JP2008038912A - Compressor internal state estimating device and air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compressor internal state estimating device and an air conditioner capable of accurately estimating an internal state of a compressor, preventing breaking (failure) due to abnormal operation of the compressor, and capable of maintaining a highly efficient operating state by not carrying out excessive protection against the compressor or the like. <P>SOLUTION: A momentary current/momentary voltage applied to a motor three-phase coil 10 is detected to estimate the internal state of the compressor from the detected value. As an estimation object of the internal state of the compressor, there is motor driving torque for example, and insufficient lubrication, liquid compression, or the like is estimated from the motor driving torque. By this, prediction of failure, diagnosis, or the like of the compressor is carried out on a real time basis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a compressor internal state estimating device and an air conditioner.

  A refrigeration cycle (evaporative compression refrigeration cycle) of an air conditioner is generally configured by a refrigerant system in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are sequentially connected. The In such a refrigeration cycle, failure due to damage inside the compressor may occur due to sudden acceleration / deceleration of the compressor, sudden fluctuations in load, or operation under inappropriate conditions due to malfunction of other equipment other than the compressor. was there. Therefore, this type of conventional refrigeration cycle controls the degree of superheat of the refrigerant sucked in the compressor suction pipe to avoid liquid compression and dilution of the lubricating oil, and reduces the saturation temperature on the low pressure side and the temperature of the compressor discharge gas. The compressor discharge pipe temperature is controlled to a temperature determined by comparison to avoid deterioration of oil and magnets in the compressor (see, for example, Patent Document 1).

JP-A-8-28996

  However, conventionally, a phenomenon occurring inside the compressor is not directly detected, but includes a time delay, a detection error, and the like. For this reason, when designing an air conditioner, in consideration of safety, the compressor and the like are supposed to be excessively protected, so that the performance of the refrigeration cycle cannot be sufficiently exhibited.

The present invention has been made to solve the above-described conventional drawbacks, and its purpose is to estimate the internal state of the compressor with high accuracy and prevent accidents due to abnormal operation of the compressor. Another object is to provide a compressor internal state estimation device and an air conditioner that can suppress excessive protection of a compressor or the like and maintain a highly efficient operation state.

  Therefore, the compressor internal state estimating apparatus according to claim 1 detects the current and / or voltage applied to the motor coil 10 of the brushless DC motor in the compressor 1 used in the refrigeration apparatus, and the compressor 1 is detected from the detected value. A compressor internal state estimating device for estimating the internal state of the compressor, wherein the internal state is estimated by a motor driving torque.

  In the compressor internal state estimating device according to claim 1, the current and / or voltage applied to the motor coil 10 can be detected by a motor drive circuit (for example, an inverter circuit), and the compressor is based on this electrical information. 1 internal state is estimated. As a result, current and / or voltage is detected by real-time processing without time delay, and the internal state of the compressor 1 can be accurately estimated within a short time. In addition, the motor driving torque can be estimated, and the high and low pressures of the refrigeration cycle of the refrigerant system in which the compressor 1 is used can be estimated from the motor driving torque.

  The compressor internal state estimating device according to claim 2 is provided with a detector 16 for detecting a current applied to the motor coil 10.

  In the compressor internal state estimating device according to the second aspect, since the current is directly detected by the detector 16, the current can be stably detected with high accuracy.

  According to a third aspect of the present invention, there is provided a compressor internal state estimating device using an arithmetic expression comprising an inductance and a current value for estimating the motor driving torque.

  In the compressor internal state estimating device according to the third aspect, the motor driving torque can be calculated easily and accurately.

  According to a fourth aspect of the present invention, there is provided a compressor internal state estimating device that uses an arithmetic expression comprising a magnetic flux and a current value for estimating the motor driving torque.

  In the compressor internal state estimating device according to the fourth aspect, the motor driving torque can be calculated easily and accurately. For example, when using a device constant such as an inductance, an error will occur depending on the change. In this case, only the detected value is used in the arithmetic expression, so that the motor drive torque can be improved more accurately. Can be calculated.

  The compressor internal state estimating device according to claim 5 is characterized in that it is possible to estimate a high pressure or a low pressure of a refrigerant system in which the compressor 1 is used.

  In the compressor internal state estimating device according to claim 5, the high pressure or low pressure of the refrigerant system can be estimated, whereby the operating state of the refrigerant system is grasped from the high pressure or low pressure, and the high or low pressure abnormality is detected. Driving in the state can be avoided.

  According to a sixth aspect of the present invention, there is provided a compressor internal state estimating device that estimates a high pressure or a low pressure based on motor driving torque and temperature information of the refrigerant system.

