Air conditioning device and method

Abstract

[Problem] To provide an air conditioning device and a method capable of easily identifying a failed section. [Solution] An air conditioner 10 structured by including a semiconductor element 221 for controlling a current flow from a power source, and a plurality of devices 240 to which power is supplied via the semiconductor element 221. The air conditioner 10 includes a voltage measurement unit 320 for measuring a voltage that is output from the semiconductor element 221 while one of the plurality of devices is in operation, and a failure detection unit 330 for detecting a failed device among the plurality of devices 240 on the basis of a result of the measuring by the voltage measurement unit 320. The semiconductor element 221 cuts off the current flow to the device 240 when the voltage measurement unit 320 detects a voltage drop.

Description

Air conditioner and method

[0001] The present invention relates to an air conditioner and a method for identifying a failure location.

[0002] In air conditioners, techniques for determining failures of various components are known.

[0003] For example, Japanese Patent Application Laid-Open No. 2006-023051 (Patent Document 1) discloses a technique for performing a failure determination by comparing a regression prediction value obtained using a part of the measured value data of operation data with a predetermined measured value data of the operation data. According to Patent Document 1, a highly accurate failure determination can be performed.

[0004] However, since Patent Document 1 requires regression prediction and measured data, it is effective for failure determination of devices with closed-loop control (for example, a compressor or a fan motor that constitutes an air conditioner), but it is not effective for failure determination of devices with open-loop control, such as a stepping motor that controls the operation of a louver of an air conditioner.

[0005] Further, failures of electronic components of an air conditioner can be roughly classified into an open-mode failure and a short-mode failure. In the case of an open-mode failure, since the operation of the failed device stops, the failure can be confirmed even by visual inspection. However, in the case of a short-mode failure, due to a fail-safe function such as fuse blowing or an overcurrent prevention function, the operation of other devices using the same power supply system as the failed device also stops, making it difficult to identify the failure location.

[0006] Therefore, in an air conditioner, a further technique for identifying a failed component has been demanded.

[0007] Japanese Patent Application Laid-Open No. 2006-023051

[0008] The present invention has been made in view of the problems in the above prior art, and an object thereof is to provide an air conditioner and a method capable of easily identifying a failure location.

[0009] In other words, the present invention provides an air conditioning system comprising a semiconductor element that controls the supply of power from a power source and a plurality of devices to which power is supplied via the semiconductor element, wherein the air conditioning system comprises a measuring means for measuring the voltage output from the semiconductor element while one of the plurality of devices is operating, and a detection means for detecting a faulty device among the plurality of devices based on the measurement result of the measuring means, and the semiconductor element cuts off the power supply to the device when the measuring means detects a drop in voltage.

[0010] According to the present invention, an air conditioning system and method can be provided that allows for easy identification of the faulty part.

[0011] A diagram illustrating the refrigeration cycle in the air conditioning system of this embodiment. A diagram showing the circuit configuration in the first example of the air conditioning system of this embodiment. A software block diagram included in the air conditioning system of this embodiment. A flowchart of the device diagnostic process performed by the air conditioning system of this embodiment. A timing chart of the fault detection process in the first example of the air conditioning system of this embodiment. A timing chart of the fault detection process in the first example of the air conditioning system of this embodiment. A diagram showing the circuit configuration in the second example of the air conditioning system of this embodiment. A timing chart of the fault detection process in the second example of the air conditioning system of this embodiment. A timing chart of the fault detection process in the second example of the air conditioning system of this embodiment.

[0012] The present invention will be described below with reference to embodiments, but the present invention is not limited to the embodiments described later. In the figures referenced below, the same reference numerals will be used for common elements, and their descriptions will be omitted as appropriate.

[0013] Figure 1 is a diagram illustrating the refrigeration cycle in the air conditioning system 10 of this embodiment. As shown in Figure 1, the refrigeration cycle in the air conditioning system 10 consists of an indoor unit 20 and an outdoor unit 30, which are connected via refrigerant piping 40. The indoor unit 20 is installed in the indoor space where air conditioning is performed, and the outdoor unit 30 is installed outside the said indoor space.

