Motor driving apparatus and home appliance including the same

A motor driving apparatus and a home appliance including the same. The motor driving apparatus includes a temperature sensing unit to sense a compressor temperature, an inverter including a plurality of switching elements to convert a direct current (DC) voltage into an alternating current (AC) voltage and to supply AC voltage to a motor used to drive the compressor, and a controller to control the inverter. The controller performs control to apply motor preheating current for preheating of the motor during a first period before startup of the motor, and varies depending on the sensed temperature a time during which the motor preheating current is applied or a current application level. A reduction in power consumption during the preheating of the compressor is achieved.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Korean Patent Application No. 10-2015-0122849, filed on Aug. 31, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

The present invention relates to a motor driving apparatus and a home appliance including the same, and more particularly, to a motor driving apparatus capable of reducing power consumption for the preheating of a compressor, and a home appliance including the same.

2. Description of the Related Art

A motor driving apparatus drives a motor including a rotor for performing rotation and a stator having a coil wound therearound.

The motor driving apparatus may be used to drive various motors, and in particular, may drive a compressor motor in order to drive a compressor in a home appliance.

SUMMARY

It is an object of the present disclosure to provide a motor driving apparatus capable of reducing power consumption for the preheating of a compressor, and a home appliance including the same.

In accordance with one aspect of the present disclosure, the above and other objects can be accomplished by the provision of a motor driving apparatus including a temperature sensing unit to sense a compressor temperature (e.g., temperature around a compressor), an inverter including a plurality of switching elements to convert a direct current (DC) voltage into an alternating current (AC) voltage by switching operation of the switching elements and to supply the AC voltage to a motor used to drive the compressor, and a controller to control the inverter, wherein the controller performs control to apply motor preheating current for preheating of the motor during a first period before startup of the motor, and varies a time during which the motor preheating current is applied or a current application level depending on the sensed temperature.

In accordance with another aspect of the present disclosure, there is provided a home appliance including a compressor, a temperature sensing unit to sense a compressor temperature (e.g., temperature around the compressor), an inverter including a plurality of switching elements to convert a direct current (DC) voltage into an alternating current (AC) voltage by switching operation of the switching elements and to supply the AC voltage to a motor used to drive the compressor, and a controller to control the inverter, wherein the controller performs control to apply motor preheating current for preheating of the motor during a first period before startup of the motor, and varies a time during which the motor preheating current is applied or a current application level depending on the sensed temperature.

DETAILED DESCRIPTION

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

With respect to constituent elements used in the following description, suffixes “module” and “unit” are given or mingled with each other only in consideration of ease in the preparation of the specification, and do not have or serve as different meanings. Accordingly, the “module” and “unit” may be used interchangeably.

A motor driving apparatus described in this specification refers to a motor driving apparatus for driving a compressor motor.

Meanwhile, a motor driving apparatus, designated by reference numeral220, according to an embodiment of the present invention may be referred to as a motor driving unit.

FIG. 1is an internal block diagram illustrating an example of a motor driving apparatus according to an embodiment of the present invention.

Explaining with reference toFIG. 1, the motor driving apparatus220according to the embodiment of the present invention may serve to drive a motor230for driving a compressor102, and may include an inverter420, an inverter controller430, motor230, compressor102, and a temperature sensing unit107. In one embodiment, temperature sensing unit107may include, but is not limited to, a Negative Temperature Coefficient (NTC) thermistor, a Resistance Temperature Detector (RTD), a thermocouple, or a semiconductor-based sensor.

Temperature sensing unit107may sense the temperature around compressor102. In particular, temperature sensing unit107may sense the refrigerant discharge temperature Tdfrom compressor102. To this end, temperature sensing unit107may be located around a refrigerant discharge portion outside compressor102.

Meanwhile, inverter controller430may receive the sensed temperature Tdfrom temperature sensing unit107.

Inverter controller430may apply motor preheating current for preheating motor230during a first period before the startup of motor230, and may vary the time during which the motor preheating current is applied or the current application level based on the sensed temperature Td.

In this way, compared to a conventional method in which constant current flows in motor230during a predetermined time regardless of the temperature of compressor102, embodiments of the present invention may reduce power consumption during the preheating of compressor102.

In particular, inverter controller430increases the time, during which motor preheating current is applied, or the current application level as the temperature Tdsensed by temperature sensing unit107is reduced. And inverter controller430reduces the time, during which motor preheating current is applied, or the current application level as the temperature Tdsensed by temperature sensing unit107is increased, thereby reducing power consumption during the preheating of compressor102depending on the temperature on the discharge side of compressor102.