  In the compressor internal state estimating device according to the sixth aspect, the high pressure or low pressure of the refrigerant system is estimated based on the motor driving torque and the temperature information of the refrigerant system. The operation in an abnormal state can be avoided reliably.

  The compressor internal state estimating device according to claim 7 grasps the relationship between the motor driving torque and the suction superheat degree for each predetermined temperature condition and / or pressure condition of the refrigerant system, and detects the detected motor driving torque and at that time. The intake superheat degree of the compressor 1 during operation is estimated based on the temperature information and / or pressure information.

  In the compressor internal state estimating device according to the seventh aspect, the suction superheat degree of the compressor 1 can be estimated. As a result, if the suction superheat degree is inappropriate, it is adjusted to an appropriate suction superheat degree and excessively adjusted. Overheating and damp operation can be avoided.

  A compressor driving apparatus according to an eighth aspect includes the compressor internal state estimating apparatus according to any one of the first to seventh aspects, and includes estimated motor driving torque, temperature, high pressure, low pressure, shaft lubrication, and the like. It is characterized by having the function to output the information.

  In the compressor driving device according to the eighth aspect, information such as the estimated motor driving torque, temperature, high pressure, low pressure, and shaft lubrication state can be output. It is possible to grasp with certainty.

  The compressor driving apparatus according to claim 9 is characterized in that information for improving accuracy and system optimum operation is calculated by further inputting information of the refrigerant system.

  In the compressor drive device according to the ninth aspect, information for improving accuracy and system optimum operation can be calculated, so that improvement in accuracy can be achieved and system optimum operation can be performed.

  An air conditioner according to a tenth aspect includes the compressor internal state estimating device according to any one of the first to seventh aspects, and an inverter control means for driving the compressor 1 based on the estimated internal state. It is characterized by carrying out a compressor protection operation in which 26 inverter signals are changed. Here, the compressor protection operation refers to an operation that does not result in an abnormal operation based on the estimated (detected) information.

  In the air conditioner according to the above-described aspect, the current and / or voltage applied to the motor coil 10 can be detected, and the internal state of the compressor 1 can be estimated from the detected value. Further, based on the internal state The compressor protection operation can be performed by changing the inverter signal of the inverter control means 26 for driving the compressor 1.

  The air conditioner according to claim 11 is characterized in that the inverter control means 26 performs the compressor protection operation in preference to the operation control command of the refrigerant system.

  In the air conditioner according to the eleventh aspect, the compressor protection operation is performed in preference to the refrigerant system operation control command, and the compressor 1 can be stably protected.

  The air conditioner according to a twelfth aspect of the present invention is characterized by comprising switching means for recovering from the compressor protection operation to the steady operation.

  In the air conditioner according to the twelfth aspect, since the switching means for recovering from the compressor protection operation to the steady operation is provided, the current and / or voltage applied to the motor coil 10 is detected, and the compressor 1 is detected from the detected value. If the internal state is estimated and abnormal operation does not occur even after returning to steady operation, it can be restored to steady operation.

  An air conditioner according to a thirteenth aspect includes the compressor internal state estimating device according to any one of the first to seventh aspects, and performs an apparatus failure diagnosis based on the estimated internal state. Here, the device failure diagnosis is a diagnosis of poor lubrication from the detected current disturbance, a diagnosis of liquid compression from the detected current change, and a high pressure and low pressure estimation. Diagnosing abnormalities and low-pressure abnormalities.

  In the air conditioning apparatus according to the thirteenth aspect, the apparatus failure diagnosis can be performed. In addition, the apparatus failure diagnosis detects the current and / or voltage applied to the motor coil 10, and the compressor 1 is detected from the detected value. The internal state is estimated, and this is performed based on the estimated internal state. For this reason, the reliability of the device failure diagnosis is high, and from this device failure diagnosis, it is possible to specify the failure location or to estimate the cause of the failure.

  An air conditioner according to a fourteenth aspect is characterized by comprising a storage means 21 for storing the result of the apparatus failure diagnosis.

  In the air conditioning apparatus of the above-mentioned claim 14, since the result of the apparatus failure diagnosis can be stored in the storage means 21, after the operation is stopped, the failure location is corrected using the result of the apparatus failure diagnosis. It can be carried out.

  An air conditioner according to a fifteenth aspect includes the compressor internal state estimating device according to any one of the first to seventh aspects, and is characterized in that a device failure prediction is performed based on the estimated internal state. Here, the device failure prediction means that it is predicted that the lubrication is poor due to the detected current disturbance, or that the fluid compression is predicted based on the detected current change. Or to predict that a low-pressure abnormality will occur.