[0014] The indoor unit 20 comprises an indoor heat exchanger 21, an indoor fan 22, a wind direction control plate 23, and a control device 24. The outdoor unit 30 comprises a compressor 31, a four-way valve 32, an outdoor heat exchanger 33, an expansion valve 34, and an outdoor fan 35. Here, the arrows in Figure 1 indicate the direction of refrigerant flow during cooling operation, and in the following explanation of the refrigeration cycle, unless otherwise specified, the operation during cooling operation will be used as an example for convenience. Note that during heating operation, the direction of refrigerant flow is reversed from the direction of the arrows in Figure 1.

[0015] The indoor unit 20 uses an indoor fan 22 to exchange heat between the air in the indoor space and the refrigerant flowing through the indoor heat exchanger 21, and then discharges the air back into the room to conditioned the indoor space. During cooling operation, the indoor heat exchanger 21 operates as an evaporator, exchanging heat between the low-temperature, low-pressure liquid refrigerant and the air blown in by the indoor fan 22. The indoor unit 20 can lower the temperature of the indoor space by discharging the heat-exchanged air. The refrigerant that flows out of the indoor heat exchanger 21 is a low-temperature, low-pressure gaseous refrigerant and flows to the outdoor unit 30 via the refrigerant piping 40.

[0016] The airflow control plate 23 is a plate that controls the direction in which the air that has undergone heat exchange by the indoor heat exchanger 21 flows, and is also called a louver. The indoor unit 20 may be equipped with multiple airflow control plates 23, for example, one or more vertical airflow plates and one or more horizontal airflow plates. The operation of the airflow control plate 23 is controlled by, for example, a stepping motor, thereby allowing the airflow direction to be controlled to a desired direction.

[0017] The control device 24 controls the operation of the indoor unit 20 and the outdoor unit 30 of the air conditioning system 10 based on signals received from, for example, a remote control. In this embodiment, the control device 24 can be configured in the form of, for example, a CPU or a microcomputer. By the control device 24 controlling the operation of various devices, the air conditioning system 10 can perform predetermined operations such as cooling, dehumidifying, heating, cleaning, and fault diagnosis.

[0018] Next, the outdoor unit 30 will be described. The compressor 31, driven by a motor, compresses the low-temperature, low-pressure gaseous refrigerant flowing in from the outdoor unit and discharges it as a high-temperature, high-pressure gaseous refrigerant. The gaseous refrigerant discharged from the compressor 31 passes through the four-way valve 32 and flows into the outdoor heat exchanger 33. The outdoor heat exchanger 33 performs heat exchange between the refrigerant flowing through its interior and the outside air supplied by the outdoor fan 35. During cooling operation, the outdoor heat exchanger 33 operates as a condenser and discharges the refrigerant as a high-temperature liquid through heat exchange. The outdoor heat exchanger 33 operates as an evaporator during heating operation.

[0019] The refrigerant discharged from the outdoor heat exchanger 33 is expanded in volume by the expansion valve 34, and its temperature decreases as the pressure is reduced. The refrigerant then flows to the indoor unit 20, and the cooling operation is performed to lower the temperature of the indoor space as described above.

[0020] The four-way valve 32 is a valve that switches the flow path of the refrigerant according to the operating mode of the air conditioning system 10. That is, during cooling operation, the connection is as shown by the solid line in Figure 1, and during heating operation, the connection is as shown by the dashed line. This allows either the indoor heat exchanger 21 or the outdoor heat exchanger 33 to operate as a condenser and the other as an evaporator, enabling proper air conditioning operation.

[0021] The air conditioning system 10 shown in Figure 1 is a configuration that includes one outdoor unit 30 for each indoor unit 20, similar to a so-called household air conditioner (also referred to as a room air conditioner), but the embodiment is not particularly limited. Therefore, the air conditioning system 10 can be configured, for example, with one or more outdoor units 30 for each of several indoor units 20, similar to a so-called commercial air conditioner (also referred to as a multi-split air conditioner for buildings, VRF (Variable Refrigerant Flow), etc.).

