KR20210092541A - Apparatus and mothod for motor control and conditioner using the same - Google Patents

Abstract

The present invention relates to a motor control device, a control method thereof, and an air conditioner using the same. According to an embodiment of the present invention, disclosed is the air conditioner. The motor control device is included in the air conditioner and configured to control a motor for a compressor that drives a compressor. The motor control device comprises: a link capacitor connected between an output terminal of a converter and an input terminal of an inverter for a compressor; a link voltage detecting unit for detecting a link voltage that is a voltage between both ends of the link capacitor; and a control unit for driving a load so that the link voltage drops below an allowable voltage when a level of the link voltage exceeds the allowable voltage. Accordingly, there is an effect that can prevent overcharging due to power generation of an outdoor fan caused by external wind.

Description

Electric motor control device and control method, and air conditioner using the same {APPARATUS AND MOTHOD FOR MOTOR CONTROL AND CONDITIONER USING THE SAME}

The present invention relates to an apparatus and control method for controlling an electric motor for preventing overcharging that may be caused by generation of an outdoor fan by draft, and an air conditioner using the same.

The air conditioner is installed to provide a more comfortable indoor environment for humans by discharging hot and cold air into the room to create a comfortable indoor environment, controlling the indoor temperature, and purifying the indoor air. In general, an air conditioner includes an indoor unit configured as a heat exchanger and installed indoors, and an outdoor unit configured as a compressor and a heat exchanger and supplying refrigerant to the indoor unit.

Such an air conditioner is controlled separately from an indoor unit composed of a heat exchanger and an outdoor unit composed of a compressor and a heat exchanger, and is operated by controlling power supplied to the compressor or the heat exchanger. In addition, at least one indoor unit may be connected to the outdoor unit, and the air conditioner may be operated in a cooling or heating mode by supplying a refrigerant to the indoor unit according to a requested operating state.

Such an air conditioner includes an outdoor heat exchanger serving to dissipate the compressed refrigerant, and is disposed adjacent to the outdoor heat exchanger to rotate an outdoor fan to promote heat exchange in the outdoor heat exchanger and an outdoor fan motor for rotating the outdoor fan An outdoor blower comprising a.

On the other hand, since the outdoor blower is located outdoors, rotation of the outdoor fan occurs in a non-powered state by external wind, and the electric motor for the outdoor fan operates similarly to a generator by the rotation of the outdoor fan.

That is, when the outdoor blower located outdoors is rotated by strong draft, the electric motor for the outdoor fan operates similarly to the generator, and thus charges the associated power storage capacitor, for example, a DC link capacitor.

Therefore, the voltage of the DC link capacitor is overcharged, and accordingly, there is a problem in that an overvoltage is applied to the main element by the voltage of the overcharged DC link capacitor, or the DC link capacitor is damaged. is occurring

Patent Publication No. 10-2004-0041405

SUMMARY OF THE INVENTION One object of the present invention is to provide an electric motor control device and control method capable of preventing overcharging caused by generation of an outdoor fan by draft, and an air conditioner using the same.

Another object of the present invention is to operate the compressor in a preheat mode when the magnitude of the DC link voltage exceeds the allowable voltage, thereby maintaining the DC link voltage below a certain range, thereby eliminating damage and instability due to overcharging. To provide an electric motor control device and control method, and an air conditioner using the same.

Another object of the present invention is to provide an apparatus and control method for controlling an electric motor capable of increasing the operating efficiency of the compressor and thus cooling efficiency by operating the compressor in a preheating mode using an overcharge voltage, and an air conditioner using the same will do

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. Moreover, it will be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

A motor control apparatus according to an embodiment of the present invention is a motor control apparatus included in an air conditioner and controlling a compressor electric motor for driving a compressor, and a link connected between an output terminal of a converter and an input terminal of an inverter for a compressor a capacitor, a link voltage detector detecting a link voltage that is a voltage between both ends of the link capacitor, and a controller for driving a load so that the link voltage falls below the allowable voltage when the magnitude of the link voltage exceeds the allowable voltage do.

