KR20200053957A - Power converting apparatus and Air conditioner including the same - Google Patents

Abstract

The present invention is to provide a power converting apparatus capable of detecting an electronic expansion valve (EEV) failure, and an air conditioner including the same. A power converting apparatus according to an embodiment of the present invention may include a plurality of EEVs, a current sensing unit which senses the total amount of currents flowing in coils in the plurality of EEVs, and an EEV control unit which controls the plurality of EEVs to be shut off when a current sensing value detected by the current sensing unit is equal to or greater than a preset overcurrent reference value.

Description

Power converting apparatus and air conditioner including the same}

The present invention relates to a power conversion device and an air conditioner having the same, and more particularly, to a power conversion device capable of detecting an electromagnetic expansion valve failure and an air conditioner having the same.

The air conditioner is installed to provide a more comfortable indoor environment to human beings by discharging cold and warm air into the room to create a comfortable indoor environment, adjusting the indoor temperature, and purifying the indoor air. In general, an air conditioner includes an indoor unit installed in a room configured as a heat exchanger, and an outdoor unit configured as a compressor and a heat exchanger to supply refrigerant to the indoor unit.

The power conversion device is a device that converts input power and supplies converted power. Such a power converter is disposed in an air conditioner, converts input power, and converts it into a power source for driving the air conditioner.

For example, the power converter converts AC power into DC power and supplies the converted DC power to an electronic expansion valve (EEV) that can regulate the flow rate of the refrigerant.

On the other hand, the prior literature (Korean Patent Publication No. 10-2017-0024518, publication date March 08, 2017) describes the contents of the air conditioner communication and EEV controller. However, in the prior literature, it is determined by connecting measurement equipment and transmitting / receiving control signals to determine whether an EEV is faulty. Therefore, there is a disadvantage that it is difficult to determine whether the EEV has failed without additional equipment.

On the other hand, when a defect occurs in the EEV, the PCB circuit on which the EEV control circuit or the like is mounted may be burned. 10 is a view referred to in the description of a circuit burnout due to a conventional electromagnetic expansion valve failure, and shows a conventional EEV failure generation process.

Referring to FIG. 10, when an EEV defect occurs (S1010), the resistance value of the coil inside the EEV decreases (S1020). If the resistance value of the EEV inner coil (Coil) becomes small (S1020), the current flowing through the EEV inner coil may increase (S1030).

On the other hand, if the current flowing through the coil inside the EEV increases (S1030), the current flowing through circuits such as the buffer IC on the PCB board assembly (PCBA) may increase and exceed the allowable current value (S1040), and the circuits such as the buffer IC Water may be burned (S1050).

In addition, when the PCB board assembly (PCBA) burnout due to the EEV defect occurs, there is a problem in that the quality of service is increased by replacing the PCB board assembly (PCBA) as well as the EEV (S1060).

An object of the present invention is to provide a power conversion device capable of detecting an EEV defect and an air conditioner having the same.

An object of the present invention is to provide a power converter and an air conditioner having the same, which can prevent circuit burnout due to EEV defects.

An object of the present invention is to provide a power conversion device capable of reducing service quality cost and an air conditioner having the same.

Power conversion device and air conditioner according to an embodiment of the present invention for achieving the above object, a plurality of electromagnetic expansion valve, a current sensing unit for sensing the sum of the current flowing through the coils in the plurality of electromagnetic expansion valve, and, When the current sensing value sensed by the sensing unit is equal to or greater than a preset overcurrent reference value, a malfunction of the electromagnetic expansion valve may be detected by including an electromagnetic expansion valve control unit that controls a plurality of electromagnetic expansion valves to be turned off.

According to at least one of the embodiments of the present invention, it is possible to effectively detect an EEV defect.

In addition, according to at least one of the embodiments of the present invention, it is possible to prevent circuit damage due to EEV defects.

In addition, according to at least one of the embodiments of the present invention, it is possible to reduce the quality of service cost.