  In the air conditioning apparatus according to the fifteenth aspect, the apparatus failure prediction can be performed. In addition, the apparatus failure prediction detects the current and / or voltage applied to the motor coil 10 and uses the detected value to determine the compressor 1. The internal state is estimated, and this is performed based on the estimated internal state. For this reason, the reliability of device failure prediction is high, and abnormal operation that becomes a failure can be avoided based on the device failure prediction.

  An air conditioner according to a sixteenth aspect is characterized in that the air conditioner includes a communication unit 31 that communicates information on the device failure prediction to the outside.

  In the air conditioning apparatus according to the sixteenth aspect, since the information on the apparatus failure prediction can be communicated to the outside by the communication means 31, the user or the like can know the information on the apparatus failure prediction, and then the apparatus failure is predicted. Can be avoided.

  The air conditioner according to claim 17 is characterized in that the operation control method or parameter of the refrigerant system is changed based on the estimated internal state.

  In the air conditioner according to the seventeenth aspect, since the operation control method and parameters of the refrigerant system can be changed based on the estimated internal state, operation with high efficiency can be performed.

  The air conditioner according to claim 18 is characterized in that the refrigerant system state during operation is estimated based on the estimated internal state using a preset refrigerant system model.

  In the air conditioner according to claim 18, since the refrigerant system state during operation is estimated based on the estimated internal state using a preset refrigerant system model, a highly responsive internal State estimation can be performed.

  According to the compressor internal state estimating device of the first aspect, the internal state of the compressor can be accurately estimated by real time processing without time delay. As a result, changes in internal characteristics over time can be detected from the internal state of this compressor, the failure occurrence can be predicted in advance, the failure location can be identified by focusing on changes from the initial characteristics, The cause can be estimated. In other words, by estimating the internal state of the compressor, it is possible to accurately predict and diagnose failures in real time, prevent breakdown due to abnormal operation of the compressor, and improve compressor reliability. it can. In addition, it is possible to maintain an appropriate and highly efficient operation. Furthermore, since accurate estimation is possible, excessive design can be avoided and the performance of the refrigeration cycle in which this compressor internal state estimation device is used can be fully exhibited. Further, the motor driving torque can be estimated, and the high pressure of the refrigeration cycle of the refrigerant system in which the compressor is used can be estimated from the motor driving torque. Thereby, abnormal operation of the compressor can be avoided.

  According to the compressor internal state estimating device of the second aspect, the current can be detected stably and with high accuracy. Thereby, the reliability of the internal state estimation of the compressor based on the detected instantaneous current is improved.

  According to the compressor internal state estimation device of claim 3 or claim 4, the motor drive torque can be calculated easily and accurately. Thereby, the reliability of the internal state estimation of the compressor based on the calculated motor driving torque is improved.

  According to the compressor internal state estimating device of the fifth aspect, the high and low pressures of the refrigerant system can be estimated. Thereby, the operation state of the refrigerant system can be grasped from the high and low pressures, the operation in the high and low pressure abnormal state can be avoided, and the failure of the compressor and the like can be prevented.

  According to the compressor internal state estimating device of claim 6, the estimated high and low pressures are highly reliable, operation in an abnormal state can be reliably avoided, and failure of the compressor can be surely prevented. Can do.

  According to the compressor internal state estimating device of the seventh aspect, the intake superheat degree of the compressor can be estimated. Thereby, if the suction superheat degree is inappropriate, it can be adjusted to an appropriate suction superheat degree to avoid excessive overheat operation and wet operation.

  As in claim 8, it can also be configured as a compressor drive device comprising the compressor internal state estimation device of claims 1 to 7, and according to this compressor drive device, the interior of the compressor The user or the like can surely grasp the state.

  According to the compressor driving device of the ninth aspect, the accuracy can be improved and the system can be optimally operated. That is, it is possible to prevent the compressor from being broken and to operate efficiently.

  According to the air conditioner of the tenth aspect, the compressor protection operation can be performed by changing the inverter signal of the inverter control means for driving the compressor based on the internal state. Thereby, failure of a compressor etc. can be prevented and it becomes an air harmony device excellent in durability.

  According to the air conditioner of claim 11, the compressor can be protected stably. Thereby, it is excellent in durability and a stable operation over a long period of time becomes possible.

