KR20160006954A - Power converting apparatus and home appliance including the same - Google Patents

Abstract

The present invention relates to a power conversion device and a home appliance having the same. The power conversion device according to an embodiment of the present invention comprises: a first power output unit having a switching element, a first diode element, and a primary inductor of a transformer, wherein input power is converted based on a switching operation of the switching element to output first output power; and a second power output unit having a secondary inductor of the transformer and a second diode element, wherein input power is converted to output second output power. Accordingly, a plurality of insulated output power can be output.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power converting apparatus and a home appliance having the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion device and a home appliance having the power conversion device, and more particularly, to a power conversion device capable of outputting a plurality of insulated output power supplies and a home appliance having the power conversion device.

The power conversion apparatus is a device that converts input power and supplies the converted power. These power conversion devices are respectively disposed in the home appliances, and convert the input power into power for driving the home appliances.

On the other hand, various functions of home appliances are installed, and various levels of driving power are required. Accordingly, various researches have been made on a power conversion device capable of being isolated and capable of outputting multiple power sources and a home appliance having the power conversion device.

It is an object of the present invention to provide a power conversion device capable of outputting a plurality of insulated output power supplies and a home appliance having the same.

According to an aspect of the present invention, there is provided a power conversion apparatus including a switching element, a first diode element, and a primary side inductor of a transformer, And a second power output unit having a secondary side inductor and a second diode element of the transformer and converting the input power to output a second output power.

According to another aspect of the present invention, there is provided a home appliance including a converter for converting an input AC power to a DC power source, a dc-stage capacitor for storing a DC power source, a DC power source for converting a DC power stored in the dc- And a power conversion unit for outputting a plurality of output power levels. The power conversion unit includes a switching element, a first diode element, and a primary side inductor of a transformer. The switching unit switches the input power according to a switching operation of the switching element And a second power output unit having a secondary side inductor and a second diode element of the transformer and converting the input power to output a second output power.

According to the embodiment of the present invention, the power conversion apparatus includes a counter-current element, a first diode element, and a primary-side inductor of the transformer, and based on the switching operation of the switching element, And a second power source output section for converting the input power source and outputting the second output power source, by providing the first power source output section for outputting the output power of the transformer and the second diode inductor and the second diode element of the transformer, . Thus, it becomes possible to output a plurality of insulated output power supplies.

On the other hand, in the power conversion apparatus according to the embodiment of the present invention, since the first output voltage is not converted according to the turns ratio, the first output voltage is not converted to the high voltage, and the stepped down voltage is output according to the attribute of the buck type .

Further, since there is no voltage stress, a snubber circuit is unnecessary, and a separate insulation is not required at the first output voltage feedback. Therefore, it is possible to reduce the manufacturing cost while outputting a plurality of insulated output voltages.

1 is a perspective view showing a refrigerator according to the present invention.
2 is a view schematically showing the configuration of the refrigerator of FIG.
3 is a block diagram schematically illustrating the interior of the refrigerator shown in FIG.
4 is a circuit diagram showing a compressor driving apparatus of the refrigerator of FIG.
5 is an example of an internal circuit diagram of a power conversion apparatus according to an embodiment of the present invention.
6 is a diagram referred to explain the power conversion apparatus 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.

Meanwhile, the power conversion apparatus described in this specification may be a power conversion apparatus provided in the home appliance. The home appliances include a refrigerator, a washing machine, a dryer, an air conditioner, a dehumidifier, a cooking appliance, a cleaner, and the like. Hereinafter, the refrigerator will be mainly described among various home appliances.

1 is a perspective view showing a refrigerator according to the present invention.

The refrigerator 1 according to the present invention includes a case 110 having an inner space divided into a freezing chamber and a refrigerating chamber, a freezing chamber door 120 for shielding the freezing chamber, The outer appearance of the refrigerator is formed by the door 140 of the refrigerator.

A door handle 121 protruding frontward is further provided on the front surface of the freezing compartment door 120 and the refrigerating compartment door 140 so that the user can easily grip the freezing compartment door 120 and the refrigerator compartment door 140 .

Meanwhile, a home bar 180 may be provided on the front of the refrigerator compartment door 140, which is a means for allowing a user to take out a stored beverage such as beverage without opening the refrigerator compartment door 140.

The dispenser 160 may be provided on the front surface of the freezer compartment door 120 as a convenience means for allowing a user to easily remove ice or drinking water without opening the freezer compartment door 120. In addition, A control panel 200 for controlling the driving operation of the refrigerator 1 and showing the state of the refrigerator 1 in operation can be further provided on the upper side.

