KR20140112297A - Power converter and air conditioner including the same - Google Patents

Abstract

The present invention relates to a power conversion apparatus and an air conditioner having the same. An electric power conversion apparatus according to an embodiment of the present invention includes a rectifying section for rectifying an input AC power source, an interleave converter having a plurality of converters for converting a rectified power source into a DC power source and outputting a converted DC power source, And a converter control unit for controlling the interleaved converter. The converter control unit varies the number of converters operated in the interleaved converter according to the load level corresponding to both ends of the capacitor. Thus, it becomes possible to drive efficiently at various loads.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter and an air conditioner including the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion device and an air conditioner having the same, and more particularly, to a power conversion device that can be efficiently driven at various loads and an air conditioner having the same.

The air conditioner is disposed in a room such as a room, a living room, an office or a business store, and is capable of maintaining a comfortable indoor environment by controlling the temperature, humidity, cleanliness and airflow of the air.

The air conditioner is generally divided into an integral type and a separated type. The integral type and the separate type are the same as the functional type, but the integral type is formed by integrating the functions of cooling and heat dissipation to form a hole in the wall of the house or by hanging the device on the window. Side, an outdoor unit that performs heat dissipation and compression functions is installed, and the two devices separated from each other are connected by a refrigerant pipe.

On the other hand, as requirements for high performance and high efficiency of the air conditioner have been increased, various efforts have been tried.

It is an object of the present invention to provide a power conversion apparatus which can be efficiently driven at various loads, and an air conditioner having the power conversion apparatus.

According to an aspect of the present invention, there is provided a power conversion apparatus including: a rectifier for rectifying an input AC power; and a plurality of converters for converting rectified power to DC power and outputting the converted DC power A converter connected to an output terminal of the interleaved converter and a converter control unit for controlling the interleaved converter, wherein the converter control unit varies the number of the converters operated in the interleaved converter according to the load level corresponding to both ends of the capacitor .

According to another aspect of the present invention, there is provided an air conditioner including a compressor and a power conversion unit for supplying driving power to a motor in the compressor. The power conversion unit includes a rectifier for rectifying the input AC power, An interleave converter including a plurality of converters for converting rectified power to direct current power and outputting the converted direct current power, a capacitor connected to the output terminal of the interleave converter, and a converter controller for controlling the interleave converter, Varies the number of converters operated in the interleaved converter depending on the load level corresponding to both ends of the capacitor.

According to an embodiment of the present invention, a power conversion apparatus and an air conditioner having the same include an interleave converter, and the converter control unit controls the operation of the interleave converter according to the load level corresponding to both ends of the capacitor, The number of converters is varied. As a result, the operation efficiency can be increased not only in the low load region but also in the high load region. Further, as the load region changes, the output voltage of the interleaved converter can be actively varied, and the operation efficiency in the entire load region can be increased. Particularly, it is possible to efficiently drive a compressor or the like in which load fluctuation is severe.

Particularly, when the load level corresponding to both ends of the capacitor is equal to or lower than the first level, by controlling the first converter in the interleaved converter to operate only in the low load region, the switching loss by the second converter can be eliminated, Further, the output of the direct current power source can be further lowered, and the width of the dc voltage across the capacitor can be widened.

On the other hand, when the level of the load corresponding to both ends of the capacitor is larger than the first level, the first converter and the second converter of the interleaved converter are controlled to operate, so that it can be stably operated even at a high load.

Further, when the first converter and the second converter are interleaved at a high load, the input current ripple and noise can be reduced.

As a result, by using the interleaved converter, the number of driven converters can be varied for each load, thereby enabling the efficient operation of the front-wheel-drive unit in various loads.