In addition, the controller may set the allowable voltage by assigning a weight to the output voltage of the converter, and the allowable voltage may be a value reduced by a predetermined or more from the limit voltage of the link capacitor.

In addition, the motor control device further includes an outdoor fan inverter for driving an outdoor fan electric motor rotating the outdoor fan, and an input terminal of the outdoor fan inverter is connected to the link capacitor, based on the power provided from the link capacitor. The outdoor fan may be driven.

Also, when the level of the link voltage exceeds the allowable voltage, the controller may control the compressor inverter to operate the compressor in a preheating mode until the link voltage falls below the allowable voltage.

In addition, the motor control device further includes a power supply unit for supplying power to the solenoid valve based on the power provided from the link capacitor, wherein the control unit is configured to control the link voltage when the level of the link voltage exceeds an allowable voltage. It may be controlled to further drive the solenoid valve until it falls below the allowable voltage.

In addition, the control unit is provided with the level of the link voltage from the link voltage detector, and a voltage determining unit that determines whether the level of the link voltage exceeds an allowable voltage, and the voltage determining unit determines whether the level of the link voltage is the allowable voltage When it is confirmed that the excess voltage is exceeded, a load driving unit for monitoring the link voltage and controlling the load to drive the load until the link voltage falls below the allowable voltage may be included.

In addition, the voltage determining unit may set the allowable voltage by assigning a weight to the output voltage of the converter, and set the allowable voltage to satisfy that the allowable voltage is reduced by a predetermined or more from the limit voltage of the link capacitor.

Also, when the level of the link voltage exceeds the allowable voltage, the load driving unit may control the compressor inverter to operate the compressor in a preheating mode until the link voltage falls below the allowable voltage.

In addition, the load driving unit may control the solenoid valve to be further driven until the link voltage falls below the allowable voltage if the level of the link voltage exceeds the allowable voltage even while the compressor is operated in the preheating mode. can do.

A motor control method according to an embodiment of the present invention is a control method of an electric motor control device included in an air conditioner and performing control of a compressor electric motor for driving a compressor and an outdoor fan electric motor for rotating an outdoor fan, comprising: detecting a link voltage that is a voltage between both ends of a link capacitor connected between an output terminal and an input terminal of the inverter, determining whether the link voltage exceeds an allowable voltage, and if the link voltage exceeds an allowable voltage, the and driving the load such that the link voltage drops below the allowable voltage.

The driving of the load so that the link voltage falls below the allowable voltage may include controlling the compressor to operate in a preheating mode until the link voltage falls below the allowable voltage.

In addition, the driving of the load so that the link voltage falls below the allowable voltage may include controlling the solenoid valve to be further driven until the link voltage falls below the allowable voltage.

The air conditioner according to an embodiment of the present invention includes a compressor for compressing a refrigerant, a compressor electric motor for driving the compressor, an outdoor fan disposed adjacent to an outdoor heat exchanger and rotating to promote heat exchange in the outdoor heat exchanger, the outdoor and a motor for an outdoor fan that rotates the fan, and a motor control device for controlling driving of the motor for the compressor and the motor for the outdoor fan. The motor control device includes a link capacitor connected to an output terminal of a converter, an input terminal of an inverter for a compressor, and an input terminal of an inverter for an outdoor fan, a link voltage detector detecting a link voltage that is a voltage between both ends of the link capacitor, and a magnitude of the link voltage and a control unit for driving a load such that the link voltage falls below the allowable voltage when the permissible voltage is exceeded.

The electric motor control apparatus and control method according to the present invention, and an air conditioner using the same, have the effect of preventing overcharging due to power generation of an outdoor fan caused by draft and preventing damage caused by such overcharging.

The motor control apparatus and control method according to the present invention, and an air conditioner using the same, operate the compressor in the preheat mode when the DC link voltage exceeds the allowable voltage, thereby maintaining the DC link voltage within a certain range to prevent overcharging. It has the effect of removing damage and instability caused by

The motor control apparatus and control method according to the present invention, and an air conditioner using the same, operate the compressor in the preheat mode using an overcharge voltage, thereby increasing the operating efficiency of the compressor and thus improving the cooling efficiency.

