KR102343260B1 - Power converter and air conditioner including the same - Google Patents

Abstract

The present invention relates to a power converter and an air conditioner having the same. A power conversion device according to an embodiment of the present invention includes an inductor, a first diode unit connected to the inductor, a switching unit connected to both ends of the first diode unit, and a second diode connected between the inductor and the dc terminal as an output terminal. and a converter for converting the input AC voltage and outputting the converted voltage to the dc terminal, and a converter control unit for outputting a converter switching control signal to the switching unit, wherein the converter control unit includes: In the period, the switching unit controls to repeat the switching operation, and in the second period in which the input AC voltage falls, the switching unit controls to repeat the switching operation. Accordingly, it is possible to improve the power factor.

Description

Power converter, and an air conditioner having the same {Power converter and air conditioner including the same}

The present invention relates to a power converter and an air conditioner having the same, and more particularly, to a power converter capable of improving a power factor, and an air conditioner having the same.

The power converter is a device that converts input power and outputs the converted power.

On the other hand, in home appliances and the like, a converter for converting a commercial AC voltage into a DC voltage is provided as an example of the power conversion device.

On the other hand, power factor regulation for home appliances is being discussed for energy efficiency, and accordingly, there are various discussions about power factor improvement.

In particular, various efforts are being made to improve the power factor for home appliances that consume large amounts of energy, such as air conditioners, washing machines, refrigerators, and TVs.

An object of the present invention is to provide a power conversion device capable of improving a power factor, and an air conditioner having the same.

A power conversion device according to an embodiment of the present invention for achieving the above object is between an inductor, a first diode part connected to the inductor, a switching part connected to both ends of the first diode part, and a dc terminal that is an inductor and an output terminal and a converter having a second diode unit connected to the converter for converting an input AC voltage and outputting the converted voltage to a dc terminal, and a converter control unit for outputting a converter switching control signal to the switching unit, wherein the converter control unit includes an input AC In a first section in which the voltage rises, the switching unit controls to repeat the switching operation, and in a second section in which the input AC voltage falls, the switching unit controls to repeat the switching operation.

In addition, the power conversion device according to another embodiment of the present invention for achieving the above object is an inductor, a first diode unit connected to the inductor, a switching unit connected to both ends of the first diode unit, an inductor and an output terminal a converter having a second diode unit connected between the dc terminals, converting the input AC voltage and outputting the converted voltage to the dc terminal, and a converter control unit outputting a converter switching control signal to the switching unit, the converter control unit comprising: , based on the temperature around the converter or the size of the load connected to both ends of the dc terminal, the switching unit operates in the first switching mode in which the switching unit switches for a partial period in response to the input AC voltage, or the switching unit responds to the input AC voltage for the entire period It is controlled to operate in the second switching mode during which it is switched.

In addition, the air conditioner according to an embodiment of the present invention for achieving the above object includes an inductor, a first diode part connected to the inductor, a switching part connected to both ends of the first diode part, and a dc terminal that is an output terminal with the inductor. A power conversion device comprising a converter having a second diode unit connected therebetween, converting an input AC voltage and outputting the converted voltage to a dc terminal, and a converter control unit outputting a converter switching control signal to the switching unit, , the converter control unit controls the switching unit to repeat the switching operation in a first section in which the input AC voltage rises, and controls the switching unit to repeat the switching operation in a second section in which the input AC voltage falls.

According to an embodiment of the present invention, a power conversion device, and an air conditioner having the same, include a switching converter including a switching unit, and a converter control unit for outputting a converter switching control signal to the switching unit, and the converter control unit includes an input In a first section in which the AC voltage rises, the switching unit controls to repeat the switching operation, and in a second section in which the input AC voltage falls, the switching unit controls to repeat the switching operation. Accordingly, it is possible to improve the power factor.

In particular, since the voltage utilization rate is improved by switching even in the falling section of the input voltage, the size of the inductor in the converter can be reduced.

Meanwhile, by providing a non-switching section between the first section and the second section, and varying the switching section and the non-switching section according to the size of the load, optimal control for each load is possible.

In particular, as the size of the load increases, by increasing the switching period, it is possible to improve the power factor despite the load fluctuation.

Meanwhile, by varying the switching frequency of the switching unit, it is possible to improve efficiency and reduce EMI noise. Also, the size of the inductor can be reduced.

Meanwhile, according to another embodiment of the present invention, since the partial switching method and the full-section switching method can be selectively applied, the size of the heat sink for reducing heat generation can be reduced.

1 is an example of a circuit diagram of a power conversion device according to an embodiment of the present invention.
Figure 2 shows an example of the input current waveform according to the operation of the power converter of Figure 1.
3A and 3B are diagrams referenced for explaining the operation of the power converter of FIG. 1 .
4A to 4C are diagrams referenced to explain various operating modes of the power converter of FIG. 1 .
5A to 5B are diagrams referenced for explaining a change in the operation mode of the power conversion device according to the load size or the ambient temperature.
6A to 6B are diagrams referenced to explain switching frequency variation.
7A to 7B are diagrams referenced to explain an input current and frequency spectrum according to a switching frequency change.
FIG. 8 is an example of an internal block diagram of the converter control unit of FIG. 1 .
9A to 10D are diagrams illustrating various input currents and frequency spectra according to input currents.
11 is a block diagram of an air conditioner according to an embodiment of the present invention.
12 is a view showing a schematic view of the air conditioner of FIG. 11 .
13 is an internal block diagram of the driving device of the outdoor unit of FIG. 11 .
Fig. 14 illustrates a circuit diagram of an inverter in the driving device of Fig. 13;
15 is an internal block diagram of the inverter control unit of FIG. 14 .