1 is a configuration diagram of an air conditioner according to an embodiment of the present invention.
Fig. 2 is a schematic view of the air conditioner of Fig. 1. Fig.
3 is an internal block diagram of the power converter of the outdoor unit of FIG.
Fig. 4 illustrates a circuit diagram of a converter in the power converter of Fig.
Figure 5 illustrates an internal block diagram of the converter control of Figure 4;
6A is a diagram illustrating a load region of a power conversion apparatus.
6B is a diagram illustrating the load versus power factor corresponding to each load region.
7A to 7B are diagrams illustrating operations of the power conversion apparatus of FIG.
Figs. 8A and 8B are views referred to explain the operation of the first converter of Fig. 4; Fig.
Figure 9 illustrates a circuit diagram of an inverter in the power converter of Figure 3;
10 is an internal block diagram of the inverter control 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.

FIG. 1 is a schematic view of an air conditioner according to an embodiment of the present invention, and FIG. 2 is a schematic view of the air conditioner of FIG. 1

Referring to the drawings, an air conditioner 100 includes an outdoor unit 150 and an indoor unit 170.

The outdoor unit 150 operates in a cooling mode or a heating mode in response to a request of the connected indoor unit 170 or an external control command and supplies the refrigerant to the indoor unit 170.

To this end, the outdoor unit 150 includes a compressor 152 that compresses the refrigerant, a compressor motor 152b that drives the compressor, an outdoor heat exchanger 154 that dissipates the compressed refrigerant, An outdoor fan 155 disposed at one side of the outdoor heat exchanger 154 and configured to include an outdoor fan 155a for accelerating the heat radiation of the refrigerant and an electric motor 5b for rotating the outdoor fan 155a, An accumulator (156) for expanding the refrigerant, a cooling / heating switching valve (160) for switching the flow path of the compressed refrigerant, a condenser for temporarily storing the gasified refrigerant to remove moisture and foreign substances, (153), and the like. At least one of an inverter compressor and a constant speed compressor may be used as the compressor 152. [

The outdoor unit 150 may further include at least one pressure sensor (not shown) for measuring the pressure of the refrigerant, at least one temperature sensor (not shown) for measuring the temperature, and the like.

The indoor unit 170 includes an indoor heat exchanger 208 disposed inside the room and performing a cooling / heating function, an indoor fan 209a disposed at one side of the indoor heat exchanger 208 for promoting heat radiation of the refrigerant, And an indoor air blower 209 composed of an electric motor 209b for rotating the indoor fan 209a. At least one indoor heat exchanger 208 may be installed.

The indoor unit 170 may further include a discharge port (not shown) for discharging the heat-exchanged air and a wind direction control unit (not shown) for closing the discharge port (not shown) and controlling the direction of the discharged air. For example, a vane may be provided to open and close at least one of an air inlet (not shown) and an air outlet (not shown), and the vane may open and close the air inlet and the air outlet, And the direction of the discharge air.

On the other hand, the indoor unit 170 can adjust the air volume by controlling the air sucked in and the air sucked in accordance with the rotating speed of the indoor fan 209a.

The indoor unit 170 may further include a display unit (not shown) for displaying an operation state and setting information of the indoor unit 170, and an input unit (not shown) for inputting setting data. In addition, it may further include an indoor temperature sensing unit (not shown) for sensing a room temperature, a human body sensing unit (not shown) for sensing a human body in the indoor space, and the like.

On the other hand, the air conditioner 100 may be composed of a cooler for cooling the room, or a heat pump for cooling or heating the room.

Although the indoor unit 170 is shown as a stand type in the drawing, the indoor unit 170 may be of a ceiling type or a wall type, and may have various forms such as an integral type in which there is no distinction between an outdoor unit and an indoor unit.

On the other hand, the indoor unit 170 and the outdoor unit 150 are connected by a refrigerant pipe, and cold air is discharged from the indoor unit 170 to the room as the refrigerant circulates. At this time, a plurality of indoor units 170 may be connected to one outdoor unit 150, and at least one indoor unit may be connected to each of the plurality of outdoor units.

The indoor unit 170 and the outdoor unit 150 may be connected to each other via a communication line to transmit / receive a control command according to a predetermined communication method.

