KR102080516B1 - Motor driving device and air conditioner including the same - Google Patents

Abstract

Motor driving device and an air conditioner having the same according to an embodiment of the present invention, the rectifier connected to the generator rectifying the input power supplied from the generator, boost converter for boosting and outputting the rectified power from the rectifier output from the boost converter A dc stage capacitor for storing the voltage, a dc stage voltage detector connected to the first stage of the dc stage capacitor, and a first switching element and a first resistor connected in series to the second stage of the dc stage capacitor, When the direct current voltage detected by the dc terminal voltage detector is equal to or greater than the first reference value, the first switching element includes an energy reduction unit that can be stably operated even in an unstable generator power supply environment.

Description

Motor driving device and air conditioner having same {Motor driving device and air conditioner including the same}

The present invention relates to a motor drive device and an air conditioner having the same, and more particularly, to a motor drive device and an air conditioner having the same that can operate stably in a generator power use region.

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

The air conditioner is separated and controlled by 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, the air conditioner may be connected to at least one indoor unit to the outdoor unit, the refrigerant is supplied to the indoor unit in accordance with the requested operating state, it is operated in the cooling or heating mode.

The air conditioner is cooled or heated according to the flow of the refrigerant. During the cooling operation, when the liquid refrigerant of high temperature and high pressure is supplied to the indoor unit from the compressor of the outdoor unit to the heat exchanger of the outdoor unit, the refrigerant is expanded and vaporized in the heat exchanger of the indoor unit. When the temperature of the air decreases and the indoor unit fan rotates, cold air is discharged into the room. When the high temperature and high pressure gas refrigerant is supplied to the indoor unit during the heating operation, the high temperature and high pressure gas refrigerant is liquefied in the indoor unit heat exchanger. The air warmed by the emitted energy is discharged into the room according to the operation of the indoor fan.

In such an air conditioner, the refrigerant is circulated by the driving of the compressor, and the stable operation of the compressor may be an important issue as the cool air is discharged through the heat exchange of the refrigerant.

In the environment where commercial power is not supplied stably, the air conditioner is operated continuously even if the compressor operates when the voltage of the supplied power is low or the power waveform such as the generator is irregular and power is supplied with large voltage fluctuations. There is a difficult problem. In general, the generator is a low-capacity generator, and the supplied power is also an unstable operating power with a high voltage fluctuation.

In addition, air conditioners are currently being developed to reduce the weight of passive components, and thus boost capless converters have been in the spotlight.

The boost capless method operates the converter switching frequency from tens to hundreds of kHz, and injects high frequency into the inverter, thereby providing 1/10 times the reactor and 1/100 the capacity of the high voltage capacitor. This can be reduced.

However, the boost capless method has a problem in that the input voltage is increased by the reactance component inside the generator when the generator power is used.

Accordingly, in order to prevent an excessive increase in the input voltage, an air conditioner's own overvoltage (DC Link) safety device is additionally required, and frequent operation of the safety device has limited limitations on convenience and product expansion.

Accordingly, there is a demand for an air conditioner capable of operating stably even in a generator power supply environment.

Disclosure of Invention An object of the present invention is to provide a motor driving apparatus and an air conditioner having the same, which can stably operate even in a generator power supply environment where voltage is unstable.

An object of the present invention is to provide a motor driving apparatus and an air conditioner having the same, which can extend a boost capless method to an unstable voltage region.

An object of the present invention is to provide a motor drive device and an air conditioner having the same that can be driven stably regardless of the generator capacity.

Motor driving apparatus and an air conditioner having the same according to an embodiment of the present invention for achieving the above object is a rectifier connected to the generator to rectify the input power supplied from the generator, boost to boost the output rectified from the rectifier boost DC stage capacitor for storing the output voltage from the converter, the boost converter, a dc stage voltage detector connected to the first stage of the dc stage capacitor, and a first switching element connected in series to the second stage of the dc stage capacitor It includes a resistance element, and includes an energy reduction unit in which the first switching element is turned on when the DC voltage detected by the dc terminal voltage detection unit is equal to or greater than the first reference value, so that it is stable even in a generator power supply environment where voltage is unstable. Can drive

According to at least one of the embodiments of the present invention, it is possible to operate stably even in a generator power usage environment where voltage is unstable.

In addition, according to at least one of the embodiments of the present invention, the boost capless method may be extended to an unstable voltage region.

In addition, according to at least one of the embodiments of the present invention, it is possible to drive stably regardless of the generator capacity.

In addition, according to at least one of the embodiments of the present invention, it is possible to stably protect the circuit elements during overvoltage.

On the other hand, various other effects will be disclosed directly or implicitly in the detailed description according to the embodiment of the present invention to be described later.

1 is a diagram illustrating a configuration of an air conditioner according to an embodiment of the present invention.
2 is a schematic diagram of an outdoor unit and an indoor unit of an air conditioner according to an embodiment of the present invention.
3 is a simplified internal block diagram of an air conditioner according to an embodiment of the present invention.
4 is a simplified internal block diagram of a motor drive apparatus according to an embodiment of the present invention.
5 and 6 are views referred to for description of the operation of the boost converter when using a generator power source.
7 is a simplified internal block diagram of a motor drive apparatus according to an embodiment of the present invention.
8 is a flowchart illustrating a method of operating a motor driving apparatus according to an embodiment of the present invention.
9 to 11 are views referred to for describing the operation of the motor drive apparatus according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

The suffixes "module" and "unit" for components used in the following description are merely given in consideration of ease of preparation of the present specification, and do not impart any particular meaning or role by themselves. Therefore, the "module" and "unit" may be used interchangeably.