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

1 is a view illustrating the configuration of an air conditioner according to an embodiment of the present invention.
2 is a schematic view of the outdoor unit and the indoor unit of FIG. 1.
FIG. 3 is a simplified internal block diagram of the air conditioner of FIG. 1.
4 is a simplified internal block diagram of a power conversion device according to an embodiment of the present invention.
5 is a diagram illustrating an electromagnetic expansion valve driving circuit according to an embodiment of the present invention.
6 is a diagram illustrating a power conversion device according to an embodiment of the present invention.
7 is a flowchart illustrating an operation method of an air conditioner according to an embodiment of the present invention.
8 is a flowchart illustrating an operation method of an air conditioner according to an embodiment of the present invention.
9 is a view referred to for a description of current sensing and overcurrent discrimination according to an embodiment of the present invention.
10 is a view referred to in the description of a circuit burnout due to a conventional electromagnetic expansion valve failure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the present invention is not limited to these embodiments and can be modified in various forms.

In the drawings, in order to clearly and briefly describe the present invention, illustration of parts irrelevant to the description is omitted, and the same reference numerals are used for the same or extremely similar parts throughout the specification.

On the other hand, the suffixes "module" and "part" for the components used in the following description are given only by considering the ease of writing the present specification, and do not impart a particularly important meaning or role in itself. Therefore, the "module" and the "unit" may be used interchangeably.

Further, in this specification, terms such as first and second may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

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

Referring to FIG. 1, the air conditioner 100 according to an embodiment of the present invention may include a plurality of units. For example, the air conditioner 100 according to an embodiment of the present invention includes indoor units 31 to 35, outdoor units 21 and 22 connected to the indoor units 31 to 35, and indoor units 31 To 35) may include a remote control (41 to 45) connected to each. In addition, the air conditioner 100 according to an embodiment of the present invention may further include a central controller 10 for controlling the plurality of indoor units 31 to 35 and the outdoor units 21 and 22.

The central controller 10 is connected to the plurality of indoor units 31 to 36 and the plurality of outdoor units 21 and 22 to monitor and control its operation. At this time, the central controller 10 may be connected to a plurality of indoor units to perform operation setting, lock setting, schedule control, group control, and the like for the indoor unit.

The air conditioner may be any of a stand type air conditioner, a wall-mounted air conditioner, and a ceiling type air conditioner, but for convenience of description, the ceiling type air conditioner will be described as an example. In addition, the air conditioner may further include at least one of a ventilation device, an air cleaning device, a humidifying device, and a heater, and may operate in conjunction with the operation of the indoor unit and the outdoor unit.

The outdoor units (21, 22) are a compressor (not shown) that receives and compresses refrigerant, an outdoor heat exchanger (not shown) that exchanges heat between the refrigerant and outdoor air, and an accumulator that extracts gas refrigerant from the supplied refrigerant and supplies it to the compressor. (Not shown) and a four-way valve (not shown) for selecting the flow path of the refrigerant according to the heating operation. In addition, it may further include a plurality of sensors, valves and oil recovery.

The outdoor units 21 and 22 operate a compressor and an outdoor heat exchanger provided to compress or heat exchange the refrigerant according to the setting to supply the refrigerant to the indoor units 31 to 35.

The outdoor units 21 and 22 are driven by the request of the central controller 10 or the indoor units 31 to 35, and as the cooling / heating capacity varies depending on the indoor units being driven, the number of outdoor units and the compressor installed in the outdoor unit The number of operations is variable.

At this time, the outdoor units 21 and 22 are described on the basis of supplying refrigerant to each of the outdoor units and the connected indoor units, but the plurality of outdoor units are interconnected according to the connection structure of the outdoor unit and the indoor unit, and the refrigerant to the plurality of indoor units You can also supply

The indoor units 31 to 35 are connected to any one of the plurality of outdoor units 21 and 22 to receive coolant and discharge cold and hot air into the room. The indoor units 31 to 35 include an indoor heat exchanger (not shown), an indoor fan (not shown), an expansion valve (not shown) for expanding the supplied refrigerant, and a plurality of sensors (not shown).

At this time, the outdoor units (21, 22) and the indoor units (31 to 35) are connected by a communication line to transmit and receive mutual data, and the outdoor unit and the indoor unit are connected by a separate communication line to the central controller (10) to control the central controller (10). It works.

The remote controllers 41 to 45 are respectively connected to the indoor unit, input a user's control command into the indoor unit, and receive and display status information of the indoor unit. At this time, the remote control communicates by wire or wireless depending on the connection type with the indoor unit, and in some cases, a single remote control unit is connected to a plurality of indoor units, so that the settings of the plurality of indoor units may be changed through one remote control input.

