KR102197318B1 - Air conditioner for preventing communication noise between indoor unit and outdoor unit - Google Patents

Abstract

The present invention relates to an air conditioner that prevents communication noise between an indoor unit and an outdoor unit caused by an incorrect connection between an external power source and a power line. An air conditioner according to an embodiment of the present invention receives the external power through an indoor unit connected to an external power source and a first power line and a second power line connected to the indoor unit, and the indoor unit through a communication line connected to the indoor unit. And an outdoor unit performing data communication with the outdoor unit, wherein the outdoor unit has a lower voltage of a voltage of the first power line and a voltage of the second power line and a reference potential difference through switching of the first and second power lines. It is characterized in that data communication with the indoor unit is performed using a communication voltage.

Description

Air conditioner that prevents communication noise between indoor unit and outdoor unit {AIR CONDITIONER FOR PREVENTING COMMUNICATION NOISE BETWEEN INDOOR UNIT AND OUTDOOR UNIT}

The present invention relates to an air conditioner that prevents communication noise between an indoor unit and an outdoor unit caused by an incorrect connection between an external power source and a power line.

A general air conditioner includes an outdoor unit that compresses and heats a refrigerant, and an indoor unit that discharges hot and cold air into the room by using the refrigerant supplied from the outdoor unit.

A power line and a communication line are installed between the indoor unit and the outdoor unit. Accordingly, when the indoor unit is connected to an external power supply, the outdoor unit operates by receiving external power through a power line. In addition, the outdoor unit performs data communication with the indoor unit by generating a constant voltage required for data transmission/reception using an external power supplied through a power line, loading data on the generated constant voltage and transmitting the data to the communication line.

To explain the data communication method in more detail, when the external power source is a commercial AC power of 220 [V], the outdoor unit is a voltage supplied from the neutral line among the external power supplied through the power line (eg, 0 [V]). Generates a voltage with a constant potential difference from ), and transmits and receives data by loading data on the generated voltage.

In this way, when the live line and the neutral line of the power line and the external power supply are connected in reverse, the outdoor unit generates a voltage having a constant potential difference from the voltage supplied from the live line for data communication (eg, 220 [V]). do.

In this case, the size of the voltage for data communication becomes very large, and when the generated voltage approaches or exceeds the insulation voltage of the communication line, noise occurs in the signal transmitted and received between the indoor unit and the outdoor unit. There is a problem that communication itself becomes impossible.

An object of the present invention is to provide an air conditioner that prevents communication noise between an indoor unit and an outdoor unit caused by an incorrect connection between an external power supply and a power line.

In addition, an object of the present invention is to provide an air conditioner that switches power lines based on the magnitude of a voltage applied to each power line connected to both ends of an external power source.

Another object of the present invention is to provide an air conditioner for switching power lines connected to both ends of an external power source based on a communication rate.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention that are not mentioned can be understood by the following description, and will be more clearly understood by examples of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by the means shown in the claims and combinations thereof.

The outdoor unit of the present invention performs data communication using a communication voltage having a lower voltage and a reference potential difference among the voltage of the first power line and the voltage of the second power line through switching of the first and second power lines. Communication noise between indoor and outdoor units caused by incorrect wiring between power and power lines can be prevented.

In addition, the outdoor unit of the present invention transmits a switching request signal to the indoor unit when a communication voltage having a difference between the voltage of the second power line and the reference potential is generated, and the voltage of the second power line is higher than the voltage of the first power line. The first and second power lines are switched according to the switching request signal, so that the power lines can be switched based on the magnitude of the voltage applied to each power line connected to both ends of the external power source.

In addition, the outdoor unit of the present invention transmits a switching request signal to the indoor unit when the communication rate, which is the ratio of the number of times of receiving the response signal to the number of transmission of the request signal, is less than the reference communication rate, and the indoor unit transmits a switching request signal to the indoor unit. By switching the power supply line connected to both ends of the external power supply can be switched based on the communication rate.

According to the present invention, by preventing communication noise between the indoor unit and the outdoor unit caused by incorrect wiring between the external power supply and the power line, there is an effect of ensuring communication quality even if a communication line having a low insulation voltage is installed between the indoor unit and the outdoor unit. .

In addition, according to the present invention, by comparing the voltage applied to each power line connected to both ends of the external power supply and switching the power line or by switching the power line connected to both ends of the external power supply based on the communication rate, data between the indoor and outdoor unit It is possible to keep the communication voltage for communication low, and accordingly, there is an effect of reducing noise of data communication.