In addition to the above-described effects, the specific effects of the present invention will be described together while describing specific details for carrying out the invention below.

1 is a diagram illustrating the configuration of an air conditioner according to an embodiment of the present invention.
FIG. 2 is a view for explaining the outdoor unit and the indoor unit shown in FIG. 1 .
3 is a block diagram of an apparatus for controlling an electric motor according to an embodiment of the present invention.
4 is a block diagram illustrating a control unit for controlling the motor control device shown in FIG. 3 .
5 is a block diagram of a motor control apparatus according to another embodiment of the present invention.
6 is a block diagram illustrating a control unit for controlling the motor control device shown in FIG. 5 .
7 is a view for explaining a motor control method according to an embodiment of the present invention.

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

Although the first, second, etc. are used to describe various elements, these elements are not limited by these terms, of course. These terms are only used to distinguish one component from other components, and unless otherwise stated, the first component may be the second component, of course.

Also, when it is described that a component is "connected", "coupled" or "connected" to another component, the components may be directly connected or connected to each other, but other components are "interposed" between each component. It is to be understood that “or, each component may be “connected,” “coupled,” or “connected” through another component.

Also, as used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "consisting of" or "comprising" should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps.

Hereinafter, a motor control apparatus and a control method according to some embodiments of the present invention, and an air conditioner using the same will be described.

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

Referring to FIG. 1 , an air conditioner 100 according to an embodiment of the present invention includes an indoor unit 10 , at least one outdoor unit 20 connected to the indoor unit 10 , and the indoor unit 10 and the outdoor unit 20 . It may include a controller (not shown) for controlling the.

A controller (not shown) may be connected to the indoor unit 10 and the outdoor unit 20 to monitor and control the operation thereof. In this case, the controller (not shown) may be connected to a plurality of indoor units to perform operation setting, lock setting, schedule control, and the like for the indoor units. The controller (not shown) may have a structure included in the indoor unit 10 or the outdoor unit 20 . A controller (not shown) may be included in the indoor unit 10 or the outdoor unit 20 .

The air conditioner 100 is applicable to any of a stand-type air conditioner, a wall-mounted air conditioner, a ceiling-type air conditioner, and a duct-type air conditioner. Explain.

The outdoor unit 20 selects a compressor that receives and compresses a refrigerant, an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air, an accumulator that extracts a gaseous refrigerant from the supplied refrigerant and supplies it to the compressor, and a refrigerant flow path according to the heating operation. It may include a four-way valve that In addition, it may further include a plurality of sensors, valves and an oil recovery unit.

The outdoor unit 20 operates a provided compressor and an outdoor heat exchanger to compress or heat exchange the refrigerant according to a setting to supply the refrigerant to the indoor unit 10 . The outdoor unit 20 is driven at the request of a controller (not shown) or the indoor unit 10, and as the cooling/heating capacity is changed in response to the driven indoor unit 10, the number of compressors installed in the outdoor unit 20 increases. become variable.

The indoor unit 10 is connected to the outdoor unit 20, receives a refrigerant, and discharges hot or cold air to an air conditioning target. The indoor unit 10 may include an indoor heat exchanger, an indoor unit fan, an expansion valve through which the supplied refrigerant is expanded, and a plurality of sensors.

At this time, the outdoor unit 20 and the indoor unit 10 are connected to each other through a communication line to transmit and receive data. The outdoor unit and the indoor unit are connected to a controller (not shown) through a communication line and operate under the control of the controller (not shown).

A remote controller (not shown) may be connected to the indoor unit 10 , input a user's control command to the indoor unit 10 , and receive and display status information of the indoor unit 10 . In this case, the remote controller (not shown) communicates with the indoor unit 10 by wire or wirelessly depending on the connection type. To this end, the remote controller (not shown) may include a communication module capable of transmitting or receiving data.

For example, a user may input a target temperature through a remote controller (not shown). In this case, the remote controller (not shown) receives the user input for the target temperature and transmits it to the controller (not shown).