Meanwhile, according to an embodiment, the remote controllers 41 to 45 may include various sensors such as a temperature sensor.

2 is a schematic view of the outdoor unit and the indoor unit of FIG. 1.

Referring to FIG. 2, the air conditioner 100 is largely divided into an indoor unit 31 and an outdoor unit 21.

The indoor unit 31 is disposed indoors to perform an air-conditioning / heating function, and an indoor fan 109a and an indoor fan arranged on one side of the indoor heat exchanger 108 to promote heat dissipation of the refrigerant. And an indoor blower 109 made of an electric motor 109b for rotating the fan 109a.

At least one indoor heat exchanger 108 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 with a cooler that cools the room, or may be configured with a heat pump that cools or heats the room.

The outdoor unit 21 includes a compressor 102 serving to compress the refrigerant, an electric motor 102b for driving the compressor, an outdoor heat exchanger 104 serving to dissipate the compressed refrigerant, and outdoor An outdoor blower 105, which is disposed on one side of the heat exchanger 104 to promote heat dissipation of the refrigerant, and an outdoor fan 105 composed of an electric fan 105b that rotates the outdoor fan 105a, and expansion to expand condensed refrigerant. Mechanism 106, a cooling / heating switching valve 110 for changing the flow path of the compressed refrigerant, and an accumulator 103 for storing the vaporized refrigerant for a while to remove moisture and foreign substances, and then supplying the refrigerant at a constant pressure to the compressor. And the like.

Meanwhile, although the indoor unit 31 and the outdoor unit 21 are each shown in FIG. 2, a driving device for an air conditioner according to an exemplary embodiment of the present invention is not limited thereto, and the multi-type having a plurality of indoor units and outdoor units Of course, it can be applied to an air conditioner, an air conditioner having a single indoor unit, and a plurality of outdoor units.

FIG. 3 is a simplified internal block diagram of the air conditioner of FIG. 1.

Referring to FIG. 3, the air conditioner 100 includes a compressor 102, an outdoor fan 105a, an indoor fan 109a, a control unit 170, a discharge temperature detector 118, and an outdoor temperature detector 138 ), An indoor temperature sensing unit 158, and a memory 140. 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 is provided with a plurality of operation buttons, and transmits a signal for the operating target temperature of the input air conditioner to the control unit 170.

The display unit 130 may display an operation state of the air conditioner 100. For example, the display unit 130 may include display means for outputting an operation state of the indoor unit 21, and display an operation state and an error.

The display unit 130 may include one or more of display means such as LED, 7-segment, LCD, OLED, and may be implemented as a touch screen in some cases.

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

The discharge temperature sensing unit 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 detection unit 138 may detect the outdoor temperature To, which is the temperature around the outdoor unit 31 of the air conditioner 100, and control the signal for the detected outdoor temperature To 170 ).

The indoor temperature sensing unit 158 can detect the indoor temperature (Ti), which is the temperature around the indoor unit (21) of the air conditioner (100), and controls the signal for the detected indoor temperature (Ti) (170) ).

The control unit 170, based on the detected refrigerant discharge temperature (Tc), the detected outdoor temperature (To), at least one of the detected indoor temperature (Ti), and the input target temperature, the air conditioner (100) It can be controlled to drive. For example, by calculating the final target superheat, the air conditioner 100 may be controlled 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 drawing, respectively, the compressor driving unit 113, the outdoor fan driving unit 200 ), The indoor fan driving unit 300 can be controlled.

For example, the control unit 170 may output a corresponding speed command value signal to the compressor driving unit 113, the outdoor fan driving unit 200, or the indoor fan driving unit 300 based on the target temperature.

And based on each speed command value signal, the compressor motor (not shown), the motor 250, and the indoor fan motor 109b, respectively, may be operated at a target rotation speed.

Meanwhile, the control unit 170 may control the overall operation of the air conditioner 100 in addition to the control of the compressor driving unit 113, the outdoor fan driving unit 200, or the indoor fan driving unit 300.