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

The suffixes “module” and “part” for the components used in the following description are given simply in consideration of the ease of writing the present specification, and do not impart a particularly important meaning or role by themselves. Accordingly, the terms “module” and “unit” may be used interchangeably.

1 is an example of a circuit diagram of a power conversion device according to an embodiment of the present invention.

Referring to the drawings, the power conversion device 400 according to an embodiment of the present invention may convert an input AC power to power. In particular, it can be converted to DC power. The power-converted DC power may be stored as a Vdc voltage in a dc terminal capacitor C, which is an output terminal.

On the other hand, a predetermined load 205 may be connected to both ends of the dc terminal.

For example, a dc load or an ac load may be connected. Specifically, the load 205 may be a concept including the inverter 420 and the motor 250 of FIG. 13 .

When the load 205 is fluctuated heavily, the dc terminal voltage Vdc may fluctuate, and accordingly, the input current based on the input AC voltage Vs may fluctuate.

Since the power factor is a ratio of the input AC voltage to the input current, the greater the fluctuation of the input current, the worse the power factor may be.

In the present invention, it is possible to improve the power factor, and proposes a power conversion device 400 having a converter 410, which can be implemented as a simple circuit element. In particular, as the converter 410 , a switching converter is proposed.

The switching converter, compared to the PFC, has a simple circuit and is effective in reducing costs because a relatively inexpensive iron core inductor or reactor is used instead of a powder-type inductor core (reactor core).

In accordance with an embodiment of the present invention, the power conversion device 400 includes an inductor (L), a first diode unit 405 connected to the inductor (L), and connected to both ends of the first diode unit 405 . A converter comprising a switching unit 409 and a second diode unit 407 connected between the inductor L and the dc terminal serving as the output terminal, converting the input AC voltage Vs and outputting the converted voltage to the dc terminal 410 , and a converter control unit 415 outputting a converter switching control signal Scc to the switching unit 409 may be included.

On the other hand, the power conversion device 400, the input voltage detection unit (A) for detecting the input voltage (Vs), the input current detection unit (D) for detecting the input current (Is), and the output terminal dc terminal voltage ( Vdc) may further include a dc terminal voltage detection unit (B) for detecting.

The input voltage detection unit (A) or the dc terminal voltage detection unit (B) may include a resistance element, an amplifier, or a voltage transformer. The detected input voltage Vs and the dc terminal voltage Vdc may be input to the converter control unit 415 .

The input current detection unit D may include a resistance element, an amplifier, or a voltage transformer. The detected input current Is may be input to the converter controller 415 .

The first diode unit 405 may include four bridge diodes Da, Db, Dc, and Dd.

Referring to the circuit configuration of FIG. 1 in more detail, one end of the inductor L is connected to one end of the input voltage source 201, and between the other end of the inductor L and the capacitor C disposed at both ends of the dc end, the first Two diode units 407 are connected.

The second diode unit 407 includes a diode D1 and a diode D2. The anode of the diode D1 may be connected to the other end of the inductor L, and the anode of the diode D2 may be connected to the other end of the input voltage source 201 .

Meanwhile, in parallel to the second diode unit 407 , the first diode unit 407 is connected.

That is, the anode of the diode Da is connected between the anode of the diode D1 and the other end of the inductor L, and between the other end of the input voltage source 201 and the anode of the diode D2, the diode Dd A cathode may be connected.

Meanwhile, a switching unit 409 including a switching element S1 is connected between both ends of the first diode unit 405 .

Meanwhile, a reverse flow prevention diode d3 may be connected between the switching unit 409 and the first diode unit 405 and between the second diode unit 407 .

On the other hand, the dc terminal capacitor (C) is connected to both ends of the reverse flow prevention diode (d3) and the switching element (S1). And, the load 205 is connected to both ends of the dc terminal capacitor C, that is, both ends of the dc terminal.

Meanwhile, the converter control unit 415 generates a converter switching control signal Scc based on the input voltage Vs, the input current Is, and the dc terminal voltage Vdc, and outputs it to the switching unit 409 . can do

When the switching element S1 of the switching unit 409 is implemented as an IGBT, a converter switching control signal Scc corresponding to turn-on duty may be input to a gate terminal. Accordingly, the switching element S1 may repeat switching (turn on and off) or may be turned off for a predetermined period of time.

Meanwhile, the converter control unit 415 controls the switching unit 409 to repeat switching operations (turn-on and turn-off) in the first section Ta in which the input AC voltage Vs rises, and the input AC voltage In the second section Tc in which (Vs) falls, the switching unit 409 may be controlled to repeatedly turn on and turn off. Accordingly, it is possible to improve the power factor of the power conversion device 400 despite the load variation.

Meanwhile, the converter controller 415 may control the switching unit 409 to be turned off in the third period Tb between the first period Ta and the second period Tc.

Meanwhile, the converter controller 415 may vary the length of the first section Ta and the second section Tc according to the size of the load 205 connected to both ends of the dc terminal.

Meanwhile, the converter controller 415 may control the first section Ta and the second section Tc to become longer as the size of the load 205 connected to both ends of the dc terminal increases.

On the other hand, the converter control unit 415, as the voltage command value for the dc terminal increases, the first section (Ta) and the second section (Tc) to control so that the longer, and the third section (Tb) can be controlled so that the smaller have.

On the other hand, the converter control unit 415, when the size of the load 205 connected to both ends of the dc terminal is less than the first predetermined value, the first switching mode having a first section (Ta) and a second section (Tc) Controlled to operate, and when the magnitude of the load 205 connected to both ends of the dc terminal is equal to or greater than the first predetermined value, the second section having a first section (Ta), a second section (Tc), and a third section (Tb) It can be controlled to operate in two switching modes or a third switching mode in which the first switching mode and the second switching mode are mixed.