  According to the air conditioner of the twelfth aspect, when the operation is not abnormal even when the operation is returned to the steady operation, the operation can be returned to the steady operation. As a result, if the estimated internal state is normal, normal (steady) operation can be performed, and high-efficiency operation can be performed as an air conditioner.

  According to the air conditioner of the thirteenth aspect, the reliability of the device failure diagnosis is high, and the failure location can be identified or the cause of the failure can be estimated from the device failure diagnosis. Thereby, after that, a failure location can be repaired or the cause of the failure can be removed, and the operation in a failed state can be avoided.

  According to the air conditioner of the fourteenth aspect, since the result of the device failure diagnosis can be stored in the storage means, the failure location is corrected by using the result of the device failure diagnosis after the operation is stopped. be able to.

  According to the air conditioner of the fifteenth aspect, the reliability of the device failure prediction is high, and abnormal operation that becomes a failure can be avoided based on the device failure prediction.

  According to the air conditioning apparatus of the sixteenth aspect, the user or the like can know the information of the apparatus failure prediction, and can avoid the operation that causes the apparatus failure thereafter.

  According to the air conditioner of the seventeenth aspect, it is possible to perform the operation with high efficiency and to reduce the running cost.

  According to the air conditioner of claim 18, it is possible to estimate the internal state with high responsiveness. As a result, the reliability of the estimated internal state can be improved, abnormal operation can be reliably avoided, and a compressor failure or the like can be reliably prevented.

  Next, a specific embodiment of the compressor internal state estimating device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a simplified diagram of a compressor driving device 40 provided with the compressor internal state estimating device (compressor internal state estimating means) 28. The compressor driving device 40 provided with the compressor internal state estimating device 28 is used in an air conditioner as shown in FIG. In this air conditioner, an outdoor heat exchanger 2, an expansion valve (electric expansion valve) 3, an indoor heat exchanger 4 and the like are sequentially connected to the compressor 1 to form a refrigerant circulation circuit (refrigerant system). . Then, by switching the four-way switching valve 5, a cooling operation and a heating operation can be performed. Moreover, the outdoor heat exchanger 2 and the indoor heat exchanger 4 are provided with temperature detection means 22 and 23, respectively, and the temperature of each heat exchanger 2 and 4 can be detected. Each temperature detecting means 22, 23 can be composed of a temperature sensor such as a temperature thermistor.

  As shown in FIG. 1, the compressor 1 includes a brushless DC motor 6 having a three-phase coil 10 of a U phase 7, a V phase 8, and a W phase 9 and an inverter 11. The inverter 11 in this case is a sine wave PWM control system. That is, the inverter 11 converts the AC input power into a direct current by the AC-DC conversion circuit unit 12, smoothes it by the smoothing circuit unit 13, and has an arbitrary frequency by the DC-AC conversion circuit unit (inverter unit) 14. Convert to AC power. The inverter 11 can control the frequency and voltage by changing the ON / OFF pattern of the transistor of the inverter unit 14 with an inverter signal from an inverter control means (not shown).

  The instantaneous current applied to the motor three-phase coil 10 can be detected by a current detector (current sensor) 16, and the instantaneous voltage applied to the motor three-phase coil 10 is detected by a voltage detector (voltage sensor) 17. The In this case, the current detector 16 and the voltage detector 17 are interposed between the AC-DC conversion circuit unit 12 and the smoothing circuit unit 13. The voltage can be obtained by calculation from the ON / OFF ratio of the transistor and the DC voltage, and the current can be obtained from the switch pattern of the transistor and the DC current.

  By the way, in the said air conditioning apparatus, when performing a cooling operation, the motor 6 of the compressor 1 is driven by switching the four-way switching valve 5 to the state shown by the solid line in FIG. As a result, the refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger 2, is decompressed and expanded by the expansion valve 3, passes through the indoor heat exchanger 4, and is returned to the compressor 1. At this time, the outdoor heat exchanger 2 functions as a condenser, and the indoor heat exchanger 4 functions as an evaporator, so that a cooling operation can be performed.

  Further, when performing the heating operation, the motor 6 of the compressor 1 is driven by switching the four-way switching valve 5 to the state shown by the broken line in FIG. As a result, the refrigerant discharged from the compressor 1 passes through the indoor heat exchanger 4, is decompressed and expanded by the expansion valve 3, passes through the outdoor heat exchanger 2, and is returned to the compressor 1. At this time, the indoor heat exchanger 4 functions as a condenser, and the outdoor heat exchanger 2 functions as an evaporator, so that heating operation can be performed.