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

Meanwhile, the air conditioner further includes a power supply unit (not shown) that supplies power to each unit, such as a compressor 102, an outdoor fan 105a, an indoor fan 109a, a control unit 170, and a memory 140. Can be.

The power supply unit may convert and supply input power to power required for driving each unit. Accordingly, at least some components of the power supply unit may be referred to as power conversion devices.

The power conversion device described below may be provided in the power supply unit of the air conditioner.

4 is a simplified internal block diagram of a power conversion device.

Referring to FIG. 4, the power conversion device may include an input power supply unit 405, a converter 410, a power conversion unit 440, and a DC output unit 450.

Power is input to the input power unit 405. For example, AC power may be input to the input power unit 405. In addition, the input power unit 405 may further include a filter unit that removes noise from the input AC power.

The converter 410 may convert AC power into DC power, and output the converted DC power. To this end, the converter 410 may include a rectifying unit and rectify the input AC power to output the rectified power.

For example, the converter 410 may include a bridge diode. The internal structure of the converter 410 also varies according to the type of input power.

Meanwhile, the converter 410 may be made of a diode or the like 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.

Meanwhile, for 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 source, six switching elements and six diodes may be used. .

In addition, the power conversion device, a dc stage capacitor (C) for storing the DC power converted by the converter 410, a power converter 440 for converting and outputting the DC power stored in the dc stage capacitor (C) It can contain.

The dc stage capacitor (C) smooths the input power and stores it. In the drawing, one device is illustrated as a dc terminal capacitor (C), but a plurality of devices are provided to secure device stability.

On the other hand, since both ends of the dc terminal capacitor (C), DC power is stored, it may be referred to as a dc terminal or a dc link terminal.

The power converter 440 may convert and output the DC power stored in the dc terminal capacitor C. For example, the power converter 440 may output the step-down voltage. The power converter 440 may include an AC-DC converter such as a switched-mode power supply (SMPS) using a high-frequency transformer or a non-isolated step-down buck converter. .

In addition, the DC output unit 450 connected to the secondary side of the power conversion unit 440 includes a secondary-side rectification unit, and the secondary side output voltage of the switching transformer of the power conversion unit 440 is flown and smoothed at the load side. The required constant voltage can be supplied.

The plurality of DC voltages output from the DC output unit 450 may be supplied to each unit (load 1, load 2, load 3, ...) in the air conditioner 100.

For example, the power conversion device may convert AC power into DC power, and supply the converted DC power to an electronic expansion valve (EVE) that can regulate the flow rate of the refrigerant.

5 is a diagram illustrating an electromagnetic expansion valve driving circuit according to an embodiment of the present invention, and FIG. 6 is a diagram illustrating a power conversion device according to an embodiment of the present invention.

The electromagnetic expansion valve driving circuit according to an embodiment of the present invention may be connected to a configuration for supplying power to the electromagnetic expansion valve. Accordingly, the electromagnetic expansion valve driving circuit according to an embodiment of the present invention may be implemented as part of a power conversion device, and the power conversion device may include an electronic expansion valve driving circuit.

5 and 6, an electromagnetic expansion valve driving circuit and a power conversion device according to an embodiment of the present invention include a plurality of electromagnetic expansion valves 530 and a coil 531 inside the plurality of electromagnetic expansion valves 530 , 532, 533, 534, the current sensing unit 540 for sensing the sum of the currents flowing through, and, when the current sensing value sensed by the current sensing unit 540 is greater than a predetermined overcurrent reference value, the plurality of electrons It may include an electronic expansion valve control unit 510 to control the expansion valve off (off).

Here, the electromagnetic expansion valve control unit 510 may be a dedicated micom for controlling the electronic expansion valve. Alternatively, the electronic expansion valve control unit 510 may be implemented as a block of the control unit 170.

The electronic expansion valve control unit 510 may generate a valve control signal for controlling opening and closing of the electromagnetic expansion valve 530 and supply it to each valve. For example, the electromagnetic expansion valve control unit 510 may generate EEV signals 1, 2, 3, 4 and supply them to each of the electromagnetic expansion valves 531, 532, 533, and 534.

Meanwhile, the plurality of electromagnetic expansion valves 530 may include coils therein, and opening and closing of the valves may be controlled according to a current applied to the internal coils. In the following drawings, only the coils 531, 532, 533, and 534 inside the plurality of electromagnetic expansion valves 530 are briefly illustrated.