On the other hand, when the temperature around the converter 410 is equal to or higher than the first temperature, the converter control unit 415 controls the converter to operate in the first switching mode including the first section Ta and the second section Tc, When the ambient temperature is less than the first temperature, the control may be performed to operate in a second switching mode including a first section Ta, a second section Tc, and a third section Tb.

Meanwhile, the converter control unit 415, the converter control unit 415 may vary the switching frequency of the switching unit 409 in the first period Ta and the second period Tc.

On the other hand, the converter control unit 415 controls the switching frequency of the switching unit 409 to decrease as the magnitude of the input voltage Vs increases, and as the magnitude of the input voltage Vs decreases, the switching unit 409 decreases. can be controlled to increase the switching frequency of

On the other hand, the converter control unit 415, when the load 205 includes a motor (250 in FIG. 13) and an inverter (420 in FIG. 8), the output voltage output to the motor, and the magnitude of the input AC voltage (Vs) Based on the dc stage voltage command value (V ^* dc) can be generated.

^{In addition, the converter control unit 415 generates a dc stage voltage command value (V *} dc) based on the output voltage Vout output to the motor 250 and the magnitude of the input AC voltage Vs, and the dc stage Based on the voltage setpoint (V ^* dc) and the dc stage voltage (Vdc), a current setpoint (I ^* ) is generated, and ^{based on the current setpoint (I *} ), a turn-on duty is generated, and the turn Based on the on-duty, the converter switching control signal Scc may be generated and output.

Meanwhile, the converter controller 415 may generate and output the converter switching control signal Scc based on the magnitude of the load 205 connected to both ends of the dc terminal and the magnitude of the input AC voltage Vs.

On the other hand, the converter control unit 415 calculates the size of the load 205 connected to both ends of the dc terminal based on the ^{voltage command value (V *} d, V ^{* q) or the output voltage (Vd or Vq), and the dc terminal} The lengths of the first section Ta and the second section Tc may vary according to the size of the load 205 connected to both ends.

Figure 2 shows an example of the input current waveform according to the operation of the power converter of Figure 1.

Referring to the drawings, the converter controller 415, depending on the size of the load (205), dc terminal voltage command value (V ^* dc) operation to and a constant dc terminal voltage command value (V ^* dc), and an input voltage (Vs ), it can be divided into a first section Ta, a second section Tc in which the switching unit 409 repeats the switching operation, and a third section Tb in which the switching unit 409 is turned off. have.

The first section Ta is a section in which the input AC voltage Vs rises, and may include a plurality of switching sections Tsw having a turn-on period Ton and a turn-off period Toff.

Meanwhile, as the input AC voltage Vs increases, the switching period of the plurality of switching sections may become longer. That is, the switching frequency may be reduced. According to this, since the switching frequency is not constant, EMI different from the switching frequency can be further reduced. This will be described again with reference to FIG. 6A.

On the other hand, in the first section Ta and the second section Tc, the input voltage Vs is a ^{section lower than the dc terminal voltage command value (V *} dc), and the peak value of the input voltage Vs and the dc terminal voltage command value ( As ^{the difference between V *} dc) increases, the lengths of the first section Ta and the second section Tc may become smaller.

On the other hand, in the first section Ta and the second section Tc, the input voltage Vs is a ^{section lower than the dc terminal voltage command value (V *} dc), and the peak value of the input voltage Vs and the dc terminal voltage command value ( As ^{the difference between V *} dc) is small, the lengths of the first section Ta and the second section Tc may increase.

In addition, the third section Tb is a section in which the input voltage Vs ^{is higher than the dc stage voltage command value (V *} dc). Even without a separate switching operation, the input current Is is the dc stage according to the Vs voltage. flow in the direction The higher the input voltage (Vs), or dc The lower the terminal voltage command value (V ^* dc), that is, the larger the difference between the peak value of the input voltage (Vs) and a dc terminal voltage command value (V ^* dc), the third section (Tb) can be large.

On the other hand, the input voltage (Vs) is smaller, or dc The smaller the greater the bus voltage command value (V ^* dc), that is, smaller the difference between the peak value of the input voltage (Vs) and a dc terminal voltage command value (V ^* dc) As the number increases, the third section Tb may become smaller.

Fig. 2(a) shows a first switching mode based on a switching operation of the switching unit 409, and thus, as shown in Fig. 2(b), an input current Is similar to the input voltage vs. ) waveform can be acquired. Accordingly, the power factor can be improved.

Meanwhile, the first switching mode of FIG. 2A exemplifies a partial switching mode.

In the present invention, in addition to the first section Ta in which the input AC voltage Vs rises, the switching operation is performed also in the second section Tc in which the input AC voltage Vs falls, so that the voltage utilization rate is improved. Therefore, the power factor can be improved. Also, the size of the inductor L can be reduced.

Meanwhile, in FIG. 2 , the switching operation is exemplified by comparison with the ^{dc terminal voltage command value (V *} dc) based on the sinusoidal input voltage (Vs), but various modifications are possible.

For example, the converter control unit 415 may control the switching unit 409 to perform a switching operation based on a current command value in the form of a sine wave. In particular, when the sinusoidal current command value is less than the first reference value, the switching operation may be controlled, and if the first reference value or more, it may be controlled to be turned off.

3A and 3B are diagrams referenced for explaining the operation of the power converter of FIG. 1 . In the figure, the current flow diagram for the positive half cycle of the input voltage Vs is illustrated.

Referring to the drawings, FIG. 3A illustrates the flow path 1 of the input current Is in the Ton period in the first period Ta and the second period Tc of FIG. 2 , and FIG. 3B . exemplifies the flow (path 1) of the input current Is in the Toff section and the third section Tb in the first section Ta and the second section Tc of FIG. 2 .

