JP2008280992A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of accurately detecting high temperatures by a thermistor temperature sensor for temperature protection and correctly determining a disconnection failure of the sensor from extremely low temperatures to high temperatures. <P>SOLUTION: This air conditioner calculates a required rotating speed of an electric compressor based on information from an air conditioning temperature sensor. When a command rotating speed is transmitted from a controller for transmitting the required rotating speed as a command rotating speed, an electric compressor driving device performs failure diagnosis of the thermistor temperature sensor for temperature protection. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to failure diagnosis of a temperature sensor that detects the temperature of an electric compressor or an electric compressor driving device.

  The air conditioner will be described using a vehicle air conditioner as an example. In FIG. 8, due to the action of the indoor blower fan 51, air is sucked from the air introduction port 52 of the blower duct 53, and the heat exchanged by the indoor heat exchanger 54 is blown out from the air blowing port 55 into the vehicle interior. The indoor heat exchanger 54 is operated by an electric compressor 60 using a motor as a drive source, a four-way switching valve 59 for switching between a refrigerant flow and selecting cooling or heating, an expansion device 56 and an outdoor fan 57. The refrigeration cycle is configured together with the outdoor heat exchanger 58 that exchanges heat with the outside.

  The operation of the inverter device 120 as the electric compressor driving device for driving the motor, the indoor fan 51, the four-way switching valve 59, and the outdoor fan 57 is controlled by an air conditioner controller 62. The air conditioner controller 62 includes an indoor air blowing fan switch 63 for setting automatic / strong / weak / off of indoor air blowing, an air conditioner switch 64 for selecting cooling / heating / operation OFF, a temperature control switch 65, and a vehicle interior that is a temperature sensor for air conditioning. It is connected to a communication device 66 for communicating with a temperature sensor 67, a vehicle exterior temperature sensor 68, and a vehicle controller (not shown). Further, the air conditioner controller 62 calculates the required rotational speed of the electric compressor 60 based on information from the switches, sensors, and the like, and transmits the calculated rotational speed to the inverter device 120 via the communication line 12 as the command rotational speed. Then, the inverter device 120 receives the command rotational speed and controls the electric compressor 60 to the command rotational speed.

  For example, when the indoor blower fan switch 63 is operated to automatically blow air and the air conditioner switch 64 instructs heating, the air conditioner controller 62 sets the four-way switching valve 59 to the broken line state of FIG. And the outdoor heat exchanger 58 as an evaporator, the outdoor fan 57 is turned on, and the indoor fan 51 is set automatically. Further, according to the temperature adjustment switch 65, the temperature of the indoor heat exchanger 54 is adjusted by varying the rotational speed of the electric compressor 60 using the inverter device 120. When the operation is turned off by the air conditioner switch 64, the electric compressor 60 and the outdoor blower fan 57 are turned off.

  On the other hand, when the indoor blower fan switch 63 is turned off, the indoor blower fan 51 is turned off, and the electric compressor 60 and the outdoor blower fan 57 are also turned off to protect the refrigeration cycle.

  FIG. 9 shows the inverter device 120 and its surrounding electric circuit. The control circuit 107 of the inverter device 120 controls the switching element 2 constituting the inverter circuit 10 on the basis of the command rotational speed from the communication line 12 and switches the DC voltage from the battery 1 by PWM modulation. Then, an alternating current is output to the stator winding 4 that is a component of the motor 11, and power is output from the rotor 5. The motor 11 is a drive source of the electric compressor 60 and is built in. The direct current value detected by the current sensor 6 is transmitted to the control circuit 107 and used for protection of the switching element 2 and calculation of power consumption. The diode 3 constituting the inverter circuit 10 serves as a return route for the current flowing through the stator winding 4.