[0022] In the following description, this embodiment will be explained with reference to the first and second examples. In the following description, matters common to the first and second examples will be omitted as appropriate.

[0023] First, a first example of this embodiment will be described. Figure 2 is a diagram showing the circuit configuration in the first example of the air conditioning system 10 of this embodiment. In Figure 2, solid lines indicate power connections, and dashed lines indicate control signal connections.

[0024] As shown in Figure 2, the air conditioning system 10 of this embodiment is connected to a commercial power supply 210 and power is supplied to it. The power supplied from the commercial power supply 210 is converted to DC by the AC / DC converter 221 on the power supply board 220 and supplied to various devices 240 included in the air conditioning system 10 via the semiconductor element 222. The semiconductor element 222 in this embodiment is, for example, an element that can control the passage / interruption of current for overcurrent protection, and can be, for example, a semiconductor switch such as a MOSFET, a latch-off type or auto-reset type electronic fuse or load switch. The operation of the semiconductor element 222 can be controlled by the CPU 231. The current output from the AC / DC converter 221 can also be supplied to the control board 230. Note that the power supply board 220 and the control board 230 do not necessarily have to be configured as separate boards, and may be configured as a single board that has the functions of both the power supply board 220 and the control board 230 as shown in Figure 2.

[0025] The control board 230 includes a CPU 231 that constitutes the control device 24, and can perform various types of control. For example, the CPU 231 can control the operation of semiconductor elements 222 and devices 240. Note that the CPU 231 is just one example of the control device 24 and does not limit the embodiment; for example, it may be a device such as a microcomputer.

[0026] Device 240 is a variety of devices for driving the air conditioning system 10. In the embodiment described, device 240 can be, for example, a device for performing open-loop control, and in particular can be a stepping motor for controlling the movement of louvers. The air conditioning system 10 may include a plurality of devices 240, each of which can operate by receiving control signals from the CPU 231.

[0027] Incidentally, in conventional air conditioning systems 10, if a device 240 fails in short-circuit mode, it is difficult to identify which of the multiple devices 240 has failed. In particular, conventional air conditioning systems 10 protect the circuit in the event of a short-circuit failure by using a fuse instead of a semiconductor element 222 as in this embodiment. Therefore, when the fuse blows, it is difficult to identify the failed device 240. Also, in the case of conventional air conditioning systems 10 that do not use a fuse, even if a device 240 fails in short-circuit mode, the AC / DC converter stops due to the overcurrent protection function of the AC / DC converter, and the entire system stops, making it difficult to identify the failed device 240. Therefore, in this embodiment, the air conditioning system 10 is configured to include a functional means as shown in Figure 3, making it easier to identify the failed device 240.

[0028] Figure 3 is a software block diagram included in the air conditioning system 10 of this embodiment. As shown in Figure 3, the air conditioning system 10 of this embodiment is composed of various functional means, including an operation control unit 310, a voltage measurement unit 320, a fault detection unit 330, a notification unit 340, and an operation unit 350. The details of each functional means will be described below.

[0029] The operation control unit 310 is a means for controlling the operation of various devices 240 and semiconductor elements 222. The operation control unit 310 constitutes the control means in this embodiment. The operation control unit 310 in this embodiment can control the operation of each of the multiple devices 240, for example, it can control the power supply to the devices 240 and the amount of operation. The operation control unit 310 can also control the operation of the semiconductor elements 222, for example, if the semiconductor element 222 is a semiconductor switch, it can control the on / off switching operation of the switch. Furthermore, if the semiconductor element 222 is a latch-off type electronic fuse or load switch, for example, the operation control unit 310 can release the latch-off by outputting an enable signal.

[0030] The voltage measurement unit 320 is a means for measuring the voltage output by the power supply board 220. The voltage measurement unit 320 constitutes the measurement means in this embodiment. For example, if device 240 fails in short-circuit mode, a voltage drop occurs. Therefore, the failure of device 240 can be detected by measuring the output voltage of the voltage measurement unit 320.