According to FIG. 3A , along path 1 , an input current Is flows through the input voltage source 201 , the inductor L, the diode Da, the switching element S1 , and the diode D4 .

Meanwhile, according to FIG. 3B , an input current Is flows through the input voltage source 201 , the inductor L, the diode D1 , the capacitor C, and the diode D4 according to path 2 .

On the other hand, the current flow chart for the positive half cycle of the input voltage Vs is similar to FIGS. 3A to 3B .

The converter control unit 415, based on the temperature around the converter 410 or the size of the load 205 connected to both ends of the dc terminal, the switching unit 409 is switched in response to the input AC voltage (Vs) for some period to operate in a first switching mode (mode 1), or to operate in a second switching mode (mode 2) in which the switching unit 409 switches during the entire period in response to the input AC voltage Vs, or first switching It can be controlled to operate in a third switching mode (mode 3) in which the mode (mode 1) and the second switching mode (mode 2) are mixed.

This will be described with reference to FIGS. 4A to 5B.

4A to 4C are diagrams referenced to explain various operating modes of the power converter of FIG. 1 .

First, FIG. 4A illustrates a first switching mode (mode 1) in which the switching unit 409 switches in response to the input AC voltage Vs for a partial period.

Referring to the drawing, according to the first switching mode (mode 1), the input current Is1 has a peak value of Ipk1, a first period Ta1 for switching while the input voltage rises, and a second period for switching during a fall ( Ta3), and a third section Ta3 that is not switched may be provided.

Next, FIG. 4B illustrates a second switching mode (mode 2) in which the switching unit 409 switches in response to the input AC voltage Vs for the entire period.

Referring to the drawing, according to the second switching mode (mode 2), the input current Is2 may have a peak value Ipk2 and a period Tk in which the input voltage is continuously switched during a positive half cycle.

Comparing FIGS. 4B and 4A , it can be seen that the magnitude or peak value of the input current in the second switching mode (mode 2) is larger.

That is, as the switching period increases, the peak value of the input current may increase, and accordingly, the dc terminal voltage Vdc may be increased.

Accordingly, the converter controller 415, to increase the size of the load, if the increase in the dc terminal voltage required, dc terminal voltage command value (V ^* dc) is set to be increased, and the increased dc terminal voltage command value (V ^* dc ), it is possible to control the switching period to become longer. ^{That is, after setting the V *} dc value in FIG. 2 to increase, it is possible to control the switching period to be long.

Meanwhile, as the switching period becomes longer, the non-switching period, that is, the turn-off period, may become smaller.

As such, as the size of the load increases, by increasing the switching period, it is possible to improve the power factor despite the load fluctuation.

On the other hand, according to the second switching mode (mode 2), since the amount of heat generated increases, when the temperature around the converter 415 is high, it is preferable not to use the converter 415 to reduce the temperature.

That is, when the temperature around the converter is equal to or higher than the first temperature, the converter control unit 415 controls to operate in the first switching mode including the first section Ta and the second section Tc, and the temperature around the converter When is less than the first temperature, it is possible to control the operation to operate in the second switching mode including the first section Ta, the second section Tc, and the third section Tb.

Next, FIG. 4C illustrates a third switching mode (mode 3) in which the switching unit 409 performs a mixed operation of the first switching mode (mode 1) and the second switching mode (mode 2).

5A to 5B are diagrams referenced for explaining a change in the operation mode of the power conversion device according to the load size or the ambient temperature.

The converter control unit 415 is configured to operate in a first switching mode having a first section Ta and a second section Tc when the size of the load 205 connected to both ends of the dc terminal is less than a first predetermined value. A second switching having a first section (Ta), a second section (Tc), and a third section (Tb) when the size of the load 205 connected to both ends of the control and the dc terminal is equal to or greater than the first predetermined value mode or a third switching mode in which the first switching mode and the second switching mode are mixed may be controlled to operate.

In FIG. 5A , when the size of the load 205 is V_load1, it operates in the first switching mode, and when the size of the load 205 is V_load2 larger than V_load1, it operates in the second switching mode or the third switching mode. example of doing

On the other hand, when the temperature around the converter 410 is equal to or higher than the first temperature, the converter control unit 415 controls the converter to operate in the first switching mode including the first section Ta and the second section Tc, When the ambient temperature is less than the first temperature, it is possible to control the operation to operate in the second switching mode including the first section Ta, the second section Tc, and the third section Tb.

In FIG. 5B , when the temperature around the converter 410 is Tma, the second switching mode is operated, and when the temperature around the converter 410 is Tmb lower than Tma, the operation in the first switching mode is exemplified.

As described above, since the partial switching method and the full switching method can be selectively applied, the size of the heat sink for reducing heat generation can be reduced.

Meanwhile, the converter controller 415 may vary the switching frequency of the switching unit 409 in the first period Ta and the second period Tc.

On the other hand, the converter control unit 415 controls the switching frequency of the switching unit 409 to decrease as the magnitude of the input voltage Vs increases, and as the magnitude of the input voltage Vs decreases, the switching unit 409 decreases. can be controlled to increase the switching frequency of The variable switching frequency will be described with reference to FIGS. 6A to 6B .

6A to 6B are diagrams referenced to explain switching frequency variation.

First, FIG. 6A illustrates that, during the positive half cycle of the input voltage Vs, the switching frequency is divided into a decreasing section Tfsa, a constant section Tfi, and an increasing section Tfsb.

During the decreasing period Tfsa, the switching frequency sequentially decreases from Fmax to Fmin, and during the increasing period Tfsb, the switching frequency sequentially increases from Fmin to Fmax.

Meanwhile, the decreasing section Tfsa and the increasing section Tfsb may correspond to the Ta section and the Tc section of FIG. 2 , respectively.