A thermistor temperature sensor 8 and a thermistor temperature sensor 9 are provided for temperature protection. When these inverters 120 are energized, these temperature sensors are subjected to failure diagnosis such as disconnection or short circuit by the control circuit 107 (see, for example, Patent Document 1). If normal, the temperature of the electric compressor 60 (such as the motor winding 4 of the motor 11) from the thermistor temperature sensor 8 and the temperature of the inverter device 120 (such as the inverter circuit 10) from the thermistor temperature sensor 9 are the control circuit 107. Is transmitted to. When the temperature reaches a predetermined temperature (around 100 ° C.), the control circuit 107 adjusts or stops driving the switching element 2 to protect the electric compressor 60 and the inverter device 120 from overheating.
Japanese Patent Laid-Open No. 2001-132657 (page 9, FIG. 5)

  If the thermistor temperature sensor for temperature protection is connected to a fixed resistor so as to divide the reference DC voltage, and if the thermistor temperature sensor is on the ground side, if the disconnection failure occurs, the divided voltage becomes the reference DC voltage. Will be equal. On the other hand, when there is a short circuit failure, the divided voltage is equal to the ground voltage.

  The purpose of the temperature protection thermistor temperature sensor is to detect the winding temperature of the motor that is the drive source of the electric compressor, the temperature of the inverter circuit of the inverter device, and the like, and protect the portion from overheating. Therefore, it is necessary to accurately detect a high temperature around 100 ° C. That is, it is necessary to accurately detect the divided voltage between the resistance value of the thermistor temperature sensor that becomes smaller at a high temperature and the fixed resistance. For this purpose, the fixed resistance value must be reduced.

  On the other hand, when the fixed resistance value is reduced, the resistance value of the thermistor temperature sensor becomes extremely large at an extremely low temperature of around −20 ° C., so that the divided voltage becomes substantially equal to the reference DC voltage and cannot be distinguished from a disconnection failure. That is, at a very low temperature, there is a problem that even if it is normal, it is judged as a disconnection failure.

  The present invention solves such a conventional problem, and an object thereof is to provide an air conditioner that can accurately detect a high temperature and correctly determine a disconnection failure of the sensor by a temperature protection thermistor temperature sensor. .

  In order to solve the above-described problem, an air conditioner according to the present invention calculates an required rotational speed of an electric compressor based on at least information from an air conditioning temperature sensor and transmits it as a command rotational speed, and the command rotational speed. And a thermistor temperature sensor for temperature protection provided in the electric compressor or the electric compressor driving device, and the air conditioner controller has the command rotational speed or A failure diagnosis of the temperature protection thermistor temperature sensor is performed at the timing of transmitting the drive command.

  With the above configuration, the electric compressor driving device, the air conditioner controller, or the like performs failure diagnosis at the timing when the air conditioner controller transmits the command rotational speed or the drive command. The air conditioner controller transmits the command rotational speed or the drive command when driving the electric compressor, that is, when operating the heat pump. At extremely low temperatures, the heat pump does not function sufficiently, and the electric compressor is not driven from the viewpoint of refrigeration cycle protection. That is, at an extremely low temperature, the air conditioner controller does not transmit the command rotational speed or the drive command. Therefore, when the failure diagnosis is performed at the timing when the air conditioner controller transmits the command rotation speed or the drive command, the normal state is not determined as a disconnection failure.

  Therefore, the thermistor temperature sensor for temperature protection can accurately detect the high temperature and correctly determine the disconnection failure of the sensor.

  The air conditioner of the present invention can accurately detect a high temperature by a thermistor temperature sensor for temperature protection, and can correctly determine a disconnection failure of the sensor.

  The first invention calculates the required rotational speed of the electric compressor based on at least information from the temperature sensor for air conditioning, transmits the command rotational speed as a command rotational speed, receives the command rotational speed, and electrically operates the command rotational speed. An electric compressor driving device for controlling the compressor and a temperature protection thermistor temperature sensor provided in the electric compressor or the electric compressor driving device, and at a timing at which the air conditioner controller transmits a command rotational speed or a driving command, A failure diagnosis of the protective thermistor temperature sensor is performed.

  With the above configuration, the air conditioner controller does not transmit the command rotation speed or drive command at extremely low temperatures, so when performing failure diagnosis at the timing of transmitting the command rotation speed or drive command from the air conditioner controller, the normal state Is not considered a disconnection failure. Therefore, the thermistor temperature sensor for temperature protection can accurately detect the high temperature and correctly determine the disconnection failure of the sensor.

