KR20190075621A - Power converting apparatus and air conditioner including the same - Google Patents

Abstract

The present invention relates to a motor driving apparatus and an air conditioner having the same. According to the present invention, the motor driving apparatus and the air conditioner having the same include: a converter which converts input AC power into DC power; an input voltage detection unit which detects an input voltage of a front end of the converter; a DC-terminal capacitor which stores a ripple voltage from the converter; a DC-terminal voltage detection unit which detects a voltage of both ends of the DC-terminal capacitor; an inverter which converts the DC power stored in the DC-terminal capacitor to output the AC power into the motor; and a control unit which controls the inverter wherein the control unit controls harmonic wave component of the input voltage from the input voltage detection unit to be complemented, and controls delay of a DC-terminal voltage to be complemented based on the DC-terminal voltage from the DC-terminal voltage detection unit. Therefore, it is possible to reduce harmonic wave of an input current in a motor driving apparatus using a low volume of capacitor.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor driving apparatus and an air conditioner having the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor driving apparatus and an air conditioner having the same, and more particularly, to a motor driving apparatus that can reduce harmonics of an input current in a motor driving apparatus using a capacitor of a low capacity, Lt; / RTI >

The air conditioner is installed to provide a comfortable indoor environment for humans by discharging cold air to the room to adjust the room temperature and purify the room air to create a pleasant indoor environment. Generally, the air conditioner includes an indoor unit which is constituted by a heat exchanger and installed in a room, and an outdoor unit which is constituted by a compressor, a heat exchanger and the like and supplies the refrigerant to the indoor unit.

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

On the other hand, according to IEC 61000, an international surge protection standard, a specification for harmonic reduction is set. Accordingly, various attempts have been made to reduce the harmonics by the input alternating current in the air conditioner.

An object of the present invention is to provide a motor drive apparatus capable of reducing harmonics of an input current in a motor drive apparatus using a capacitor of a low capacity and an air conditioner having the motor drive apparatus.

According to an aspect of the present invention, there is provided a motor drive apparatus and an air conditioner having the same, including a converter for converting input AC power to DC power, an input voltage detecting unit for detecting an input voltage at a front end of the converter, A dc short-circuit voltage detector for detecting a voltage across the dc short-circuit capacitor, an inverter for converting the direct-current power stored in the dc short-circuit capacitor and outputting an alternating-current power to the motor, The control unit controls to compensate for the harmonic component of the input voltage from the input voltage detecting unit and controls to compensate for the delay of the dc step voltage based on the dc step voltage from the dc step voltage detecting unit.

According to an embodiment of the present invention, a motor driving apparatus and an air conditioner having the same include a converter for converting an input AC power source to a DC power source, an input voltage detecting unit for detecting an input voltage at a front end of the converter, A dc short-circuit voltage detector for detecting a voltage across the dc short-circuit capacitor, an inverter for converting the direct-current power stored in the dc short-circuit capacitor and outputting an alternating current power to the motor, and a controller for controlling the inverter And the control unit controls to compensate for the harmonic component of the input voltage from the input voltage detecting unit and controls the delay of the dc step voltage based on the dc step voltage from the dc step voltage detecting unit so as to use the capacitor of low capacity The harmonic of the input current can be reduced.

Particularly, when a low capacity capacitor is used, since the voltage across the dc short capacitor is pulsated, the harmonic component of the input voltage is compensated while compensating for the delay of the dc short voltage, thereby reducing the harmonic of the input current .

On the other hand, the harmonics reduction of the input current can not be smoothly performed according to the magnitude of the input current only by delay compensation of the dc step voltage. However, after compensating the harmonic components of the input voltage, The harmonics of the input current can be stably reduced, regardless of the power consumption.

On the other hand, by compensating the harmonic component of the input voltage and performing the delay compensation of the dc short-circuit voltage, the harmonic of the input current can be quickly reduced.