1 is a view showing an air conditioner according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining movement of a refrigerant between an indoor unit and an outdoor unit shown in FIG. 1;
3 is an internal block diagram of the outdoor unit and the indoor unit shown in FIG. 1.
4 is a view for explaining a control flow between the indoor unit and the indoor unit shown in FIG. 1;
5 is a diagram showing an internal circuit of the indoor unit and the outdoor unit shown in FIG. 4;
6 is a flowchart illustrating a process of performing data communication by generating a communication voltage according to a voltage comparison result of two power lines by an outdoor unit.
7 is a flow chart illustrating a process of switching two power lines according to a communication rate of an outdoor unit with an indoor unit.

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

Hereinafter, when a component is described as being "connected", "coupled" or "connected" to another component, the components may be directly connected or connected to each other, but other components are "connected" between each component. It is to be understood that intervening" or each component may be "connected", "coupled" or "connected" through other components.

The present invention relates to an air conditioner that prevents communication noise between an indoor unit and an outdoor unit caused by an incorrect connection between an external power source and a power line.

Hereinafter, an air conditioner according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7.

FIG. 1 is a diagram illustrating an air conditioner according to an embodiment of the present invention, and FIG. 2 is a diagram for explaining movement of a refrigerant between an indoor unit and an outdoor unit shown in FIG. 1.

3 is an internal block diagram of the outdoor unit and the indoor unit shown in FIG. 1. FIG. 4 is a diagram for explaining a control flow between the indoor unit and the indoor unit shown in FIG. 1, and FIG. 5 is a diagram illustrating an internal circuit of the indoor unit and the outdoor unit shown in FIG. 4.

6 is a flowchart illustrating a process of performing data communication by generating a communication voltage according to a voltage comparison result of two power lines by an outdoor unit. In addition, FIG. 7 is a flowchart illustrating a process of switching between two power lines according to a communication rate of an outdoor unit with an indoor unit.

Referring to FIG. 1, an air conditioner 100 according to an embodiment of the present invention may include an indoor unit 10 and an outdoor unit 20. The air conditioner 100 of the present invention is an arbitrary device that performs an air conditioning function using the indoor unit 10 and the outdoor unit 20, and may be a ventilation device, an air cleaning device, a humidifying device, a cooling and heating device, or the like. However, in the following description, for convenience of description, it is assumed that the air conditioner 100 is a cooling and heating device.

Meanwhile, in FIG. 1, the outdoor unit 20 and the indoor unit 10 are shown to be connected one-to-one, but a plurality of indoor units 10 may be connected to one outdoor unit 20. In addition, although the indoor unit 10 is shown as a stand type in FIG. 1, the indoor unit 10 may be various types of indoor units 10 installed at arbitrary locations such as a wall-mounted type and a ceiling type.

The outdoor unit 20 may receive and compress a refrigerant and may exchange heat between the compressed refrigerant and outdoor air, and the indoor unit 10 may discharge hot and cold air into the room by using the refrigerant supplied from the outdoor unit 20. .

Referring to FIG. 2, an indoor unit 10 disposed indoors may include an indoor heat exchanger 108 and an indoor blower 109 to perform a cooling/heating function. Here, the indoor blower 109 may include an indoor fan 109a disposed on one side of the indoor heat exchanger 108 to promote heat dissipation of a refrigerant, and an indoor electric motor 109b that rotates the indoor fan 109a. .

Meanwhile, the outdoor unit 20 disposed outdoors may include a compressor 102 for compressing a refrigerant and an outdoor heat exchanger 104 for dissipating the compressed refrigerant, and disposed on one side of the outdoor heat exchanger 104 Thus, it may include an outdoor fan 105 comprising an outdoor fan 105a for promoting heat dissipation of the refrigerant and an outdoor motor 105b for rotating the outdoor fan 105a. In addition, the outdoor unit 20 has an expansion mechanism 106 for expanding the condensed refrigerant, a cooling/heating switching valve 111 for switching a flow path of the compressed refrigerant, and a gasified refrigerant for a short period of time to remove moisture and foreign substances and It may include an accumulator 103 for supplying a refrigerant having a to the compressor 102.

The internal components of the indoor unit 10 and the outdoor unit 20 shown in FIG. 2 are according to an embodiment, and the components are not limited to the embodiment shown in FIG. 2, and some components are It can be added, changed or deleted.