On the other hand, the compressor 152 can be driven by the driving power supplied through the following power conversion device 200. [ Specifically to the motor in compressor 152. The driving power from the power inverter 200 can be supplied.

Fig. 3 is an internal block diagram of the power converter of the outdoor unit of Fig. 1, and Fig. 4 illustrates a circuit diagram of the converter in the power converter of Fig.

The power conversion apparatus 200 according to the embodiment of the present invention includes a filter unit 403, a rectification unit 405, a converter 410, a converter control unit 415, a capacitor C, an inverter 420, (Not shown).

The filter unit 403 may be disposed between the input AC power supply 201 and the rectifying unit 405 and may filter the harmonic current generated in the input AC power supply 201 or the power inverter 200. To this end, the filter unit 403 may include an inductor, which is an inductive element, a capacitor, which is a capacitive element, and the like. For example, the filter unit 403 may include an LCL filter in which an inductor, a capacitor, and an inductor are disposed.

The rectifying unit 405 receives the input AC power source 201 that has passed through the filter unit 403, and rectifies it. FIG. 4 illustrates that the four diodes Da, Db, Dc, and Dd are used as a bridge in the rectifying unit 405 for a single-phase AC power supply, but various examples are possible.

The converter 410 converts the rectified power from the rectifying unit 405 into direct current power and outputs it. And in particular, to the capacitor C disposed at the output terminal of the converter 410. [

In the embodiment of the present invention, the converter 410 is a cascade converter having a plurality of converters 410a, 410b, .... Interleaved converters, interleaved boost converters, interleaved buck-boost converters, and interleaved buck converters are possible, but the following description focuses on interleaved boost converters.

The plurality of boost converters 410a, 410b, ... in the interleaved boost converter 410 are connected in parallel with each other to perform an interleaving operation. A plurality of boost converters are connected in parallel to each other, and voltage control by interleaving is performed, so that voltage control by current distribution becomes possible. Thus, the circuit element durability in the interleaved boost converter 410 can be improved. Further, the ripple of the input current can be reduced.

For example, when the first boost converter 410a and the second boost converter 410b in the interleaved boost converter 410 are connected in parallel to perform an interleaving operation, the first boost converter 410a and the second boost converter 410b in the interleave- The first switching element S1 in the first boost converter 410b and the second switching element S2 in the second boost converter 410b have an electrical phase difference of 180 degrees and are turned on and off. In this case, the efficiency in the low load region is lower than that in the high load region due to the switching loss.

In order to solve this problem, in the embodiment of the present invention, the number of the converters operated in the interleaved converter is varied in accordance with the load level corresponding to both ends of the capacitor which is the output stage of the interleave converter. As a result, the operation efficiency can be increased for the entire load region.

Particularly, in the low load region, only the first boost converter 410a of the interleave converter 410 is controlled to operate, and in the high load region, the first boost converter 410a and the second boost converter 410b of the interleave converter 410 ). The interleaved converter 410 having such a configuration is exemplified as shown in FIG.

In the interleaved boost converter, a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar mode transistor (IGBT), or the like may be used as a switching element to be used.

Each of the boost converters 410a, 410b, ... in the interleave converter 410 may be implemented by the same type of switching device, for example, a MOSFET or an IGBT. However, the present invention is not limited to this, It is also possible that a device is used. Specifically, it is possible that a MOSFET element is used for the first boost converter 410a and an IGBT element is used for the second boost converter 410b. Particularly, when a MOSFET device is used for the first boost converter 410a operated in a low load region, high-speed switching is possible and operation efficiency can be improved. In addition, the second boost converter 410b operating in a high load region When an IGBT element is used, it can be stably operated.

4 illustrates a first boost converter 410a and a second boost converter 410b of the plurality of boost converters 410. In FIG. Hereinafter, among the plurality of boost converters 410, the first boost converter 410a and the second boost converter 410b will be mainly described.