FIGS. 2A and 2Bare views referenced to explain a compressor preheating method.

First,FIG. 2Aillustrates a method in which current is applied to compressor motor230through inverter420so that compressor motor230generates heat.

Next,FIG. 2Billustrates a method in which a sump heater is located around compressor102and heat is transferred to compressor102through the sump heater.

The method ofFIG. 2Brequires a separate sump heater, thus causing an increase in manufacturing costs and the like. Therefore, the present invention adopts the method ofFIG. 2A, which requires no separate heater.

In particular, rather than the previously described conventional method in which constant current flows in motor230during a predetermined time regardless of the temperature of compressor102, embodiments of the present invention adopt a method of sensing the temperature Tdaround compressor102and varying the time during which motor preheating current is applied or the current application level based on the sensed temperature Td. This will be described later with reference toFIGS. 5 and 6.

FIG. 3is an internal circuit diagram illustrating an example of the motor driving apparatus ofFIG. 1.

Explaining with reference toFIG. 3, motor driving apparatus220according to one embodiment of the present invention may serve to drive a motor in a sensorless manner, and may include inverter420and inverter controller430.

Additionally, motor driving apparatus220according to the embodiment of the present invention may further include a converter410, a dc-terminal voltage detector B, a smoothing capacitor C, and an output current detector E. In addition, motor driving apparatus220may further include an input current detector A and a reactor L, for example.

Hereinafter, operations of the respective constituent units inside motor driving apparatus220will be described.

The reactor L is located between a commercial AC power source405having a voltage Vsand converter410to perform power-factor correction and boosting operation. In addition, the reactor L may perform a function for limiting harmonic current by high-speed switching.

The input current detector A may detect input current isfrom commercial AC power source405. To this end, a current transformer (CT), a shunt resistor, etc. may be used as the input current detector A. The detected input current ismay be input to inverter controller430as a pulse type discrete signal.

Converter410may convert the AC voltage of commercial AC power source405, having passed through the reactor L, into a DC voltage. Although a single-phase AC power source is shown as commercial AC power source405inFIG. 3, a three-phase AC power source may be used. The internal structure of converter410may be changed depending on the type of commercial AC power source405.

Converter410may include, for example, a diode without a switching element and perform rectification operation without performing separate switching operation.

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

Converter410may be a half bridge converter in which two switching elements and four diodes are connected to one another. In a three-phase AC power source, six switching elements and six diodes may be used.

When converter410includes a switching element, boosting operation, power-factor improvement, and DC voltage conversion may be performed by switching operation of the switching element.

The smoothing capacitor C smooths an input voltage and stores the smoothed voltage. Although one smoothing capacitor C is illustrated inFIG. 3, a plurality of smoothing capacitors may be included in order to ensure stability.

Although the smoothing capacitor is illustrated inFIG. 3as being connected to the output terminal of converter410, the DC voltage may be directly input to the smoothing capacitor without being limited thereto. For example, the DC voltage from a solar cell may be input to the smoothing capacitor C directly or after DC/DC conversion. Hereinafter, parts shown inFIG. 3will be focused upon.

Since the DC voltage is stored in the smoothing capacitor C, both terminals of the smoothing capacitor C may be referred to as dc-terminals or dc-link terminals.

The dc-terminal voltage detector B may detect a dc-terminal voltage Vdcbetween both terminals of the smoothing capacitor C. To this end, the dc-terminal voltage detector B may include a resistor, an amplifier, etc. The detected dc-terminal voltage Vdcmay be input to inverter controller430as a pulse type discrete signal.

Inverter420may include a plurality of inverter switching elements and may convert the do voltage Vdcsmoothed by on/off operation of the switching elements into three-phase AC voltages Va, vband vchaving a predetermined frequency and output the three-phase AC voltages to three-phase synchronous motor230.

Inverter420includes upper-arm switching elements Sa, Sb, and Sc and lower-arm switching elements S′a, S′b, and S′c, each pair of an upper-arm switching element and a lower-arm switching element being connected in series, and three pairs of upper-arm and lower-arm switching elements Sa and S′a, Sb and S′b, and Sc and S′c being connected in parallel. Diodes may be connected in anti-parallel to the respective switching elements Sa, S′a, Sb, S′b, Sc, and S′c.