On the other hand, by controlling the delay compensation value of the dc short voltage to be larger as the ripple voltage ripple becomes larger, the harmonics of the input current can be stably reduced even if a capacitor of a low capacity 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 view of the outdoor unit and the indoor unit of FIG.
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.
5 is a waveform diagram in the motor driving apparatus of Fig.
6 is an example of an internal block diagram of the inverter control unit according to the embodiment of the present invention.
Figs. 7A to 7B are waveform diagrams in the motor driving apparatus controlled by the inverter control unit in Fig.
8 is a circuit diagram of a motor driving apparatus according to an embodiment of the present invention.
9 to 10 are views referred to in the description of the operation of the motor driving apparatus of FIG.
11 is a flowchart showing an operation method of the motor driving apparatus according to the embodiment of the present invention.
12 to 13B are views referred to in the description of the operation method of FIG.
FIG. 14 is a diagram illustrating a configuration of an air conditioner according to another embodiment of the present invention. FIG.
15 is a schematic view of the outdoor unit and the indoor unit of Fig.

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

The suffix "module" and " part "for components used in the following description are given merely for convenience of description, and do not give special significance or role in themselves. Accordingly, the terms "module" and "part" may be used interchangeably.

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

1, a large-sized air conditioner 50 includes a plurality of indoor units 31 to 35, a plurality of outdoor units 21 and 22 connected to a plurality of indoor units, Remote controllers 41 to 45 connected to the respective indoor units, and a remote controller 10 for controlling the plurality of indoor units and the outdoor units.

The remote controller 10 is connected to a plurality of indoor units 31 to 36 and a 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, and the like for the indoor units.

The air conditioner may be any of a stand-type air conditioner, a wall-mounted air conditioner, and a ceiling-type air conditioner, but a ceiling-type air conditioner will be described as an example for convenience of explanation. In addition, the air conditioner may further include at least one of a ventilator, an air purifier, 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 provided with a compressor (not shown) for receiving and compressing the refrigerant, an outdoor heat exchanger (not shown) for exchanging heat between the refrigerant and the outdoor air, an accumulator for extracting the gas refrigerant from the supplied refrigerant, And a four-way valve (not shown) for selecting the flow path of the refrigerant according to the heating operation. In addition, a number of sensors, valves, oil recovery devices, and the like are further included, but a description thereof will be omitted below.

The outdoor units (21, 22) operate the compressor and the outdoor heat exchanger to compress or heat-exchange the refrigerant according to the setting, and supply the refrigerant to the indoor units (31 to 35). The outdoor units 21 and 22 are driven by the request of the remote controller 10 or the indoor units 31 to 35. The number of operation of the outdoor units and the number of operation of the compressors installed in the outdoor units The number of operations is variable.

At this time, the outdoor units (21, 22) are explained on the basis that the plurality of outdoor units supply the refrigerant to the indoor units connected to the indoor units, respectively. However, according to the connection structure of the outdoor units and the indoor units, .

The indoor units 31 to 35 are connected to any one of the plurality of outdoor units 21 and 22 to receive the refrigerant and discharge the cold air to the room. The indoor units 31 to 35 include an indoor heat exchanger (not shown), an indoor fan (not shown), an expansion valve (not shown) in which the refrigerant to be supplied is expanded, and a plurality of sensors (not shown).

At this time, the outdoor units 21 and 22 and the indoor units 31 to 35 are connected to each other via a communication line to transmit and receive data, and the outdoor unit and the indoor unit are connected to the remote controller 10 by a separate communication line, .

The remote controllers 41 to 45 are connected to the indoor units, respectively, to input control commands of the user to the indoor units, and to receive and display status information of the indoor units. At this time, the remote controller communicates wired or wirelessly according to the connection form with the indoor unit, and in some cases, one remote controller is connected to the plurality of indoor units, and the settings of the plurality of indoor units can be changed through one remote control input.

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

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

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

The outdoor unit 21 includes a compressor 102 for compressing the refrigerant, a compressor 102b for driving the compressor, an outdoor heat exchanger 104 serving to dissipate the compressed refrigerant, An outdoor fan 105 which is disposed at one side of the heat exchanger 104 and includes an outdoor fan 105a for accelerating the heat radiation of the refrigerant and an electric motor 105b for rotating the outdoor fan 105a and an outdoor fan 105 for expanding the condensed refrigerant An accumulator 103 for temporarily storing the gasified refrigerant to remove moisture and foreign substances, and then supplying a refrigerant with a predetermined pressure to the compressor, a compressor 106 for compressing the refrigerant, a cooling / heating switching valve 110 for changing the flow path of the compressed refrigerant, And the like.