The first boost converter 410a includes a first diode D1 whose one end is connected to the capacitor C, a first inductor L1 connected between the first diode D1 and the rectifying unit 405, And a first boost switching element S1 connected in parallel to the first diode D1 and the first diode D1.

The second boost converter 410b includes a second diode D2 whose one end is connected to the capacitor C, a second inductor L2 connected between the second diode D2 and the rectifying unit 405, And a second boost switching element S2 connected in parallel to the second inductor L2 and the second diode D2.

When the first boost converter 410a and the second boost converter 410b are connected in parallel to perform an interleaving operation, the first switching device S1 in the first boost converter 410a and the second switching device The second switching element S2 in the switching element 410b has an electrical phase difference of 180 degrees and is turned on / off, resulting in a switching loss. In this case, the efficiency in the low load region is lower than that in the high load region due to the switching loss.

In order to improve this point, in the embodiment of the present invention, the number of the converters operated in the interleaved converter is varied according to the load level corresponding to both ends of the capacitor which is the output terminal of the interleave converter 410. As a result, the operation efficiency can be increased for the entire load region.

Particularly, in the low load region, only the first boost converter 410a of the interleave converter 410 is controlled to operate, and in the high load region, the first boost converter 410a and the second boost converter 410b of the interleave converter 410 ).

6A) and a high load region (AE2 in FIG. 6A), and the load region is divided into a load region AE1 in FIG. 6A and a load region AE2 in FIG. 6A according to the load corresponding to the voltage across the capacitor C. [ Accordingly, only the first boost switching element S1 in the first converter 410a is controlled to operate in the low load region, and the first converter 410a and the second converter 410b are interleaved in the high load region, The first boost switching element S1 and the second boost switching element S2 can be alternately controlled.

Meanwhile, the first boost converter 410a and the second boost converter 410b are connected in parallel to each other and can operate in a boost mode, respectively. The boost mode operation will be described later with reference to Figs. 8A to 8B.

The power conversion apparatus 200 further includes an input voltage detecting section A for detecting the output terminal voltage of the rectifying section 405 and an output terminal for detecting the output terminal voltage of the interleaved boost converter 410, The voltage detection unit B and the current detection units F1 and F2 for detecting the currents flowing through the inductors L1 and L2 in the interleaved boost converter 410. [

The input voltage detecting section A can detect the output terminal voltage of the rectifying section 405. For this purpose, the input voltage detector A may include a resistor, an amplifier, and the like. The detected input voltage V _c1 may be input to the converter control unit 415 as a discrete signal in the form of a pulse.

The output voltage detection unit B, that is, the dc voltage detection unit B, can detect the output voltage of the interleaved boost converter 410. In particular, the voltage V _dc across the capacitor C can be detected.

The capacitor C is disposed between the inverter 420 and the load 205 and stores the output DC power of the interleaved converter. In the drawing, one element is exemplified by the smoothing capacitor C, but a plurality of elements are provided so that the element stability can be ensured. On the other hand, since both ends of the capacitor C are stored with DC power, they may be referred to as a dc stage or a dc link stage.

If the inverter including the inverter 420 and the motor 205 is referred to as a load, a load 205 may be connected to both ends of the capacitor C of the power converter as shown in the drawing. Accordingly, the dc short-circuit voltage (V _dc ) can correspond to the voltage of the load 205. The detected output voltage V _dc can be input to the converter control unit 415 as a discrete signal in the form of a pulse.

The first current detector F1 detects the current i _L1 flowing through the first inductor L1 in the first boost converter 410a and the second current detector F2 detects the current i _L1 flowing through the second boost converter 410b. It is possible to detect the current (i _L2 ) flowing through the second inductor (L2). For this purpose, a CT (current trnasformer), a shunt resistor, or the like may be used as the first and second current detectors F1 and F2. The detected input alternating current (i _L1 , i _L2 ) can be input to the converter control unit 415 as a discrete signal in the form of a pulse.

Meanwhile, the converter control unit 415 includes a first converter control unit (not shown) for controlling the first boost converter 410a and a second converter control unit (not shown) for controlling the second boost converter 410b .