  According to a second aspect of the present invention, in the air conditioner of the first aspect, before the air conditioner controller transmits the command rotational speed or the drive command, a fault diagnosis of the temperature protection thermistor temperature sensor is performed, and as a result, the fault is diagnosed. Only when the air conditioner controller transmits the command rotation speed or the drive command, the failure diagnosis of the temperature protection thermistor temperature sensor is performed again.

  As a result, before the air conditioner controller transmits the command rotational speed or the drive command, a fault diagnosis of the temperature sensor for temperature protection is performed. The electric compressor can be started quickly without diagnosing a failure.

  According to a third invention, in the air conditioner of the first or second invention, the temperature protection thermistor temperature sensor is connected to the electric compressor driving device. The temperature protection thermistor temperature sensor may be connected to any of the electric compressor driving device, the air conditioner controller, and other devices. Then, failure diagnosis may be performed with the device. Further, only the data may be transmitted from the device to which the temperature protection thermistor temperature sensor is connected, and the failure diagnosis may be performed by the device that receives the data. On the other hand, the temperature protection thermistor temperature sensor is provided in the electric compressor or the electric compressor driving device. Therefore, the distance between the temperature protection thermistor temperature sensor and the electric compressor driving device is closer than the distance between the air conditioner controller and other devices. Therefore, the wiring can be shortened. Thereby, noise resistance is also increased.

  According to a fourth aspect of the present invention, in the air conditioner of the first to third aspects, the temperature sensor for air conditioning includes an outdoor temperature sensor for detecting an outdoor temperature. The outdoor temperature sensor detects an outdoor temperature that is usually lower than the room. Therefore, the conditions for operating the heat pump can be accurately determined. This ensures that the air conditioner controller does not transmit the command rotational speed or drive command at extremely low temperatures, and when performing failure diagnosis, the normal state is not determined as a disconnection failure.

  According to a fifth aspect of the present invention, in the air conditioners of the first to fourth aspects, the electric compressor is a high pressure type. In the high-pressure type electric compressor, the motor part has a high pressure and a high temperature. Therefore, the temperature difference from the cryogenic temperature is large, and the possibility of erroneous diagnosis of disconnection is increased, so that the effect of the present invention is great.

  According to a sixth aspect of the present invention, in the air conditioners of the first to fifth aspects, the electric compressor driving device is mounted on the electric compressor. In such an inverter device-integrated electric compressor, both the electric compressor and the inverter device are placed in the same place and in the same environment. Therefore, if both thermistor temperature sensors for temperature protection are diagnosed as disconnected at an extremely low temperature, it can be estimated that the diagnosis is erroneous. In addition, the accuracy of diagnosis can be improved while comparing both values.

  A seventh aspect of the present invention is the air conditioner of the first to sixth aspects, which is mounted on a vehicle. When parked outdoors, the vehicle may be placed in a cryogenic environment. Therefore, there is a high possibility of erroneous diagnosis of disconnection, and the effect of the present invention is great.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration diagram of an example of an air conditioner according to Embodiment 1 of the present invention. In this case, the vehicle air conditioner will be described. In the figure, due to the action of the indoor blower fan 51, air is sucked from the air introduction port 52 of the blower duct 53, and the heat exchanged by the indoor heat exchanger 54 is blown out from the air blowing port 55 into the vehicle interior. The indoor heat exchanger 54 is operated by an electric compressor 60 using a motor as a drive source, a four-way switching valve 59 for switching between a refrigerant flow and selecting cooling or heating, an expansion device 56 and an outdoor fan 57. The refrigeration cycle is configured together with the outdoor heat exchanger 58 that exchanges heat with the outside.

  The operation of the inverter device 20 as the electric compressor driving device that drives the motor, the indoor air blowing fan 51, the four-way switching valve 59, and the outdoor air blowing fan 57 is controlled by an air conditioner controller 62. The air conditioner controller 62 includes an indoor air blowing fan switch 63 for setting automatic / strong / weak / off of indoor air blowing, an air conditioner switch 64 for selecting cooling / heating / operation OFF, a temperature control switch 65, and a vehicle interior that is a temperature sensor for air conditioning. It is connected to a communication device 66 for communicating with a temperature sensor 67, a vehicle exterior temperature sensor 68, and a vehicle controller (not shown).