The outdoor unit 20 may supply the refrigerant to the indoor unit 10 after performing compression and heat exchange operations of the refrigerant through the above-described components, and the indoor unit 10 heats the refrigerant supplied from the outdoor unit 20 to the indoor unit. Cold and hot air can be discharged.

Since the content of the refrigerant circulation cycle between the indoor unit 10 and the outdoor unit 20 is generally known in the art, further detailed descriptions will be omitted in the present specification.

3 is a block diagram for explaining an internal control operation of the indoor unit 10 and the outdoor unit 20. Referring to FIG. 3, the indoor unit 10 includes an indoor unit communication unit 120a, a first memory 140a, an indoor unit control unit 170a, an output unit 550, an input unit 110, a display 180, and a switching switch unit. 190a) may be included. In addition, the indoor unit 10 may further include an indoor fan driving unit 127a for driving the indoor fan 109a shown in FIG. 2.

The indoor unit communication unit 120a may provide a user command input to the indoor unit 10 to the outdoor unit 20 by exchanging signals with the outdoor unit 20 through the communication line 630. Here, the communication line 630 may be a line that physically connects the indoor unit 10 and the outdoor unit 20, and for data communication between the indoor unit 10 and the outdoor unit 20 through the communication line 630, FIG. 4 And it will be described later with reference to FIG.

In addition, the indoor unit communication unit 120a may include a wireless communication module, and may perform data communication with an external wireless terminal through the wireless communication module. In one example, when the air conditioner 100 of the present invention is provided in a building, etc., the indoor unit communication unit 120a performs data communication with a central management server that manages a plurality of air conditioners 100 through a wireless communication module. can do. In another example, when the air conditioner 100 of the present invention is provided in a home, the indoor unit communication unit 120a may perform data communication with a home access point (AP), a remote control, and a user terminal.

The first memory 140a may store various programs for processing or controlling the indoor unit controller 170a and various data for controlling the overall operation of the indoor unit 10. For example, in the first memory 140a, reference data required to control the internal components of the indoor unit 10, reference data required to remotely control the outdoor unit 20, data transmitted and received through the indoor unit communication unit 120a, etc. Can be saved.

The indoor unit controller 170a may control the overall operation of each component in the indoor unit 10. More specifically, the indoor unit control unit 170a may control the operation of the indoor unit 10 based on data received from the outdoor unit 20, and may output the operation state of the indoor unit 10 through the display 180. In addition, it is also possible to control the data transmission/reception operation through the indoor unit communication unit 120a.

The input unit 110 may be composed of a plurality of buttons or a touch screen installed to receive a user command (eg, a set (desired) temperature), and may be installed on the outer surface of the indoor unit 10.

The indoor fan driving unit 127a may include an arbitrary circuit for driving the indoor fan 109a, and may drive the indoor blower 109 through the circuit. More specifically, the indoor fan driving unit 127a may supply driving power to the indoor blower 109 under the control of the indoor unit controller 170a to control the rotation operation and rotation speed of the indoor fan 109a.

The indoor fan 109a is rotated by the indoor fan driving unit 127a to promote heat dissipation of the refrigerant by the indoor heat exchanger 108, thereby discharging hot and cold air into the room.

The display 180 may be configured with any display means installed on the outer surface of the indoor unit 10. The display 180 may visually display the operating state of the indoor unit 10 and may visually output an abnormality occurrence signal to be described later.

The output unit 550 may be composed of a speaker, a buzzer, etc. installed in the indoor unit 10. The output unit 550 may audibly output the operating state of the indoor unit 10 and may audibly output an abnormality occurrence signal to be described later.

Meanwhile, in addition to the above-described components, the indoor unit 10 may further include a changeover switch unit 190a, and the changeover switch unit 190a will be described later with reference to FIGS. 4 and 5.

Referring to FIG. 3 again, the outdoor unit 20 may include an outdoor unit communication unit 120b, a second memory 140b, an outdoor unit control unit 170b, a display unit 510, and a voltage measurement unit 210, and Fig. 2 It may further include an inverter 220 and an outdoor fan driving unit 127b for driving the compressor 102 and the outdoor blower 105 shown in FIG.

The outdoor unit communication unit 120b may receive a user command from the indoor unit 10 by exchanging signals with the indoor unit 10 through the communication line 630. Also, like the indoor unit communication unit 120a, the outdoor unit communication unit 120b may include a wireless communication module, and may perform data communication with an external wireless terminal through the wireless communication module.