The switching elements in inverter420perform on/off operation based on an inverter switching control signal Sicfrom inverter controller430. Thus, the three-phase AC voltages having the predetermined frequency are output to three-phase synchronous motor230.

Inverter controller430may control switching operation of inverter420in a sensorless manner. To this end, inverter controller430may receive output current iodetected by the output current detector E.

Inverter controller430outputs the inverter switching control signal Sicto inverter420in order to control switching operation of inverter420. The inverter switching control signal Sicis generated and output based on the output current iodetected by the output current detector E, as a pulse width modulation (PMW) switching control signal. A detailed operation for outputting the inverter switching control signal Sicfrom inverter controller430will be described later with reference toFIG. 4.

The output current detector E may detect output current ioflowing between inverter420and three-phase motor230. That is, the output current detector E detects current flowing to motor230. The output current detector E may detect all of output current ia, iband icof respective phases, or may detect two-phase output current based on three-phase balance.

The output current detector E may be located between inverter420and motor230, and may be a current transformer, a shunt resistor, etc. in order to detect current.

When a shunt resistor is used as the output current detector E, three shunt resistors may be located between inverter420and synchronous motor230, or may be connected respectively, at one terminal thereof, to three lower-arm switching elements S′a, S′b and S′c. Alternatively, two shunt resistors may be used based on three-phase balance. Alternatively, when a single shunt resistor is used, the corresponding shunt resistor may be located between the above-described capacitor C and inverter420.

The detected output current iomay be applied to inverter controller430as a pulse type discrete signal, and the inverter switching control signal Sicmay be generated based on the detected output current io. Hereinafter, assume that the detected output current iois made up of three-phase output currents ia, ib, and ic.

Three-phase motor230includes a stator and a rotor. The AC voltage of each phase, which has the predetermined frequency, is applied to the coil of the stator of each phase a, b, or c, so as to rotate the rotor.

Motor230may include a surface-mounted permanent-magnet synchronous motor (SMPMSM), an interior permanent magnet synchronous motor (IMPSM), and a synchronous reluctance motor (Synrm), for example. The SMPMSM and the IPMSM are permanent magnet synchronous motors (PMSMs) using a permanent magnet, and the Synrm does not include a permanent magnet.

FIG. 4is an internal block diagram of the inverter controller illustrated inFIG. 3.

Referring toFIG. 4, inverter controller430may include an axis-transformation unit310, a speed calculator320, a current command generator330, a voltage command generator340, an axis-transformation unit350, and a switching control signal output unit360.

Axis-transformation unit310may receive detected three-phase current ia, ib, and icfrom the output current detector E and transform the three-phase current ia, ib, and icinto two-phase current iαand iβof a stationary coordinate system.

Speed calculator320may output a calculated position {circumflex over (θ)}rand a calculated speed {circumflex over (ω)}rbased on the two-phase current iαand iβof the stationary coordinate system axis-transformed in axis-transformation unit310.

Current command generator330generates a current command value i*qbased on the calculated speed {circumflex over (ω)}rand a speed command value {circumflex over (ω)}r. For example, current command generator330may perform PI control in a PI controller335based on a difference between the calculated speed {circumflex over (ω)}rand the speed command value {circumflex over (ω)}rand generate the current command value i*q. Although a q-axis current command value i*qis illustrated as the current command value inFIG. 4, a d-axis current command value i*dmay also be generated unlikeFIG. 4. The value of the d-axis current command value i*dmay be set to 0.

Current command generator330may further include a limiter (not illustrated) for limiting the level of the current command value i*qso as not to exceed an allowable range.

Next, voltage command generator340generates d-axis and q-axis voltage command values v*dand v*qbased on the d-axis and q-axis current idand iqaxis-transformed into the two-phase rotating coordinate system by the axis-transformation unit and the current command values i*dand i*qfrom current command generator330. For example, voltage command generator340may perform PI control in a PI controller344based on a difference between the q-axis current iqand the q-axis current command value i*qand generate a q-axis voltage command value v*q. Additionally, voltage command generator340may perform PI control in a PI controller348based on a difference between the d-axis current idand the d-axis current command value i*dand generate a d-axis voltage command value v*d. Voltage command generator340may further include a limiter (not illustrated) for limiting the level of the d-axis and q-axis voltage command values v*dand v*q, so as not to exceed an allowable range.

The generated d-axis and q-axis voltage command values v*dand v*qare input to axis-transformation unit350.