  The air conditioner controller 62 calculates a required rotation speed of the electric compressor 60 based on information from the switches, sensors, and the like, and transmits the calculated rotation speed to the inverter device 20 via the communication line 12 as a command rotation speed. The inverter device 20 performs failure diagnosis of the thermistor temperature sensor. If the diagnosis result is normal, the command rotational speed is received, and the electric compressor 60 is controlled to the command rotational speed.

  However, the air conditioner controller 62 transmits the command rotational speed when driving the electric compressor 60, that is, when operating the heat pump. At an extremely low temperature of around −20 ° C., the efficiency of the heat pump is low, and the electric compressor 60 is not driven from the viewpoint of refrigeration cycle protection. That is, at a very low temperature, the air conditioner controller 52 does not transmit the command rotational speed. In this case, instead of the electric compressor 60, an electric heater, a heat storage device, or the like is driven.

  As an example, when the air blower fan switch 63 is operated to automatically blow the air and the air conditioner switch 64 instructs heating, the air conditioner controller 62 confirms the temperature outside the vehicle interior with the outside temperature sensor 68. If it is 0 degreeC or more, it will be judged that heat pump heating is possible. Then, the four-way switching valve 59 is set to the broken line state of FIG. 1, the indoor heat exchanger 54 is operated as a condenser, and the outdoor heat exchanger 58 is operated as an evaporator, the outdoor air fan 57 is turned on, and the indoor air fan 51 Is set to automatic. Also, the command rotational speed is transmitted to the inverter device 20, and the temperature of the indoor heat exchanger 54 is adjusted by varying the rotational speed of the electric compressor 60 according to the temperature adjustment switch 65. If the outside temperature is 0 ° C. or less, the electric heater is operated.

  FIG. 2 shows the inverter device 20 and its surrounding electric circuit. The control circuit 7 of the inverter device 20 controls the switching element 2 constituting the inverter circuit 10 on the basis of the command rotational speed from the communication line 12 and switches the DC voltage from the battery 1 by PWM modulation. Then, an alternating current is output to the stator winding 4 that is a constituent element of the motor 11, and the power at the command rotational speed is output from the rotor 5. The motor 11 is a drive source of the electric compressor 60 and is built in.

  A thermistor temperature sensor 8 and a thermistor temperature sensor 9 are provided for temperature protection. The temperature of the electric compressor 60 (such as the motor winding 4 of the motor 11) from the thermistor temperature sensor 8 and the temperature of the inverter device 20 (such as the inverter circuit 10) from the thermistor temperature sensor 9 are transmitted to the control circuit 7. When the command rotational speed of these temperature sensors is transmitted from the air conditioner controller 62 to the inverter device 20 via the communication line 12, the control circuit 7 performs fault diagnosis such as disconnection or short circuit. If normal, the electric compressor 60 is driven. When the temperature reaches a predetermined temperature (around 100 ° C.), the control circuit 7 adjusts or stops driving the switching element 2 to protect the electric compressor 60 and the inverter device 20 from overheating.

  In the above example, the air conditioner controller 62 transmits the command rotational speed when the temperature outside the passenger compartment is 0 ° C. or higher. Therefore, a normal state is not determined as a disconnection failure. Therefore, the thermistor temperature sensor 8 and the thermistor temperature sensor 9 for temperature protection can accurately detect a high temperature and correctly determine a disconnection failure of the sensor.

  FIG. 3 is a flowchart showing the operation of the heating operation example. The right side is a flowchart of the air conditioner controller 62, and the left side is a flowchart of the inverter device 20. In step 10, the air conditioner controller 62 performs failure diagnosis of the interior temperature sensor 67 and the exterior temperature sensor 68. If the result is a failure (N), in step 15, a failure is output by display, voice, etc., and the process ends. If the result is normal (Y), the outside temperature of the passenger compartment is confirmed by the outside temperature sensor 68 in step 20. As a result, if the outside temperature of the passenger compartment is 0 ° C. or less (N), it is determined that heat pump heating is not possible, and in step 25, the electric heater is operated.