  During each operation, the compressor 1 is damaged due to the acceleration / deceleration of the compressor 1, sudden fluctuations in the load, or operation under inappropriate conditions due to malfunction of other devices other than the compressor 1. May cause failure. Therefore, by estimating the internal state of the compressor 1 by the compressor internal state estimation device 28, the occurrence of a failure is predicted in advance, the failure location is specified, or the cause of the failure is estimated.

  That is, the compressor internal state estimation device 28 shown in FIG. 1 detects an instantaneous current and / or instantaneous voltage applied to the motor three-phase coil 10, and uses the detected value to determine the internal state of the compressor (specifically, the motor drive). Torque, etc.), and includes the detectors 16 and 17, a calculation device (calculation means) 20, a storage device (storage means) 21 and the like. Note that the computing means 20, the storage means 21, and the like can be configured by a microcomputer or the like.

  The calculation of the motor driving torque in the brushless DC motor includes a case where an arithmetic expression composed of an inductance and a current value is used and a case where an arithmetic expression composed of a magnetic flux and a current value is used. An arithmetic expression composed of an inductance and a current value can be expressed as in Expression 5 using Expressions 1 to 4 below. That is, the instantaneous voltage V can be expressed by Equation 1, the magnetic flux φ can be expressed by Equation 2, and the direction of the magnetic flux vector can be expressed by Equations 3 and 4.

  The motor position (rotor position) θ can be estimated from θ, that is, the detected instantaneous current I and instantaneous voltage V, from the equations 1 to 4, but the detected values and constants used at this time are used as they are. Furthermore, the current values id and iq obtained by coordinate conversion of the input currents iu, iv, and iw of the compressor 1 are obtained, and the motor drive torque Tm is obtained by these as shown in Equation 5.

  An arithmetic expression composed of the magnetic flux and the current value is for obtaining a torque acting on the stator by the outer product of the primary magnetic flux and the current, and the rotor torque of the motor 6 is a reaction force of the stator torque. For this reason, it can be expressed as the following Expression 6.

  In Equation 6, α and β are fixed coordinate systems, and the three phases u, v, and w are converted into two phases. Also, λα is calculated by the following equation 7, and λβ is calculated by the following equation 8.

  In this apparatus, the temperature information of the refrigerant system (evaporation temperature and condensation temperature detected from the detection means 22, 23, etc.) is input to the storage means 21. As shown in FIG. 3, a torque-high pressure diagram corresponding to a plurality of evaporation temperatures Te is created in advance for each of a plurality of compressor rotation speeds, and this diagram is input to the storage means 21. For this reason, the compressor internal state estimating device 28 estimates the condensation temperature Tc from the calculated motor driving torque Tm and the evaporation temperature Te based on this graph, and condenses from the condensation temperature Tc based on the refrigerant characteristics. The pressure (high pressure) Pc can be estimated. For example, when the compressor rotational speed is 60 rps and the evaporation temperature Te is 10 ° C., if the motor drive torque Tm is 10 Nm, the condensation temperature Tc can be estimated to be about 50 ° C. Further, a torque-low pressure diagram corresponding to a plurality of condensing temperatures Tc is created for each of a plurality of compressor rotation speeds, and the evaporation temperature Te is estimated from the motor driving torque Tm and the condensing temperature Tc based on this graph. The evaporation pressure (low pressure) Pe can be estimated from the evaporation temperature Te. In this way, it is possible to estimate the condensation temperature Tc and the evaporation temperature Te, but if such control is performed, the following advantages arise. That is, when the condensation temperature Tc and the evaporation temperature Te are measured as in the prior art, a considerable time delay occurs until the temperature of the measurement unit reaches the steady temperature, and an accurate temperature cannot be obtained. On the other hand, when the high and low pressures are estimated from the motor torque, there is no such time delay, and therefore protection can be performed without delay even in the protection control for high and low pressure abnormalities. As a result, severe damage can be avoided. Note that the condensation temperature Tc and the evaporation temperature Te obtained by this control may be used to determine whether there is an abnormality in the sensor that measures the condensation temperature Tc and the evaporation temperature Te.

  Further, the relationship between the motor driving torque and the suction superheat degree is grasped for each predetermined temperature condition and / or pressure condition of the refrigerant system, and based on the detected motor driving torque and the temperature information and / or pressure information at that time. Thus, the intake superheat degree of the compressor 1 during operation can be estimated. That is, for example, for each predetermined condensation pressure Pc and evaporation pressure Pe, a relationship between the motor driving torque Tm and the suction superheat degree is grasped, and a torque-SH diagram is created in advance. Then, a specific relationship diagram as shown in FIG. 4 is selected from the detected condensing pressure Pc and evaporation pressure Pe, and the suction superheat degree at that time is estimated from the grasped (calculated) motor driving torque Tm.