Axis-transformation unit350receives the position {circumflex over (θ)}rcalculated by speed calculator320and the d-axis and q-axis voltage command values v*dand v*qand performs axis-transformation.

First, axis-transformation unit350transforms a two-phase rotating coordinate system into a two-phase stationary coordinate system. At this time, the position {circumflex over (θ)}rcalculated by speed calculator320may be used.

Switching control signal output unit360generates and outputs an inverter switching control signal Sicvia a pulse width modulation (PWM) method based on the three-phase output voltage command values v*a, v*b, and v*c.

The output inverter switching control signal Sicmay be converted into a gate drive signal by a gate driver (not illustrated) and input to the gate of each switching element of inverter420. Accordingly, the switching elements Sa, S′a, Sb, S′b, Sc, and S′c of inverter420may perform switching operation.

FIG. 5is an internal block diagram for explaining an operation of the inverter controller during the preheating of the motor.

Explaining with reference toFIG. 5, inverter controller430operates so that motor preheating current flows in compressor motor230during a first period before the startup of motor230.

The output current detector E may not detect output current ioduring the first period before the startup of motor230. Alternatively, speed calculator320may not perform motor rotor position estimation and speed calculation based on output current iodetected by the output current detector E.

The temperature Tdsensed by temperature sensing unit107may be the temperature around compressor102, and more particularly, the temperature on the discharge side of compressor102.

The temperature Tdsensed by temperature sensing unit107may be applied to current command generator330in inverter controller430.

Current command generator330may receive a discharge temperature command value T*ovia external or internal calculation.

Accordingly, during the first period before the startup of motor230, current command generator330may generate a preheating current command value based on the temperature Tdsensed by temperature sensing unit107and the discharge temperature command value T*oof compressor102.

Voltage command generator340may generate a preheating voltage command value based on the preheating current command value.

Then, switching control signal output unit360may output a preheating switching control signal, which is required in order to cause motor preheating current to flow in motor230, based on the preheating voltage command value.

At this time, switching control signal output unit350may output a preheating switching control signal for turning on one upper-arm switching element among three upper-arm switching elements in inverter420and turning on two lower-arm switching elements among three lower-arm switching elements in inverter420during the first period.

Accordingly, DC current may flow in motor230during the first period, whereby compressor102is preheated.

Inverter controller430may perform control so that the time during which motor preheating current is applied or the current application level is increased as the sensed temperature Tdis reduced.

In particular, current command generator330in inverter controller430may perform control so that the time during which motor preheating current is applied or the application level is increased.

In this way, power consumption may be reduced during the preheating of compressor102.

After the first period, inverter controller430may operate as illustrated inFIG. 4.

That is, speed calculator320may calculate the speed of motor230based on output current flowing in motor230, current command generator330may generate a current command value based on a speed command value and the speed calculated by speed calculator320, voltage command generator340may generate a voltage command value based on the current command value, and switching control signal output unit360may output a switching control signal based on the voltage command value.

FIG. 6is a flowchart illustrating a method of operating a motor driving apparatus according to an embodiment of the present invention, andFIGS. 7 to 9are views referenced to explain the operating method ofFIG. 6.

Next, inverter controller430performs control to turn on the lower-arm switching elements S′a, S′b, and S′c, in order to stop motor230(S615).

Next, inverter controller430performs control to cause preheating current to flow in motor230during a first period for the startup of motor230(S625) when a motor restarting input is received (S620).

Inverter controller430may perform control to turn on one upper-arm switching element among three upper-arm switching elements in inverter420and to turn on two lower-arm switching elements among three lower-arm switching elements in inverter420during the first period.

FIG. 7illustrates that, during the first period, only a first upper-arm switching element Sais turned on and the other second and third upper-arm switching elements Sband Scare turned off, and that only a first lower-arm switching element S′ais turned off and the other second and third lower-arm switching elements S′band S′aare turned on.

Accordingly, constant DC current flows in motor230, whereby compressor102is preheated by preheating current.

Inverter controller430may apply motor preheating current for the preheating of motor230during the first period before the startup of motor230, and may vary the time during which motor preheating current is applied or the current application level based on the sensed temperature.

FIG. 8is a view illustrating the relationship between preheating current iphand the sensed temperature Td.

Referring toFIG. 8, the magnitude of preheating current iphis reduced as the sensed temperature Tdis increased, and the magnitude of preheating current iphis increased as the sensed temperature Tdis reduced.