The indoor unit 31 includes an indoor heat exchanger 109 disposed inside the room and performing a cooling / heating function, an indoor fan 109a disposed at one side of the indoor heat exchanger 109 for promoting heat radiation of the refrigerant, And an indoor air blower 109 composed of an electric motor 109b for rotating the fan 109a.

At least one indoor heat exchanger 109 may be installed. At least one of an inverter compressor and a constant speed compressor may be used as the compressor 102. [

Further, the air conditioner 50 may be constituted by a cooling unit that cools the room, or a heat pump that cools or heats the room.

2, the indoor unit 31 and the outdoor unit 21 are shown as one unit. However, the driving unit of the air conditioner according to the embodiment of the present invention is not limited to this, The present invention is also applicable to an air conditioner, an air conditioner having one indoor unit and a plurality of outdoor units.

The compressor 102 in the outdoor unit 21 of Fig. 1 can be driven by the motor drive unit 200 for the compressor shovel driving the compressor motor 250. Fig.

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, a motor driving device 220 according to an embodiment of the present invention is a device for driving a motor in a sensorless manner and may be called a motor driving device.

The motor driving apparatus 220 according to the embodiment of the present invention may be referred to as a motor driving unit, which is a capacitorless type motor driving apparatus having a dc short capacitor C of a low capacity.

The motor driving apparatus 220 according to the embodiment of the present invention includes a converter 410, an inverter 420, an inverter control unit 430, a dc short voltage detection unit B, a dc short capacitor C, E), an input voltage detecting unit (A), and a dc stage reactor (L).

On the other hand, in the case of using the dc short capacitor C having a small capacity, it is possible to use a film capacitor rather than an electrolytic capacitor, so that the size of the motor driving apparatus 200 can be reduced, have.

On the other hand, when the dc short capacitor C having a small capacity is used, the dc short-circuit voltage is pulsated, and accordingly, the change or size of the ripple of the dc short-circuit voltage becomes large. The greater the pulsation of the dc short-circuit voltage, the larger the harmonic component of the input current can be.

In the present invention, a method of reducing the harmonic of the input current in the motor driving apparatus 220 using the dc short-circuit capacitor C of a small capacity is proposed in relation to the harmonic quality regulation. This will be described with reference to FIG.

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

4, the motor driving apparatus 220x includes a rectifying section 410x for rectifying an input AC power source 201x, a dc stage reactor L, a dc short-circuit capacitor C, and an inverter 420x can do.

The motor driving apparatus 220x shown in Fig. 4 includes a voltage detecting unit (not shown) for detecting the voltage at both ends of the dc-stage reactor L connected between the rectifying unit 410x and the dc short-circuit capacitor C to reduce the harmonic of the input current (101x).

The harmonic of the input current can be reduced by performing control based on the voltage detected by the voltage detector 101x and the voltage across the dc short capacitor C. [

However, even if the harmonics of the input current are reduced through the PI control based on the voltage detected by the voltage detection section 101x and the voltage across the dc short capacitor C, 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 can not be stably performed.

5 is a waveform diagram in the motor driving apparatus of Fig.

5 (b), harmonics are present in the input current waveform ism. As shown in Fig. 5 (a), the motor driving apparatus 220x shown in Fig. The dc component (Vdcm) of the current becomes unstable.

Therefore, the present invention proposes a method for stably reducing the harmonic of the input current.

On the other hand, when the dc short capacitor C having a small capacity is used, the dc short-circuit voltage is pulsated, and accordingly, the change or size of the ripple of the dc short-circuit voltage becomes large. The greater the pulsation of the dc short-circuit voltage, the larger the harmonic component of the input current can be.

Accordingly, the present invention proposes a method for stably reducing the harmonics of the input current in the motor driving apparatus 220 using the low-capacitance dc-stage capacitor C with respect to the harmonic quality regulation. This will be described with reference to FIG.