  Accordingly, in the torque-SH diagram of FIG. 4, the horizontal axis is the suction superheat degree and the vertical axis is the motor drive torque. For example, if the torque is Tmot in FIG. 4, the Tmot suction superheat degree is represented. The suction superheat degree can be estimated from the value of the axis (horizontal axis). Thereby, if the estimated suction superheat degree is inappropriate, it can adjust to the appropriate suction superheat degree and can avoid an excessive superheat driving | operation and wet operation.

  The compressor internal state estimation device 28 detects in advance a steady state (steady state instantaneous torque or steady state instantaneous current) from the motor driving torque or motor driving current and the temperature information and / or pressure information of the refrigerant system. It is also possible to estimate the internal state such as poor lubrication or liquid compression by inputting the steady state data into the storage means 21 and comparing the table of this data with the detected instantaneous torque or instantaneous current.

  That is, the frictional characteristics of the sliding surface are rough when the lubrication is poor, and the frictional resistance increases. In this case, the portion corresponding to the range H2 in FIG. 5 increases with respect to the normal current indicated by the broken line. Moreover, in the graph which shows the relationship between the oil dilution degree and torque of FIG. 7, it has shown that it has increased in the range H3 with respect to normal torque.

  In liquid compression or the like, a large increase in torque or current occurs as shown in FIG. Here, the large increase is an increase exceeding a predetermined amount set in advance. Therefore, when the load torque when the bearing of the compressor 1 is abnormally increased more than usual, it can be detected that poor lubrication, liquid compression, or the like has occurred, and the operating frequency of the compressor 1 is lowered. For example, abnormal operation can be avoided. Instead of estimating abnormal operation based on the amount of increase in torque or current as described above, abnormal operation may occur when torque or current increases rapidly, that is, when the increase amount per unit time exceeds the reference amount. It is also possible to estimate that.

  The instantaneous current can also be expressed as a sine wave. If this current waveform becomes an abnormal waveform as shown in FIG. 9, it can be estimated that an impact load such as a bearing abnormality or liquid compression is applied. That is, if an impact load such as bearing abnormality or liquid compression is applied, the current waveform is distorted as shown in FIG. Thereby, if a waveform is detected and the waveform has a beard, it can be estimated that an impact load has been applied. That is, by estimating the internal state of the compressor 1 based on the distortion amount with respect to the sine wave obtained by analyzing the harmonic component of the detected instantaneous current, it is estimated that the lubrication is defective based on the disturbance of the instantaneous current. Can do. In addition to estimating the lubrication failure or the like based on the strain amount as described above, the determination can be made based on the repetition amount for each mechanical rotation frequency. That is, the determination can be made based on the number of repetitions in which a certain amount of strain is repeated or the total amount of strains repeatedly generated.

  Therefore, as the compressor internal state estimating device 28 for this purpose, as shown in FIG. 8, the storage means 21 stores a threshold value (predetermined reference value) corresponding to temperature information and / or pressure information from the refrigerant system. As long as the instantaneous current harmonic component can be analyzed by the computing means 20. Thereby, this threshold value is compared with the detected instantaneous current harmonic component waveform to estimate lubrication failure or liquid compression. In such a case, abnormal operation can be avoided by reducing the operation frequency of the compressor 1 or the like. In addition, in this case, the threshold value (predetermined reference value) corresponds to temperature information and pressure information from the refrigerant system, and the reliability of the estimated internal state can be improved. Thereby, failure of the compressor can be reliably prevented.

  Next, FIG. 10 shows another air conditioner. In this case, an instantaneous current and / or instantaneous voltage applied to the motor three-phase coil 10 is detected, and the internal state of the compressor 1 is estimated from the detected value. Based on the estimated internal state, the compressor 1 is A compressor protection operation can be performed in which the inverter signal of the inverter control means 26 for driving is changed. Here, the compressor protection operation is a failure avoidance operation and refers to an operation that does not cause poor lubrication or liquid compression.

  Specifically, the compressor 1 includes a motor 6, an inverter 11, a sensing 25 as detection means for detecting an instantaneous current and / or an instantaneous voltage applied to the motor 6, and an inverter control means 26. Further, the control unit 27 of the apparatus includes a compressor internal estimation unit 28 and a failure avoidance control unit 29 that receives a command from the compressor internal estimation unit 28. The compressor internal estimation means 28 includes the calculation means 20 (not shown in this case) of FIG. 1 and a storage means 21 and the like. In addition, since the other structure is the same as that of the air conditioning apparatus shown in FIG. 1, the same part is shown with the same code | symbol and the description is abbreviate | omitted.