The control panel 200 may include an input unit 220 including a plurality of buttons, and a display unit 230 for displaying a control screen and an operating state.

The display unit 230 displays information such as a control screen, an operating state, and a room temperature. For example, the display unit 230 can display the service type (each ice, water, sculptured ice) of the dispenser, the set temperature of the freezer, and the set temperature of the freezer.

The display unit 230 may be implemented as a liquid crystal display (LCD), a light emitting diode (LED), an organic light emitting diode (OLED), or the like. Also, the display unit 230 may be implemented as a touch screen capable of performing the function of the input unit 220 as well.

The input unit 220 may include a plurality of operation buttons. For example, the input unit 220 may include a dispenser setting button (not shown) for setting a dispenser service type (ice, water, sculpted ice, etc.), a freezer room temperature setting button (not shown) And a refrigerator compartment temperature setting button (not shown) for setting the freezer compartment temperature. Meanwhile, the input unit 220 may be implemented as a touch screen capable of performing the function of the display unit 230 as well.

Meanwhile, the refrigerator according to the present invention is not limited to the double door type shown in the drawing, but may be a one door type, a sliding door type, a curtain door type, Type, and the like, and it is sufficient to provide a compressor and a fan for a refrigerator refrigeration cycle or a refrigeration cycle.

2 is a view schematically showing the configuration of the refrigerator of FIG.

The refrigerator 1 includes a compressor 112, a condenser 116 for condensing the refrigerant compressed by the compressor 112, a condenser 116 for condensing the refrigerant condensed in the condenser 116, A refrigerating compartment evaporator 122 disposed in a refrigerating compartment (not shown), a freezing compartment evaporator 124 disposed in a freezing compartment (not shown), and a refrigerant condenser 123 condensed in the refrigerating compartment evaporator 122 or the freezing compartment evaporator 124 A refrigerating compartment expansion valve 132 for expanding the refrigerant supplied to the refrigerating compartment evaporator 122 and a freezing compartment expansion valve 134 for expanding the refrigerant supplied to the freezing compartment evaporator 124 do.

The refrigerator 1 may further include a gas-liquid separator (not shown) in which refrigerant having passed through the evaporators 122 and 124 is separated into a liquid and a gas.

The refrigerator 1 further includes a refrigerator compartment fan 142 and a freezer compartment fan 142 for sucking the refrigerant that has passed through the refrigerating compartment evaporator 122 and the freezing compartment evaporator 124 and blowing them into a refrigerating compartment (not shown) and a freezing compartment (not shown) 144).

The controller may further include a compressor driving unit 113 for driving the compressor 112 and a refrigerating compartment fan driving unit 143 and a freezing compartment fan driving unit 145 for driving the refrigerating compartment fan 142 and the freezing compartment fan 144.

3 is a block diagram schematically illustrating the interior of the refrigerator shown in FIG.

3 includes a compressor 112, a refrigerating compartment fan 142, a freezing compartment fan 144, a control unit 310, and a temperature sensing unit 320. The apparatus further includes a compressor driving unit 113, a refrigerating compartment fan driving unit 143, a freezing compartment fan driving unit 145, a machine room fan 115, a machine room fan driving unit 400, and an input unit 220.

For a description of the compressor 112, the refrigerating compartment fan 142, and the freezing compartment fan 144, see FIG.

The input unit 220 includes a plurality of operation buttons and transmits a signal to the control unit 310 about the input freezing room set temperature or the refrigerating room setting temperature.

The temperature sensing unit 320 senses the temperature in the refrigerator and transmits a signal indicating the sensed temperature to the controller 310. [ Here, the temperature sensing unit 320 senses the refrigerator compartment temperature and the freezer compartment temperature, respectively. It is also possible to detect the temperature of each chamber in the refrigerating chamber or each chamber in the freezing chamber.

The control unit 310 controls the compressor driving unit 113 and the fan driving unit 143 or 145 directly to control the on / off operation of the compressor 112 and the fan 142 or 144, And finally control the compressor 112, and the fan 142 or 144. [0050] Here, the fan driving unit may be a refrigerator compartment fan driving unit 143 or a freezing compartment fan driving unit 145.