Converter control section 415 controls at least one of the first and second input currents i _L1 and i _L2 detected by the first and second current detection sections F1 and F2 and at least one of the first and second input currents i _L1 and i _L2 detected by the dc voltage detection section B The load on both ends of the capacitor can be calculated based on the dc voltage source Vdc. The load can be calculated. When the calculated load corresponds to the low load region, the turn-on / turn-off timing of the first boost switching element S1 in the first boost converter 410a can be controlled.

On the other hand, the converter control section 415 can control so that the first and second boost converters 410a and 410b are all operated when the calculated load amount corresponds to the high load region. That is, the converter control unit 415 controls the turn-on / turn-off timing of the first boost switching element S1 in the first boost converter 410a and the turn-on / off timing of the second boost switching element S2 in the second boost converter 410b. The turn-on / turn-off timing of the transistor can be controlled. At this time, the first boost converter 410a and the second boost converter 410b may perform an interleaving operation.

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 250. The motor 250 at this time may be a motor in the compressor.

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 a switching control signal of a pulse width modulation (PWM), the output current detection section is output is generated and based on the output current (i _o) detected from (E of FIG. 9).

Figure 5 illustrates an internal block diagram of the converter control of Figure 4;

Referring to the drawings, FIG. 5A illustrates an internal block diagram of the converter control unit 415 of FIG. The converter control unit 415 may include a current command generation unit 310, a voltage command generation unit 320, and a switching control signal output unit 330.

The current command generation section 310 generates a current command based on the dc terminal voltage Vdc and the dc terminal voltage command value V ^* dc detected by the output voltage detection section B, that is, the dc terminal voltage detection section B, (I ^* _d , i ^* _q ) can be generated from the _d- axis and q-axis current command values.

The voltage command generation unit 320 generates a voltage command based on the d and q axis current command values i ^* _d and i ^* _q and the detected first and second input currents i _L1 and i _L2 through a PI controller, q-axis voltage command value (v ^* _d , v ^* _q ).

Switching control signal output unit 330 includes a d, q-axis voltage command value (v ^* _d, v ^* _q), the first boost switching element (S1) and a second boost converter in the first boost converter (410a) based on ( The first converter switching control signal Scc1 and the second converter switching control signal Scc2 are supplied to the first and second boost converters 410a and 410b to drive the second boost switching device S2 in the first and second boost switching devices 410a and 410b, .

The converter control unit 415 outputs the dc terminal voltage Vdc detected by the dc terminal voltage detection unit B and the first input current detected by the first current detection unit F1 and the second current detection unit F2 i _L1 and the second input current i _L2 so as to drive the first switching element S1 when the calculated load amount corresponds to the low load region, (Scc1) to the first boost converter 410a.

On the other hand, when the calculated load corresponds to the high load region, the converter control section 415 controls the first converter switching control signal Scc1 and the second converter switching control signal Scc2 so as to interleave the first switching element S1 and the second switching element S2 And outputs the second converter switching control signal Scc2 to the first boost converter 410a and the second boost converter 410b, respectively.

6A is a diagram illustrating a load region of a power conversion apparatus.

Converter control section 415 controls at least one of the first and second input currents i _L1 and i _L2 detected by the first and second current detection sections F1 and F2 and at least one of the first and second input currents i _L1 and i _L2 detected by the dc voltage detection section B The load on both ends of the capacitor can be calculated based on the dc voltage source Vdc. The load at this time can mean power.

The converter control unit 415 determines that the load is low when the level of the load to be calculated is equal to or less than the first power level Px and determines that the load is high if the level of the load to be calculated exceeds the first power level Px . Alternatively, when the first power level Px is equal to or lower than the first power level Px, it is determined as a low load. When the second power level Px is higher than the second power level Px, it can be determined as a high load.

Accordingly, as shown in Fig. 6B, the load 205 can be divided into the respective low load regions Ae1 and Ae2. On the other hand, the first power level Px at this time can be stored in a memory (not shown) in the power inverter 200.