Meanwhile, in FIG. 6A , the switching frequency is exemplified during full switching according to the second switching mode. However, in contrast to this, the switching frequency may be varied even during partial switching according to the first switching mode. can

That is, in FIG. 6A , during the positive half cycle of the input voltage Vs, the switching frequency is divided into a decreasing section (Tfsa) and an increasing section (Tfsb), and the switching frequency in a constant section (Tfi) is 0 days can

FIG. 6B illustrates the switching period at point K and the switching period at point M in FIG. 6A .

Since the switching frequency is sequentially decreased, the switching period Tfsa2 at the M point becomes longer than the switching period Tfsa1 at the K point.

7A to 7B are diagrams referenced to explain an input current and frequency spectrum according to a switching frequency change.

First, FIG. 7A shows the frequency spectrum Fs7a of the input current Is7a and the input current Is7a when operating in the first switching mode with the switching frequency of the switching unit 409 constant. indicates.

For example, when a switching operation is performed with a switching frequency of 5 KHz, a harmonic component corresponding to 5 KHz appears in the frequency spectrum. In particular, peak noise appears.

Next, FIG. 7B shows the input current Is7b and the frequency spectrum Fs7b of the input current Is7b when the switching unit 409 operates in the first switching mode while varying the switching frequency.

It can be seen that peak noise among frequency components is reduced compared to FIG. 7B .

In this way, by varying the switching frequency of the switching unit 409, it is possible to improve efficiency and reduce EMI noise. Also, the size of the inductor L for noise reduction can be reduced.

FIG. 8 is an example of an internal block diagram of the converter control unit of FIG. 1 .

Referring to the drawings, the converter control unit 415 includes a phase extraction unit 805, a dc terminal voltage command generation unit 810, a current command generation unit 820, a duty generation unit 830, and a switching control signal output unit ( 840), a switching frequency variable unit 850, and a partial switching control unit 860 may be provided.

The phase extractor 805 may extract the phase θ of the input voltage Vs. In addition, the magnitude (E) of the input voltage (Vs) and the frequency (ω) of the input voltage (Vs) may be extracted. To this end, the phase extractor 805 may include a phase locked loop (PLL).

On the other hand, the magnitude E of the extracted input voltage Vs is transmitted to the dc terminal voltage command generation unit 810 , and the frequency ω of the extracted input voltage Vs is transmitted to the duty generation unit 830 . The phase θ of the extracted input voltage Vs may be transmitted to the switching frequency variable unit 850 and the partial switching control unit 860 .

^{The dc stage voltage command generation unit 810 may generate a dc stage voltage command value (V *} dc) based on the output voltage Vout output to the motor 250 and the magnitude of the input AC voltage Vs. have.

The output voltage Vout may correspond to a d-axis voltage command value (V ^* d) and a q-axis voltage command value (V ^* q) from the inverter control unit ( 430 in FIG. 13 ). Accordingly, the dc stage voltage command generation unit 810 may receive the d-axis voltage command value (V ^* d) and the q-axis voltage command value (V ^* q) from the inverter control unit ( 430 of FIG. 13 ).

The current command generation unit 820 may generate a current command ^{value I * based on the dc terminal voltage command value (V *} dc) and the detected dc terminal voltage (Vdc).

The duty generator 830 may generate a turn-on duty based on the ^{command current I * and the detected input current Is.}

The switching control signal output unit 840 may output the converter switching control signal Scc based on a turn-on duty or the like.

On the other hand, the switching control signal output unit 840, a first operator for the operation of the duty and the switching frequency information (Fss) from the switching frequency variable unit 850, and a part from the partial switching control unit 860 A second operator for operation with the switching information Sps may be further included. Here, the first operator and the second operator may be multipliers.

The switching frequency variable unit 850 may vary the switching frequency based on the phase θ of the input voltage Vs. As shown in FIG. 6A , as the input voltage Vs increases, the switching frequency may decrease, and as the input voltage Vs decreases, the switching frequency may be set to increase. The switching frequency information Fss may be transmitted to the switching control signal output unit 840 .

The partial switching control unit 860 may set a partial switching period based on the phase θ of the input voltage Vs. The partial switching period information Sps may be transmitted to the switching control signal output unit 840 .

9A to 10D are diagrams illustrating various input currents and frequency spectra according to input currents.

Hereinafter, it is described on the assumption that the load 205 includes the inverter 420 and the motor 250 .

First, FIGS. 9A and 9B illustrate a case in which the driving frequency is changed when driving at a fixed switching frequency and the dc terminal voltage is approximately 310V.

It is exemplified that the operating frequency of FIG. 9A is approximately 20 Hz, and the operating frequency of FIG. 9B is approximately 50 Hz.

As such, as the operating frequency increases, the size of the load increases, so that the switching period may be longer, and accordingly, the size of the input current may be increased.

That is, it can be seen that the input current Is9b of FIG. 9B has a larger magnitude and a switching period than the input current Is9a of FIG. 9A .

Meanwhile, in FIG. 9C , similar to FIG. 9A , the operating frequency is approximately 20 Hz, but there is a difference in varying the switching frequency.

Accordingly, although there is not much difference between the input current Is9c of FIG. 9C and the input current Is9a of FIG. 9A, there is a difference in the frequency spectrum. That is, it can be seen that the frequency spectrum fs9c according to the input current Is9c of FIG. 9C has less noise than the frequency spectrum fs9a of FIG. 9A .

Meanwhile, in FIG. 9D, the switching frequency is variable similar to that of FIG. 9C, but there is a difference in that the operating frequency is approximately 50 Hz.

Accordingly, it can be seen that the input current Is9d of FIG. 9D has a larger magnitude and a switching period than the input current Is9c of FIG. 9C .