  Thus, also in the air conditioner shown in FIG. 10, the instantaneous current and / or instantaneous voltage applied to the motor three-phase coil 10 is detected, and the internal state of the compressor (such as poor lubrication or liquid compression) is detected from this detected value. The information of the internal state of the compressor is input to the failure avoidance control means 29. The failure avoidance control means 29 stores data from a preset refrigerant system model, and receives a command signal from the refrigerant system control means 30 that performs the refrigerant system operation control.

  Therefore, in the air conditioner of FIG. 10, the internal state of the compressor 1 is estimated. If this estimation is, for example, poor lubrication, the failure avoidance control means 29 to the control means of the compressor 1 prevents the lubrication failure. A control signal is transmitted to 26. For this reason, for example, the control which changes the rotation speed of the motor 6 or the control which changes the system control command value (operation control parameter) of the refrigerant | coolant system control means 30 is performed, and abnormal operation is avoided.

  By the way, when this device is operated, various devices are controlled by the refrigerant system control means 30, but the internal state of the compressor 1 is estimated and abnormal operation such as poor lubrication is performed. When estimated, the control of the inverter control means 26 (compressor protection operation) has priority over the operation control of the refrigerant system control means 30. Thereby, the reliability of failure avoidance of the compressor 1 can be improved.

  If the estimated internal state returns to the normal state, the compressor protection operation is restored to the steady operation. That is, the failure recovery control means 29 is provided with a switching means (not shown), and when it is estimated that an abnormal operation such as poor lubrication is performed by this switching means, the compressor protection operation is performed and the normal state is restored. When it is estimated that the vehicle is operating, it is assumed to be in steady operation. As a result, the air conditioner can be operated with high efficiency.

  The failure avoidance control means 29 can perform device failure diagnosis based on the estimated internal state of the compressor 1. Here, the device failure diagnosis is a diagnosis of poor lubrication from the detected disturbance of the instantaneous current, a diagnosis of liquid compression from the detected change in the instantaneous current, and a high / low pressure estimation. It is diagnosed as inhalation superheat abnormality. The diagnosis result is stored in the storage means 21. Thus, after the operation is stopped, the failure location can be corrected using the result of the device failure diagnosis.

  As described above, the air conditioner shown in FIG. 10 can perform device failure diagnosis, and has high reliability in device failure diagnosis. From this device failure diagnosis, the failure location can be identified or the cause of failure can be estimated. You can do it. Thereby, after that, a failure location can be repaired or the cause of the failure can be removed, and the operation in a failed state can be avoided.

  Further, the failure avoidance control means 29 cannot diagnose a failure, but if it can be predicted that a failure will occur if the operation in this state is continued, a failure prediction of the device is performed. Here, the device failure prediction is, for example, predicting that a lubrication failure may occur due to the detected disturbance of the instantaneous current. This failure prediction information is communicated to the outside (that is, a user or the like) via the communication means 31. As the communication means 31, for example, a display means (notifying blinking of display light, generation of sound) for notifying the user or the like of this failure prediction information can be configured.

  For this reason, in the air conditioning apparatus shown in FIG. 10, the apparatus failure prediction can be performed, and the reliability of the apparatus failure prediction is high, and the abnormal operation that causes the failure is avoided based on the apparatus failure prediction. be able to. Furthermore, since the information on the device failure prediction can be communicated to the outside by the communication means 31, the user or the like can know the information on the device failure prediction and can take subsequent measures.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, the air conditioner shown in FIG. 1 estimates high / low pressure, suction superheat, poor lubrication, liquid compression, and the like, but these single types may be arbitrarily combined with multiple types. It may be. Further, in the air conditioner shown in FIG. 10, the compressor protection operation, the device failure diagnosis, and the device failure prediction are possible, but the compressor protection operation is performed and the device failure diagnosis and the device failure prediction are not performed. Those that perform failure diagnosis and do not perform compressor protection operation and device failure prediction, those that perform device failure prediction and do not perform compressor protection operation and device failure diagnosis, and those that are arbitrarily combined from these Etc. In addition, changes such as a predetermined amount that serves as a reference for a sudden increase in instantaneous current for estimating the internal state and a predetermined amount that serves as a reference for a rapid increase in motor drive torque for estimating the internal state are abnormal as a device. It can be changed arbitrarily within the range that does not become operation. Furthermore, even if the compressor driving device has a function of outputting information such as estimated motor driving torque, temperature, high pressure, low pressure, and shaft lubrication state, information on the refrigerant system is further input. Thus, information for improving accuracy and system optimum operation may be calculated. Thus, if information such as the estimated motor driving torque can be output, the user or the like can surely grasp the internal state of the compressor 1, and information for improving accuracy and optimal system operation is calculated. As a result, accuracy can be improved and system optimum operation can be performed. The motor 6 is not limited to a brushless DC motor.