Meanwhile, the current sensing unit 540 may be connected to one end of all coils 531, 532, 533, and 534 to sense the sum of currents flowing through the coils 531, 532, 533, and 534. For example, the current sensing unit 540 may be a current trnasformer (CT) sensor connected to the coils 531, 532, 533, and 534.

The electronic expansion valve control unit 510 may control the electronic expansion valve 530 based on the current sensing value sensed by the current sensing unit 540.

For example, the electronic expansion valve control unit 510 controls the plurality of electromagnetic expansion valves 530 to be turned off when the current sensing value sensed by the current sensing unit 540 is equal to or greater than a preset overcurrent reference value. can do.

That is, the electromagnetic expansion valve control unit 510 may determine whether or not the overcurrent is based on the overcurrent reference value set based on the sum of the currents flowing through the electromagnetic expansion valve inner coils 531, 532, 533, and 534.

If an overcurrent has occurred, the electronic expansion valve control unit 510 may determine that the electronic expansion valve 530 is defective.

In this case, the electronic expansion valve control unit 510 may control the electronic expansion valve 530 to be turned off to prevent further circuit burnout.

Accordingly, even if a defect occurs in the electromagnetic expansion valve 530, additional damage can be prevented. In addition, since only the electronic expansion valve 530 needs to be checked and replaced during service, quality cost can be reduced.

The power conversion device according to an embodiment of the present invention may further include a buffer IC 520 disposed between the plurality of electromagnetic expansion valves 530 and the electronic expansion valve control unit 510. Here, the buffer IC 520 is an IC used for buffer use such as noise removal and impedance matching.

According to an embodiment, a diode (not shown) for preventing reverse current may be disposed between the buffer IC 520 and each coil 531, 532, 533, 534.

Meanwhile, the preset overcurrent reference value may be set lower than the allowable current of the buffer IC 520. Since the buffer IC 520 is a circuit material connected to each coil 531, 532, 533, and 534, it is directly affected by the electromagnetic expansion valve 530 defect. Accordingly, if the sum of the currents flowing through the coils 531, 532, 533, and 534 is lower than the allowable current of the buffer IC 520, the buffer IC 520 is not burned and other circuits can be protected.

Meanwhile, the preset overcurrent reference value is set based on the current sensing value sensed by the current sensing unit 540 when the air conditioner 100 is turned on and the electronic expansion valve 530 is initially opened (closed). Can be. For example, during the initial operation (full open / close) of the electromagnetic expansion valve 530, an overcurrent reference value may be set by setting a predetermined margin to the current sensing value sensed by the current sensing unit 540.

Referring to FIG. 6, a power converter according to an embodiment of the present invention may include regulators 451 and 452 for stably generating and outputting voltages of various sizes required by a plurality of loads. For example, the power conversion device may include a 15V regulator 451 for a 15V load such as an electromagnetic expansion valve 530, a 5V regulator 452 for a 5V load such as an electromagnetic expansion valve controller 510, and the like.

The 15V regulator 451 may supply a driving voltage of the electromagnetic expansion valve 530 under the control of the electronic expansion valve control unit 510.

In addition, when the current sensing value sensed by the current sensing unit 540 is equal to or greater than a preset overcurrent reference value, the electronic expansion valve control unit 510 supplies the plurality of electromagnetic expansion valves 530 supplied from the 15V regulator 451. ) Can be cut off. Accordingly, the operation of the electronic expansion valve 530 in a defective state may be completely blocked to prevent further circuit burnout.

When the EEV coils 531, 532, 533, and 534 fail, the resistance value of the EEV coils 531, 532, 533, and 534 decreases, and the current value flowing through the EEV coils 531, 532, 533, and 534 increases.

The air conditioner 100 according to an embodiment of the present invention, when the current sensing value sensed by the current sensing unit 540 is equal to or greater than a preset overcurrent reference value, the plurality of electromagnetic expansion valves in the display unit 130 ( 530).

For example, when the current value sensed by the current sensing unit 540 reaches the set current value by setting a current value lower than the allowable current of the buffer IC 520 as a reference value, an error code can be displayed. have.