(Not shown), a refrigerator compartment fan motor (not shown), and a freezer compartment fan motor (not shown) are respectively connected to the compressor driving unit 113, the refrigerating compartment fan driving unit 143 and the freezing compartment fan driving unit 145 And each of the electric motors (not shown) is operated at a target rotational speed under the control of the control unit 310.

The machine room fan drive unit 400 includes a machine room electric fan 115c and the machine room fan motor 115c is operated at a target rotation speed under the control of the control unit 310. [

When such an electric motor is a three-phase electric motor, it can be controlled by a switching operation in an inverter (not shown) or can be controlled at a constant speed by using AC power as it is. Here, each electric motor (not shown) may be any one of an induction motor, a BLDC (blush less DC) electric motor, a synRM (synchronous reluctance motor) electric motor,

The control unit 310 can control the operation of the entire refrigerator 1 in addition to the control of the operation of the compressor 112 and the fan 142 or 144 or 115 as described above. That is, the control unit 310 can control the overall operation of the refrigerant cycle in accordance with the set temperature from the input unit 220. For example, the three-way valve 130, the refrigerating compartment expansion valve 132, and the freezing compartment expansion unit 132, as well as the compressor driving unit 113, the refrigerating compartment fan driving unit 143, the freezing compartment fan driving unit 145, The valve 134 can be further controlled. The operation of the condenser 116 can also be controlled. In addition, the control unit 310 may control the operation of the display unit 230.

2 and 3 illustrate that the evaporators 122 and 124 are used in the refrigerating and freezing chambers respectively and that the fans 142 and 144 and the driving units 143 and 145 are used in the refrigerating and freezing chambers. (Not shown), and a common fan (not shown) and a driving unit (not shown) may be used. In this case, a damper (not shown) may be provided between the refrigerating chamber and the freezing chamber, and a fan (not shown) may blow forced air generated by one evaporator to be supplied to the freezing chamber and the refrigerating chamber.

4 is a circuit diagram showing a compressor driving apparatus of a refrigerator according to an embodiment of the present invention.

The compressor driving apparatus 113 of the refrigerator according to the embodiment of the present invention includes a converter 410, an inverter 420, an inverter control unit 430, a power conversion unit 440, A detection unit B, a smoothing capacitor C, and an output current detection unit E. Further, the driving apparatus 113 may further include an input current detecting section A, a reactor L, and the like.

The reactor L is disposed between the commercial AC power source 405 (v _s ) and the converter 410, and performs a power factor correcting or boosting operation. The reactor L may also function to limit the harmonic current due to the fast switching of the converter 410.

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

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

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

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

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

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

The smoothing capacitor C smoothes the input power supply and stores it. 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, both ends of the smoothing capacitor C are referred to as a dc stage or a dc stage because the dc power source is stored.

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

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

The inverter 420 includes a pair of upper arm switching elements Sa, Sb and Sc and lower arm switching elements S'a, S'b and S'c serially connected to each other, The switching elements are connected to each other in parallel (Sa & S a, Sb & S'b, Sc & S'c). Diodes are connected in anti-parallel to each switching element Sa, S'a, Sb, S'b, Sc, S'c.

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

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

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

To this end, the inverter control unit 430 includes an axis conversion unit (not shown), a speed calculation unit (not shown), a current command generation unit (not shown), a voltage command generation unit (not shown), an axis conversion unit , And a switching control signal output unit (not shown).

(Not shown) receives the three-phase output currents (ia, ib, ic) detected by the output current detecting unit E and converts the three-phase output currents ia, ib and ic into two phase currents iα and iβ in the stationary coordinate system.

On the other hand, the axial conversion unit (not shown) can convert the two-phase current i ?, i? Of the still coordinate system into the two-phase current id, iq of the rotational coordinate system.

)와 연산된 속도(

)를 출력할 수 있다.Based on the two-phase current (i?, I?) Of the stationary coordinate system changed in the axis in the axial conversion unit (not shown), the speed calculating unit (not shown)

) And the calculated speed (

Can be output.

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

)와 속도 지령치(ω^* _r)의 차이에 기초하여, PI 제어기(미도시)에서 PI 제어를 수행하며, 전류 지령치(i^* _q)를 생성할 수 있다. On the other hand, the current command generator (not shown)

(I ^* _q ) on the basis of the speed command value? ^* _R and the speed command value? ^* _R. For example, the current command generator (not shown)

(PI) controller (not shown) based on the difference between the speed command value? ^* _R and the speed command value? ^* _R , thereby generating the current command value i ^* _q .