[0031] The fault detection unit 330 is a means for detecting faults in various components included in the air conditioning system 10. The fault detection unit 330 constitutes the detection means in this embodiment. The fault detection unit 330 in this embodiment can detect a fault in the device 240 based on the voltage measured by the voltage measurement unit 320. The detection result from the fault detection unit 330 can be output to, for example, the operation control unit 310, which in turn can control the operation control unit 310 to stop the power supply to the device 240 in which a fault has been detected.

[0032] The notification unit 340 is a means for notifying the user of various states of the air conditioning system 10. The notification unit 340 constitutes the notification means in this embodiment. The notification unit 340 in this embodiment can, for example, notify the user of which device 240 is malfunctioning. The form of notification by the notification unit 340 is not particularly limited and can be, for example, sound or LED lamp display.

[0033] The control unit 350 is a means for operating the air conditioning system 10 of this embodiment. The control unit 350 constitutes the operating means in this embodiment. The control unit 350 of this embodiment can take the form of, for example, a remote control or a button provided on the air conditioning system 10, but is not particularly limited to any specific embodiment. By operating via the control unit 350, the air conditioning system 10 can perform operations such as cooling, dehumidifying, heating, cleaning, and fault diagnosis. In particular, the fault diagnosis operation may be performed not by the user of the air conditioning system 10, but by a service engineer performing repairs, and may be executed by inputting a specific operation via the control unit 350.

[0034] The software blocks described above correspond to functional means realized by the CPU 231 executing the program of this embodiment, thereby enabling each piece of hardware to function. Furthermore, the functional means shown in each embodiment may be entirely implemented in software, or some or all of them may be implemented as hardware that provides equivalent functionality.

[0035] Up to this point, the functional means included in the air conditioning system 10 of this embodiment have been described. Next, the processes performed by the air conditioning system 10 of this embodiment using the various functional means described above will be explained with reference to Figure 4. Figure 4 is a flowchart of the device diagnostic process performed by the air conditioning system 10 of this embodiment.

[0036] The air conditioning system 10 starts the device diagnostic process from step S1000. In step S1001, N=1 is defined to select the first device for diagnosis. Then, in step S1002, the operation control unit 310 operates the Nth device.

[0037] Next, in step S1003, the process branches depending on whether the voltage measurement unit 320 has detected a voltage drop. If a voltage drop is detected (YES), the process proceeds to step S1004. Since the detection of a voltage drop in step S1003 is highly likely to be due to the device being diagnosed failing in short mode, the operation control unit 310 stops the operation of the device in step S1004. Stopping the operation of the device in step S1004 can be done, for example, by controlling the semiconductor switch, which is a semiconductor element 222, to the OFF position. Note that if an electronic fuse or load switch is used as the semiconductor element 222, the device will be automatically disconnected by overcurrent when the device fails in short mode, so the operation of the device can be stopped without going through the operation control unit 310.

[0038] Subsequently, in step S1005, the notification unit 340 notifies that the device being diagnosed is malfunctioning. Then, in step S1008, the air conditioning system 10 terminates the fault diagnosis process.

[0039] On the other hand, if no voltage drop is detected in step S1003 (NO), the device being diagnosed is considered not faulty, and the process proceeds to step S1006. At this time, the operation control unit 310 stops the operation of the device being diagnosed. In step S1006, the process branches depending on whether all devices have been diagnosed or not. If all devices have been diagnosed (YES), the process proceeds to step S1008 and the fault diagnosis process ends. If not all devices have been diagnosed (NO), the process proceeds to step S1007.

[0040] In step S1007, N is incremented by 1 to select the next device for diagnosis. Then, the process returns to step S1002 and each of the above-described processes is performed for all devices.

[0041] As shown in Figure 4, the air conditioning system 10 of this embodiment can easily identify a device that has failed in short-circuit mode. In particular, in the process shown in Figure 4, the operation of the device is stopped immediately when a voltage drop is detected, so an overcurrent is not allowed to continue flowing, and a safe diagnostic process can be performed.

[0042] In the process shown in Figure 4, the process terminates once the faulty device is identified and notified. However, for example, the process may be continued without terminating, with the next device being selected for diagnosis.