The second memory 140b may store various programs for processing or controlling the outdoor unit controller 170b and various data for controlling the overall operation of the outdoor unit 20. For example, the second memory 140b includes reference data required to control the internal components of the outdoor unit 20, control data for controlling the operation of the inverter 220, and control for controlling the operation of the outdoor fan driving unit 127b. Data, data transmitted/received through the outdoor unit communication unit 120b, and the like may be stored.

The outdoor unit control unit 170b may generate control signals for controlling the compressor 102 and the outdoor fan driving unit 127b, respectively, based on data stored in the second memory 140b and data received from the indoor unit 10, The generated control signals may be provided to the inverter 220 and the outdoor fan driver 127b, respectively. Accordingly, the inverter 220 may provide driving power to the compressor 102 according to a control signal, and the outdoor fan driver 127b may provide driving power to the outdoor blower 105 according to the control signal.

More specifically, the inverter 220 may include a plurality of switching elements for power conversion, and each switching element switches according to a control signal provided from the outdoor unit control unit 170b to supply driving power to the compressor 102 , It is possible to control the driving and driving speed of the compressor 102.

In addition, the outdoor fan driving unit 127b may include an arbitrary circuit for driving the outdoor blower 105, and the circuit operates according to a control signal provided from the outdoor unit control unit 170b to drive the outdoor blower 105 By supplying power, the rotational operation and rotational speed of the outdoor fan 105a can be controlled.

The outdoor fan 105a rotates by the outdoor fan driving unit 127b so that the refrigerant supplied from the compressor 102 flows into the outdoor heat exchanger 104 to suck in outdoor air to heat exchange with the outdoor air. Air can be discharged outdoors.

The display unit 510 may be configured with a light emitting diode (LED) or the like for visually outputting the operating state of the outdoor unit 20. The display unit 510 may output light of different colors according to the operating state of the outdoor unit 20 or may output light with different flashing patterns.

Meanwhile, the indoor unit control unit 170a may identify voltages applied to the first power line 610 and the second power line 620 through the voltage measurement unit 210, respectively, for which FIGS. 4 and 5 It will be described in detail with reference to.

Hereinafter, a connection relationship between the indoor unit 10 and the outdoor unit 20 through the power lines 610 and 620 and the communication line 630 and a method of performing data communication will be described in detail with reference to FIGS. 4 and 5.

The indoor unit 10 may be connected to an external power supply 400. Here, the external power supply 400 is AC power and may supply power through a live line and a neutral line. For example, when the external power source 400 is an AC power source of 220 [V] or 60 [Hz], the external power source 400 may supply a voltage of 220 [V] through a live wire, and 0 [V] through a neutral wire. Can supply voltage of

The outdoor unit 20 includes a first power line 610 connected between a first power terminal L1 of the indoor unit 10 and a second power terminal L2 of the outdoor unit 20, and a first neutral of the indoor unit 10. The external power 400 may be supplied through the second power line 620 connected between the terminal N1 and the second neutral terminal N2 of the outdoor unit 20.

The outdoor unit 20 may further include a converter 230 that converts the external power supply 400 supplied as described above into DC power, and a DC link capacitor that stores the DC power converted by the converter 230. Meanwhile, the above-described inverter 220 may convert the DC power stored in the DC link capacitor into a driving current for driving the compressor 102 and output it.

The converter 230 may be configured to include any AC-DC power conversion circuit, for example, may be configured as a diode bridge (diode bridge).

Inverter 220 may be configured to include any DC-AC power conversion circuit, for example, in order to convert DC power into a three-phase driving current, a pair of upper-arm switching elements and lower-arm switching elements for each phase. Can be configured.

Meanwhile, the outdoor unit 20 performs data communication with the indoor unit 10 through a communication line 630 connected between the first communication terminal C1 of the indoor unit 10 and the second communication terminal C2 of the outdoor unit 20. Can be done.

Referring to FIG. 4, the indoor unit 10 may be connected to both ends of an external power supply 400, and the outdoor unit 20 may be connected to the indoor unit 10 through first and second power lines 610 and 620. . The indoor unit 10 may be directly supplied with power through both ends of the external power supply 400, and the outdoor unit 20 is supplied with power through first and second power lines 610 and 620 extending from the indoor unit 10. Can be supplied.