Next, the voltage command generator (not shown) generates a voltage command generator (not shown) based on the d-axis and q-axis currents (i _d , i _q ) The d-axis and q-axis voltage instruction values (v ^* _d , v ^* _q ) are generated based on the instruction values (i ^* _d and i ^* _q ).

On the other hand, the generated d-axis and q-axis voltage command values (v ^* _d , v ^* _q ) are input to an axial conversion unit (not shown).

)와, d축, q축 전압 지령치(v^* _d,v^* _q)를 입력받아, 축변환을 수행한다.The axis converting unit (not shown) is connected to a position calculating unit (not shown)

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

)가 사용될 수 있다.First, the axis converting unit (not shown) performs conversion from the two-phase rotating coordinate system to the two-phase stationary coordinate system. At this time, the position calculated in the speed calculation unit (not shown)

) Can be used.

Then, the axial conversion unit (not shown) performs conversion from the two-phase stationary coordinate system to the three-phase stationary coordinate system. Through this conversion, the axial conversion unit (not shown) outputs three-phase output voltage instruction values v ^* a, v ^* b, and v ^* c.

The switching control signal output unit (not shown) outputs the inverter switching control signal Sic 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.

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

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

Three shunt resistors are placed between the inverter 420 and the synchronous motor 230 or the three lower arm switching elements S'a, S'b, S'c To be connected to each other. On the other hand, it is also possible to use two shunt resistors using three phase equilibrium. On the other hand, when one shunt resistor is used, the shunt resistor may be disposed between the capacitor C and the inverter 420 described above.

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

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

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

On the other hand, the inverter control unit 430 can control the switching operation of the switching elements in the converter 410 when the converter 410 includes the switching elements. For this purpose, the inverter control unit 430 can receive the input current (i _s ) detected by the input current detection unit (A). The inverter control unit 430 may output the converter switching control signal Scc to the converter 410 to control the switching operation of the converter 410. [ The converter switching control signal (Scc) is generated by a switching control signal of a pulse width modulation method (PWM), based on the input current (i _s) to be detected from the input current detecting unit (A) can be output.

The power converting unit 440 may perform power conversion using a dc voltage stored in the dc short capacitor C to perform a plurality of output power levels.

Particularly, in the present invention, in consideration of the case where the double insulation standard is to be satisfied as in the refrigerator 1, the power conversion unit 440 is a non-insulation type, Output power level.

To this end, the power conversion unit 440 includes a buck converter. This will be described later with reference to FIG.

FIG. 5 is an example of an internal circuit diagram of a power conversion apparatus according to an embodiment of the present invention, and FIG. 6 is a diagram referred to explain the power conversion apparatus of FIG.

5, the power conversion unit 440 includes a first power output unit 505 for converting an input power to output a first output power Vout1, And a second power supply output unit 510 for outputting a second power supply voltage Vout2.

The first power output unit 505 includes a switching element 510, a first diode element D1 and a primary side inductor L1 of the transformer T. The first power output unit 505 includes a switching element 510, , And can convert the input power and output the first output power Vout1.

The second power output unit 510 includes a secondary side inductor L2 and a second diode D2 of the transformer T and can convert the input power to output the second output power Vout2 .

On the other hand, in the present invention, it is assumed that the first power output unit 505 includes a buck converter to generate a plurality of non-insulated output power supplies.

That is, as shown in the drawing, both ends of the switching element 510 are connected between the first capacitor C and one end of the primary side inductor L1 of the transformer T, and the switching element 510 and the transformer T are connected, The cathode terminal of the first diode element D1 is connected between one end of the primary inductor L1 of the first diode element D1 and the cathode terminal of the first diode element D1 is connected between the anode terminal of the first diode element D1 and the other end of the primary inductor L1, And a second capacitor C1 for storing the output power supply Vout1 are connected.

The first power output unit 505 may further include a switching control unit 520 that controls the switching device 510 based on the first output power source Vout1 fed back.

The switching control unit 520 can output a pulse width variable (PWM) signal in accordance with the power supply level of the first output power supply Vout1, thereby controlling the switching operation of the switching device 510. [

The dc terminal voltage Vdc is conducted between the switch element 510 and the primary inductor L1 by the turn-on operation of the switching element 510 and the power conversion is performed, and the turn- The first diode D1 and the primary-side inductor L1 are conducted, and power conversion is performed. That is, it performs the same operation as the buck converter. That is, the first output power supply Vout1, which is lower than the dc voltage source Vdc, may be output.