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

6, the inverter control unit 430 includes an axis conversion unit 310, a speed calculation unit 320, a current command generation unit 330, a voltage command generation unit 340, an input voltage compensation unit 380, a dc terminal voltage delay compensating unit 390, an axis converting unit 350, and a switching control signal outputting unit 360.

The axial conversion unit 310 receives the three-phase output currents ia, ib, ic detected by the output current detection unit E and converts the three-phase output currents ia, ib, ic into the two-phase currents iα, iβ in the stationary coordinate system.

On the other hand, the axis converting unit 310 can convert the two-phase current i ?, i? Of the still coordinate system into the two-phase current id, iq of the rotating coordinate system.

)와 연산된 속도(

)를 출력할 수 있다.Based on the two-phase current (i?, I?) Of the stationary coordinate system changed in the axis by the axis converting unit 310, the speed calculating unit 320 calculates the speed

) And the calculated speed (

Can be output.

)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 generates the current command

(I ^* _q ) on the basis of the speed command value? ^* _R and the speed command value? ^* _R. For example, the current command generation section 330 generates the current command

The PI controller 335 performs the PI control based on the difference between the speed command value? ^* _R and the speed command value? ^* _R , and generates the current command value i ^* _q . In the figure, the q-axis current command value (i ^* _q ) is exemplified by the current command value, but it is also possible to generate the d-axis current command value (i ^* _d ) unlike the 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 section 330 may further include a limiter (not shown) for limiting the current command value (i ^* _q ) so that the current command value (i ^* _q ) does not exceed the allowable range.

Next, the voltage command generating unit 340 generates the voltage command generating unit 340 with the d-axis and q-axis currents (i _d , i _q ) axially transformed into the two-phase rotational coordinate system in the axial converting unit and the current command value based on ^{_{i * d, i * q)}} , and generates a d-axis, q-axis voltage command value ^{_{(v * d, v * q}} ). For example, the voltage command generation unit 340 performs 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 ) It is possible to generate the axial voltage command value v ^* _q . The voltage command generation unit 340 performs 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 , It is possible to generate the command value v ^* _d . The voltage command generator 340 may further include a limiter (not shown) for limiting the level of the d-axis and q-axis voltage command values v ^* _d and v ^* _q so as not to exceed the permissible range .

Meanwhile, the generated d-axis and q-axis voltage command values (v ^* _d , v ^* _q ) are input to the input voltage compensating unit 380.

The input voltage compensating unit 380 can extract a harmonic component of the input voltage Vs from the input voltage detecting unit A and perform control on the extracted harmonic component. The output of the input voltage compensating unit 380 is input to the dc terminal voltage delay compensating unit 390.

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

On the other hand, the dc short voltage delay compensator 390 can control the delay compensation value of the dc short voltage to be larger as the ripple of the pulse voltage, that is, the dc short voltage Vdc becomes larger.

On the other hand, the output of the dc short-circuit voltage delay compensator 390 may be the d-axis and q-axis voltage command values v ^* _d and v ^* _q and may be input to the axis converter 350.

)와, d축, q축 전압 지령치(v^* _d,v^* _q)를 입력받아, 축변환을 수행한다.The axis transforming unit 350 transforms the position calculated by the velocity calculating unit 320

) And the d-axis and q-axis voltage command values (v ^* _d , v ^* _q ).

)가 사용될 수 있다.First, the axis converting unit 350 performs conversion from a two-phase rotating coordinate system to a two-phase stationary coordinate system. At this time, the position calculated by the speed calculator 320 (

) Can be used.

Then, the axial conversion unit 350 performs conversion from the two-phase stationary coordinate system to the three-phase stationary coordinate system. Through this conversion, the axial conversion unit 1050 outputs the three-phase output voltage instruction values v ^* a, v ^* b, v ^* c.

The switching control signal output section 360 generates the switching control signal Sic for inverter according to the pulse width modulation (PWM) method based on the three-phase output voltage instruction values v ^* a, v ^* b and v ^* And outputs it.