It is a simplified diagram showing an embodiment of a compressor driving device in which the compressor internal state estimating device of the present invention is used. It is a schematic diagram of an air harmony device using the above-mentioned compressor drive device. It is a torque-high pressure diagram of the air conditioning apparatus. It is a graph which shows the relationship between the torque of the said air conditioning apparatus, and a superheat degree. It is a graph which shows the relationship between the electric current in the abnormal operation state of the said air conditioning apparatus, and a normal current. It is a graph which shows the relationship between the torque etc. of the said air conditioning apparatus, and time. It is a graph which shows the relationship between the torque of the said air conditioning apparatus, and an oil dilution degree. It is a simplification figure showing other embodiments of an air harmony device in which a compressor internal state estimating device of this invention was used. It is a harmonic component waveform figure of the instantaneous electric current of the said air conditioning apparatus. It is a simplification figure showing another embodiment of an air harmony device in which the compressor internal state estimating device of this invention was used.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Compressor 10 ... Coil 16 ... Detector 21 ... Memory | storage means 26 ... Inverter control means 31 ... Communication means

Claims (18)

  In the compressor (1) used in the refrigeration apparatus, the current and / or voltage applied to the motor coil (10) of the brushless DC motor is detected, and the internal state of the compressor (1) is estimated from the detected value. A compressor internal state estimation device, wherein the internal state estimation is a motor drive torque.   The compressor internal state estimating device according to claim 1, further comprising a detector (16) for detecting a current applied to the motor coil (10).   2. The compressor internal state estimating device according to claim 1, wherein an arithmetic expression comprising an inductance and a current value is used for estimating the motor driving torque.   2. The compressor internal state estimating apparatus according to claim 1, wherein an arithmetic expression including a magnetic flux and a current value is used for estimating the motor driving torque.   The compressor internal state estimation device according to any one of claims 1 to 4, wherein the high pressure or low pressure of a refrigerant system in which the compressor (1) is used can be estimated.   6. The compressor internal state estimating device according to claim 5, wherein the high pressure or the low pressure is estimated based on a motor driving torque and temperature information of the refrigerant system.   Understand the relationship between the motor drive torque and the suction superheat degree for each predetermined temperature condition and / or pressure condition of the refrigerant system, and based on the detected motor drive torque and the temperature information and / or pressure information at that time, The compressor internal state estimation device according to any one of claims 1 to 4, wherein the suction superheat degree of the compressor (1) in operation is estimated.   The compressor internal state estimation device according to any one of claims 1 to 7 is provided, and has a function of outputting information such as estimated motor drive torque, temperature, high pressure, low pressure, and shaft lubrication state. Compressor drive device characterized.   9. The compressor driving apparatus according to claim 8, wherein information for improving accuracy and system optimum operation is calculated by inputting information of the refrigerant system.   The compressor internal state estimating device according to any one of claims 1 to 7 is provided, and based on the estimated internal state, an inverter signal of inverter control means (26) for driving the compressor (1) is obtained. An air conditioner that performs a compressor protection operation to be changed.   The air conditioner according to claim 10, wherein the inverter control means (26) performs the compressor protection operation in preference to a refrigerant system operation control command.   The air conditioner according to claim 10 or 11, further comprising switching means for recovering from the compressor protection operation to a steady operation.   An air conditioner comprising the compressor internal state estimating device according to any one of claims 1 to 7 and performing device failure diagnosis based on the estimated internal state.   14. An air conditioner according to claim 13, further comprising storage means (21) for storing the result of the apparatus failure diagnosis.   An air conditioner comprising the compressor internal state estimating device according to any one of claims 1 to 7 and performing device failure prediction based on the estimated internal state.   16. The air conditioner according to claim 15, further comprising a communication means (31) for communicating the information on the prediction of the apparatus failure to the outside.   The air conditioner according to any one of claims 10 to 16, wherein an operation control method or a parameter of the refrigerant system is changed based on the estimated internal state.   The air conditioner according to any one of claims 10 to 17, wherein a refrigerant system state during operation is estimated based on the estimated internal state using a preset refrigerant system model. .