On the other hand, the first power level Px may vary depending on operating conditions and the like. For example, when the maximum load used for a certain period of time is equal to or less than a predetermined value, the first power level Px may be lowered.

6B is a diagram illustrating the load versus power factor corresponding to each load region.

Referring to the drawings, a first power level Px or less may be a low load area Ae1, and a first power level Px may be a high load area Ae2.

Meanwhile, when only the first boost converter 410a of the interleaved boost converter operates, the operation efficiency (power factor) with respect to the load can be exemplified by the LP1 curve as shown in the figure, and the first and second boost converters 410a, and 410b are all operating, they can be illustrated by the LP2 curve.

When the first and second boost converters 410a and 410b are both operated, the LP1 curve and the LP2 curve in the drawing show that the operation efficiency is lowered in the low load region according to the switching loss and the first boost converter 410a It is found that the operation efficiency is lowered in the high load region.

In order to solve this problem, in the embodiment of the present invention, only the first boost converter 410a is controlled to operate in the low load region based on the first power level Px, and in the high load region, And controls both the second boost converters 410a and 410b to operate.

Accordingly, the operation efficiency of the power conversion apparatus 200 with respect to the load can be improved as shown by a thick solid line in FIG. 6B. Particularly, the operation efficiency can be improved for the entire load region.

 The first converter switching control signal Scc1 and the second converter switching control signal Scc2 are set so as to drive the first boost switching element S1 in the first boost converter 410a and the second boost switching element S2 in the second boost converter 410b To the first boost converter 410a and the second boost converter 410b, respectively.

7A to 7B are diagrams illustrating operations of the power conversion apparatus of FIG.

First, FIG. 7A illustrates that only the first boost converter 410a operates in the low load region.

The converter control unit 415 can determine that the calculated load is equal to or lower than the first power level Px and that only the first boost converter 410a operates.

The first converter switching control signal Scc1 from the converter control unit 415 causes the first boost switching element S1 in the first boost converter 410a to be turned on. As a result, a current is accumulated in the first inductor, and energy stored in the first inductor is transferred to the capacitor (C) when the first boost switching element (S1) is turned off.

In this manner, when the load is low, only the first boost switching element S1 is operated and the second boost switching element S2 in the second boost converter 410b is turned off, thereby reducing the switching loss, By operating only the 1-boost converter 410a, the output DC voltage can be further lowered and the operation efficiency can be improved.

Next, FIG. 7B illustrates the operation of the first boost converter 410a and the second boost converter 410b in the high load region.

Converter controller 415 determines that the load is high when the calculated load exceeds the first power level Px and controls the first boost converter 410a and the second boost converter 410b to interleave have.

The first converter switching control signal Scc1 from the converter control unit 415 causes the first boost switching element S1 in the first boost converter 410a to be turned on. At this time, the second boost switching element S2 in the second boost converter 410b may be turned off.

Next, when the first boost switching element S1 is turned off, the second converter switching control signal Scc2 from the second converter control section 415b causes the second boost switching element S2 are turned on.

As described above, by interleaving the first boost converter 410a and the second boost converter 410b at a high load, input current ripple and noise can be reduced. Further, the operation efficiency can be increased even in a high load region.

As a result, by using the interleaved converter, the number of driven converters can be varied for each load, thereby enabling the efficient operation of the front-wheel-drive unit in various loads. Particularly, it is possible to efficiently drive a compressor or the like in which load fluctuation is severe.

Figs. 8A and 8B are views referred to explain the operation of the first converter of Fig. 4; Fig.

8A and 8B illustrate that the first boost converter 410a operates in the boost mode.

8A shows that when the first boost switching element S1 in the first boost converter 410a is turned on, a closed loop is formed by the first inductor L1 and the first boost switching element S1, (Ia) flows. As a result, energy based on the current Ia is accumulated in the first inductor L1. At this time, the first diode D1 does not conduct.