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

As described above, the motor driving apparatus 100 controls the motor 230 by controlling the output current io flowing through the motor (motor) to control the vector for driving the motor 230 through the control of the inverter 420. [ In particular, it is essential to detect the phase current.

The inverter control unit 430 can control the motor 230 at a desired speed and torque by using the sensed phase current using the current command generation unit 330 and the voltage command generation unit 340 .

Figs. 7A to 7B are waveform diagrams in the motor driving apparatus controlled by the inverter control unit in Fig.

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

FIG. 8 is a circuit diagram of the motor driving apparatus according to the embodiment of the present invention, and FIGS. 9 to 10 are drawings referred to in the description of the operation of the motor driving apparatus of FIG.

8 and 9, a motor driving apparatus 220 according to an embodiment of the present invention includes a converter 410, an inverter 420, an inverter control unit 430, a dc voltage detection unit B, dc capacitor C, an output current detection unit E, an input voltage detection unit A, and a dc stage reactor L. [

The input voltage detecting section A can detect the input voltage V _s input from the commercial AC power supply 201. For this purpose, a voltage trnasformer (VT), a shunt resistor, or the like may be used as the input voltage detector A. The detected input voltage V _s can be input to the inverter control unit 430 as a discrete signal in the form of a pulse.

The converter 410 converts the commercial AC power source 201 that has passed through the reactor L into DC power and outputs the DC power. Although the commercial AC power source 201 is shown as a three-phase AC power source in the figure, it may be a single-phase AC power source. The internal structure of the converter 410 also changes depending on the type of the commercial AC power source 201.

Meanwhile, the converter 410 may include a diode without a switching element, and may perform a rectifying operation without a separate switching operation.

For example, as shown in the figure, 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 can be used in the form of a bridge.

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

When the converter 410 includes a switching element, the boosting operation, the power factor correction, and the DC power conversion can 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 short-circuit capacitor C. Since the dc stage reactor L and the dc single capacitor C are connected to each other, the harmonic current due to the LC resonance can be partially reduced.

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

In the drawing, one element is exemplified by the dc short-circuit capacitor C, but a plurality of elements are provided, thereby ensuring the element stability.

On the other hand, both ends of the dc short-circuit capacitor C may be referred to as a dc stage or a dc stage since the dc power source is stored.

the dc short-circuit voltage detector B can detect the dc short-circuit voltage Vdc at both ends of the dc short-circuit capacitor C. For this purpose, the dc voltage detection unit B may include a resistance element, an amplifier, and the like. The detected dc voltage source Vdc can be input to the inverter control unit 430 as a discrete signal in the form of a pulse.

The inverter 420 includes a plurality of inverter switching elements and converts the smoothed DC power supply Vdc into a three-phase AC power supply va, vb, vc having a predetermined frequency by on / off operation of the switching element, And outputs it to the synchronous motor 230.

The inverter 420 includes a pair of upper arm switching elements Sa, Sb and Sc and lower arm switching elements S'a, S'b and S'c serially connected to each other, The switching elements are connected to each other in parallel (Sa & S a, Sb & S'b, Sc & S'c). Diodes are connected in anti-parallel to each switching element Sa, S'a, Sb, S'b, Sc, 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. [ Thus, three-phase AC power having a predetermined frequency is output to the three-phase synchronous motor 230.

The inverter control unit 430 can control the switching operation of the inverter 420 based on the sensorless method. To this end, the drive controller 430, and can receive the output current (i _o) detected by the output current detector (E).

The inverter control unit 430 outputs the inverter switching control signal Sic to the inverter 420 to control the switching operation of the inverter 420. [ Inverter switching control signal (Sic) is output is generated by a switching control signal of a pulse width modulation (PWM), based on the output current (i _o) detected by the output current detector (E). The detailed operation of outputting the inverter switching control signal Sic in the inverter control unit 430 is shown in Fig.

On the other hand, the inverter control unit 430 controls to compensate for the harmonic component of the input voltage Vs from the input voltage detecting unit A, and based on the dc step voltage Vdc from the dc step voltage detecting unit B, dc < / RTI > Accordingly, the harmonic of the input current can be reduced in the motor 230 driving apparatus using a capacitor of a low capacity.

