JP5902521B2 - Control device for compressor motor and air conditioner equipped with the same - Google Patents

Description

  The present invention relates to a compressor motor control device that can vary the rotational speed of a compressor by inverter control, and an air conditioner equipped with the compressor motor control device.

  Conventionally, the rotation speed of a compressor motor mounted on an air conditioner, a refrigerator, or the like is controlled under various conditions.

  Patent Document 1 stores the number of revolutions when the compressor motor stops abnormally, sets the number of revolutions as an upper limit or a lower limit, limits the predetermined period, and adjusts the predetermined period according to the number of occurrences of abnormal signals. Is disclosed.

JP 2011-259640 A

  By the way, the drive control of the compressor motor is influenced by the load of the compressor. However, the load of the compressor is infinite due to, for example, an ambient temperature (indoor / outdoor) or a transient change of the refrigeration cycle state in an air conditioner. Since the state is considered, it is not possible to confirm the operation under all load conditions.

  For this reason, although the rotation speed has no problem in operation, the abnormal stop related to the compressor drive control is the same because the environmental temperature and other loads are specific conditions. When the operation is instructed at 3350 rpm (for example, if the operation occurs at 3350 rpm, the rotation speed of the compressor may slightly fluctuate, so even if the operation is instructed at 3350 rpm, the actual number of rotations may be 3340 to 3360 rpm). It can happen rarely. Such a vicinity of the rotational speed takes into consideration the fluctuation of the actual rotational speed of the compressor.

  Such limited conditions can be avoided by slightly increasing or decreasing the compressor speed. In addition, such a specific condition often occurs during a transient change in the refrigeration cycle state, and if the refrigeration cycle state transits the transition period, it can often be driven without any problem even at the same rotational speed.

  However, in the technique described in Patent Document 1, since the rotation speed of the compressor is limited for a predetermined period regardless of the timing of occurrence of the abnormality, the time for performing the limitation unnecessarily becomes long. In addition, when an abnormality occurs due to a transient change in the refrigeration cycle state after a certain period of time has elapsed, it is conceivable that if the predetermined period is too short, there is no effect at all.

  Therefore, although the predetermined period is extended little by little every time an abnormality occurs, the occurrence of an abnormality occurs several times before the effect is exerted, and the usability deteriorates.

  In view of the above, the present invention provides a compressor motor that can improve the comfort by limiting the number of rotations of the compressor only for a necessary time from the occurrence of an abnormality of the compressor, and suppressing the limitation of unnecessary capacity. The object is to provide a control device and an air conditioner equipped with the same.

In order to achieve the above object, a compressor motor control device according to the present invention controls a drive speed of a compressor motor based on a rotation speed detection section that detects the rotation speed of the compressor motor and a signal from the rotation speed detection section. A drive control unit, an abnormality determination unit for determining an abnormality relating to compressor driving, a storage unit for storing the number of rotations of the compressor motor when an abnormality relating to compressor driving occurs, and a compressor operating time until the occurrence of the abnormality The drive control unit sets a time limit according to the compressor operation time stored in the storage unit in the subsequent operation when an abnormality occurs, and the elapsed time from the time of the abnormality being within the time limit. For example , the drive control is performed by limiting the number of rotations that is unlikely to cause an abnormality according to the number of rotations of the compressor motor stored in the storage unit.

  According to the above configuration, when an abnormality occurs in the compressor drive, the abnormality occurrence state such as the rotation speed of the compressor motor when the abnormality relating to the compressor drive or the compressor operation time until the abnormality occurs is stored in the storage unit, and the next time Since the compressor drive control is performed according to the stored time limit under the limiting conditions that are unlikely to cause the abnormality, it is possible to reduce the probability of motor stoppage due to the compressor motor abnormality determination.

  Here, the control after the abnormality determination of the compressor motor can include not only an aspect in which the compressor motor is immediately stopped and restarted by the abnormality determination, but also an aspect in which the abnormality determination is repeated several times. Therefore, the start time of the compressor operation time stored in the storage unit can be either the start or restart of the compressor motor, or the determination of the compressor motor abnormality.

  Further, in the drive control of the compressor motor after the next time, the following modes are conceivable as modes in which the drive control is performed while limiting the number of revolutions so that the occurrence of abnormality is not likely to occur. That is, the drive control unit adjusts the rotation speed of the compressor motor so that the rotation speed of the compressor motor at the time of abnormality does not increase in the vicinity of the rotation speed when the rotation speed is in the high rotation speed range. If the rotation speed at the time of abnormality is in the low rotation speed range of the operating range, limit the rotation speed of the compressor motor so that it does not fall near that rotation speed. When the rotation speed is in the middle range, the drive control is performed by limiting the rotation speed of the compressor motor so that it does not stay in the vicinity of the rotation speed.

  In this case, the time limit can be set to a compressor operating time stored in the storage unit or a longer time at a predetermined rate than the compressor operating time.

  According to the above configuration, since the time limit is set to a time corresponding to the compressor operating time, as in Patent Document 1, an abnormality occurrence state is obtained as compared with a case where the predetermined period is uniformly extended for every abnormality occurrence. It can be limited in time.