8B shows that when the first boost switching element S1 in the first boost converter 410a is turned off the first diode D1 is conductive and the first inductor L1 and the first diode D1 are turned on, RTI ID = 0.0 > Ib. ≪ / RTI > The current Ib may be the sum of the energy stored in the first inductor L1 and the current based on the input AC power supply 201 in Fig. 8A.

That is, the first boost switching element S1 in the first boost converter 410a performs the turn-on / off operation, that is, the PWM operation.

Since the operation of the second converter is the same as that of Figs. 8A to 8B, the description thereof will be omitted.

Figure 9 illustrates a circuit diagram of an inverter in the power converter of Figure 3;

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 controller 430. [

The inverter 420 drives the motor 250 by converting a DC power supply across the capacitor C to an AC power supply in the motor 250 operating mode.

The inverter control unit 430 can control the operation of the switching element in the inverter 420. [ To this end, the drive controller 430, it is possible to input the output current detector (E in Fig. 9), the output current (i _o) detected by the.

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 a switching control signal of a pulse width modulation (PWM), the output current detection section is output is generated and based on the output current (i _o) detected from (E of FIG. 9).

The output current detection section (E in FIG. 9) can detect the output current (i ₀ ) flowing between the inverter 420 and the three-phase motor 250. That is, the current flowing in the motor 250 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 250. In order to detect the current, 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 250 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 controller 430, it is by the inverter switching control signal (Sic) based on the detected output current (i _o) . In the output current detection (i _o) will now be described in that the three-phase output currents (ia, ib, ic) of the.

10 is an internal block diagram of the inverter control unit of FIG.

10, 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 axis conversion unit 350, And a switching control signal output 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 a two-phase current 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.

)를 연산할 수 있다. 즉, 위치 신호에 기반하여, 시간에 대해, 나누면, 속도를 연산할 수 있게 된다.Based on the position signal H of the rotor input from the position sensing unit 235, the speed calculating unit 320 calculates a speed

) Can be calculated. That is, based on the position signal, it is possible to calculate the speed by dividing it with respect to time.

On the other hand, the position sensing unit 235 can sense the rotor position of the motor 250. For this, the position sensing unit 235 may include a Hall sensor.

)와 연산된 속도(

)를 출력할 수 있다.On the other hand, the speed calculating section 320 calculates the position (H) based on the position signal H of the input rotor

) And the calculated speed (

Can be output.

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

)와 목표 속도(ω)의 차이인 속도 지령치(ω^* _r)에 기초하여, PI 제어기(535)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

) Based on the speed command value ω ^* _r and the target speed ω and generates the current command value i ^* _q based on the speed command value ω ^* _r . For example, the current command generation section 330 generates the current command

The PI controller 535 performs the PI control based on the speed command value? ^* _{R that} is the difference between the target speed? And the target speed?, 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 544 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 . Further, voltage command generation unit 340, on the basis of the difference between the d-axis current (i _d) and, the d-axis current command value (i ^* _d), and performs the PI control in the PI controller (548), d-axis voltage It is possible to generate the command value v ^* _d . On the other hand, the value of the d-axis voltage command value v ^* _d may be set to zero corresponding to the case where the value of the d-axis current command value i ^* _d is set to zero.

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 .

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

The power conversion apparatus and the air conditioner having the power conversion apparatus according to the embodiment of the present invention are not limited to the configuration and method of the embodiments described above, All or some of the embodiments may be selectively combined.

The method for operating the charging apparatus of the present invention can be implemented as a code that can be read by a processor on a recording medium readable by a processor included in the charging apparatus. The processor-readable recording medium includes all kinds of recording apparatuses in which data that can be read by the processor is stored.