[0043] Here, the detection of a faulty device, as described in Figure 4, will be explained with reference to Figures 5 and 6. Figures 5 and 6 are timing charts of the fault detection process in the first example of the air conditioning system 10 of this embodiment. Figure 5 shows an example in which a semiconductor switch that can be switched on / off by the operation control unit 310 is used as the semiconductor element 222, and Figure 6 shows an example in which a latch-off type electronic fuse or load switch is used as the semiconductor element 222.

[0044] First, FIG. 5 will be described. In FIG. 5, in order from the top, the voltage output from the power supply board 220 (power supply board voltage), the energization control to the device side, the load side power supply voltage, and the operation control state of each device are shown respectively. The power supply board voltage can be monitored by the voltage measurement unit 320.

[0045] Here, consider the case where device 1 among the N devices fails in the short mode. First, as shown in FIG. 5, when the energization control to the device side is turned on in a state where a voltage is output from the power supply board 220, the load side power supply voltage rises and reaches a predetermined value. At this time, when the operation control unit 310 activates the operation state of device 1 and device 1 operates, since device 1 fails in the short mode, the value of the power supply board voltage decreases. When the voltage measurement unit 320 detects the voltage drop, the operation control unit 310 turns off the energization to the device side, that is, switches the semiconductor switch to off (step S1004 in FIG. 4). Thereby, the load side power supply voltage becomes zero, and it is possible to prevent an overcurrent from flowing.

[0046] Further, since a voltage drop has occurred due to operating device 1, the failure detection unit 330 can detect that device 1 has failed in the short mode. On the other hand, for other devices that are not faulty, for example, device 2 and device N, as shown in FIG. 5, even if the operation state is activated, no voltage drop occurs and they operate normally.

[0047] As shown in FIG. 5, by turning off the energization control upon detecting the voltage drop, it is possible to identify the faulty device while protecting the circuit and the device.

[0048] Next, FIG. 6 will be described. Similar to FIG. 5, in FIG. 6, in order from the top, the voltage output from the power supply board 220, the load side power supply voltage, the energization control to the device, and the operation state of each device are shown respectively.

[0049] Now, similar to the case in Figure 5, let's consider the case where device 1 among the N devices has failed in short-circuit mode. First, as shown in Figure 6, when the power supply control to the device side is turned on while voltage is being output from the power supply board 220, the load-side power supply voltage rises to a predetermined value. At this time, the operation control unit 310 activates the operating state of device 1, and when device 1 operates, the power supply board voltage value drops because device 1 has failed in short-circuit mode.

[0050] When an overcurrent occurs due to a voltage drop, the electronic fuse, which is a semiconductor element 222, automatically cuts off the power supply to the device. Therefore, the load-side power supply voltage becomes zero, preventing the flow of overcurrent. As shown in Figure 6, the latch-off of the electronic fuse is released by applying an enable signal via the operation control unit 310, allowing power to be supplied to the device again.

[0051] Furthermore, since a voltage drop occurred when device 1 was operated, the fault detection unit 330 can detect that device 1 has failed in short-circuit mode. On the other hand, other devices that are not faulty, such as device 2 and device N, operate normally without a voltage drop even when their operating state is activated after the latch-off is released, as shown in Figure 6.

[0052] As shown in Figure 6, the overcurrent caused by the voltage drop triggers the electronic fuse to cut off the power, protecting the circuit and devices while allowing the faulty device to be identified.

[0053] Up to this point, we have described a first example of an embodiment for identifying a faulty device. Next, we will describe a second example of this embodiment. In the second example of the embodiment described, a fault in the electronic fuse of the power supply board 220 can also be detected.

[0054] Figure 7 shows the circuit configuration in a second example of the air conditioning system 10 of this embodiment. In Figure 7, solid lines indicate power connections, and dashed lines indicate control signal connections.