FIG. 2 is a view for explaining the outdoor unit and the indoor unit shown in FIG. 1 .

Referring to FIG. 2 , the air conditioner 100 is largely divided into an indoor unit 10 and an outdoor unit 20 .

The outdoor unit 20 includes a compressor 102a serving to compress the refrigerant, a compressor electric motor 102b for driving the compressor, an outdoor heat exchanger 104 serving to radiate heat from the compressed refrigerant, and an outdoor unit. An outdoor blower 105 comprising an outdoor fan 105a disposed adjacent to the heat exchanger 104 and rotating to promote heat exchange in the outdoor heat exchanger and an outdoor fan electric motor 105b rotating the outdoor fan 105a; An expansion mechanism 106 for expanding the condensed refrigerant, a cooling/heating switching valve 110 for changing the flow path of the compressed refrigerant, and a compressor that temporarily stores the vaporized refrigerant to remove moisture and foreign substances and then compresses the refrigerant at a constant pressure. and an accumulator 103 supplied to the

The indoor unit 10 includes an indoor heat exchanger 108 for cooling, heating, or dehumidification, and an indoor fan 109a for facilitating heat dissipation of the refrigerant, which is disposed on one side of the indoor heat exchanger 108. and an indoor blower 109 including an electric motor 109b for rotating the indoor fan 109a.

At least one indoor heat exchanger 108 may be installed. Compressor 102a, various compression methods such as an inverter compressor and a constant speed compressor may be applied.

In addition, the air conditioner 50 may be configured as an air conditioner for cooling the room, and may be modified as a heat pump for cooling or heating the room.

Meanwhile, although FIG. 2 shows one indoor unit 10 and one outdoor unit 20, the driving device of the air conditioner according to the embodiment of the present invention is not limited thereto, and a multi-type having a plurality of indoor units and outdoor units. Of course, it is applicable to an air conditioner, an air conditioner including one outdoor unit and a plurality of indoor units.

Since the outdoor blower is located outdoors, rotation of the outdoor fan occurs in a non-powered state by external wind, and the electric motor for the outdoor fan operates similarly to a generator by the rotation of the outdoor fan. That is, outdoor located outdoors When the blower is rotated by a strong draft, the electric motor for the outdoor fan operates similarly to a generator, thereby charging an electric charge in an associated power storage capacitor, for example, a DC link capacitor. Accordingly, the voltage of the DC link capacitor is excessively charged, and accordingly, an overvoltage may be applied to the main element by the voltage of the overcharged DC link capacitor, or the DC link capacitor may be damaged.

Accordingly, in the present invention, the voltage of the DC link capacitor can be properly maintained by efficiently controlling the power stored by the outdoor fan rotating by the draft.

Hereinafter, each configuration will be described based on the cooling operation of the air conditioner 100, but it is obvious to those skilled in the art that the heating operation, the dehumidifying operation, or the blowing operation are also included in the scope of the present invention.

3 is a block diagram of a motor control device for a compressor according to an embodiment of the present invention, and FIG. 4 is a block diagram illustrating a control unit of the motor control device shown in FIG. 3 .

3 and 4 , the motor control device 200 of the air conditioner 100 according to an embodiment of the present invention includes a converter 202 , a memory 220 , an inverter 232 for a compressor, and an outdoor unit. It includes a fan inverter 235 , a link capacitor C , a link voltage detection unit 205 , and a control unit 260 . The motor control apparatus 200 according to an embodiment of the present invention may further include a reactor L and a current detection unit (not shown).

The reactor L is disposed between the commercial AC power supply and the converter 202 to perform power factor correction or step-up operation. In addition, the reactor L may perform a function of limiting the harmonic current caused by the high-speed switching of the converter 202 .

The converter 202 converts commercial AC power passing through the reactor L into DC power and outputs it. Although the drawing shows the commercial AC power as a single-phase AC power, it may also be a three-phase AC power. The internal structure of the converter 202 also varies according to the type of commercial AC power. For example, in the case of a single-phase AC power supply, a half-bridge converter in which two switching elements and four diodes are connected may be used, and in the case of a three-phase AC power supply, six switching elements and six diodes may be used. The converter 202 includes a plurality of switching elements, and performs step-up, power factor improvement, or DC power conversion by a switching operation.