Next, FIGS. 10A and 10B exemplify a case in which driving is performed at a fixed switching frequency, but the operating frequency is changed.

The operating frequency of FIG. 10A is approximately 60 Hz, and the operating frequency of FIG. 10B is approximately 79 Hz. Accordingly, the dc terminal voltage may also be changed to 310V and 330V.

As such, as the operating frequency increases, the size of the load increases, so that the switching period may be longer, and accordingly, the size of the input current may be increased.

That is, it can be seen that the input current Is10b of FIG. 10B has a larger magnitude and a switching period than the input current Is10a of FIG. 10A .

Meanwhile, in FIG. 10C , similar to FIG. 10A , the operating frequency is approximately 26 Hz, but there is a difference in varying the switching frequency.

Accordingly, although there is not much difference between the input current Is10c of FIG. 10C and the input current Is10a of FIG. 10A, there is a difference in the frequency spectrum. That is, it can be seen that the frequency spectrum fs10c according to the input current Is10c of FIG. 10C has less noise than the frequency spectrum fs10a of FIG. 10A .

Meanwhile, in FIG. 10D , the switching frequency is variable similar to FIG. 10C , but the difference is that the operating frequency is approximately 79 Hz. Also, the dc terminal voltage may be changed to 310V and 330V.

Accordingly, it can be seen that the input current Is10d of FIG. 10D has a larger magnitude and a switching period than the input current Is10c of FIG. 10C .

On the other hand, the power conversion device 400 described in Figures 1 to 10d, it is possible to be applied to various electronic devices.

For example, it can be applied to home appliances such as air conditioners, laundry processing devices (washing machines, dryers), refrigerators, TVs, cooking devices, and vacuum cleaners.

Hereinafter, it will be described based on the power conversion device 400 is employed in the air conditioner among various home appliances.

11 is a block diagram of an air conditioner according to an embodiment of the present invention, and FIG. 12 is a schematic diagram of the air conditioner of FIG. 11 .

Referring to the drawings, the 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 refrigerant to the indoor unit 170 .

To this end, the outdoor unit 150 includes a compressor 152 that compresses the refrigerant, a compressor electric motor 152b that drives the compressor, and an outdoor heat exchanger 154 that radiates heat from the compressed refrigerant. and an outdoor blower 155 comprising an outdoor fan 155a disposed on one side of the outdoor heat exchanger 154 to promote heat dissipation of the refrigerant and an electric motor 5b rotating the outdoor fan 155a, and the condensed refrigerant. An expansion mechanism 156 that expands, a cooling/heating switching valve 160 that changes the flow path of the compressed refrigerant, and an accumulator that temporarily stores the vaporized refrigerant to remove moisture and foreign substances and supplies the refrigerant at a constant pressure to the compressor (153) and the like. At least one of an inverter compressor and a constant speed compressor may be used as the compressor 152 .

In addition, 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 indoors to perform a cooling/heating function, an indoor fan 209a disposed at one side of the indoor heat exchanger 208 to promote heat dissipation of the refrigerant; and an indoor blower 209 including an electric motor 209b that rotates the indoor fan 209a. At least one indoor heat exchanger 208 may be installed.

In addition, 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 opening and closing the discharge port (not shown) and controlling the direction of the discharged air. For example, a vane for guiding air while opening and closing at least one of an air inlet (not shown) and an air outlet (not shown) may be installed, and the vane not only opens and closes the air inlet and the air outlet, but also opens and closes the intake air and the direction of the discharge air.

Meanwhile, the indoor unit 170 may adjust the air volume by controlling the intake air and the discharged air according to the rotation speed of the indoor fan 209a.

In addition, the indoor unit 170 may further include a display unit (not shown) for displaying the operating 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 the indoor temperature, a human body sensing unit (not shown) for sensing a human body existing in the indoor space.

Meanwhile, the air conditioner 100 may be configured as an air conditioner for cooling an indoor space, or may be configured as a heat pump for cooling or heating an indoor space.

Meanwhile, in the drawings, a stand-type indoor unit 170 is described as an example, but it is also possible to use a ceiling-type or wall-mounted type, and various forms such as an integral type in which there is no distinction between an outdoor unit and an indoor unit are possible.

Meanwhile, a refrigerant pipe is connected between the indoor unit 170 and the outdoor unit 150 , and hot and cold air is discharged from the indoor unit 170 into the room according to the circulation of the refrigerant. In this case, 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.

In addition, the indoor unit 170 and the outdoor unit 150 may be connected by a communication line to transmit/receive control commands according to a predetermined communication method.

Meanwhile, the compressor 152 may be driven by driving power supplied through the following driving device 200 . Specifically to the motor in the compressor 152 . Driving power from the driving device 200 may be supplied.

13 is an internal block diagram of the driving device of the outdoor unit of FIG. 11 , and FIG. 4A illustrates an example of a circuit diagram of a converter in the driving device of FIG. 13 .

The driving device 200 according to an embodiment of the present invention may include a converter 410 , a converter controller 415 , a capacitor C, an inverter 420 , and an inverter controller 430 .

In particular, the converter 410, the converter control unit 415, the input voltage detection unit (A), the input current detection unit (D), the dc terminal voltage detection unit (B) of the driving device 200, the power conversion device described in FIG. (400).

The converter 410 converts the input AC power into DC power and outputs it. In particular, it is output to the capacitor C disposed at the output terminal of the converter 410 . The description of the converter 410 will be omitted with reference to FIG. 1 and the like.

Meanwhile, DC power is stored at both ends of the capacitor C, and accordingly, it may be referred to as a dc terminal. In addition, the power supply across the capacitor C may be referred to as a dc stage power supply.