The first and second power lines 610 and 620 may be connected to a live wire and a neutral wire of the external power supply 400, respectively. For example, when the first power line 610 is connected to a live wire of the external power supply 400, the second power line 620 may be connected to a neutral wire of the external power supply 400. Conversely, when the first power line 610 is connected to the neutral line of the external power source 400, the first power line 610 may be connected to the live line of the external power source 400.

The indoor unit 10 and the outdoor unit 20 may drive and control various internal components described in FIG. 3 by using an external power supply 400 supplied through the first and second power lines 610 and 620.

Meanwhile, the indoor unit 10 and the outdoor unit 20 may use a communication voltage having a predetermined size for mutual data communication. More specifically, the indoor unit 10 and the outdoor unit 20 may perform data communication with each other by transmitting data on a communication voltage having a predetermined size. Accordingly, a communication voltage of a predetermined size may be applied to the communication line 630 connecting the indoor unit 10 and the outdoor unit 20.

This communication voltage may be generated based on the external power supply 400. More specifically, the outdoor unit 20 generates a communication voltage having a reference potential difference from a voltage supplied through any one of the first and second power lines 610 and 620 to which the external power supply 400 is supplied. can do.

For example, the outdoor unit 20 may generate a communication voltage by using a voltage supplied through the second power line 620 among the first and second power lines 610 and 620, and may generate a communication voltage of 220[v]. The live wire and the neutral wire of the external power source 400, which is an AC power source, may be connected to the first and second power lines 610 and 620, respectively. In an ideal case, the voltage Vl supplied to the first power line 610 through the live line is 220 [V], and the voltage Vn supplied to the second power line 620 through the neutral line is 0 [V]. I can.

At this time, the outdoor unit 20 may generate a communication voltage of 72[V] having a voltage (0[V]) supplied through the second power line 620 and a reference potential difference (eg, 72[V]). have.

In order to generate a communication voltage having a difference between the voltage of the second power line 620 and the reference potential, a method of distributing the voltage between the first power line 610 and the second power line 620 is used in the outdoor unit 20. Alternatively, a method of reducing the voltage between the first power line 610 and the second power line 620 may be used. To this end, the outdoor unit 20 may be provided with a voltage distribution circuit or a buck converter.

In addition, the outdoor unit 20 may be provided with various circuits known in the art to generate a voltage having a reference potential difference from a voltage applied from a power line.

In the above-mentioned communication voltage generation method, when the first and second power lines 610 and 620 are connected opposite to the live wire and the neutral wire of the external power supply 400, the outdoor unit 20 is connected to the second power line 620 through the live wire. ), a communication voltage of 292 [V] having a voltage of 220 [V] and a reference potential difference (eg, 72 [V]) may be generated.

In this case, the magnitude of the communication voltage may be close to or exceed the insulation voltage of the communication line 630, and accordingly, noise occurs in data transmitted and received between the indoor unit 10 and the outdoor unit 20 There is a problem that communication itself becomes impossible.

In order to prevent this, the outdoor unit 20 of the present invention is further configured of the voltage of the first power line 610 and the voltage of the second power line 620 through switching of the first and second power lines 610 and 620. Data communication with the indoor unit 10 may be performed using a communication voltage having a low voltage and a reference potential difference.

Hereinafter, for convenience of description, the voltages of the first power line 610 and the second power line 620 in the state in which the first and second power lines 610 and 620 are not switched are respectively used as the first power voltage. And a second power voltage, wherein the outdoor unit 20 generates a communication voltage having a reference potential difference from the voltage applied through the second power line 620 among the first and second power lines 610 and 620 It is assumed to be explained.

First, a process in which the outdoor unit 20 switches the power line by comparing the voltage of the first power line 610 and the voltage of the second power line 620 will be described.

When the second power voltage is lower than the first power voltage, the outdoor unit 20 may generate a communication voltage having a difference between the second power voltage and the reference potential without switching the first and second power lines 610 and 620. have.

On the other hand, the outdoor unit 20 may switch the first and second power lines 610 and 620 when the first power voltage is lower than the second power voltage. When the first power line 610 and the second power line 620 are switched, a second power voltage may be applied to the first power line 610, and a first power voltage may be applied to the second power line 620. Can be authorized. In this case, the outdoor unit 20 may generate a communication voltage having a reference potential difference from the first power voltage applied to the second power line 620.

The outdoor unit 20 may measure the first power voltage and the second power voltage, respectively, and determine whether to switch the first and second power lines 610 and 620 according to the measurement result.