In the drawings, parts not related to the description are omitted in order to clearly and briefly describe the present invention, and the same reference numerals are used for the same or extremely similar parts throughout the specification.

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

Referring to FIG. 1, the air conditioner may include an indoor unit 1 and an outdoor unit 2. In addition, the indoor unit 1 may include a remote controller 3 for inputting a control command.

In addition, other home appliances may be provided in the room where the air conditioner is installed, in addition to the air conditioner. For example, a home house has a washing machine, a lamp 4, a refrigerator, and an image display device 5. A home appliance, such as a fan, is provided and operated with power supplied.

In this case, the home appliance and the air conditioner may be operated by receiving any one of power generated and supplied from the power plants 21, 22, and 23, that is, power generated and supplied from the commercial power source 20 and the generator 10.

The generator 10 may be connected with a specific home appliance, in which case the generator 10 may be used as a dedicated generator for a particular home appliance.

In addition, when a plurality of home appliances are provided and connected to a power source, in particular, when a plurality of home appliances are connected to the generator 10, a switch for selecting a predetermined home appliance to supply power to some home appliances ( 30) may be further provided. In this case, since the capacity of the generator 10 is limited, power cannot be supplied to all home appliances when the number of loads connected, that is, the number of home appliances is plural, may be configured to switch a target to be supplied with power.

In some cases, the switch 30 may not only select a load but also select one of the commercial power 20 and the generator 10 to be supplied to the home appliance.

In this case, the generator 10 may change the type or number of home appliances that can be connected according to its capacity. For example, the general household generator 10 is a small capacity, about 600 to 1Kwh is used a lot.

On the other hand, the air conditioner may be controlled based on the voltage of the power supplied from the generator (10).

For example, the generator 10 may be overloaded when the air conditioner is connected or a plurality of home appliances are connected and operated at the same time. In this case, when the air conditioner is connected to the generator 10, the air conditioner may reduce the power consumption corresponding to the voltage of the power supplied from the generator 10 to reduce the load on the generator 10.

The air conditioner according to the present invention may include an indoor unit 1 and an outdoor unit 2 connected to the indoor unit 1.

The indoor unit 1 of the air conditioner may be any of a stand type air conditioner, a wall-mounted air conditioner, and a ceiling type air conditioner, but the drawing illustrates the wall-mounted indoor unit 1.

Meanwhile, the air conditioner may further include at least one of a ventilation device, an air cleaning device, a humidifier, and a heater, and may operate in conjunction with the operation of the indoor unit and the outdoor unit.

The outdoor unit 2 includes a compressor (not shown) for receiving and compressing a refrigerant, an outdoor heat exchanger (not shown) for exchanging refrigerant and outdoor air, and an accumulator for extracting a gas refrigerant from the supplied refrigerant and supplying it to the compressor (not shown). And a four-way valve (not shown) for selecting a flow path of the refrigerant according to the heating operation. In addition, although a plurality of sensors, valves and oil recovery device, etc. are further included, the description of the configuration will be omitted below.

The outdoor unit 2 supplies a refrigerant to the indoor unit 1 by compressing or heat-exchanging the refrigerant according to a setting by operating a compressor and an outdoor heat exchanger. The outdoor unit 2 may be driven by the demand of the remote controller (not shown) or the indoor unit 1. In this case, as the cooling / heating capacity is changed corresponding to the indoor unit being driven, the number of operation of the outdoor unit and the number of operation of the compressor installed in the outdoor unit may be changed.

At this time, the outdoor unit 2 supplies the compressed refrigerant to the connected indoor unit 1.

The indoor unit 1 receives a coolant from the outdoor unit 2 and discharges cold air into the room. The indoor unit 1 includes an indoor heat exchanger (not shown), an indoor unit fan (not shown), an expansion valve (not shown) in which the supplied refrigerant is expanded, and a plurality of sensors (not shown).

At this time, the outdoor unit 2 and the indoor unit 1 are connected by a communication line to transmit and receive data, and the outdoor unit and the indoor unit are connected to a remote controller (not shown) by wire or wirelessly and operate under the control of a remote controller (not shown). can do.

The remote controller 3 may be connected to the indoor unit 1 to input a user's control command to the indoor unit 1 and receive and display state information of the indoor unit. At this time, the remote control may communicate by wire or wirelessly according to the connection form with the indoor unit.

2 is a schematic diagram of an outdoor unit and an indoor unit of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 2, the air conditioner 100 is largely divided into an indoor unit 1 and an outdoor unit 2.

The outdoor unit 2 includes a compressor 102 that serves to compress the refrigerant, a compressor electric motor 102b that drives the compressor, an outdoor side heat exchanger 104 that serves to radiate the compressed refrigerant, and an outdoor unit. An outdoor blower 105 disposed at one side of the heat exchanger 104 to facilitate heat dissipation of the refrigerant and an outdoor blower 105 configured to rotate the outdoor fan 105a and a motor 450 to expand the condensed refrigerant; The mechanism or expansion valve 106, the cooling / heating switching valve or the four-way valve 110 to change the flow path of the compressed refrigerant, and the gasified refrigerant is temporarily stored to remove moisture and foreign matter, and then the refrigerant of a constant pressure is transferred to the compressor. It may include an accumulator 103 to be supplied.