In addition, in order to prevent further circuit burnout, the control unit 170 and / or the electronic expansion valve control unit 510 may turn off the electronic expansion valve 530 and block the 15V regulator 451 control signal.

On the other hand, the current value sensed by noise or the like may be sensed. Therefore, in order to improve the accuracy, the circuit protection logic can be operated after a plurality of overcurrent determinations without turning off the electromagnetic expansion valve 530 with one overcurrent determination or blocking the driving voltage.

For example, the electronic expansion valve control unit 510 performs a plurality of times the process of determining whether or not the overcurrent reference value is exceeded within a predetermined time, and when it is determined that the overcurrent exceeds the preset reference number of times, the plurality of electromagnetic expansion valves ( 530) may be controlled to be off.

Referring to Figure 6, the power conversion apparatus according to an embodiment of the present invention, a rectifier 410 for rectifying the input AC power, a dc stage capacitor (C) for storing the output power of the rectifier 410, and, A power converter 441 for converting and outputting power stored in the dc terminal capacitor C may be further included.

The power converter 441 may convert and output DC power stored in the dc terminal capacitor C. For example, the power converter 441 may output voltages stepped down to a plurality of levels required by loads such as 5V and 15V. The power converter 441 may include an AC-DC converter such as a switched-mode power supply (SMPS) using a high-frequency transformer or a non-isolated step-down buck converter. .

7 is a flowchart illustrating an operation method of an air conditioner according to an embodiment of the present invention.

Referring to FIG. 7, the air conditioner 100 according to an embodiment of the present invention, through the current sensing unit 540, is applied to the coils 531, 532, 533, 534 inside the electromagnetic expansion valve 530. A total of flowing currents may be sensed (S710).

The electronic expansion valve control unit 510 may compare the current sensing value sensed by the current sensing unit 540 with a preset overcurrent reference value to determine whether an overcurrent exists (S720).

If it is determined as overcurrent (S720), the electronic expansion valve control unit 510 may block a signal related to the electromagnetic expansion valve 530 (S730).

For example, the electronic expansion valve control unit 510 no longer supplies the EEV operation signal supplied to the electronic expansion valve 530, so that the electromagnetic expansion valve 530 is in an off state. Can be controlled.

In addition, the electromagnetic expansion valve controller 510 may cut off the driving voltage of the electromagnetic expansion valve 530 supplied from the 15V regulator 451.

Accordingly, the operation of the electromagnetic expansion valve 530 which is in a defective state may be blocked to prevent further circuit burnout.

On the other hand, under the control of the control unit 170, the display unit 130 may display an error code corresponding to the failure of the plurality of electromagnetic expansion valves 530 (S740).

For an embodiment in which the electronic expansion valve control unit 510 is provided separately from the control unit 170, when it is determined as an overcurrent (S720), the electronic expansion valve control unit 510 may transmit a signal indicating an EEV failure to the control unit 170. have.

8 is a flowchart illustrating an operation method of an air conditioner according to an embodiment of the present invention, and shows a process for protecting a PCB board assembly (PCBA) burnout when an EEV defect occurs.

Referring to FIG. 8, when an EEV defect occurs (S80), resistance values of the EEV internal coils 531, 532, 533, and 534 are reduced (S820). When the resistance value of the EEV inner coils 531, 532, 533, and 534 decreases (S820), the current flowing through the EEV inner coils 531, 532, 533, and 534 may increase (S830).

On the other hand, when the current flowing through the EEV inner coils 531, 532, 533, and 534 increases (S830), the current flowing in circuits, such as the buffer IC 520 on the PCB board assembly (PCBA), increases and may exceed the allowable current value. Circuitry such as the buffer IC 520 may be burned.

The air conditioner 100 according to an embodiment of the present invention may compare the current sensing value sensed by the current sensing unit 540 with a preset overcurrent reference value to determine whether an overcurrent exists (S840).

9 is a diagram for reference to a description of current sensing and overcurrent discrimination according to an embodiment of the present invention, the voltage supplied to the electronic expansion valve 530 and the EEV inner coil 531 during the initial operation of the air conditioner 100 ).