On the other hand, when the capacitor of a low capacity is used, the inverter control unit 430 compensates the harmonic component of the input voltage Vs while compensating the delay of the dc short-circuit voltage because the voltage across the dc short- . Hence, the harmonic of the input current can be reduced in the motor 230 driving apparatus.

On the other hand, harmonics reduction of the input current can not be smoothly performed depending on the magnitude of the input current only by delay compensation of the dc step voltage. However, by compensating the harmonic component of the input voltage Vs and performing delay compensation of the dc step voltage, The harmonics of the input current can be stably reduced regardless of the magnitude of the current.

On the other hand, the inverter control unit 430 can compensate the harmonic component of the input voltage Vs and then perform the delay compensation of the dc step voltage. Hence, the harmonics of the input current can be reduced quickly.

On the other hand, the inverter control unit 430 controls the delay compensation value of the dc short-circuit voltage so that the larger the ripple of the ripple voltage becomes, the higher the harmonic of the input current can be stably reduced even if the capacitor of low capacity is used .

An output current detector (E) detects the inverter 420 and the three-phase motor output current (i _o) flowing between (230). That is, the current flowing in the motor 230 is detected. The output current detection unit E can detect all of the output currents ia, ib, ic of each phase or can detect the output currents of two phases using the three-phase balance.

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

Three shunt resistors are placed between the inverter 420 and the synchronous motor 230 or the three lower arm switching elements S'a, S'b, S'c To be connected to each other. 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 shunt resistor may be disposed between the capacitor C and the inverter 420 described above.

The detected output current (i _o) are, as discrete signals (discrete signal) of the pulse type, may be applied to the inverter controller 430, the inverter switching control signal (Sic) based on the detected output current (i _o) Is generated. The output current (i _o) detected in the following may be written in parallel to the three-phase output currents (ia, ib, ic) of the.

 On the other hand, the three-phase motor 230 has a stator and a rotor, and each phase alternating current power of a predetermined frequency is applied to a coil of a stator of each phase (a, b, c) .

The motor 230 may be, for example, a Surface Mounted Permanent Magnet Synchronous Motor (SMPMSM), an Interior Permanent Magnet Synchronous Motor (IPMSM) A synchronous motor (Synchronous Reluctance Motor; Synrm), and the like. Among them, SMPMSM and IPMSM are permanent magnet applied Permanent Magnet Synchronous Motor (PMSM), and Synrm is characterized by having no permanent magnet.

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

The input voltage compensating section 380 includes a primary controller 810 for extracting harmonic components of the input voltage Vs from the input voltage detecting section A and performing control on the extracted harmonic components, A controller 820 may be provided.

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

Thus, since the primary controller 810 and the secondary controller 820 operate in parallel to each other, the time delay due to the operation of the plurality of controllers can be reduced, and therefore the harmonics of the input current can be reduced .

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

On the other hand, the dc terminal voltage delay compensator 390 calculates an error between the detected dc terminal voltage Vdc from the dc terminal voltage detector B and the delayed dc terminal voltage Vdc, The calculation error can be compensated by using the delay compensation value.

The switching control signal output section 360 can output the inverter 420 switching control signal to the inverter 420 based on the dc terminal voltage compensated in the dc terminal voltage delay compensation section 390 and the voltage command value .

FIG. 11 is a flowchart showing an operation method of the motor driving apparatus according to the embodiment of the present invention, and FIGS. 12 to 13B are diagrams referred to in the explanation of the operation method of FIG.

11, the input voltage detecting unit A detects the input voltage Vs (S910), and the detected input voltage Vs is transmitted to the inverter control unit 430. FIG.

The input voltage compensating unit 380 in the inverter control unit 430 extracts the harmonic component of the input voltage Vac from the input voltage detecting unit A and compensates the extracted harmonic component in operation S920.

As described above, the input voltage compensating unit 380 extracts the harmonic components of the input voltage Vac from the input voltage detecting unit A, performs the control on the extracted harmonic components, and outputs the result And outputs the sum.