[0055] As shown in Figure 7, the air conditioning system 10 of this embodiment is connected to a commercial power supply 210 and power is supplied to it. The power supplied from the commercial power supply 210 is converted to DC by the AC / DC converter 221 of the power supply board 220 and output via the electronic fuse 223. The voltage (intermediate potential) output from the power supply board 220 can be measured by the voltage measurement unit 320. In the circuit of this embodiment, two resistors R are provided and a pull-down process is performed to measure the intermediate potential, as shown in Figure 7. By performing the pull-down process, it is possible to prevent the input to the voltage measurement unit 320 from becoming undefined.

[0056] The power output from the power supply board 220 is supplied to the control board 230, and after passing through the semiconductor switch 232, is supplied to the various devices 240 included in the air conditioning system 10. The control board 230 also includes a CPU 231 which constitutes the control device 24, and can perform various controls. The CPU 231 can, for example, control the operation of the electronic fuse 223, the semiconductor switch 232, and each device 240. Note that the CPU 231 is just one example of the control device 24 and does not limit the embodiment; for example, it may be a device such as a microcomputer. The semiconductor switch 232 is for preventing power from being supplied to the device 240 when the electronic fuse 223 fails in short-circuit mode (it is for protecting the device 240), and the air conditioning system 10 in this embodiment does not necessarily have to be equipped with a semiconductor switch 232.

[0057] Device 240 is a variety of devices for driving the air conditioning system 10, and can be, for example, a stepping motor for controlling the movement of the louvers. The air conditioning system 10 may include multiple devices 240, each of which can operate by receiving control signals from the CPU 231.

[0058] In the second example of the air conditioning system 10, which has the circuit configuration shown in Figure 7, a malfunction of the electronic fuse 223 itself can be detected by measuring the intermediate potential between the electronic fuse 223 and the semiconductor switch 232.

[0059] Furthermore, the air conditioning system 10 in the second example can be configured to have the same functional means as the software block shown in Figure 3 in the first example.

[0060] Figures 8 and 9 are timing charts for fault detection processing in a second example of the air conditioning system 10 of this embodiment. Figure 8 shows the timing chart for the process of detecting that the electronic fuse 223 has failed in short mode, and Figure 9 shows the timing chart for the process of detecting that the electronic fuse 223 has failed in open mode.

[0061] First, let's explain Figure 8. Figure 8(a) is the timing chart when the electronic fuse 223 is functioning normally, and Figure 8(b) is the timing chart when the electronic fuse 223 is in short-circuit mode.

[0062] When the electronic fuse 223 is functioning normally, if a predetermined voltage is output from the power supply board 220, the operation control unit 310 controls the electronic fuse 223 to the OFF state and controls the semiconductor switch 232 to the OFF state, and the voltage value measured by the voltage measurement unit 320 becomes 0V. That is, because the electronic fuse 223 is in the OFF state, the intermediate potential becomes 0V due to the pull-down resistor, as shown in Figure 8(a). Note that when performing the fault detection process, the semiconductor switch 232 is set to the OFF state in order to not supply power to the device 240, but it does not necessarily have to be in the OFF state; it may also be in the ON state.

[0063] On the other hand, if the electronic fuse 223 is short-circuited, a predetermined voltage value is measured. That is, because the electronic fuse 223 is short-circuited, even if the electronic fuse 223 is controlled to be in the off state, the voltage measurement unit 320 will measure an intermediate potential of a predetermined value, as shown in Figure 8(b).

[0064] Next, Figure 9 will be explained. Figure 9(a) is the timing chart when the electronic fuse 223 is functioning normally, and Figure 9(b) is the timing chart when the electronic fuse 223 is in open mode.

[0065] When the electronic fuse 223 is functioning normally, if a predetermined voltage is output from the power supply board 220, the operation control unit 310 controls the electronic fuse 223 to the ON state and the semiconductor switch 232 to the OFF state, so that the voltage measured by the voltage measurement unit 320 is a predetermined value. That is, because the electronic fuse 223 is in the ON state, as shown in Figure 9(a), the value measured is the voltage obtained by dividing the voltage output by the power supply board 220 with a resistor. Note that when performing the fault detection process, the semiconductor switch 232 is set to the OFF state in order to not supply power to the device 240, but it does not necessarily have to be in the OFF state; it may also be in the ON state.