Meanwhile, a load 205 as shown in FIG. 1 may be connected to both ends of the capacitor C. As shown in FIG. In this case, the load 205 may be a concept including the inverter 420 and the motor 250 of FIG. 13 .

On the other hand, the converter control unit 415, based on the dc terminal voltage (Vdc) or the dc terminal voltage command value of both ends of the capacitor (C), to control the switching element (S1) in the switching unit 409 in the converter 410 can The description of the converter control unit 415 will be omitted with reference to FIG. 1 and the like.

The inverter 420 includes a plurality of inverter switching elements, and converts a dc stage power supply (Vdc) into a three-phase AC power supply (va, vb, vc) of a predetermined frequency by on/off operation of the switching element, three-phase synchronous It can output to the motor 250 . At this time, the motor 250 may be a motor in the compressor.

The inverter controller 430 outputs the inverter switching control signal Sic to the inverter 420 in order to control the switching operation of the inverter 420 . The inverter switching control signal Sic is a pulse width modulation (PWM) switching control signal, and is generated and output based _{on the output current value i o detected by the output current detection unit (E of FIG. 14 ).}

Fig. 14 illustrates a circuit diagram of an inverter in the driving device of Fig. 13;

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

The switching elements in the inverter 420 turn on/off 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 the DC power across the capacitor C into AC power in the motor 250 operation mode.

The inverter controller 430 may control the operation of the switching element in the inverter 420 . _{To this end, the inverter control unit 430 may receive the output current i o} detected by the output current detection unit (E of FIG. 14 ).

The inverter controller 430 outputs the inverter switching control signal Sic to the inverter 420 in order to control the switching operation of the inverter 420 . The inverter switching control signal Sic is a pulse width modulation (PWM) switching control signal, and is generated and output based _{on the output current value i o detected by the output current detection unit (E of FIG. 14 ).}

The output current detection unit (E of FIG. 14 ) may detect the _{output current i o} flowing between the inverter 420 and the three-phase motor 250 . That is, the current flowing through the motor 250 is detected. The output current detection unit E may detect all of the output currents ia, ib, and ic of each phase, or may detect the output currents of two phases using three-phase balance.

The output current detection unit E may be located between the inverter 420 and the motor 250 , and a current transformer (CT), a shunt resistor, or the like may be used to detect the current.

When a shunt resistor is used, three shunt resistors are located between the inverter 420 and the synchronous motor 250 , or the three lower arm switching elements S'a, S'b, S'c of the inverter 420 . ) can be connected at one end to each. On the other hand, using three-phase equilibrium, it is also possible that two shunt resistors are used. On the other hand, when one shunt resistor is used, it is also possible that the shunt resistor is disposed between the above-described capacitor C and the inverter 420 .

The detected output current i _o is a discrete signal in the form of a pulse, and may be applied to the controller 430 , and the inverter switching control signal Sic is generated based on the _{detected output current i o .} is created Hereinafter, it is assumed that the detected output current (i _o ) is the three-phase output current (ia, ib, ic).

15 is an internal block diagram of the inverter control unit of FIG. 14 .

15 , the inverter control unit 430 includes an axis conversion unit 310 , a position estimation 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 axis conversion unit 310 receives the three-phase output current (ia, ib, ic) detected by the output current detection unit (E) and converts it into a two-phase current (iα, iβ) of a stationary coordinate system.

Meanwhile, the axis conversion unit 310 may convert the two-phase currents (iα, iβ) of the stationary coordinate system into the two-phase currents (id, iq) of the rotational coordinate system.

)를 추정할 수 있다. 또한, 위치 추정부(320)는, 회전자 위치(

)에 기초하여, 속도(

)를 추정할 수도 있다. The position estimating unit 320, the rotor position (

) can be estimated. In addition, the position estimation unit 320, the rotor position (

), based on the speed(

) can be estimated.

)와 연산된 속도(

)를 출력할 수 있다.As a result, the position estimating unit 320, based on the three-phase output current (ia, ib, ic) detected by the output current detection unit (E), the calculated position (

) and the calculated speed (

) can be printed.

)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(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, the calculation speed (

) and the target speed ω, a speed command value ω ^* _r is calculated, and a current command value i ^* _q is generated based on the speed command value ω ^* _{r .} For example, the current command generation unit 330 may set the calculation speed (

) and the target speed ω ^{, based on the speed command value ω *} _r , the PI controller 335 may perform PI control and generate the ^{current command value i *} _{q .} In the drawing, the q-axis current command value (i ^* _q ) is exemplified as the current command value, but unlike the drawing, it is also possible to generate the ^{d-axis current command value (i *} _{d ) together.} On the other hand, the value of the d-axis current command value (i ^* _d ) may be set to 0.

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

Next, the voltage command generation unit 340 includes the d-axis and q-axis currents (i _d ,i _q ) that are axis-transformed into the two-phase rotational coordinate system by the axis transformation unit, and the current command values ( Based on i ^* _d ,i ^* _q ), d-axis and q-axis voltage command values (v ^* _d ,v ^* _q ) are generated. 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 ), q} A shaft voltage setpoint (v ^* _q ) can be generated. In addition, the voltage command generator 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 ), and the d-axis voltage} A setpoint (v ^* _d ) can be generated. Meanwhile, the value of the d-axis voltage command value (v ^* _d ) may be set to 0, corresponding to the case where the value of the d-axis current command value (i ^* _{d) is set to 0.}

On the other hand, the voltage command generation unit 340, the d-axis, q-axis voltage command value (v ^* _d , v ^* _q ) may further include a limiter (not shown) for limiting the level so as not to exceed the allowable range. .

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

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

) and d-axis and q-axis voltage command values (v ^* _d ,v ^* _q ) are received and axis transformation is performed.

