage detector B, A dc stage capacitor C, an output current detector E, an input voltage detector A, and a dc stage reactor L may be included.

The input voltage detector A can detect the input voltage V _s input from the commercial AC power supply 201. To this end, as the input voltage detector A, a voltage trnasformer (VT), a shunt resistor, or the like may be used. The detected input voltage V _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 201 which passed through the reactor L into DC power, and outputs it. Although the commercial AC power supply 201 is shown as a three-phase AC power supply in the figure, it may be a single phase AC power supply. The internal structure of the converter 410 also varies according to the type of the commercial AC power supply 201.

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, as shown in the drawing, when the input power source is a three-phase AC power source, six diodes may be used in the form of a bridge. As another example, when the input power source is a single-phase AC power source, four 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 dc stage reactor L may be connected between the converter 410 and the dc stage capacitor C. Since the dc stage reactor L and the dc stage capacitor C are connected to each other, it is possible to partially reduce the harmonic current caused by LC resonance.

The dc terminal capacitor C may store input power. In the present invention, as described above, a capacitor having a low capacitance in the form of a film is used.

On the other hand, in the figure, one device is exemplified by the dc terminal capacitor C, but a plurality of devices may be provided to ensure device stability.

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

The dc terminal voltage detector B may detect the dc terminal voltage Vdc which is both ends of the dc terminal 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. The detailed operation of the output of the inverter switching control signal Sic in the inverter controller 430 is described with reference to FIG. 6.

On the other hand, the inverter control unit 430 controls to compensate the harmonic components of the input voltage Vs from the input voltage detector A, and based on the dc terminal voltage Vdc from the dc terminal voltage detector B, It can be controlled to compensate for the delay of the dc terminal voltage. Accordingly, in the motor 230 driving apparatus using the capacitor having a low capacitance, it is possible to reduce harmonics of the input current.

On the other hand, when the capacitor having a low capacitance, the inverter control unit 430 pulsates the voltage across the dc terminal capacitor (C), the compensation of the harmonic components of the input voltage (Vs) while compensating for the delay of the dc terminal voltage. Can be. Accordingly, the harmonics of the input current can be reduced in the motor 230 driving device.

On the other hand, only by the compensation of the delay of the dc terminal voltage, harmonic reduction of the input current cannot be smoothly performed according to the magnitude of the input current, but after compensating the harmonic components of the input voltage Vs, the delay compensation of the dc terminal voltage is performed. Regardless of the magnitude of the current, harmonics of the input current can be stably reduced.

Meanwhile, the inverter controller 430 may compensate for the harmonic component of the input voltage Vs and then perform delay compensation of the dc terminal voltage. As a result, the harmonics of the input current can be reduced quickly.

Meanwhile, the inverter controller 430 controls the delay compensation value of the dc terminal voltage to become larger as the ripple of the pulsation voltage increases, so that harmonics of the input current can be stably reduced even when a capacitor having a low capacitance is used. .

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.

Meanwhile, FIG. 10 illustrates an internal block diagram of the inverter controller 430 as shown in FIG. 6, except that the input voltage compensator 380 is further illustrated. The following description focuses on differences from FIG. 6.

The input voltage compensator 380 extracts harmonic components of the input voltage Vs from the input voltage detector A, and performs a control on the extracted harmonic components, respectively, and a secondary controller. The controller 820 may be provided.

The primary controller 810 and the secondary controller 820 are connected in parallel, respectively, and the output of the primary controller 810 and the output of the secondary controller 810 may be summed in the adder 825, respectively.

As described above, since the primary controller 810 and the secondary controller 820 operate in parallel with each other, time delays caused by a plurality of controller operations can be reduced, and therefore, harmonics of the input current can be quickly reduced. You can do it.

On the other hand, the dc stage voltage delay compensator 390 compensates for the delay of the dc stage voltage based on the dc stage voltage Vdc from the dc stage voltage detector B after the harmonic component compensation of the input voltage Vs. can do.

On the other hand, the dc stage voltage delay compensator 390 calculates an error between the detected dc stage voltage Vdc from the dc stage voltage detector B and the delayed dc stage voltage Vdc to determine the dc stage voltage. Compensation errors can be compensated for using the delay compensation value.

The switching control signal output unit 360 may output the inverter 420 switching control signal to the inverter 420 based on the dc terminal voltage compensated by the dc terminal voltage delay compensator 390 and the voltage command value. .

11 is a flowchart illustrating a method of operating a motor driving apparatus according to an exemplary embodiment of the present invention, and FIGS. 12 to 13B are views referred to in describing the operating method of FIG. 11.

First, referring to FIG. 11, the input voltage detector A detects the input voltage Vs (S910), and the detected input voltage Vs is transmitted to the inverter controller 430.

The input voltage compensator 380 in the inverter controller 430 extracts harmonic components of the input voltage Vac from the input voltage detector A and compensates for the extracted harmonic components (S920).

As described above, the input voltage compensator 380 extracts harmonic components of the input voltage Vac from the input voltage detector A, and performs control on the extracted harmonic components, respectively. Can be summed and output.

Next, the dc terminal voltage detection unit B detects the dc terminal voltage Vdc (S930). The detected dc terminal voltage Vdc is transmitted to the inverter controller 430.

On the other hand, the detected dc terminal voltage Vdc is the actual dc terminal voltage Vdcr and the delayed dc terminal voltage as shown in FIG. 12A due to the detection circuit and the computational delay in the inverter controller 430. The difference with (Vdcl) will occur.