As shown in FIG. 4, the voltage measuring unit 210 provided in the outdoor unit 20 is connected to the first power line 610 and the second power line 620, respectively, to measure a first power voltage and a second power voltage. Can be measured. More specifically, referring to FIG. 5, the voltage measurement unit 210 measures the first power voltage through the potential difference between the first power line 610 and the ground voltage 0[V] applied to the ground terminal G. can do. Also, the voltage measurement unit 210 may measure the second power voltage through a potential difference between the second power line 620 and the ground voltage.

The outdoor unit control unit 170b may identify the first power voltage and the second power voltage through the voltage measurement unit 210 and compare the magnitudes of the identified two voltages. As a result of the comparison, if the first power voltage is higher than the second power voltage, the outdoor unit controller 170b may determine that switching of the first and second power lines 610 and 620 is not required. On the other hand, if the second power voltage is higher than the first power voltage, the outdoor unit controller 170b may determine that switching of the first and second power lines 610 and 620 is necessary.

When it is determined by the outdoor unit control unit 170b that switching is necessary, one end of the external power supply 400 connected to the first power line 610 may be connected to the second power line 620 and the second power line ( The other end of the external power supply 400 connected to 620 may be connected to the first power line 610.

When the outdoor unit 20 generates a communication voltage having a reference potential difference from the voltage of the second power line 620 among the first and second power lines 610 and 620, as described above, the second power line 620 When the voltage of is higher than the voltage of the first power line 610, the outdoor unit 20 may transmit a switching request signal to the indoor unit 10.

In this case, the indoor unit 10 may switch between the first power line 610 and the second power line 620 according to the switching request signal. In other words, switching of the power line may be performed inside the indoor unit 10 according to a request signal from the outdoor unit 20.

On the other hand, when it is determined that switching is necessary, noise may occur in data transmitted between the indoor unit 10 and the outdoor unit 20 due to an increase in the size of the communication voltage. In order to minimize noise, the outdoor unit 20 may transmit a switching request signal at the lowest communication speed supported by the communication line 630.

When the switching request signal is received, the indoor unit 10 may connect one end of the external power supply 400 connected to the first power line 610 to the second power line 620, and to the second power line 620. The other end of the connected external power supply 400 may be connected to the first power line 610.

More specifically, the indoor unit 10 includes a changeover switch unit 190a selectively connecting both ends of the external power supply 400 to the first power line 610 and the second power line 620, and a change request signal Accordingly, the first power line 610 and the second power line 620 may be switched by controlling the switching switch unit 190a.

4 and 5, the indoor unit 10 may include a changeover switch unit 190a provided between both ends of the external power source 400 and the first and second power lines 610 and 620. When a switching request signal is received from the outdoor unit 20, the indoor unit 10 controls the switching switch unit 190a to connect both ends of the external power supply 400 to the first and second power lines 610 and 620 in order. Alternatively, both ends of the external power supply 400 may be cross-connected to the first and second power lines 610 and 620.

As shown in FIG. 5, the switching switch unit 190a is provided at one end of the first power line 610 to selectively connect the first power line 610 to one end or the other end of the external power supply 400. 1 switch 191 and a second switch 192 provided at one end of the second power line 620 to selectively connect the second power line 620 to one end or the other end of the external power supply 400. I can.

The first and second switches 191 and 192 may be configured as arbitrary elements that open and close a circuit. For example, the first and second switches 191 and 192 may be relays.

The indoor unit communication unit 120a may receive a switching request signal from the outdoor unit 20 and provide it to the indoor unit control unit 170a. The indoor unit controller 170a may generate control signals corresponding to the switching request signal for the first and second switches 191 and 192, respectively, and provide them to each switch. Each switch may switch between the first and second power circuits by operating according to the control signal.

For example, if the user connects the power plug extending from the indoor unit 10 to the external power supply 400 in reverse, the neutral wire of the external power supply 400 may be connected to the first power line 610 and the second power line A live wire of the external power source 400 may be connected to 620.

The outdoor unit 20 has a size of the second power voltage applied to the second power line 620 through the voltage measuring unit 210 described above is greater than the level of the first power voltage applied to the first power line 610. It can be identified, and accordingly, a switching request signal can be transmitted to the indoor unit 10.