For example, when the dc terminal voltage Vdc is 310V, the first output power supply Vout1 may be about 16V.

The anode terminal of the second diode element D2 is connected to one end of the secondary side inductor L2 and the cathode terminal of the second diode element D2 and the secondary side inductor L2 are connected to the second power source output unit 515, And a third capacitor C2 for storing the second output power supply Vout2 may be connected between the other ends of the second output power supply Vout2.

The second power source output section 515 can output the second output power source Vout2 in accordance with the turns ratio between the primary side inductor L1 of the transformer T and the secondary side inductor L2.

The second output power supply Vout2 can be generated and output according to the induced voltage between the primary side inductor L1 and the secondary side inductor L2.

For example, when the first output power supply Vout1 is approximately 16V, the second output power supply Vout2 may be approximately 12V.

On the other hand, due to the transformer T, the first power output unit 505 and the second power output unit 510 can be isolated.

On the other hand, Fig. 5 illustrates a flyback type power conversion device 600. Fig.

In order to output a plurality of output powers through the flyback type power converter 600, a tap of +2 to the number of output power supplies is required. In the figure, four tabs are used for outputting two output power supplies (Vout a, Vout b).

That is, four inductors la, Lb, Lc and Ld are used. In the drawing, La and Lb constitute a transformer (Ta) by a main winding, and Lc and Ld are auxiliary windings.

On the other hand, in such a flyback type power converter 600, a separate snubber circuit (not shown) is connected to the primary side in order to prevent voltage stress amplified N times from the secondary side due to the winding ratio N: There is a disadvantage in that it is necessary to provide the above.

Further, there is a disadvantage in that, in the feedback of the output power source (Vout a), an insulating element, for example, a photo-coupler must be used.

However, since the first output voltage Vout1 is not converted according to the turns ratio, the first output voltage Vout1 is not converted to a high voltage, and the voltage And the reduced voltage is output.

Further, since there is no voltage stress, a snubber circuit is unnecessary, and when the first output voltage Vout1 is fed back, no separate insulation is required, so that an insulating element, for example, a porter coupler, or the like may not be used. Therefore, it is possible to reduce the manufacturing cost while outputting a plurality of insulated output voltages.

The power conversion apparatus and the refrigerator having the same according to the present invention are not limited to the configuration and the method of the embodiments described above but can be applied to all or some of the embodiments so that various modifications can be made. Some of which may be selectively combined.

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 details may be made therein without departing from the spirit and scope of the present invention.

Claims (9)

A first power supply output section having a switching element, a first diode element, and a primary side inductor of a transformer, for converting the input power and outputting a first output power based on the switching operation of the switching element;
And a second power output unit having a secondary side inductor and a second diode element of the transformer and converting the input power to output a second output power. The method according to claim 1,
Wherein the first power output unit is a buck converter. The method according to claim 1,
Wherein the first power output unit comprises:
Further comprising: a switching control unit for controlling the switching device based on the first output power fed back. The method of claim 3,
Wherein the second power output unit comprises:
And the second output power is outputted in accordance with a ratio of turns between a primary side inductor of the transformer and a secondary side inductor. The method according to claim 1,
Both ends of the switching element are connected between the first capacitor and one end of the primary winding of the transformer,
A cathode terminal of the first diode element is connected between the switching element and one end of the primary winding of the transformer,
And a second capacitor for storing the first output power source is connected between the anode terminal of the first diode element and the other end of the primary side inductor. 6. The method of claim 5,
An anode terminal of the second diode element is connected to one end of the secondary side inductor,
And a third capacitor for storing the second output power source is connected between the cathode terminal of the second diode element and the other end of the secondary side inductor. The method according to claim 1,
The first output power source and the second output power source,
Wherein the first and second inductors are different from each other in correspondence with the turns ratio between the primary side inductor of the transformer and the secondary side inductor. 8. The method of claim 7,
Wherein the level of the first output power is greater than the level of the second output power. A converter for converting input AC power into DC power;
A dc capacitor that stores the DC power; And
And a power conversion unit converting the DC power stored in the dc capacitor and outputting a plurality of output power levels,
Wherein the power conversion unit comprises:
A first power supply output section having a switching element, a first diode element, and a primary side inductor of a transformer, for converting the input power and outputting a first output power based on the switching operation of the switching element;
And a second power output unit having a secondary side inductor and a second diode element of the transformer and converting the input power to output a second output power.

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