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

On the other hand, the detected dc voltage (Vdc) is the actual dc voltage (Vdcr) and the delayed dc voltage (Vdcr) due to the detection circuit and the calculation delay in the inverter control unit (Vdcl).

Next, the dc terminal voltage delay compensation unit 390 in the inverter control unit 430 calculates an error due to the dc terminal voltage delay (S940).

The dc stage voltage delay compensation unit 390 in the inverter control unit 430 calculates an error err by the dc stage voltage delay as shown in Fig. 12 (b).

Next, the dc stage voltage delay compensation unit 390 in the inverter control unit 430 compensates the dc stage voltage based on the calculated error (S950).

The dc terminal voltage delay compensation unit 390 in the inverter control unit 430 generates the compensated dc voltage terminal Vdcc based on the error err due to the dc terminal voltage delay as shown in Figure 12C .

The dc terminal voltage delay compensation unit 390 in the inverter control unit 430 compares the error errf which is the difference between the compensated dc terminal voltage Vdcc and the delayed dc terminal voltage Vdcl as shown in Figure 12 (d) .

The dc-stage voltage delay compensation unit 390 in the inverter control unit 430 performs compensation by Td using the error errf as shown in FIG. 12 (e). That is, a signal (cmp) whose phase is pulled by Td is generated.

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

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

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

Next, FIG. 13A (b) illustrates a dc component waveform of the output current before and after the time 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 time T1 is stable.

Next, FIG. 13B (a) illustrates the dc short-circuit voltage waveform before and after the Ta point. That is, the dc short-circuit voltage waveform (Vdca) before the Ta point is pulsating irregularly, but the dc short-circuit voltage waveform (Vdcb) after the Ta point is regularly pulsating.

Next, FIG. 13A (a) illustrates the input current waveform before and after the Ta point. That is, a harmonic appears in the input current waveform Isa before the Ta point, and the harmonics are reduced in the input current waveform Isb after the Ta point.

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

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

3 to 13B are applicable to various home appliances in addition to the air conditioner 100 of FIG. For example, it can be applied to various fields such as laundry processing apparatuses (washing machines, dryers, etc.), refrigerators, water purifiers, and robot cleaners.

FIG. 14 is a diagram illustrating a configuration of an air conditioner according to another embodiment of the present invention. FIG.

Referring to the drawings, the air conditioner 100b of FIG. 14 differs from the system air conditioner of FIG. 1 in that it includes one outdoor unit 31b.

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 as shown in FIG.

The indoor unit 31b of the air conditioner may be any of a stand-type air conditioner, a wall-mounted type air conditioner, and a ceiling type air conditioner, but the stand type indoor unit 31b is exemplified in the figure.

Meanwhile, the air conditioner 100b may further include at least one of a ventilator, an air purifier, 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 refrigerant, an outdoor heat exchanger (not shown) for exchanging heat between the refrigerant and outdoor air, an accumulator for extracting the gas refrigerant from the supplied refrigerant and supplying it to the compressor And a four-way valve (not shown) for selecting the flow path of the refrigerant according to the heating operation. In addition, a number of sensors, valves, oil recovery devices, and the like are further included, but a description thereof will be omitted below.

The outdoor unit 21b operates the compressor and the outdoor heat exchanger to compress or heat-exchange the refrigerant according to the setting to supply the refrigerant to the indoor unit 31b. The outdoor unit 21b can be driven by a demand of a remote controller (not shown) or the indoor unit 31b. At this time, as the cooling / heating capacity is changed corresponding to the indoor unit to be driven, the number of operation of the outdoor unit and the number of operation of the compressor installed in the outdoor unit can be varied.

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

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

At this time, the outdoor unit 21b and the indoor unit 31b are connected to each other via a communication line to exchange data. The outdoor unit and the indoor unit are connected to a remote controller (not shown) by wire or wireless, can do.

The remote controller (not shown) is connected to the indoor unit 31b, and inputs a control command of the user to the indoor unit, and receives and displays the status information of the indoor unit. At this time, the remote controller can communicate by wire or wireless according to the connection form with the indoor unit.

15 is a schematic view of the outdoor unit and the indoor unit of Fig.