  If the vehicle exterior temperature is 0 ° C. or higher (Y), it is determined that heat pump heating is possible, and in step 30, the heat pump heating is activated. Specifically, as in the above example, the four-way switching valve 59 and the like are set. In step 40, the required rotational speed of the electric compressor 60 is calculated based on information from the vehicle interior temperature sensor 67, the vehicle exterior temperature sensor 68, various switches, and the like, and set as the command rotational speed. In step 50, the command rotational speed is transmitted to inverter device 20 via communication line 12.

  After step 25 and step 50, in step 60, it is confirmed by the air conditioner switch 64 whether the heating operation is stopped. If the heating operation is continued (N), the process returns to step 20. If the heating operation is stopped (Y), in step 65, a stop command is output, various outputs are stopped, and the process ends.

  In step 70, the inverter device 20 confirms whether or not the command rotational speed is output from the air conditioner controller 62 (step 50). If not (N), reconfirm. If there is an output (Y), a failure diagnosis of the thermistor temperature sensor 8 and the thermistor temperature sensor 9 is performed at step 80. Here, the air conditioner controller 62 transmits the command rotational speed when the temperature outside the passenger compartment is 0 ° C. or higher. Therefore, the thermistor temperature sensor 8 and the thermistor temperature sensor 9 are placed outside the passenger compartment at 0 ° C. or higher. Therefore, a normal state is not determined as a disconnection failure. If the result is a failure (N), in step 85, the failure is output by display, voice, etc., and the process ends.

  If the result is normal (Y), the command rotational speed is input at step 90 and the motor 11 is operated at step 100. In step 110, it is confirmed whether or not a stop command is output from the air conditioner controller 62 (step 65). If there is no stop command (N), the process returns to step 90. If there is a stop command (Y), the motor 11 is stopped in step 120 and the process is terminated.

  With the above configuration, since the air conditioner controller 62 does not transmit the command speed at an extremely low temperature, the inverter device 20 is connected to the thermistor temperature sensor 8 and the thermistor temperature sensor after the command speed is transmitted from the air conditioner controller 62. When the failure diagnosis of 9 is performed, the normal state is not judged as a disconnection failure. Accordingly, the thermistor temperature sensors for temperature protection (thermistor temperature sensor 8 and thermistor temperature sensor 9) can accurately detect the high temperature and correctly determine the disconnection failure of the sensor.

  In the above embodiment, the motor 11 is built in the electric compressor 60. However, the present invention can be applied to a case where the motor 11 is not built in. In step 20, it is determined that the heat pump heating is possible when the temperature outside the passenger compartment is 0 ° C. or higher, but it is necessary to set the temperature appropriately by each device. Further, in the failure diagnosis in step 80, the determination may be made in consideration of the relationship with the temperature at which the normal state is not determined as a disconnection failure. In step 70, it is confirmed whether or not the command rotational speed is output from the air conditioner controller 62. However, instead of the command rotational speed, a drive command for commanding motor drive may be used. For example, when the rotational speed is fixed at a constant value, only a drive command is required. Further, the drive command may be output before the command rotational speed. In step 15 and step 85, fault output is performed and the process ends. However, various processes other than the end of the process after the fault output can be considered. In step 20, the electric heater and the heat pump heating may be used separately, or both may be activated.

  The thermistor temperature sensors for temperature protection (thermistor temperature sensor 8 and thermistor temperature sensor 9) are shown as being connected to the electric compressor driving device (inverter device 20), but are connected to either the air conditioner controller 62 or other devices. May be. Then, failure diagnosis may be performed with the connected device. Further, only the data may be transmitted from the device to which the temperature protection thermistor temperature sensor is connected, and the failure diagnosis may be performed by the device that receives the data. For example, the thermistor temperature sensor 8 and the thermistor temperature sensor 9 may be connected to the inverter device 20, and the inverter device 20 may transmit only data such as resistance values and voltages to the air conditioner controller 62, and the air conditioner controller 62 may perform failure diagnosis. .

  In step 20, the vehicle exterior temperature sensor 68 is used to confirm the vehicle exterior temperature. However, if it is possible to determine whether heat pump heating is possible, the vehicle interior temperature sensor 67 is used instead of confirming the vehicle interior temperature. May be.