[0066] On the other hand, if the electronic fuse 223 is malfunctioning in open mode, 0V is measured. That is, because the electronic fuse 223 is in an open state, even if the electronic fuse 223 is controlled to be in the ON state, the voltage value measured by the voltage measurement unit 320 will be 0V, as shown in Figure 9(b).

[0067] As shown in Figures 8 and 9, according to the configuration of the second example of this embodiment, the fault detection unit 330 can detect whether the electronic fuse 223 of the power supply board 220 is normal, has a short-circuit fault, or has an open-circuit fault, based on the operating state of the electronic fuse 223 and the voltage value measured by the voltage measurement unit 320.

[0068] Furthermore, in the air conditioning system 10 of the second example configuration, the flowchart shown in Figure 4, as in the first example, can be performed, and the device 240 can be diagnosed.

[0069] According to the embodiments of the present invention described above, it is possible to provide an air conditioning system and method that can easily identify the location of a malfunction.

[0070] Each of the functions of the embodiments of the present invention described above can be realized by a device-executable program written in C, C++, C#, Java®, etc. The program of this embodiment can be stored and distributed on a device-readable recording medium such as a hard disk drive, CD-ROM, MO, DVD, flexible disk, EEPROM®, EPROM, etc., and can also be transmitted over a network in a format that can be used by other devices.

[0071] Although the present invention has been described above with reference to embodiments, the present invention is not limited to the embodiments described above. It is included within the scope of the present invention as long as it achieves the effects and benefits of the present invention within the range of embodiments that a person skilled in the art could conceive.

[0072] 10...Air conditioning unit, 20...Indoor unit, 21...Indoor heat exchanger, 22...Indoor fan, 23...Airflow control plate, 24...Control device, 30...Outdoor unit, 31...Compressor, 32...Four-way valve, 33...Outdoor heat exchanger, 34...Expansion valve, 35...Outdoor fan, 40...Refrigerant piping, 210...Commercial power supply, 220...Power supply board, 221...AC / DC converter, 222...Semiconductor element, 223...Electronic fuse, 230...Control board, 231...CPU, 232...Semiconductor switch, 240...Device, 310...Operation control unit, 320...Voltage measurement unit, 330...Fault detection unit, 340...Notification unit, 350...Operation unit

Claims

1. An air conditioning system comprising a semiconductor element that controls the supply of power from a power source, and a plurality of devices to which power is supplied via the semiconductor element, wherein the air conditioning system comprises a measuring means for measuring the voltage output from the semiconductor element while one of the plurality of devices is operating, and a detection means for detecting a faulty device among the plurality of devices based on the measurement result of the measuring means, wherein the semiconductor element cuts off power to the device when the measuring means detects a drop in voltage.

2. The air conditioning device according to claim 1, wherein the semiconductor element comprises a MOSFET, and further includes a control means that controls the semiconductor element to cut off power to the device when the measuring means detects a decrease in voltage.

3. The air conditioning device according to claim 1, wherein the semiconductor element is an element that cuts off the power supply when an overcurrent is detected.

4. The air conditioning device according to claim 3, further comprising a semiconductor switch disposed downstream of the semiconductor element, wherein the detection means detects a failure of the semiconductor element based on a value measured by the measuring means.

5. The air conditioning system according to claim 1, further comprising a notification means for notifying the malfunctioning device.

6. The air conditioning system according to claim 1, characterized in that it starts an operating mode for diagnosing a malfunction by a specific operation.

7. The air conditioning apparatus according to claim 1, wherein the plurality of devices are devices that perform open-loop control.

8. The air conditioning apparatus according to claim 7, wherein the plurality of devices are stepping motors.

9. A method performed by an air conditioning system comprising a semiconductor element that controls the supply of power from a power source and a plurality of devices to which power is supplied via the semiconductor element, the method comprising: measuring the voltage output from the semiconductor element while one of the plurality of devices is operating; detecting a faulty device among the plurality of devices based on the measurement result in the measuring step; and cutting off power to the device when a drop in voltage is detected in the measuring step.

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