The indoor unit 10 may provide a control signal to the switching switch unit 190a according to the switching request signal received from the outdoor unit 20. As the first switch 191 is switched according to the control signal, the first power line 610 can be connected to the live wire of the external power supply 400, and the second switch 192 is switched according to the control signal, thereby The line 620 may be connected to the neutral line of the external power supply 400.

Thereafter, the outdoor unit 20 may generate a communication voltage having a voltage of the second power line 620 and a reference potential difference. In other words, the outdoor unit 20 may generate a communication voltage by using a voltage of a neutral line to which a relatively low voltage is applied among live wires and neutral wires of the external power supply 400. Accordingly, the communication voltage may be kept very low compared to the insulation voltage of the communication line 630, and noise generated in data communication between the indoor unit 10 and the outdoor unit 20 may be significantly reduced.

Next, a process of switching the power line by the outdoor unit 20 based on the communication rate for the communication line 630 will be described.

The outdoor unit 20 may determine a communication rate based on a ratio of the number of times of receiving the response signal to the number of transmission of the request signal, and determine whether to switch the first and second power lines 610 and 620 according to the determined communication rate. .

More specifically, when the communication rate for the communication line 630 is greater than or equal to the reference communication rate, the outdoor unit 20 adjusts the difference between the second power voltage and the reference potential without switching the first and second power lines 610 and 620. It can generate a communication voltage with. On the other hand, when the communication rate is less than the reference communication rate, the outdoor unit 20 may switch the first and second power lines 610 and 620 and generate a communication voltage having a difference between the second power voltage and the reference potential. Here, the reference communication rate is a criterion for determining whether the communication state is normal or bad, and may be set to an arbitrary value by the user, for example, 90%.

The outdoor unit 20 may transmit a request signal to the indoor unit 10 through a communication line in order to check a communication state with the indoor unit 10. When a request signal is received from the outdoor unit 20, the indoor unit 10 may transmit a response signal corresponding to the request signal to the outdoor unit 20 with reference to the first memory 140a.

Meanwhile, as described above, when the size of the communication voltage is close to the insulation voltage of the communication line 630, noise may occur in data transmitted and received through the communication line 630. In this case, the indoor unit communication unit 120a may not receive a complete request signal due to noise, and accordingly, the outdoor unit communication unit 120b may not receive the response signal itself. Also, even if the request signal is received by the indoor unit communication unit 120a, a complete response signal may not be received from the outdoor unit communication unit 120b due to noise.

The outdoor unit 20 may determine a ratio of the number of times of reception of the response signal to the number of transmission of the request signal as the communication rate. For example, when a response signal is received 232 times for a request signal transmitted 256 times, the outdoor unit 20 may determine the communication rate as 90.625%.

When the outdoor unit 20 generates a communication voltage having a voltage of the second power line 620 and a reference potential difference, the first power line 610 is connected to the live line of the external power supply 400 and the second power line 620 ) Is connected to the neutral line of the external power supply 400, since the size of the communication voltage is generated low, the communication rate may be determined to be high.

On the other hand, when the first power line 610 is connected to the neutral wire of the external power supply 400 and the second power line 620 is connected to the live wire of the external power supply 400, the communication voltage is high, so The rate can be determined low.

Accordingly, when the outdoor unit 20 generates a communication voltage having a reference potential difference from the voltage of any one of the first and second power lines 610 and 620, the communication rate determined by the above-described method is less than the reference communication rate. On the back, the outdoor unit 20 may transmit a switching request signal to the indoor unit 10.

In this case, the indoor unit 10 may switch between the first power line 610 and the second power line 620 according to the switching request signal. Details of the indoor unit 10 switching the power line have been described in detail with reference to FIG. 5, and thus detailed descriptions will be omitted herein.

As described above, according to the present invention, by comparing the voltage applied to each power line connected to both ends of the external power source and switching the power line or switching the power line connected to both ends of the external power source based on the communication rate, the indoor unit The communication voltage for data communication between outdoor units can be kept low, and thus noise of data communication can be reduced.

On the other hand, when the outdoor unit 20 generates a communication voltage having a reference potential difference from the voltage of the second power line 620, the voltage of the second power line 620 is higher than the voltage of the first power line 610 The generation signal can be output.