The link capacitor C is connected to the output terminal of the converter 202 . In addition, the link capacitor C is connected to the input terminal of the inverter 232 for the compressor and the input terminal of the inverter 235 for the outdoor fan. The link capacitor C may serve to smooth the converted DC power output from the converter 202 . The electric power smoothed by the link capacitor C and stored may be used by the inverter 232 for the compressor and the inverter 235 for the outdoor fan.

The link voltage detector 205 may detect the link voltage Vdc stored in the link capacitor C, and provides the detected level of the link voltage Vdc to the controller 260 . . The link voltage detection unit 205 may include a voltage transformer (VT) or a resistance element.

The memory 220 is electrically connected to the controller 260 . The memory 220 may store basic data for the unit, control data for operation control of the unit, and input/output data. The memory 220 may be various storage devices such as ROM, RAM, EPROM, flash drive, hard drive, and the like.

Although not shown, the motor control apparatus 200 may include a current detection unit. A current detection unit (not shown) may detect an output current flowing between each inverter and an electric motor connected thereto. To this end, the current detector (not shown) may use a current transformer (CT), a shunt resistor, or the like for current detection. Information on the current detected by the current detector (not shown) is provided to the controller 260 , and the controller may use the information on the current to control the inverter.

The compressor inverter 232 drives the compressor motor 102b, and the outdoor fan inverter 235 drives the outdoor fan motor 105b.

The compressor inverter 232 includes a plurality of switching elements for inverters, and converts DC power smoothed by the on/off operation of the switching elements into three-phase AC power of a predetermined frequency and outputs the converted power. For example, an upper-arm switching element and a lower-arm switching element connected in series with each other become a pair, and a total of three pairs of the upper-arm switching element and the lower-arm switching element may be connected to each other in parallel.

The three-phase AC power output from the inverter 232 for the compressor is applied to each phase (u, v, w) of the three-phase motor 250 . Here, the compressor motor 102b is a three-phase electric motor, and has a stator and a rotor, and each phase AC power of a predetermined frequency is applied to the coils of each phase stator, and the rotor rotates. As the type of the three-phase motor 250, various types such as a BLDC motor and a synRM motor are possible.

For example, the inverter 232 for the compressor controls the driving of the compressor 102a through PWM duty ratio control of the power applied to the electric motor 102b for the compressor. Here, the compressor motor 102b is a three-phase motor, and includes a stator and a rotor, and each phase AC power of a predetermined frequency is applied to the coils of each phase, and the rotor rotates. As the type of the three-phase motor 250, various types such as a BLDC motor and a synRM motor are possible.

The inverter 235 for the outdoor fan may also be understood in place of the description of the inverter 232 for the compressor described above.

The controller 260 controls the compressor inverter 232 and the outdoor fan inverter 235 to control the operation of the compressor motor 102b and the outdoor fan motor 105b.

The controller 260 may generate and output a switching control signal to each inverter, respectively. For example, the switching control signal may be a pulse width modulation (PWM) switching control signal. For example, the controller 260 may individually control each inverter through PWM duty ratio control.

On the other hand, the outdoor fan motor 105b and the outdoor fan inverter 235 are connected to the link capacitor (C). Accordingly, when the outdoor fan rotates due to the draft, the electric motor 105b for the outdoor fan operates similarly to the generator, and thus generated power may be stored in the link capacitor C.