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

The outdoor unit 21b includes a compressor 102b that compresses the refrigerant, an electric motor 102bb that drives the compressor, an outdoor heat exchanger 104b that dissipates the compressed refrigerant, An outdoor fan 105b which is disposed at one side of the heat exchanger 104b and includes an outdoor fan 105ab for accelerating the heat radiation of the refrigerant and an electric motor 105bb for rotating the outdoor fan 105ab and an outdoor fan 105b for expanding the condensed refrigerant An accumulator 103b for temporarily storing the gasified refrigerant to remove water and foreign matter and supplying a refrigerant of a predetermined pressure to the compressor, a compressor 106b for compressing the refrigerant, a cooling / heating switching valve 110b for changing the flow path of the compressed refrigerant, And the like.

The indoor unit 31b includes an indoor heat exchanger 109b disposed inside the room and performing a cooling / heating function, an indoor fan 109ab disposed at one side of the indoor heat exchanger 109b for promoting heat radiation of the refrigerant, And an indoor fan 109b composed of an electric motor 109bb for rotating the fan 109ab.

At least one indoor heat exchanger 109b may be installed. At least one of an inverter compressor and a constant speed compressor can be used as the compressor 102b.

Further, the air conditioner 100b may be constituted by a cooler for cooling the room, or a heat pump for cooling or heating the room.

The compressor 102b in the outdoor unit 21b of Fig. 14 can be driven by the 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 .

Meanwhile, the motor driving apparatus or the air conditioner operating method of the present invention can be implemented as a processor-readable code on a recording medium readable by a processor included in a motor driving apparatus or an air conditioner. The processor-readable recording medium includes all kinds of recording apparatuses in which data that can be read by the processor is stored. Examples of the recording medium that can be read by the processor include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an 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 . In addition, the processor-readable recording medium may be distributed over network-connected computer systems so that code readable by the processor in a distributed fashion can be stored and executed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

Claims (10)

A converter for converting input AC power into DC power;
An input voltage detector for detecting an input voltage at the front end of the converter;
A dc capacitor storing a ripple voltage from the converter;
A dc voltage detection unit detecting a voltage across the dc short capacitor;
An inverter for converting a DC power stored in the dc-stage capacitor and outputting an AC power to the motor; And
And a controller for controlling the inverter,
Wherein,
Wherein the control unit controls to compensate for the harmonic component of the input voltage from the input voltage detecting unit and to compensate for the delay of the dc step voltage based on the dc step voltage from the dc step voltage detecting unit Device. The method according to claim 1,
Wherein,
And the delay compensation value of the dc voltage is larger as the ripple of the ripple voltage increases. The method according to claim 1,
Wherein,
And an input voltage compensator for extracting a harmonic component of the input voltage from the input voltage detector and performing control on the extracted harmonic component. The method of claim 3,
Wherein,
And a dc terminal voltage delay compensator for compensating a delay of the dc terminal voltage based on the dc terminal voltage from the dc terminal voltage detector after the harmonic component compensation of the input voltage. Device. The method of claim 3,
Wherein the input voltage compensator comprises:
A primary controller for extracting a harmonic component of the input voltage from the input voltage detector and performing control on the extracted harmonic components, and a secondary controller. 5. The method of claim 4,
Wherein the dc stage voltage delay compensator comprises:
Wherein the error between the dc voltage detected by the dc voltage detection unit and the delayed dc voltage is calculated and the calculation error is compensated for using the delay compensation value of the dc voltage. Device. 5. The method of claim 4,
And a switching control signal output unit for outputting an inverter switching control signal to the inverter based on the dc step voltage compensated in the dc step voltage delay compensating unit and the voltage command value. 8. The method of claim 7,
And an output current detector for detecting an output current flowing in the motor,
Wherein,
A speed calculator for calculating 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 speed command value from the speed calculator;
And a voltage command generator for generating a voltage command value based on the current command value and the output current. The method according to claim 1,
And a dc stage reactor connected between the converter and the dc short-circuit capacitor. An air conditioner comprising: the motor driving apparatus according to any one of claims 1 to 9.

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