More specifically, the outdoor unit control unit 170b may visually output an abnormality occurrence signal indicating a erroneous connection of the external power supply 400 through the display unit 510 formed of an LED. In addition, the outdoor unit 20 may transmit an abnormality occurrence signal to the indoor unit 10, and the indoor unit 10 randomly displays an error signal indicating an incorrect wiring of the external power supply 400 in response to the received abnormality occurrence signal. It may be output visually through the display 180 configured as a means, or may be output aurally through an output unit 550 configured with a speaker or a buzzer.

Hereinafter, referring to FIG. 6, the outdoor unit 20 transmits a signal using a communication voltage having a lower voltage and a reference potential difference among the voltage of the first power line 610 and the voltage of the second power line 620. An example of the method will be described.

In FIG. 6, it is assumed that the outdoor unit 20 generates a communication voltage having a difference between a voltage applied to the second power line 620 and a reference potential.

Referring to FIG. 6, the outdoor unit 20 may identify first and second power voltages through a voltage detector (S11), and compare the magnitudes of the two identified voltages (S12).

As a result of the comparison, when the first power voltage is greater than or equal to the second power voltage, the outdoor unit 20 may continuously measure the first and second power voltages (S11). On the other hand, when the first power voltage is less than the second power voltage, the outdoor unit 20 may transmit a switching request signal to the indoor unit 10 (S13).

The indoor unit 10 can switch the first and second power lines 610 and 620 according to the switching request signal, and accordingly, a second power voltage is applied to the first power line 610 and the second power line ( A first power voltage may be applied to 620.

Next, the outdoor unit 20 generates a communication voltage having a reference potential difference from the first power voltage applied to the second power line 620 (S14), and performs data communication with the indoor unit 10 using the generated communication voltage. It can be performed (S15).

Hereinafter, an example of a method of determining whether or not to switch the power line based on the communication rate by the outdoor unit 20 will be described with reference to FIG. 7.

In FIG. 7, it is assumed that the outdoor unit 20 generates a communication voltage having a reference potential difference from a voltage applied to any one of the first power line 610 and the second power line 620.

Referring to FIG. 7, the outdoor unit 20 may transmit a request signal to the indoor unit 10 using a currently generated communication voltage (S21). The outdoor unit 20 may compare the number of transmissions of the request signal with the reference number (S22), and continuously transmit the request signal until the request signal becomes the same as the reference number.

Subsequently, the outdoor unit 20 may receive a response signal corresponding to the request signal from the indoor unit 10 (S23) and count the number of times the response signal is received (S24).

When the number of times of transmission of the request signal becomes the reference number, the outdoor unit 20 determines the communication rate based on the ratio of the number of receptions of the response signal to the number of transmissions of the request signal (S25), and compares the determined communication rate with the reference communication rate. I can (S26).

As a result of the comparison, if the communication rate is greater than or equal to the reference communication rate, the request signal transmission operation of step 21 is continuously performed, and when the communication rate is less than the reference communication rate, a switching request signal may be transmitted to the indoor unit 10 (S27).

The first and second power lines 610 and 620 may be switched according to the switching request signal, and the communication voltage may decrease accordingly. When the communication voltage is decreased, noise generated in data communication between the indoor unit 10 and the outdoor unit 20 may be reduced, and a communication rate may be increased.

The present invention described above prevents communication noise between the indoor unit and the outdoor unit caused by incorrect wiring between the external power supply and the power line, so that communication quality can be guaranteed even if a communication line having a low insulation voltage is installed between the indoor unit and the outdoor unit.

The above-described present invention is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those of ordinary skill in the technical field to which the present invention belongs. Is not limited by

Claims (8)

A first switch connected to an external power source and selectively connecting a first power line to one end or the other end of the external power source, and a second switch selectively connecting a second power line to one end or the other end of the external power source. Indoor unit; And
An outdoor unit that receives the external power through the first power line and the second power line and performs data communication with the indoor unit through a communication line connected to the indoor unit,
Before switching of the first and second power lines through the first and second switches, the outdoor unit generates a first communication voltage having a reference potential difference from the voltage of any one of the first and second power lines And, if the communication rate based on the first communication voltage is less than the reference communication rate, transmits a switching request signal to the indoor unit,
The indoor unit switches the first power line and the second power line by controlling the first and second switches according to the switching request signal,
The outdoor unit performs data communication with the indoor unit using a second communication voltage having a lower voltage and a reference potential difference among the switched voltage of the first power line and the voltage of the second power line.
Air conditioning system.
delete delete delete delete The method of claim 1,
The communication rate is determined based on a ratio of a number of times of receiving a response signal to a number of times of transmitting a request signal.
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