The indoor unit 1 includes an indoor heat exchanger 109 disposed indoors to perform a cooling / heating function, an indoor fan 109a disposed on one side of the indoor heat exchanger 109 to promote heat dissipation of the refrigerant, and an indoor unit. The indoor blower 109 etc. which consist of the electric motor 109b which rotates the fan 109a are included.

At least one indoor side heat exchanger 109 may be installed. The compressor 102 may be at least one of an inverter compressor and a constant speed compressor.

In addition, the air conditioner 100 may be configured as a cooler for cooling the room, or may be configured as a heat pump for cooling or heating the room.

On the other hand, the outdoor fan 105a in the outdoor unit 2 may be driven by the outdoor fan driver 200 which drives the motor 450.

On the other hand, the compressor 102 in the outdoor unit 2 may be driven by a compressor motor driver (113 in FIG. 3) for driving a compressor motor (not shown).

On the other hand, the indoor fan 109a in the indoor unit 1 may be driven by the indoor fan driver 300 that drives the indoor fan motor 109b.

Hereinafter, the outdoor fan driving unit 200 may be referred to as an outdoor fan driving device. In addition, the indoor fan driving unit 300 may be referred to as an indoor fan driving device.

3 is a simplified internal block diagram of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 3, the air conditioner 100 includes a compressor 102, an outdoor fan 105a, an indoor fan 109a, a controller 170, a discharge temperature detector 118, and an outdoor temperature detector 138. ), The room temperature sensor 158 and the memory 140 may be included. In addition, the air conditioner 100 includes a compressor driving unit 113, an outdoor fan driving unit 200, an indoor fan driving unit 300, a switching valve 110, an expansion valve 106, a display unit 130, and an input unit ( 120) may be further included.

The compressor 102, the outdoor fan 105a, the indoor fan 109a, and the like may operate as described above with reference to FIG. 2.

The input unit 120 includes a plurality of operation buttons, and transmits a signal for the operation target temperature of the input air conditioner to the controller 170.

The display unit 130 may display an operating state of the air conditioner 100. For example, the display unit 130 may include display means for outputting an operating state of the indoor unit 1 to display an operation state and an error.

The display unit 130 may display a connection state between the indoor unit 1 and the outdoor unit 2. For example, the display unit 130 may include a light emitting diode (LED), and the light emitting diode (LED) is turned on when the communication line and / or power line is in a normal connection state, and the communication line and / or It may be turned off if the power line connection is abnormal.

The memory 140 may store data necessary for the operation of the air conditioner 100.

The discharge temperature detector 118 may detect the refrigerant discharge temperature Tc in the compressor 102 and may transmit a signal for the detected refrigerant discharge temperature Tc to the controller 170.

The outdoor temperature detector 138 may detect an outdoor temperature To, which is a temperature around the outdoor unit 2 of the air conditioner 100, and may control a signal for the detected outdoor temperature To. ) Can be delivered.

The room temperature detector 158 may detect a room temperature Ti, which is a temperature around the indoor unit 1 of the air conditioner 100, and may control a signal for the detected room temperature Ti. ) Can be delivered.

The controller 170 may determine that the air conditioner 100 is based on at least one of the detected refrigerant discharge temperature Tc, the detected outdoor temperature To, the detected indoor temperature Ti, and the input target temperature. Can be controlled to drive. For example, the final target superheat degree may be calculated to control the air conditioner 100 to operate.

On the other hand, the control unit 170, for controlling the operation of the compressor 102, the indoor fan 109a, the outdoor fan 105a, as shown in the figure, respectively, the compressor drive unit 113, outdoor fan drive unit 200 ), The indoor fan driver 300 may be controlled.

For example, the controller 170 may output the speed command value signals corresponding to the compressor driver 113, the outdoor fan driver 200, or the indoor fan driver 300 based on the target temperature.

And based on each speed command value signal, the compressor motor (not shown), the motor 450, and the indoor fan motor 109b may be operated at the target rotational speed, respectively.

The controller 170 may control operations of the overall air conditioner 100 in addition to the control of the compressor driver 113, the outdoor fan driver 200, or the indoor fan driver 300.

For example, the controller 170 may control the operation of the cooling / heating switching valve or the four-way valve 110. Alternatively, the controller 170 may control the operation of the expansion mechanism or the expansion valve 106.

The air conditioner may further include a power supply unit (not shown) that supplies power to each unit such as the compressor 102, the outdoor fan 105a, the indoor fan 109a, the controller 170, the memory 140, and the like. Can be.

The compressor 102 in the outdoor unit 2 may be driven by the compressor driver 113 that drives the compressor motor. The compressor driver 113 may include a motor driving device that controls driving of the motor.

4 is a simplified internal block diagram of a motor drive apparatus according to an embodiment of the present invention.

Referring to FIG. 4, the motor driving apparatus 400 according to an exemplary embodiment of the present invention may include an inverter controller 420 that outputs a three-phase alternating current to a motor 450 such as a compressor motor and an inverter 420. 430, a converter 410 for supplying DC power to the inverter 420, a converter control unit 415 for controlling the converter 410, and a dc terminal capacitor C between the converter 410 and the inverter 420. ) May be included.