(Embodiment 2)
FIG. 4 is a flowchart showing an operation example of the inverter device according to the second embodiment. In step 200, the inverter device 20 performs failure diagnosis of the thermistor temperature sensor 8 and the thermistor temperature sensor 9. If the result is failure (N), in step 210, it is confirmed whether or not the command rotational speed is output from the air conditioner controller 62 (step 50). If not (N), reconfirm. If there is an output (Y), in step 220, failure diagnosis of the thermistor temperature sensor 8 and the thermistor temperature sensor 9 is performed again. If the result is failure (N), in step 230, the failure is output by display, voice, etc., and the process ends. If the result is normal (Y), the process proceeds to step 250 described later.

  If the result of the failure diagnosis in step 200 is normal (Y), it is confirmed in step 240 whether or not the command rotational speed is output from the air conditioner controller 62 (step 50). If not (N), reconfirm. If there is an output (Y), the command rotational speed is input at step 250, and the motor 11 is operated at step 260. In step 270, it is confirmed whether or not a stop command is output from the air conditioner controller 62 (step 65). If there is no stop command (N), the process returns to step 250. If there is a stop command (Y), in step 280, the motor 11 is stopped and the process ends.

  In the above, the inverter device 20 performs failure diagnosis of the thermistor temperature sensor 8 and the thermistor temperature sensor 9 before the command rotational speed is transmitted from the air conditioner controller 62. As a result, when a failure is diagnosed, the failure diagnosis of the thermistor temperature sensor 8 and the thermistor temperature sensor 9 is performed again when the command rotational speed is transmitted from the air conditioner controller 62.

  Thus, before the command rotation speed is transmitted from the air conditioner controller 62, failure diagnosis of the thermistor temperature sensor 8 and the thermistor temperature sensor 9 is performed. As a result, when the diagnosis is normal, the command rotation is performed by the air conditioner controller 62. At the same time as the number is transmitted, the motor 11 (electric compressor 60) can be activated quickly.

(Embodiment 3)
In the electric compressor 25 of FIG. 5, the compression mechanism 28, the motor 11, and the thermistor temperature sensor 8 are installed inside the metal housing 32. The refrigerant is sucked from the suction port 33 and is compressed by driving the compression mechanism 28 by the motor 11. The compressed refrigerant passes through the motor 11 inside the metal housing 32, cools the motor 11 at that time, and is discharged from the discharge port 34. The thermistor temperature sensor 8 is provided in the vicinity of the winding 4 of the motor 11 in order to be able to detect the accurate temperature of the winding 4.

  The winding 4 and the thermistor temperature sensor 8 of the motor 11 are connected to a terminal 39 inside the metal casing 32. Outside the metal housing 32, the terminal 39 is connected to the inverter device 20 of FIG.

  The electric compressor 25 is a high-pressure type in the high-temperature and high-pressure refrigerant in which the motor 11 is compressed. In order to protect the motor 11 from a high temperature around 100 ° C., the thermistor temperature sensor 8 needs to be able to detect accurately up to about 120 ° C. Therefore, the value of the fixed resistor for voltage division of the reference DC voltage must be made small so that the high temperature can be detected. Thereby, the possibility of misdiagnosis of disconnection at a very low temperature increases, and the effect of the present invention is great.

(Embodiment 4)
FIG. 6 shows a diagram in which the inverter device 20 is attached in close contact with the right side of the electric compressor 40. The compression mechanism 28, the motor 11, and the like are installed in the metal casing 32. The refrigerant is sucked from the suction port 33 and compressed by the compression mechanism 28 (scroll in this example) being driven by the motor 11. The compressed refrigerant cools the motor 11 when passing through the motor 11 and is discharged from the discharge port 34. A thermistor temperature sensor 8 for detecting the temperature of the winding 4 is provided in the vicinity of the winding 4 of the motor 11.

  A terminal 39 connected to the winding 4 of the motor 11 and the thermistor temperature sensor 8 inside the electric compressor 40 is connected to the inverter device 20. The inverter device 20 uses a case 30 so as to be attached to the electric compressor 40. The inverter circuit unit 10 serving as a heat source is cooled by the low-pressure refrigerant through the low-pressure pipe 38. In order to detect the temperature of the inverter circuit unit 10, a thermistor temperature sensor 9 is provided in the vicinity thereof. The connection line 36 fixed to the inverter device 20 by the holding unit 35 includes a power line to the battery 1 and a communication line 12 to the air conditioner controller 62.