Therefore, the controller 260 monitors the link voltage Vdc stored in the link capacitor C, and when the magnitude of the link voltage exceeds the allowable voltage, the control unit 260 controls to drive the load so that the link voltage falls below the allowable voltage. can

Here, the allowable voltage may be set by weighting the output voltage output from the converter 202 . For example, assuming that the output voltage output from the converter 202 is 300V, the controller 260 may set 345V as the allowable voltage by adding a predetermined weight, for example, 15% thereto. This allowable voltage may be a value reduced by a predetermined voltage or more from the physical limit voltage of the link capacitor C -for example, 390V. That is, in this example, the link voltage Vdc will be controlled to be maintained below the allowable voltage of 345V by the control of the controller 260, thereby preventing excessive overcharging of the link capacitor C and preventing damage therefrom. can be prevented in

In one embodiment, the control unit 260, when the magnitude of the link voltage (Vdc) exceeds the allowable voltage, the inverter for the compressor to operate the compressor in the preheat mode until the link voltage (Vdc) falls below the allowable voltage. can be controlled Here, the preheating mode operates the compressor at a predetermined preheating speed (eg, 10Hz) or less, and operates weakly at the level of preheating the compressor.

As described above, by operating the compressor in the preheating mode, the voltage that is excessively charged in the link voltage Vdc can be lowered to the allowable voltage or less, so that the link capacitor can be stably maintained. In addition, since the compressor is operated in the preheating mode before driving, the preheated compressor is used even when a cooling request occurs, thereby improving cooling efficiency.

In one embodiment, the control unit 260 requests the compressor when there is a request for operation of the compressor after power is applied and wake-up, that is, when operating in the driving mode, if the link voltage is excessively charged to the allowable voltage or more It is possible to control the link voltage to decrease by preheating the compressor for a certain period of time without operating it in response to the temperature. Thereafter, the controller 260 may control the compressor to operate in response to the requested temperature.

The control unit 260 may include a voltage determining unit 261 and a load driving unit 263 .

The voltage determining unit 261 may receive the magnitude of the link voltage Vdc from the link voltage detecting unit 205 and determine whether the link voltage Vdc exceeds an allowable voltage.

In an embodiment, the voltage determining unit 261 may set an allowable voltage by weighting the output voltage of the converter 202 . The voltage determining unit 261 may set the allowable voltage to satisfy that the allowable voltage is reduced by a predetermined or more from the limit voltage of the link capacitor.

When the voltage determining unit 261 determines that the level of the link voltage exceeds the allowable voltage, the load driver 263 monitors the link voltage and controls the load to drive the load until the link voltage falls below the allowable voltage. .

In an embodiment, when the level of the link voltage exceeds the allowable voltage, the load driving unit 263 may control the inverter for the compressor to operate the compressor in a preheating mode until the link voltage falls below the allowable voltage.

5 is a block diagram of a motor control apparatus for a compressor according to another embodiment of the present invention, and FIG. 6 is a block diagram illustrating a control unit of the motor control apparatus shown in FIG. 5 .

5 and 6 , the motor control device 200 of the air conditioner 100 according to an embodiment of the present invention includes a converter 202 , a memory 220 , an inverter 232 for a compressor, and an outdoor unit. It includes an inverter 235 for a fan, a link capacitor C, a link voltage detection unit 205 , a power supply unit 241 , and a control unit 260 .

Here, the converter 202, the memory 220, the inverter 232 for the compressor, the inverter 235 for the outdoor fan, the link capacitor C, and the link voltage detection unit 205 are described with reference to FIGS. 3 to 4 . Since it can be understood from the above description with reference, the description thereof will be omitted here.

The power supply unit 241 may supply power to the solenoid valve 251 based on the power provided from the link capacitor (C).

According to an embodiment, the power supply unit 241 may supply power to the solenoid valve 251 by reducing the voltage stored in the link capacitor C to a voltage of a predetermined level.

In this embodiment, the controller 260 may further utilize the solenoid valve 251 to consume the overcharged voltage in the link voltage.

That is, when the magnitude of the link voltage exceeds the allowable voltage, the controller 260 may control the solenoid valve to be additionally driven until the link voltage falls below the allowable voltage. Here, the preliminary driving means driving the solenoid valve without a request for driving the solenoid valve.

The control unit 260 may include a voltage determining unit 261 , a load selecting unit 262 , and a load driving unit 263 . The voltage determining unit 261 is replaced with the description described above with reference to FIG. 4 .