In addition, the motor driving device 400 may further include an energy reduction unit 440 that protects the motor driving device 400 by consuming energy due to excessive voltage rise when the generator power is used.

The motor driving apparatus 400 may further include a dc terminal voltage detector B, an input voltage detector A, an input current detector D, and an output current detector E.

Meanwhile, hereinafter, FIG. 4 illustrates a case in which the motor driving device 400 is used as a motor driving device converting power input from the commercial AC power supply 201 and supplying the power to the motor 450. In this case, the motor drive 400 may be referred to as a power converter. Alternatively, the motor driving device 400 may convert the input power and supply the load to the load.

On the other hand, the motor drive device 400 according to the embodiment of the present invention, it is assumed that a low-capacity dc stage capacitor (C) of several tens of μF or less. For example, the low capacitance dc terminal capacitor C may include a film capacitor, not an electrolytic capacitor.

When the capacitor of the low capacitance is used, the change of the dc terminal voltage becomes large, causing pulsation, and the smoothing operation is hardly performed.

Such a motor driving device having a low-capacity dc stage capacitor C of several tens of μF or less may be referred to as a capacitorless or capless battery driving device.

In the present specification, the motor driving device 400 including the low capacitance dc terminal capacitor C will be described.

The converter 410 converts the input AC power source 401 into a DC power source. The converter 410 may be a concept including a rectifier (see 710 of FIG. 7) and a boost converter (see 720 of FIG. 7).

For example, the input AC power source 401 may be a commercial AC power source. The converter 410 may convert a commercial AC power source into a DC power source and output the DC power source. In the figure, the input AC power source is shown as a single-phase AC power source, but may be a three-phase AC power source. The internal structure of the converter 410 also varies according to the type of the input AC power source 401.

Alternatively, the converter 410 may receive power from an individual generator system. For example, the converter 410 may be supplied with its own power from a home small generator or a power generation system of a building. The converter 410 may convert the AC power supplied from the generator into DC power and output the DC power.

Meanwhile, the converter 410 may be formed of a diode without a switching element, and may perform a rectification operation without a separate switching operation.

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

On the other hand, the converter 410, for example, a half-bridge type 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. .

Referring to FIG. 4, the input current detector A may detect an input current is input from the input AC power source 401. To this end, a CT (current trnasformer), a shunt resistor, or the like may be used as the input current detector A. FIG. The detected input current is a discrete signal in the form of a pulse and may be input to the inverter controller 430 for power consumption calculation.

Next, at the output terminal of the converter 410, a capacitor C may be provided to store or smooth the power converted by the converter 410. The both ends of the capacitor (C) at this time may be referred to as a dc end. Therefore, the capacitor C may be referred to as a dc terminal capacitor.

The converter controller 415 generates a converter switching control signal Scc based on the input voltage Vs, the input current Is, and the dc terminal voltage Vdc, and outputs the converter switching control signal Scc to the converter 410. Can be.

The dc terminal voltage detector B may detect the dc terminal voltage Vdc, which is both ends of the smoothing capacitor C. To this end, the dc terminal voltage detector B may include a resistor, an amplifier, and the like. The detected dc terminal voltage Vdc may be input to the inverter controller 430 as a discrete signal in the form of a pulse, and the inverter switching control based on the DC voltage Vdc of the dc terminal capacitor C. Signal Sic may be generated.

In addition, the detected dc voltage is applied to the converter controller 415 so that the converter switching control signal Scc may be used for generation.

In addition, the detected dc voltage may be applied to the energy reduction unit 440 and used for the switching operation of the energy reduction unit 440.

The inverter 420 can drive the motor 450. To this end, the inverter 420 is provided with a plurality of inverter switching elements, converts the smoothed DC power supply (Vdc) by a three-phase AC power source of a predetermined frequency by the on / off operation of the switching element, three-phase motor 450 Can be output to

Inverter 420 is a pair of upper arm switching element and lower arm switching element which are connected to each other in series, respectively, a total of three pairs of upper and lower arm switching elements are connected in parallel to each other. Each switching device has a diode connected in anti-parallel.

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. As a result, three-phase AC power having a predetermined frequency is output to the three-phase motor 450.

The inverter controller 430 may control the switching operation of the inverter 420. To this end, the inverter controller 430 may receive an output current i _o detected by the output current detector E. FIG.

The inverter controller 430 outputs an inverter switching control signal Sic to the inverter 420 in order to control the switching operation of the inverter 420. The inverter switching control signal Sic is a switching control signal of the pulse width modulation system PWM, and is generated and output based on the output current value i _o detected by the output current detector E. FIG.

The output current detector E detects the output current i _o flowing between the inverter 420 and the three-phase motor 450. That is, the current flowing through the motor 450 is detected. The output current detector E may detect all of the output currents ia, ib, and ic of each phase, or may detect the output currents of two phases by using three-phase equilibrium.

The output current detector E may be located between the inverter 420 and the motor 450, and a current trnasformer (CT), a shunt resistor, or the like may be used for current detection.

When a shunt resistor is used, it is possible for three shunt resistors to be located between the inverter 420 and the synchronous motor 450, or one end to each of the three lower arm switching elements of the inverter 420. 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 corresponding shunt resistor may be disposed between the above-mentioned capacitor C and the inverter 420.