  In such an inverter device-integrated electric compressor, both the electric compressor 40 (thermistor temperature sensor 8) and the inverter device 20 (thermistor temperature sensor 9) are placed in the same place and in the same environment. Therefore, when both are diagnosed as a disconnection at an extremely low temperature, it can be estimated as a misdiagnosis. In addition, the accuracy of diagnosis can be improved while comparing both values.

(Embodiment 5)
FIG. 7 shows an example in which the air conditioner of the present invention is mounted on a vehicle. The inverter device 20, the electric compressor 60, the outdoor heat exchanger 58, the outdoor fan 57, and the vehicle exterior temperature sensor 68 are mounted in an engine (motor) room outside the vehicle compartment in front of the vehicle 70. On the other hand, an indoor fan 51, an indoor heat exchanger 54, an air conditioner controller 62, and a vehicle interior temperature sensor 67 are disposed in the vehicle interior.

  In the case of outdoor parking, the vehicle may be placed in an extremely low temperature environment of about -20 ° C. Therefore, the thermistor temperature sensor 9 provided in the inverter device 20 outside the vehicle compartment and the thermistor temperature sensor 8 provided in the electric compressor 60 have a high possibility of erroneous diagnosis of disconnection, and the effect of the present invention is great.

  As described above, the air conditioner according to the present invention can accurately detect a high temperature by the temperature protection thermistor temperature sensor, and can correctly determine the disconnection failure of the sensor. Etc.

Configuration diagram of air-conditioning apparatus according to Embodiment 1 of the present invention Electric circuit diagram of the inverter device and its surroundings Flow chart showing a series of operations of the same fault diagnosis The flowchart which shows the operation | movement of a fault diagnosis series which concerns on Embodiment 2 of this invention. Sectional drawing of the high voltage | pressure type electric compressor which concerns on Embodiment 3 of this invention. Sectional drawing of the inverter apparatus integrated electric compressor which concerns on Embodiment 4 of this invention. Schematic diagram of a vehicle equipped with an inverter device according to Embodiment 5 of the present invention Configuration diagram of conventional air conditioner Electric circuit diagram of the inverter device and its surroundings

Explanation of symbols

7 Control circuit 8 Thermistor temperature sensor (for electric compressor temperature protection)
9 Thermistor temperature sensor (for inverter device temperature protection)
DESCRIPTION OF SYMBOLS 10 Inverter circuit 11 Motor 12 Communication line 20 Inverter apparatus 25 Electric compressor (high pressure type)
40 Electric compressor (for inverter unit)
60 Electric Compressor 62 Air Conditioner Controller 67 Car Interior Temperature Sensor 68 Car Outside Temperature Sensor 70 Vehicle

Claims (7)

Based on at least the information from the temperature sensor for air conditioning, the required rotation speed of the electric compressor is calculated and transmitted as the command rotation speed, and the command rotation speed is received and the electric compressor is controlled to the command rotation speed. In an air conditioner including an electric compressor driving device and a temperature protection thermistor temperature sensor provided in the electric compressor or the electric compressor driving device, the air conditioner controller transmits a command rotation speed or a driving command at a timing. An air conditioner that performs failure diagnosis of the temperature protection thermistor temperature sensor. Before the air conditioner controller transmits the command rotational speed or the drive command, the temperature protection thermistor temperature sensor is diagnosed for failure, and as a result, the air conditioner controller detects the command rotational speed or drive only when the failure is diagnosed. The air conditioner according to claim 1, wherein when the command is transmitted, a failure diagnosis of the temperature protection thermistor temperature sensor is performed again. The air conditioner according to claim 1 or 2, wherein the temperature protection thermistor temperature sensor is connected to the electric compressor driving device. The air conditioner according to any one of claims 1 to 3, wherein the air temperature sensor includes an outdoor temperature sensor that detects an outdoor temperature. The air conditioner according to any one of claims 1 to 4, wherein the electric compressor is a high-pressure type. The air conditioner according to any one of claims 1 to 5, wherein the electric compressor driving device is mounted on the electric compressor. It is mounted in a vehicle, The air conditioner as described in any one of Claims 1-6 characterized by the above-mentioned.