Accordingly, inverter controller430performs control to increase the time during which motor preheating current iphis applied or the current application level as the sensed temperature Tdis reduced, and performs control to reduce the same as the sensed temperature Tdis increased.

Subsequently, inverter controller430starts motor230after the first period for motor preheating (S630). This will be described below with reference toFIG. 9.

FIG. 9is a view illustrating different sensed temperatures Td, the first period, and the startup of the motor after the first period.

In (a), (b), and (c) ofFIG. 9, the sensed temperature Tdis represented by T1, T2and T3respectively. At this time, it is assumed that T1>T2and T1>T3. Meanwhile, T2and T3may be the same.

First,FIG. 9(a)illustrates that the sensed temperature Tdis T1and a preheating period is a first period Pa1. As described above, inverter controller430performs control to cause constant direct current having a level LV1to flow in motor230.

In order to start the motor, the first period Pa1is followed by a motor alignment period, a motor speed increasing period, and an ordinary motor operating period.

During the motor alignment period, direct current having a level LV2or direct current having a greater level than the level LV2may be applied.

The level LV1, which is the level of preheating current, may be smaller than the level LV2of direct current during the motor alignment period.

Next,FIG. 9(b)illustrates that the sensed temperature Tdis T2and a preheating period is the first period Pa1as inFIG. 9(a).

Because the sensed temperature Tdis lower than inFIG. 9(a), inverter controller430may perform control to cause constant direct current, which has a level LV3greater than the level LV1, to flow in motor230.

At this time, the level LV3, which is the level of preheating current, may be greater than the level LV2of direct current during the motor alignment period.

FIG. 9(c)illustrates that the sensed temperature Tdis T3and that the level of preheating current is the level LV1as inFIG. 9(a).

However, a preheating period is a first period Pa2, which is longer than the period Pa1, unlike inFIG. 9(a).

Because the sensed temperature Tdis lower than inFIG. 9(a), the inverter controller430may perform control to increase the time during which preheating current is applied.

Meanwhile, the method of operating motor driving apparatus220described above may be applied to various home appliances. In particular, the operating method may be applied to home appliances having compressor102. Although an air conditioner and a refrigerator are exemplified below, the operating method may be applied to other home appliances, such as a water purifier.

FIG. 10is a view illustrating the configuration of an air conditioner, which is an example of a home appliance according to an embodiment of the present invention.

Air conditioner100baccording to the present invention, as illustrated inFIG. 10, may include an indoor unit31band an outdoor unit21bconnected to indoor unit31b.

While indoor unit31bof the air conditioner may be any one of stand type, wall mount type, and ceiling type air conditioners,FIG. 10illustrates stand type indoor unit31b.

Air conditioner100bmay further include at least one of a ventilator, an air purifier, a humidifier, and a heater, which may be operatively connected to the indoor unit and the outdoor unit.

Outdoor unit21bincludes a compressor (not illustrated) for compressing a refrigerant, an outdoor heat exchanger (not illustrated) for performing heat exchange between the refrigerant and outdoor air, an accumulator (not illustrated) for extracting gaseous refrigerant from the refrigerant and supplying the extracted gaseous refrigerant to the compressor, and a four-way valve (not illustrated) for changing the flow path of refrigerant based on a heating operation. In addition, while outdoor unit21bmay further include a plurality of sensors, a valve, and an oil collector, description thereof will be omitted herein.

Outdoor unit21boperates the compressor and the outdoor heat exchanger included therein to compress the refrigerant or perform heat exchange based on settings and to supply the compressed or heat-exchanged refrigerant to indoor unit31b. Outdoor unit21bmay be driven in response to the demand of a remote control unit (not illustrated) or indoor unit31b. At this time, as the cooling/heating capacity of air conditioner100bvaries based on the indoor unit which is driven, the number of driven outdoor units and the number of driven compressors installed in outdoor units may be changed.

In this case, outdoor unit21bsupplies the compressed refrigerant to connected indoor unit31b.

Indoor unit31breceives the refrigerant from outdoor unit21bto discharge cool or hot air into a room. Indoor unit31bincludes an indoor heat exchanger (not illustrated), an indoor fan (not illustrated), an expansion valve (not illustrated) for expanding the refrigerant, and a plurality of sensors (not illustrated).

Outdoor unit21band indoor unit31bare connected to each other via communication cables to exchange data with each other. The outdoor unit and the indoor unit are connected to the remote control unit (not illustrated) by wire or wirelessly to operate under control of the remote control unit (not illustrated).