The load selector 262 may select a compressor or an electromagnetic valve as a load to consume the overcharged link voltage. The load driver 263 may control the load selected by the load selector 262 to be driven.

In an embodiment, the load selector 262 may set the load differently according to the standby mode and the driving mode.

The load selector 262 may select to use the compressor when operating in the standby mode after power is applied and wake-up, and to use the solenoid valve 251 when operating in the operation mode. Therefore, the load driving unit 263 may drive the compressor using the power over-accumulated in the link voltage Vdc when there is no request for operation of the compressor after waking up after power is applied, that is, when operating in the standby mode. On the other hand, when there is a request for operation of the compressor after power is applied and wake-up, that is, in the case of operating in the operation mode, the load driver 263 uses the power over-accumulated in the link voltage Vdc to the solenoid valve 251 . ) can be driven. This is to preferentially preheat the compressor in the standby mode, since there is no operation command to the compressor.

In an exemplary embodiment, the load selector 262 may consume power greater than the allowable voltage overcharged in the link voltage Vdc by using the compressor and the solenoid valve at the same time.

For example, if the magnitude of the link voltage exceeds the allowable voltage even while the compressor is operating in the preheat mode, the load selector 262 may also drive the solenoid valve. Accordingly, the load driving unit 263 may control the solenoid valve to be further driven until the link voltage falls below the allowable voltage.

In the above, various examples of the motor control apparatus and the air conditioner according to an embodiment of the present invention have been described with reference to FIGS. 1 to 6 . Hereinafter, a method of controlling an electric motor according to an embodiment of the present invention will be described with reference to FIG. 7 . However, since the control method of the electric motor to be described below is performed in the air conditioner described above with reference to FIGS. 1 to 6 , it can be easily understood with reference to the contents previously described with respect to FIGS. 1 to 6 .

7 is a flowchart illustrating a method of controlling an electric motor according to an embodiment of the present invention.

When power is applied (S710), the motor control apparatus 200 may determine whether a compressor operation request exists, that is, whether there is a drive request (S720).

The motor control apparatus 200 may consume the overcharged link voltage using a load when there is no request for compressor operation, that is, when operating in the standby mode (S730) (S740 to S760).

That is, the motor control device 200 may detect a link voltage that is a voltage between both ends of the link capacitor ( S740 ) and determine whether the link voltage exceeds an allowable voltage ( S750 ).

When the link voltage exceeds the allowable voltage, the motor control device 200 may drive the load so that the link voltage falls below the allowable voltage ( S760 ).

In an embodiment for step S760, the motor control apparatus 200 may control the compressor to operate in the preheating mode until the link voltage falls below the allowable voltage.

In another embodiment for step S760, the motor control device 200 may control the solenoid valve to operate until the link voltage falls below the allowable voltage.

In the above description, an embodiment in which the overcharged load is consumed only in the standby mode has been described, but as described above, it may operate to consume the overcharged load even in the operation mode.

In addition, as an embodiment for the consumption of the load, it is obvious that the various embodiments described above with reference to FIGS. 3 to 6 can be applied.

As described above, the present invention has been described with reference to the illustrated drawings, but the present invention is not limited by the embodiments and drawings disclosed in this specification, and various methods can be obtained by those skilled in the art within the scope of the technical spirit of the present invention. It is obvious that variations can be made. In addition, although the effects according to the configuration of the present invention are not explicitly described and described while describing the embodiments of the present invention, it is natural that the effects predictable by the configuration should also be recognized.

10: indoor unit
20: outdoor unit
102a: compressor 102b: motor for compressor
105a: outdoor fan 105b: electric motor for outdoor fan
200: motor control device
205: link voltage detection unit 220: memory
232: inverter for compressor 235: inverter for outdoor fan
260: control unit
261: voltage determination unit 262: load selection unit
263: load driving unit

Claims (13)