The detected output current i _o , as a discrete signal in the form of a pulse, may be applied to the inverter controller 430, and the inverter switching control signal Sic based on the detected output current i _o . Is generated.

Meanwhile, the motor 450 may be a three phase motor. The motor 450 includes a stator and a rotor, and an alternating current power of each phase of a predetermined frequency is applied to the coils of the stators of the phases a, b, and c, and the rotor rotates. .

Such a motor 450 is, for example, a Surface-Mounted Permanent-Magnet Synchronous Motor (SMPMSM), an Interior Permanent Magnet Synchronous Motor (IPMSM), and a synchronous clock. Synchronous Reluctance Motor (Synrm) and the like. Among them, SMPMSM and IPMSM are permanent magnet synchronous motors (PMSMs) with permanent magnets, and synrms have no permanent magnets.

As described above, the motor driving apparatus 400 according to an embodiment of the present invention may include a boost converter.

In addition, the motor driving apparatus 400 according to an embodiment of the present invention may use a low capacitance capacitor such as a film capacitor.

That is, the motor driving apparatus 400 according to an embodiment of the present invention may include a boost capless converter to which a converter boosting method and an inverter capless method are simultaneously applied.

The boost capless method performs switching at a high speed. For example, the boost capless method drives the converter switching frequency from tens to hundreds of kHz and injects a high frequency into the inverter, resulting in a reactor that is 1/10 times larger than a conventional inverter drive and has a high voltage capacitor capacity. Can be reduced to 1/100.

However, the boost capless method has a problem in that the input voltage is increased by the reactance component inside the generator when the generator power is used.

5 and 6 are views referred to in the description of the operation of the boost converter when using a generator power source.

Referring to FIG. 5, the boost converter includes at least one reactor, a switching element, and a film capacitor.

In addition, the generator power supply necessarily has a generator reactor component therein.

Accordingly, the reactor and generator reactor components included in the boost converter may be combined to produce a greater voltage boosting effect.

Referring to FIG. 6, it can be seen that each time the IGBT switching element operates, the boosting effect is further increased according to the input voltage boosting by the generator reactor component.

Further boosting by the generator reactor component can cause many problems because of difficulty in control.

For example, an excessive rise in input voltage can cause burnout of circuit elements, failure of individual units in the product, and malfunctions. The generator may also burst.

On the other hand, in order to prevent excessive rise of the input voltage, the air conditioner may further include its own overvoltage safety device. In this case, the cost may be excessively increased depending on the design specification of the overvoltage safety device.

In addition, when the overvoltage safety device is a method of shutting down the air conditioner product itself when the input voltage reaches a certain overvoltage, frequent operation of the safety device reduces convenience and expands the product.

That is, when the stabilizer is driven, such as shutting down the entire air conditioner before the generator explosion or damage to the air conditioner, the user's complaints may be raised by itself during frequent shutdowns, and the usability may be degraded.

Accordingly, the present invention proposes a method for reducing regenerative energy when using a generator power source and a method of stably operating an air conditioner even in a generator power supply environment.

The motor driving apparatus 400 according to an embodiment of the present invention includes a DC link voltage, that is, a regenerative reduction in operation when the DC voltage Vdc of the dc terminal capacitor C reaches an overvoltage level. It may include an energy reduction unit 440 having a circuit.

The energy reduction unit 440 may include a first switching element and a first resistance element connected in series with the dc terminal capacitor C.

In the energy reduction unit 440, when the DC voltage detected by the dc terminal voltage detection unit B is equal to or greater than a first reference value, the first switching element is turned on so that a current path is formed in the first resistance element. Can be.

 The energy reduction unit 440 is for preventing excessive rise of the DC link voltage through the switching operation of the internal first switching element.

The energy reduction unit 440 can exhaust current of electric energy by passing a current to the resistive load side through the IGBT switch operation of the regenerative reduction circuit.

On the other hand, the energy reduction unit 440 may be set to operate when the DC link voltage is greater than a predetermined reference value.

For example, when the DC link voltage is 450 V or more, the air conditioner 100 may be set to stop. In this case, 420 V lower than 450 V may be set as an operation reference value of the energy reduction unit 440. Can be.

That is, the generator regenerative energy reduction circuit can be controlled to operate in the region of 420V to 450V.

When the DC voltage Vdc sensed by the dc terminal voltage detector B is greater than or equal to a predetermined reference value, the energy reduction unit 440 may turn on the internal first switching device so that a current flows to the internal first resistance device. .

When a current path is formed through the first resistor element, an overvoltage between the converter 410 and the inverter 420 passes through the first resistor element, and more overvoltage may be emitted in the form of thermal energy. Accordingly, the internal voltage of the motor driving device 400 can be maintained at a constant voltage level.

On the other hand, the dc terminal voltage detector (B) can continuously detect the DC voltage (Vdc). In addition, the DC voltage Vdc value detected by the dc terminal voltage detector B may be transferred to the microcomputer (see 750 of FIG. 7) of the energy reduction unit 440.

When the DC voltage Vdc detected by the dc terminal voltage detector B is smaller than a reference value, the microcomputer 750 may turn off the first switching device so that the current does not flow to the first resistance device anymore. Can be.

Accordingly, the air conditioner can be stably operated even in the region of unstable generator power use.

In addition, boost capless converters can be used even in unstable generator power supply areas, and the competitiveness of air conditioners can be secured by using boost capless converters.