A remote controller (not illustrated) is connected to indoor unit31bto allow a user to input a control command for controlling the indoor unit and to receive and display state information on the indoor unit. In this case, the remote controller may communicate with the indoor unit in a wired or wireless manner depending on how the remote controller is connected to indoor unit31b.

FIG. 11is a schematic view of the outdoor unit and the indoor unit ofFIG. 10.

Explaining with reference toFIG. 11, air conditioner100bis broadly divided into indoor unit31band outdoor unit21b.

Outdoor unit21bincludes a compressor102bfor compressing a refrigerant, a compressor motor102bbfor driving the compressor, an outdoor heat exchanger104bfor dissipating heat from the compressed refrigerant, an outdoor blower105bincluding an outdoor fan105abdisposed at one side of outdoor heat exchanger104bto accelerate heat dissipation of the refrigerant and an outdoor fan motor105bbfor rotating outdoor fan105ab, an expansion unit106bfor expanding the condensed refrigerant, a cooling/heating switching valve110bfor changing the flow path of the compressed refrigerant, and an accumulator103bfor temporarily storing the gaseous refrigerant to remove moisture and foreign substances from the refrigerant and supplying the refrigerant to the compressor at a predetermined pressure.

Indoor unit31bincludes an indoor heat exchanger108bdisposed in a room to perform a cooling/heating function, and an indoor blower108bincluding an indoor fan109abdisposed at one side of indoor heat exchanger109bto accelerate heat dissipation of the refrigerant and an indoor fan motor109bbfor rotating indoor fan109ab.

At least one indoor heat exchanger109bmay be provided. At least one of an inverter compressor and a constant-speed compressor may be used as compressor102b.

Additionally, air conditioner100bmay be configured as a cooler for cooling the room, or may be configured as a heat pump for cooling or heating the room.

Compressor102bof outdoor unit21bofFIG. 10may be driven by the motor driving apparatus for driving compressor motor230illustrated inFIG. 1.

FIG. 12is a perspective view illustrating a refrigerator, which is another example of a home appliance according to an embodiment of the present invention.

Explaining with reference toFIG. 12, refrigerator100crelated to the present invention includes a case110c, which has an inner space divided into a freezing compartment and a refrigerating compartment (not illustrated), a freezing compartment door120cto shield the freezing compartment, and a refrigerating compartment door140cto shield the refrigerating compartment, case110cand doors120cand140cdefining the external appearance of the refrigerator.

Freezing compartment door120cand refrigerating compartment door140cmay be provided at front surfaces thereof with forwardly protruding door handles121cto assist the user in easily pivoting freezing compartment door120cand refrigerating compartment door140cby gripping door handles121c.

Refrigerating compartment door140cmay further be provided at the front surface thereof with a so-called home bar180c, which allows the user to conveniently retrieve stored items, such as beverages, without opening refrigerating compartment door140c.

Freezing compartment door120cmay further be provided at the front surface thereof with a dispenser160c, which allows the user to easily and conveniently retrieve ice or drinking water without opening freezing compartment door120c. Freezing compartment door120cmay further be provided with a control panel210cat the upper side of dispenser160c. Control panel210cserves to control driving operation of refrigerator100cand to display a screen showing the current operating state of refrigerator100c.

While dispenser160cis illustrated inFIG. 12as being located at the front surface of freezing compartment door120c, the present invention is not limited thereto and dispenser160cmay be located at the front surface of refrigerating compartment door140c.

In addition, the freezing compartment (not illustrated) may accommodate, in an upper region thereof, an icemaker190cused to make ice using water supplied thereto and cold air within the freezing compartment and an ice bank195clocated under icemaker190cto receive ice released from icemaker190c. Although not illustrated inFIG. 12, an ice chute (not illustrated) may be used to guide the ice received in ice bank195cto fall into dispenser160c.

Control panel210cmay include an input unit220chaving a plurality of buttons and a display unit230cto display control screens, operating states, and the like.

Display unit230cdisplays control screens, operating states, and other information, such as the temperature in the refrigerator, etc. For example, display unit230cmay display a service type of the dispenser (ice cubes, water, crushed ice), the set temperature in the freezing compartment, and the set temperature in the refrigerating compartment.