A motor control device included in an air conditioner and controlling an electric motor for a compressor that drives the compressor, the motor control device comprising:
a link capacitor connected between an output terminal of the converter and an input terminal of an inverter for a compressor;
a link voltage detector detecting a link voltage that is a voltage between both ends of the link capacitor; and
a controller for driving a load so that the link voltage falls below the allowable voltage when the level of the link voltage exceeds the allowable voltage;
A motor control device comprising a.
According to claim 1, wherein the control unit
The allowable voltage is set by assigning a weight to the output voltage of the converter, and the allowable voltage is a value reduced by a predetermined or more from the limit voltage of the link capacitor.
According to claim 1, wherein the motor control device is
an inverter for an outdoor fan that drives an electric motor for an outdoor fan that rotates the outdoor fan;
further comprising,
An input terminal of the outdoor fan inverter is connected to the link capacitor, and the motor control device drives the outdoor fan based on power provided from the link capacitor.
According to claim 3, wherein the control unit
When the level of the link voltage exceeds the allowable voltage, the motor control apparatus for controlling the inverter for the compressor to operate the compressor in a preheating mode until the link voltage falls below the allowable voltage.
According to claim 1, wherein the motor control device is
a power supply unit for supplying power to the solenoid valve based on the power provided from the link capacitor;
further comprising,
the control unit
When the magnitude of the link voltage exceeds the allowable voltage, the motor control apparatus controls to drive the solenoid valve until the link voltage falls below the allowable voltage.
According to claim 1, wherein the control unit
a voltage determining unit receiving the level of the link voltage from the link voltage detecting unit and determining whether the level of the link voltage exceeds an allowable voltage; and
a load driving unit for monitoring the link voltage and controlling the load to be driven until the link voltage falls below the allowable voltage when the voltage determining unit determines that the level of the link voltage exceeds the allowable voltage;
A motor control device comprising a.
The method of claim 6, wherein the voltage determining unit
A motor control apparatus for setting the allowable voltage by assigning a weight to the output voltage of the converter, and setting the allowable voltage to satisfy that the allowable voltage is reduced by a predetermined or more from a limit voltage of the link capacitor.
The method of claim 6, wherein the load driving unit
When the magnitude of the link voltage exceeds the allowable voltage, the motor control apparatus for controlling the inverter for the compressor to operate the compressor in a preheat mode until the link voltage falls below the allowable voltage.
The method of claim 8, wherein the load driving unit
If the level of the link voltage exceeds an allowable voltage even while the compressor is operating in the preheating mode, the motor control device controls to further drive the solenoid valve until the link voltage falls below the allowable voltage.
A control method of an electric motor control device included in an air conditioner and configured to control an electric motor for a compressor that drives the compressor and an electric motor for an outdoor fan that rotates an outdoor fan, the method comprising:
detecting a link voltage that is a voltage between both ends of a link capacitor connected between an output terminal of the converter and an input terminal of the inverter;
determining whether the link voltage exceeds an allowable voltage; and
when the level of the link voltage exceeds the allowable voltage, driving a load so that the link voltage falls below the allowable voltage;
A motor control method comprising a.
The method of claim 10, wherein the step of driving the load so that the link voltage falls below the allowable voltage comprises:
controlling the compressor to operate in a preheating mode until the link voltage falls below the allowable voltage;
A motor control method comprising a.
The method of claim 10, wherein the step of driving the load so that the link voltage falls below the allowable voltage comprises:
controlling the solenoid valve to be driven until the link voltage falls below the allowable voltage;
A motor control method comprising a.
a compressor that compresses the refrigerant;
an electric motor for driving the compressor;
an outdoor fan disposed adjacent to the outdoor heat exchanger and rotating to promote heat exchange of the outdoor heat exchanger;
an electric motor for an outdoor fan that rotates the outdoor fan; and
and a motor control device for controlling the driving of the motor for the compressor and the motor for the outdoor fan,
The motor control device is
a link capacitor connected to an output terminal of the converter, an input terminal of an inverter for a compressor, and an input terminal of an inverter for an outdoor fan;
a link voltage detector detecting a link voltage that is a voltage between both ends of the link capacitor; and
a controller for driving a load so that the link voltage falls below the allowable voltage when the level of the link voltage exceeds the allowable voltage;
An air conditioner comprising a.

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