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 (14)

A rectifying unit for rectifying the input AC power;
An interleave converter including a plurality of converters for converting the rectified power to direct current power and outputting the converted direct current power;
A capacitor connected to an output terminal of the interleaved converter; And
And a converter control unit for controlling the interleaved converter,
The converter control unit includes:
Wherein the number of converters operated in the interleaved converter is varied according to a load level corresponding to both ends of the capacitor. The method according to claim 1,
The converter control unit includes:
When the level of the load corresponding to both ends of the capacitor is larger than the first level, the controller controls the first converter of the interleaved converter to operate only when the load level corresponding to both ends of the capacitor is equal to or less than the first level, And controls the first converter and the second converter to operate. 3. The method of claim 2,
The converter control unit includes:
And controls the operation of the first switching element of the first converter when the load level corresponding to both ends of the capacitor is equal to or less than the first level, and when the level of the load corresponding to both ends of the capacitor is larger than the first level, And controls operations of the first and second switching elements of the first and second converters, respectively. The method of claim 3,
The converter control unit includes:
And controls the interleaving operation of the first and second converters when the operation of the first and second switching elements is controlled. 3. The method of claim 2,
Wherein the first converter of the interleaved converter comprises:
A first inductor connected to the rectifying unit;
A first diode connected to an output terminal of the interleaved converter;
And the first switching element connected in parallel between the first inductor and the first diode,
Wherein the second converter among the interleaved converters comprises:
A second inductor connected to the rectifying unit;
A second diode connected to an output terminal of the interleaved converter;
And the second switching element connected in parallel between the second inductor and the second diode. The method according to claim 1,
A capacitor connected to an output terminal of the interleaved converter;
And an inverter connected between the capacitor and the motor for converting an output power of the converter to an AC power and outputting the AC power. The method according to claim 1,
And a voltage detector for detecting a voltage across the capacitor,
The converter control unit includes:
And controls the operation of the interleaved converter based on the detected voltage across the capacitor. 3. The method of claim 2,
And a voltage detector for detecting a voltage across the capacitor,
The converter control unit includes:
Calculating a load connected to the power converter based on at least one of a current flowing in the first inductor in the first converter and a current flowing in the second inductor in the second converter and a voltage across the detected capacitor, And controls the operation of the interleaved converter based on the calculated load amount. compressor;
And a power conversion unit for supplying driving power to the motor in the compressor,
Wherein the power conversion unit comprises:
A rectifying unit for rectifying the input AC power;
An interleave converter including a plurality of converters for converting the rectified power to direct current power and outputting the converted direct current power;
A capacitor connected to an output terminal of the interleaved converter; And
And a converter control unit for controlling the interleaved converter,
The converter control unit includes:
Wherein the number of the converters operated in the interleaved converter is varied according to a load level corresponding to both ends of the capacitor. 10. The method of claim 9,
The converter control unit includes:
And controls the operation of the first switching element of the first converter when the load level corresponding to both ends of the capacitor is equal to or less than the first level, and when the level of the load corresponding to both ends of the capacitor is larger than the first level, And controls operations of the first and second switching elements of the first and second converters, respectively. 11. The method of claim 10,
The converter control unit includes:
And controls the first and second converters to interleave when the operation of the first and second switching elements is controlled. 11. The method of claim 10,
Wherein the first converter of the interleaved converter comprises:
A first inductor connected to the rectifying unit;
A first diode connected to an output terminal of the interleaved converter;
And the first switching element connected in parallel between the first inductor and the first diode,
Wherein the second converter among the interleaved converters comprises:
A second inductor connected to the rectifying unit;
A second diode connected to an output terminal of the interleaved converter;
And the second switching device connected in parallel between the second inductor and the second diode. 10. The method of claim 9,
A capacitor connected to an output terminal of the interleaved converter;
And an inverter connected between the capacitor and the motor for converting the output power of the converter to AC power and outputting the AC power. 11. The method of claim 10,
And a voltage detector for detecting a voltage across the capacitor,
The converter control unit includes:
Calculating a load connected to the power converter based on at least one of a current flowing in the first inductor in the first converter and a current flowing in the second inductor in the second converter and a voltage across the detected capacitor, And controls the operation of the interleaved converter based on the calculated load amount.

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