In addition, the air conditioner can be stably operated regardless of the difference between the reactor internal reactor according to the generator capacity.

Hereinafter, with reference to the drawings, it will be described in more detail the motor driving device provided in the air conditioner according to an embodiment of the present invention.

FIG. 7 is a simplified internal block diagram of a motor driving apparatus according to an embodiment of the present invention. The converter and energy reduction unit of the motor driving apparatus illustrated in FIG. 4 are illustrated in detail, and an illustration of an inverter / converter is omitted. Hereinafter, the same or similar parts as those described with reference to FIG. 4 will be omitted or briefly described.

Referring to FIG. 7, the motor driving apparatus according to an embodiment of the present invention may be connected to a generator to boost the rectified part S710 and the rectified power from the rectifier S710 to rectify the input power supplied from the generator. A boost stage (S720) for outputting, a dc stage capacitor (C) for storing the voltage output from the boost converter (S720), a dc stage voltage detection unit connected to the first stage (n1) of the dc stage capacitor (C) ( 730, and an energy reduction unit 440 including a first switching element S1 and a first resistance element R1 connected in series to the second terminal n2 of the dc terminal capacitor C. can do.

The rectifier 710 and the boost converter 720 may be a converter 410 for converting the input AC power 401 from the generator into a DC power.

The rectifier 710 may receive the AC power 401 from the generator, rectify the output, and output the rectified power.

To this end, the rectifier 710 is a pair of upper and lower arm diode elements connected to each other in series, respectively, and illustrates a pair of a total of two pairs of upper and lower arm diode elements connected in parallel to each other. That is, they may be connected to each other in the form of a bridge.

The boost converter 720 includes a switching element SW connected between the rectifier 710 and the inverter 420 between the inductor L and the diode D connected in series with each other, and the inductor L and the diode D. ) May be provided.

Energy is stored in the inductor L as the switching element SW is turned on, and energy stored in the inductor L is output via the diode D as the switching element SW is turned off. Can be.

Through the inductor L, the diode element D, and the switching element SW, the input power may be boosted to boost the level of the DC power.

The energy stored in the inductor L is stored by turning on the switching element SW, and the energy stored in the inductor L turns off the diode D by turning off the switching element SW. Can be output.

In particular, in the motor driving apparatus 400 using the low-capacity dc terminal capacitor C, the boost converter 420 may output a voltage boosted, that is, offset by a predetermined voltage.

In some embodiments, the boost converter 720 may further include a resistor R5 connected to the switching device SW. The converter controller 415 may control the operation of the boost converter 720 based on the voltage value detected by the resistance element R5 and / or the voltage value detected by the dc terminal voltage detector 730.

Accordingly, the operation of the boost converter 720 can be controlled more accurately and efficiently.

Meanwhile, when the DC voltage Vdc detected by the dc terminal voltage detector 730 is greater than or equal to a first reference value, the first switching device S1 is turned on to operate the energy reduction unit 440. Can be.

That is, when the dc terminal voltage detector 730 detects an overvoltage greater than or equal to the first reference value, the energy reduction unit 440 turns on the internal first switching device S1 to flow current to the internal first resistance device R1. Can be.

When a current path is formed through the first resistor element R1, an overvoltage between the boost converter 720 and the inverter 420 passes through the first resistor element R1, and more than necessary overvoltage may be emitted in the form of thermal energy. . Accordingly, the internal voltage of the motor driving device 400 can be maintained at a constant voltage level.

The energy reduction unit 440 may maintain the on state of the first switching device S1 until the DC voltage detected by the dc terminal voltage detection unit 730 is smaller than the first reference value.

Meanwhile, the dc terminal voltage detector 730 may continuously detect a DC voltage Vdc. The dc stage voltage detector 730 monitors the DC voltage, and the energy reduction unit 440 is configured to perform the first switching element when the DC voltage detected by the dc stage voltage detector 730 is greater than or equal to the first reference value. The on state of S1 can be maintained.

In addition, when the direct current voltage detected by the dc terminal voltage detector 730 is smaller than the first reference value, the energy reduction unit 440 turns off the first switching element S1 and no longer uses the first resistance element. The current can be prevented from flowing to (R1).

The energy reduction unit 440 may further include a microcomputer 750 for controlling a switching operation of the switching device S1.

The microcomputer 750 may control the overall operation of the energy reduction unit 440.

In addition, the DC voltage (Vdc) value detected by the dc terminal voltage detector 730 may be transferred to the microcomputer 750 of the energy reduction unit 440.

Referring to FIG. 7, the dc terminal voltage detector 730 includes a second resistor R2, a third resistor R3, and a fourth resistor R4 connected in series. The voltage across the fourth resistance element R4 can be detected. That is, the voltage of the node ns between the third and fourth resistors R3 and R4 may be detected.

In addition, by using the voltages of both ends of the fourth resistor R4 and the resistance values and ratios of the second to fourth resistors R2, R3, and R4, the dc terminal voltage may be calculated simply. .

According to an embodiment, the dc terminal voltage detection unit 730 including the second resistor element R2, the third resistor element R3, and the fourth resistor element R4 connected in series as illustrated in FIG. 7. Other circuit configurations may detect the voltage.

According to an embodiment of the present invention, the microcomputer 750 may be designed to detect the voltage at both ends of the DC link side through resistance distribution.