Next, the dc stage voltage delay compensator 390 in the inverter controller 430 calculates an error due to the dc stage voltage delay (S940).

The dc stage voltage delay compensator 390 in the inverter controller 430 calculates an error err due to the dc stage voltage delay, as shown in FIG.

Next, the dc stage voltage delay compensator 390 in the inverter controller 430 compensates for the dc stage voltage based on the calculated error (S950).

The dc stage voltage delay compensator 390 in the inverter controller 430 generates the compensated dc stage voltage Vdcc based on an error err caused by the dc stage voltage delay, as shown in FIG. .

In addition, the dc stage voltage delay compensator 390 in the inverter controller 430 has an error errf which is a difference between the compensated dc stage voltage Vdcc and the delayed dc stage voltage Vdcl, as shown in FIG. Calculate

The dc stage voltage delay compensator 390 in the inverter controller 430 compensates for Td by using the error errf as shown in FIG. That is, a signal cmp in which the phase is pulled by Td is generated.

According to the harmonic component compensation of the input voltage and the delay compensation of the dc terminal voltage, harmonics of the input current are reduced, and the dc component of the output current is also stabilized.

13A and 13B illustrate that the control of FIG. 11 is performed at time T1.

First, (a) of FIG. 13A illustrates input current waveforms before and after a T1 time point. That is, it is illustrated that harmonics appear in the input current waveform Is1 before the time point T1, but harmonics are reduced in the input current waveform Is2 after the time point T1.

Next, Fig. 13A (b) illustrates the dc component waveforms of the output current before and after the time point T1. That is, the dc component waveform iod1 of the output current before the time T1 is unstable, but the dc component waveform iod2 of the output current after the T1 time is stable.

Next, (a) of FIG. 13B illustrates a dc terminal voltage waveform before and after a Ta point of time. That is, the dc stage voltage waveform Vdca before the Ta point of time pulsates irregularly, but the dc stage voltage waveform Vdcb after the Ta point of time pulsates regularly.

Next, (a) of FIG. 13A illustrates input current waveforms before and after a Ta point in time. That is, it is illustrated that harmonics appear in the input current waveform Issa before the Ta point of time, but harmonics are reduced in the input current waveform Isb after the Ta point of time.

Next, Fig. 13A (b) illustrates the dc stage current waveform before and after the Ta point of time. That is, the dc stage current waveform idca before the Ta point is constant, but the dc stage current waveform idcb after the Ta point is pulsated regularly.

As a result, the harmonic component compensation of the input voltage and the delay compensation of the dc terminal voltage reduce the harmonics of the input current and further stabilize the dc component of the output current.

Meanwhile, the motor driving device 220 described with reference to FIGS. 3 to 13B 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.

14 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. 14 differs from the system type air conditioner of FIG. 1 in that it includes one outdoor unit 31b.

As shown in FIG. 14, 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.

15 is a schematic diagram of the outdoor unit and the indoor unit of FIG. 14.

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. 14 may be driven by a motor driving device 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 motor driving device 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 motor drive device or air conditioner of the present invention, it is possible to implement as a processor readable code on a recording medium readable by the processor provided in the motor drive device 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 (10)

A converter for converting input AC power into DC power;
An input voltage detector configured to detect an input voltage before the converter;
A dc stage capacitor for storing the pulsation voltage from the converter;
A dc end voltage detector configured to detect a voltage across the dc end capacitor;
An inverter for converting DC power stored in the dc terminal capacitor and outputting AC power to a motor; And
And a controller for controlling the inverter.
The control unit,
And control to compensate for harmonic components of the input voltage from the input voltage detector, and to compensate for the delay of the dc terminal voltage based on the dc terminal voltage from the dc terminal voltage detector. Device. The method of claim 1,
The control unit,
And the greater the ripple of the pulsating voltage, the greater the delay compensation value of the dc terminal voltage. The method of claim 1,
The control unit,
And an input voltage compensator for extracting harmonic components of the input voltage from the input voltage detector and performing control on the extracted harmonic components. The method of claim 3,
The control unit,
And a dc end voltage delay compensator configured to compensate for the delay of the dc end voltage based on the dc end voltage from the dc end voltage detector after the harmonic component compensation of the input voltage. Device. The method of claim 3,
The input voltage compensator,
And a primary controller and a secondary controller which operate in parallel with each other and perform control on the extracted harmonic components, respectively.
And the outputs of the primary controller and the secondary controller are summed in an adder, respectively. The method of claim 4, wherein
The dc stage voltage delay compensator,
And calculating an error between the detected dc terminal voltage and the delayed dc terminal voltage from the dc terminal voltage detector, and compensating the calculation error using a delay compensation value of the dc terminal voltage. Device. The method of claim 4, wherein
And a switching control signal output unit configured to output an inverter switching control signal to the inverter based on the dc terminal voltage compensated by the dc terminal voltage delay compensator and a voltage command value. The method of claim 7, wherein
And an output current detector for detecting an output current flowing through the motor.
The control unit,
A speed calculator configured to calculate a speed of the motor based on the output current;
A current command generator for generating a current command value based on the calculated speed and the speed command value from the speed calculator;
And a voltage command generation unit configured to generate a voltage command value based on the current command value and the output current. The method of claim 1,
And a dc stage reactor connected between the converter and the dc stage capacitor. An air conditioner comprising: the motor driving device according to any one of claims 1 to 9.

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