Referring to FIG. 9, when 14.96V included in the 15V voltage reference range is supplied to the electromagnetic expansion valve 530, the EEV driving current was 168.9mA. In this case, the overcurrent reference value set based on the sum of the currents flowing through the EEV inner coils 531, 532, 533, and 534 may be set to about 800 mA. However, at a driving current of about 800mA, the EEV is in a normal state, and too strict criteria may cause side effects such as frequent operation stops and service checks. Therefore, the overcurrent judgment criterion can be set to 1.4A with a margin of about 60-70%. In addition, the allowable current of circuit elements such as a buffer IC may also be considered to set an overcurrent judgment criterion.

Meanwhile, the electronic expansion valve control unit 510 may perform a plurality of times to determine whether or not the overcurrent reference value is exceeded within a predetermined time.

For example, the electromagnetic expansion valve control unit 510 may detect and discriminate the overcurrent 10 times within an hour, thereby preventing misjudgment by the surrounding environment such as external noise and temporary voltage instability.

On the other hand, if it is determined as an overcurrent (S840), the electronic expansion valve controller 510 may block a signal related to the electromagnetic expansion valve 530 (S850).

For example, the electromagnetic expansion valve controller 510 may block the driving voltage of the electromagnetic expansion valve 530 supplied from the 15V regulator 451 to protect the load using 15V (S850).

Meanwhile, the display unit 130 may display error information corresponding to a defect of the electromagnetic expansion valve 530 (S860).

During service work, the operator checks and replaces the error information corresponding to the failure of the electronic expansion valve 530, and checks and replaces only the electronic expansion valve 530 to check and replace the PCB board assembly (PCBA) as well as the EEV. Can reduce the cost of service quality.

The power conversion device and the air conditioner having the same according to the present invention are not limited to the configuration and method of the above-described embodiments, and the above embodiments are all of each embodiment so that various modifications can be made. Alternatively, a part may be selectively combined and configured.

On the other hand, the power conversion device according to an embodiment of the present invention and the method of operating the air conditioner having the same can be implemented as a code readable by a processor on a record carrier readable medium. The processor-readable recording medium includes all kinds of recording devices in which data that can be read by the processor are stored. Examples of the recording medium that can be read by the processor include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc., and include those implemented in the form of carrier waves such as transmission through the Internet. . In addition, the processor readable recording medium may be distributed over network coupled computer systems so that the processor readable code is stored and executed in a distributed fashion.

In addition, although 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, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications can be implemented by those skilled in the art, and these modifications should not be individually understood from the technical idea or prospect of the present invention.

Electronic expansion valve control: 510
Buffer IC: 520
Current sensing unit: 540

Claims (9)

A plurality of electromagnetic expansion valves;
A current sensing unit that senses the sum of currents flowing in the coils inside the plurality of electromagnetic expansion valves; And,
And an electronic expansion valve control unit configured to control the plurality of electromagnetic expansion valves to be turned off when the current sensing value sensed by the current sensing unit is equal to or greater than a preset overcurrent reference value. According to claim 1,
And a buffer IC disposed between the plurality of electromagnetic expansion valves and the electromagnetic expansion valve control unit. According to claim 2,
And the preset overcurrent reference value is lower than an allowable current of the buffer IC. According to claim 1,
And a regulator that supplies driving voltages of the plurality of electromagnetic expansion valves. The method of claim 4,
When the current sensing value sensed by the current sensing unit is greater than or equal to a preset overcurrent reference value, the electronic expansion valve control unit cuts off the driving voltages of the plurality of electromagnetic expansion valves supplied from the regulator. According to claim 1,
The electronic expansion valve control unit performs a process of determining whether or not the overcurrent reference value is abnormal within a predetermined time, and controls the plurality of electromagnetic expansion valves to be turned off when it is determined that the overcurrent exceeds a predetermined reference number of times. Power conversion device characterized in that. According to claim 1,
A rectifying unit rectifying the input AC power;
A dc terminal capacitor storing the output power of the rectifying unit; And,
Power conversion device further comprising; a power conversion unit for converting and outputting power stored in the dc terminal capacitor. An air conditioner comprising a; power conversion device of any one of claims 1 to 7. The method of claim 8,
And a display unit displaying error information for the plurality of electromagnetic expansion valves when the current sensing value sensed by the current sensing unit is equal to or greater than a preset overcurrent reference value.

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