Display unit230cmay be any one of liquid crystal display (LCD), light emitting diode (LED), and organic light emitting diode (OLED) units, and the like. Display unit230cmay be a touchscreen that may additionally perform a function of input unit220c.

Input unit220cmay include a plurality of operation buttons. For example, input unit220cmay include a dispenser setting button (not illustrated) to set a service type of the dispenser (ice cubes, water, crushed ice), a freezing compartment temperature setting button (not illustrated) to set the temperature in the freezing compartment, and a refrigerating compartment temperature setting button (not illustrated) to set the temperature in the refrigerating compartment. In addition, input unit220cmay be a touchscreen that may additionally perform a function of display unit230c.

The refrigerator according to one embodiment of the present invention is not limited to a double door type illustrated inFIG. 12, and may be any one of a one door type refrigerator, a sliding door type refrigerator, a curtain door type refrigerator and others.

FIG. 13is a diagrammatic view illustrating the configuration of the refrigerator ofFIG. 12.

Explaining with reference toFIG. 13, refrigerator100cmay include a compressor102c, a condenser116cto condense refrigerant compressed in compressor102c, a freezing compartment evaporator124cplaced in the freezing compartment (not illustrated) to evaporate the condensed refrigerant directed from condenser116c, and a freezing compartment expansion valve134cto expand the refrigerant to be directed to freezing compartment evaporator124c.

WhileFIG. 13illustrates use of a single evaporator by way of example, evaporators may be respectively placed in the freezing compartment and the refrigerating compartment.

That is, refrigerator100cmay further include a refrigerating compartment evaporator (not illustrated) placed in the refrigerating compartment (not illustrated), a 3-way valve (not illustrated) to direct the condensed refrigerant from condenser116cto the refrigerating compartment evaporator (not illustrated) or freezing compartment evaporator124c, and a refrigerating compartment expansion valve (not illustrated) to expand the refrigerant to be directed to the refrigerating compartment evaporator (not illustrated).

In addition, refrigerator100cmay further include a gas-liquid separator (not illustrated) in which the refrigerant having passed through freezing compartment evaporator124cis divided into liquid and gas.

Refrigerator100cmay further include a refrigerating compartment fan (not illustrated) and a freezing compartment fan144c, which suction cold air having passed through freezing compartment evaporator124cand blow the cold air to the refrigerating compartment (not illustrated) and the freezing compartment (not illustrated) respectively.

Refrigerator100cmay further include a compressor drive unit113cto drive compressor102c, a refrigerating compartment fan drive unit (not illustrated) to drive the refrigerating compartment fan (not illustrated), and a freezing compartment fan drive unit145cto drive freezing compartment fan144c.

Meanwhile, in the case in which common evaporator124cis used in the freezing compartment and the refrigerating compartment as shown inFIG. 13, a damper (not illustrated) may be installed between the freezing compartment and the refrigerating compartment, and a fan (not illustrated) may forcibly blow cold air generated by the single evaporator to the freezing compartment and the refrigerating compartment.

Compressor102cofFIG. 13may be driven by the motor driving apparatus for driving the compressor motor illustrated inFIG. 1.

The motor driving apparatus and the home appliance including the same according to the embodiments of the present invention are not limited to the configurations and methods of the above-described embodiments, and all or some of the respective embodiments may be selectively combined with one another in order to realize various alterations of the above-described embodiments.

Meanwhile, a motor driving method and a home appliance operating method according to the present invention may be implemented as a code that can be written on a processor readable medium and thus can be read by a processor included in the motor driving apparatus or the home appliance. The processor readable medium includes all kinds of recording devices in which data is stored in a processor readable manner.

As is apparent from the above description, according to an embodiment of the present invention, a motor driving apparatus includes a temperature sensing unit to sense a temperature around a compressor, an inverter including a plurality of switching elements and to convert a direct current (DC) voltage into an alternating current (AC) voltage by switching operation of the switching elements and to supply the AC voltage to a motor used to drive the compressor, and a controller to control the inverter, and the controller performs control to apply motor preheating current for preheating of the motor during a first period before startup of the motor, and varies a time during which the motor preheating current is applied or a current application level depending on the sensed temperature, thereby reducing power consumption during the preheating of the compressor.

In particular, the time during which the motor preheating current is applied or the current application level may be controlled so as to be increased as the sensed temperature is reduced, or may be controlled so as to be reduced as the sensed temperature is increased. Thereby, power consumption during the preheating of the compressor may be reduced depending on the temperature on the discharge side of the compressor.