When the DC voltage Vdc detected by the dc terminal voltage detector 730 becomes equal to or greater than the first reference value, the microcomputer 750 turns on the first switching element S1 to the first resistance element R1. A path through which current flows can be formed.

In addition, when the DC voltage Vdc detected by the dc terminal voltage detection unit 730 is smaller than the first reference value, the microcomputer 750 turns off the first switching element S1 and no longer uses the first resistance element. It is possible to control the current not to flow to R1.

The energy reduction unit 440 may further include a drive IC 760 that turns on / off the first switching element S1.

The drive IC 760 may turn on or turn off the first switching device S1 under the control of the microcomputer 750.

According to an embodiment, as shown in FIG. 7, the energy reduction unit 440 may further include a photo coupler 755.

The microcomputer 750 and the drive IC 760 are not directly connected, and the photo coupler 755 is turned on / off under the control of the microcomputer 750, and the drive corresponds to the on / off state of the photo coupler 755. By turning on / off the first switching element S1 by the IC 760, malfunction can be prevented and the influence of noise can be reduced.

On the other hand, the motor driving device 400 according to an embodiment of the present invention, when the DC voltage detected by the dc terminal voltage detection unit 730 is less than the target value, and controls to operate the boost converter 720, When the DC voltage detected by the dc terminal voltage detector 730 is greater than or equal to a target value, the converter controller 415 may further include controlling the boost converter 720 to stop operation.

In addition, as described with reference to FIG. 4, the motor driving apparatus 400 according to the exemplary embodiment of the present invention includes a plurality of switching elements, and, by the switching operation, direct current across the dc terminal capacitor C. The inverter may further include an inverter 420 that converts power into AC power and outputs the same to the motor 450.

The inverter 420 according to an exemplary embodiment may convert the DC power at both ends of the dc terminal capacitor C into AC power and output the AC power to the motor 450 of the compressor 455.

In addition, the motor driving apparatus 400 according to an embodiment of the present invention may further include an inverter controller 430 for controlling the inverter 420.

The inverter controller 430 controls the inverter 420 to stop the operation when the first switching device S1 is turned on, and the inverter 420 operates normally when the first switching device S1 is turned off. Can be controlled to perform.

Meanwhile, when the DC voltage detected by the dc terminal voltage detector 730 is greater than or equal to a second reference value lower than the first reference value, the switching element SW of the boost converter 720 may be turned off.

That is, in addition to the first reference value, which is an operating condition of the energy reduction unit 440, a lower second reference value may be set as an off condition of the switching element SW of the boost converter 720.

For example, when the first reference value is set to 420V, the second reference value may be set to 380V. In this case, when the DC voltage detected by the dc terminal voltage detector 730 becomes 380V, the boost converter 720 stops and no longer boosts.

The boosting generated afterwards is caused by the reactor component of the generator, and may be removed by the operation of the energy reduction unit 440.

That is, a plurality of reference values are set, the boost converter 720 is controlled at a predetermined level, and the energy reduction unit 440 operates only for an unintended overvoltage, thereby further increasing stability.

As described above, when the generator power is used, the boost capless inverter reactor capacity is increased (generator reactor + converter reactor) under the influence of the reactor internal reactor, and the energy stored in the generator side reactor is transferred to the inverter side. The boosting effect of the boost converter can be increased.

The motor driving apparatus and the air conditioner including the same according to an embodiment of the present invention may perform voltage state monitoring in real time by the dc terminal voltage detector 730 during product operation.

When the detected voltage is smaller than the target value, the boost converter 720 may operate to perform a boost operation, and when the target value is reached, the operation of the boost converter 720 may be stopped.

At this time, if the reactor component in the generator is large, boosting may occur even when the operation of the boost converter 720 is stopped.

Therefore, the motor driving apparatus and the air conditioner including the same according to an embodiment of the present invention, when the voltage sensed by the dc terminal voltage detection unit 730 is greater than or equal to the first reference value, the first of the energy reduction unit 440 side By operating the switching element S1 and switching to the regenerative energy heat at the output terminal side first resistor R1 of the first switching element S1, the voltage can be reduced.

Subsequently, when the monitored voltage falls below the first reference value, the operation of the first switching device S1 may be stopped and normal inverter control may be performed.

Accordingly, the air conditioner can be stably operated even in the region of unstable generator power use.

In addition, boost capless converters can be used even in unstable generator power supply areas, and the competitiveness of air conditioners can be secured by using boost capless converters.

In addition, the air conditioner can be stably operated regardless of the difference between the reactor internal reactor according to the generator capacity.

On the other hand, the motor driving apparatus according to an embodiment of the present invention may further include a noise filter 701 disposed between the input AC power source 401 and the rectifier 710.

Referring to FIG. 7, the noise filter 701 may be connected to the ac terminal of the input AC power source 401 and the rectifier 710 to filter the noise signal of the ac terminal.

8 is a flowchart illustrating a method of operating a motor driving apparatus according to an embodiment of the present invention.

The dc stage voltage detector 730 may continuously detect the dc voltage Vdc of the dc stage and transmit the same to the energy reduction unit 440.

The dc terminal voltage detector 730 may monitor the DC voltage, and the energy reduction unit 440 may operate according to the DC voltage detected by the dc terminal voltage detector 730.

Referring to FIG. 8, when the DC voltage sensed by the dc terminal voltage detector 730 is greater than or equal to the first reference value (S810), the first switching device S1 is turned on (S820). It is possible to control the flow of current through the resistive element R1.