)가 사용될 수 있다.First, the axis transformation unit 350 performs transformation from a two-phase rotational coordinate system to a two-phase stationary coordinate system. At this time, the position calculated by the position estimator 320 (

) can be used.

Then, the axis transformation unit 350 performs transformation from the two-phase stationary coordinate system to the three-phase stationary coordinate system. Through this conversion, the shaft conversion unit 350 outputs a three-phase output voltage command value (v ^* a, v ^* b, v ^* c).

The switching control signal output unit 360 generates a switching control signal (Sic) for an inverter according to a pulse width modulation (PWM) method based on the three-phase output voltage command value (v ^* a, v ^* b, v ^{* c)} to output

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

A power conversion device according to an embodiment of the present invention, and an air conditioner having the same, the configuration and method of the embodiments described above are not limitedly applicable, but the embodiments are such that various modifications can be made. All or part of each embodiment may be selectively combined and configured.

On the other hand, the operating method of the charging device of the present invention can be implemented as a processor-readable code on a processor-readable recording medium provided in the charging device. The processor-readable recording medium includes all types of recording devices in which data readable by the processor is stored.

In addition, although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the claims In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Claims (16)

An inductor, a first diode unit connected to the inductor, a switching unit connected to both ends of the first diode unit, and a second diode unit connected between the inductor and a dc terminal that is an output terminal, converting an input AC voltage a converter for outputting the converted voltage to the dc terminal; and
Containing; a converter control unit for outputting a converter switching control signal to the switching unit;
The converter control unit,
In a first section in which the input AC voltage rises, controlling the switching unit to repeat a switching operation,
In a second section in which the input AC voltage falls, the power converter controls the switching unit to repeat a switching operation. According to claim 1,
The converter control unit,
In a third section between the first section and the second section, a power conversion device for controlling the switching unit to be turned off. According to claim 1,
The converter control unit,
Power conversion device for varying the length of the first section and the second section according to the size of the load connected to both ends of the dc terminal. According to claim 1,
The converter control unit,
As the size of the load connected to both ends of the dc terminal increases, the power conversion device for controlling the length of the first section and the second section. In the second,
The converter control unit,
As the voltage command value for the dc terminal increases, the first section and the second section are controlled to be longer, and the third section is controlled to be smaller. 3. The method of claim 2,
The converter control unit,
When the magnitude of the load connected to both ends of the dc terminal is less than a first predetermined value, control to operate in a first switching mode having the first section and the second section,
When the magnitude of the load connected to both ends of the dc terminal is equal to or greater than the first predetermined value, a second switching mode having the first section, a second section, and a third section, or the first switching mode and the second A power conversion device that controls to operate in a third switching mode in which the switching modes are mixed. 3. The method of claim 2,
The converter control unit,
When the temperature around the converter is less than the first temperature, controlling to operate in a first switching mode having the first section and the second section,
When the temperature around the converter is greater than or equal to the first temperature, the power conversion device for controlling to operate in a second switching mode having the first section, the second section, and the third section. According to claim 1,
The converter control unit,
A power converter for varying the switching frequency of the switching unit in the first section and the second section. 9. The method of claim 8,
The converter control unit,
As the magnitude of the input voltage increases, the switching frequency of the switching unit is controlled to decrease, and as the magnitude of the input voltage decreases, the switching frequency of the switching unit is controlled to increase. According to claim 1,
an inverter connected to both ends of the dc terminal, converting the dc terminal voltage into an AC voltage and outputting it to the motor; and
It further includes; an inverter control unit for controlling the inverter,
The converter control unit,
a dc stage voltage command generator configured to generate a dc stage voltage command value based on the output voltage output to the motor and the magnitude of the input AC voltage;
a current command generation unit for generating a current command value based on the dc stage voltage command value and the dc stage voltage;
a duty generator configured to generate a turn-on duty based on the current command value; and
Power conversion device comprising a; based on the turn-on duty, the switching control signal outputting the converter switching control signal. 11. The method of claim 10,
The converter control unit,
a phase extractor for extracting a phase of the input voltage;
Power conversion device further comprising a; switching frequency variable unit for varying the switching frequency of the switching unit on the basis of the extracted phase. According to claim 1,
The converter control unit,
A power converter for generating and outputting the converter switching control signal based on the magnitude of the load connected to both ends of the dc terminal and the magnitude of the input AC voltage. 11. The method of claim 10,
The inverter control unit,
an estimator for estimating a rotor speed of the motor based on a current flowing through the motor;
a current command generation unit that generates a current command value based on the estimated speed and the speed command value;
a voltage command generator configured to generate a voltage command value based on the current command value;
a switching control signal output unit for outputting an inverter switching control signal based on the voltage command value;
Power conversion device for transmitting the voltage command value to the converter control unit. 14. The method of claim 13,
The converter control unit,
Calculate the magnitude of the load connected to both ends of the dc terminal based on the voltage command value,
Power conversion device for varying the length of the first section and the second section according to the size of the load connected to both ends of the dc terminal. An inductor, a first diode unit connected to the inductor, a switching unit connected to both ends of the first diode unit, and a second diode unit connected between the inductor and a dc terminal that is an output terminal, converting an input AC voltage a converter for outputting the converted voltage to the dc terminal; and
Containing; a converter control unit for outputting a converter switching control signal to the switching unit;
The converter control unit,
Based on the temperature around the converter or the size of the load connected to both ends of the dc terminal,
The switching unit operates in a first switching mode in which the switching unit switches for a partial period in response to the input AC voltage,
A power conversion device for controlling the switching unit to operate in a second switching mode in which the switching unit is switched during the entire period in response to the input AC voltage. An air conditioner comprising the power conversion device of any one of claims 1 to 15.

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