In addition, the energy reduction unit 440 turns off the first switching element S1 when the DC voltage detected by the dc terminal voltage detection unit 730 is smaller than the first reference value (S830) ( S840), the current may no longer flow to the first resistance element R1.

In addition, the dc terminal voltage detector 730 monitors the DC voltage, and the energy reduction unit 440 is the first voltage when the DC voltage detected by the dc terminal voltage detector 730 is equal to or greater than the first reference value. The on state of the switching element S1 can be maintained.

Thereafter, when the monitored voltage falls below the first reference value (S830), the operation of the first switching device S1 may be stopped (S840) and the normal inverter control may be performed (S850).

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9 to 11 are views referred to for describing the operation of the motor drive apparatus according to an embodiment of the present invention.

FIG. 9 illustrates a current flow when the switching element SW of the boost converter 720 is in an on state in a normal operation state.

Referring to FIG. 9, the current flow in normal operation is formed in the order of the rectifier 710, the inductor L of the boost converter 720, and the switching device SW, and the inductor L side of the boost converter 720. Induced current can be charged.

FIG. 10 illustrates a current flow when the switching element SW of the boost converter 720 is in an off state in a normal operation state.

Referring to FIG. 10, the current flow in normal operation is formed in the order of the rectifier 710, the diode L of the boost converter 720, and the film capacitor C, and the inductor L side of the boost converter 720. The voltage stored in the film capacitor C may be stored.

9 and 10, the energy charged to the inductor L side of the boost converter 720 increases the voltage through the switching element SW of the booster converter 720 on / off (boost converter). effect).

However, if the input power source is a generator, it may be affected by the reactor component of the generator.

For example, due to the generator reactor, the voltage boosted when the switching element SW of the booster converter 720 is turned on or off may increase rapidly.

However, according to an exemplary embodiment of the present invention, the energy reduction unit 440 may operate to consume and reduce excessive overvoltage as thermal energy.

11, when the voltage on the film capacitor C side increases rapidly, the first switching element S1 on the energy reduction unit 440 side may be operated.

Accordingly, the voltage on the film capacitor C side can be stabilized by converting electrical energy into thermal energy through a resistor connected in series with the first switching element S1.

According to at least one of the embodiments of the present invention, it is possible to operate stably even in a generator power usage environment where voltage is unstable.

In addition, according to at least one of the embodiments of the present invention, the boost capless method may be extended to an unstable voltage region.

In addition, according to at least one of the embodiments of the present invention, it is possible to drive stably regardless of the generator capacity.

In addition, according to at least one of the embodiments of the present invention, it is possible to stably protect the circuit elements during overvoltage.

The motor driving apparatus and the air conditioner having the same according to the present invention are not limited to the configuration and method of the embodiments described as described above, but the embodiments are all of the embodiments so that various modifications can be made. Or some may be selectively combined.

In addition, while the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Converter: 410
Converter control unit: 415
Inverter: 420
Inverter Control Unit: 430
Energy saving part: 440

Claims (12)

A rectifier connected to the generator to rectify the input power supplied from the generator;
A boost converter for boosting and outputting the power rectified from the rectifier;
A dc stage capacitor storing a voltage output from the boost converter;
A dc end voltage detector connected to a first end of the dc end capacitor to detect a dc end voltage;
The first switching device includes a first switching device and a first resistor connected to the second terminal of the dc terminal capacitor in series, and when the DC voltage detected by the dc terminal voltage detector is greater than or equal to a first reference value. An energy reduction unit that is turned on; And
A converter controller for controlling an operation of the boost converter,
The energy reduction unit,
A microcomputer that controls a switching operation of the first switching device;
A drive IC turning on or off the first switching element according to the control of the microcomputer; And
A photo coupler disposed between the microcomputer and the drive IC;
The boost converter,
An inductor and a diode connected in series with each other, and a second switching element connected between the inductor and the diode,
The microcomputer,
When the dc terminal voltage is greater than or equal to a first reference value, the first switching device is controlled to be turned on.
If the dc terminal voltage is less than the first reference value, the first switching device is controlled to be off (off),
The converter control unit,
When the dc terminal voltage is greater than or equal to a second reference value, the second switching device is controlled to be off.
And the first reference value is higher than the second reference value. The method of claim 1,
And the energy reduction unit maintains the on state of the first switching element until the DC voltage detected by the dc terminal voltage detection unit is smaller than the first reference value. delete The method of claim 1,
The dc terminal voltage detector includes a second resistor element, a third resistor element, and a fourth resistor element connected in series, and detects voltages at both ends of the fourth resistor element. delete delete The method of claim 1,
Energy is stored in the inductor according to the turn on of the second switching element, and the energy stored in the inductor is output via the diode according to the turn off of the second switching element. The method of claim 1,
The boost converter,
And a resistance element connected to the second switching element. delete The method of claim 1,
And an inverter having a plurality of switching elements, the inverter converting DC power at both ends of the dc terminal capacitor into AC power and outputting the same to a motor by a switching operation. The method of claim 10,
And an inverter controller configured to control the inverter to stop operation when the first switching element is turned on and control the inverter to perform a normal operation when the first switching element is turned off. An air conditioner comprising the motor drive device according to any one of claims 1, 2, 4, 7, 8, 10, and 11.

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