  Further, as another aspect in which the occurrence of abnormality is unlikely to occur, a predetermined ratio before and after the compressor operation time stored in the storage unit is set as the time limit, and during the time limit, the compressor at the time of abnormality stored in the storage unit is stored. A mode in which drive control is performed so as to prohibit the operation of the compressor motor at a rotation speed of a predetermined width above and below the rotation speed of the motor can be mentioned.

  According to this aspect, during the time of a predetermined ratio before and after the compressor operating time, the operation within the predetermined range above and below the rotation speed at the time of occurrence of abnormality is prohibited, so at least in the time zone in which abnormality determination is likely to occur. Operation at a rotational speed with a high probability of occurrence is prohibited, and an abnormality is unlikely to occur.

  The drive control unit limits the number of rotations of the compressor motor after the abnormality of the compressor motor occurs, and if no abnormality occurs even after the time limit has elapsed, the number of rotations and the time limit that are the limiting conditions are limited. Can be stored in the storage unit, and the operation can be performed in accordance with the restriction condition stored in the storage unit during the subsequent operation.

  Thereby, after abnormality determination, the stop probability by the abnormality determination of the compressor motor after the next time can be reduced.

  The control device for a compressor motor according to the present invention can be used for any refrigerator or air conditioner equipped with a compressor for a refrigeration cycle. When applied to an air conditioner that frequently occurs and may cause discomfort, the probability of stoppage of the compressor is reduced and the number of times the room temperature is hunted is reduced, so that comfort can be improved.

  As described above, according to the present invention, the abnormality occurrence state such as the rotation speed of the compressor motor at the time of occurrence of an abnormality relating to the compressor drive and the compressor operation time until the occurrence of the abnormality is stored in the storage unit. Since the drive control of the compressor is performed in accordance with the stored time limit under the restriction condition that is unlikely to occur, the probability of motor stoppage due to the abnormality determination of the compressor motor can be reduced.

It is a refrigerating cycle figure which uses the compressor which is embodiment of this invention as a component. It is a drive circuit diagram of the compressor motor of the present invention. It is a drive control flowchart of the compressor motor of this invention. It is a drive control flowchart of another compressor motor of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

  The embodiment shown below shows an example in which a control device for a compressor motor is mounted on an air conditioner. As shown in FIG. 1, in a separate type air conditioner in which an indoor unit and an outdoor unit are connected by piping, a compressor 1, a switching valve (four-way valve) 2, an outdoor heat exchanger 3, a throttle on the outdoor unit side. An apparatus 4 is provided, an indoor heat exchanger 5 is provided on the indoor unit side, and a refrigeration cycle 7 is configured in which these constituent members are sequentially connected by a refrigerant pipe 6 to circulate the refrigerant. And the air blowers 8 and 9 are opposingly arranged by the outdoor heat exchanger 3 and the indoor heat exchanger 5, respectively.

  The compressor 1 includes a compression mechanism (not shown) that compresses a refrigerant and a compressor motor 10 that drives the compression mechanism. The compressor motor 10 includes a rotating shaft, a rotor, a stator and a stator coil (not shown), and is driven by a compressor motor drive circuit diagram shown in FIG.

  In the motor drive circuit shown in FIG. 2, the AC voltage of the commercial power source is supplied from the AC power source 12 to the rectifier circuit 14 via the reactor 13. The reactor 13 is inserted as a power factor correction circuit for improving the power factor reduction in the smoothing circuit 15. The rectifier circuit 14 rectifies the AC voltage into a DC voltage, and the smoothing circuit 15 smoothes the ripple of the DC voltage. Although a full-wave rectifier circuit is used here, a double voltage rectifier circuit may be used.

  The rectified DC voltage is supplied to the inverter circuit 16. In the inverter circuit 16, six semiconductor switching elements 16 a to 16 f are connected in a three-phase bridge shape, and the output side of the inverter circuit 16 is connected to the three-phase brushless motor 10.

  The motor drive circuit includes a rotation speed detection unit 21 that detects the rotation speed of the compressor motor 10, a drive control unit 22 that drives and controls the compressor motor 10 based on a signal from the rotation speed detection unit 21, and a compressor An abnormality determination unit 23 that determines an abnormality relating to driving, and a storage unit 24 that stores the rotation speed of the compressor motor 10 when an abnormality relating to compressor driving occurs and the compressor operating time until the abnormality occurs. Furthermore, a current detector 25 is provided to detect an abnormality in the motor drive circuit.

  Each element of the rotation speed detection unit 21, the drive control unit 22, the abnormality determination unit 23, the storage unit 24, and the current detection unit 25 is configured by a single microcomputer in which a CPU, a ROM, and a RAM are incorporated. ing. A timer 28 is attached to the microcomputer.

  The rotation speed detection unit 21 can detect the rotation speed of the motor 10 and can also detect an abnormality related to driving of the motor based on the detected rotation speed. That is, the rotation speed detection unit 21 detects an induced voltage corresponding to the rotor position of the motor from each of the three-phase windings of the motor 10, and compares the detected voltage with a reference voltage to thereby generate a pulse signal corresponding to the rotor position. The number of rotations of the motor at that time can be detected based on this pulse signal.

  The detected rotation speed signal is input to the drive control unit 22 and the abnormality determination unit 23. The drive control unit 22 compares the detected rotational speed with the target rotational speed, adjusts the PWM (Pulse Width Modulation) duty so as to approach the target rotational speed, and commutates each semiconductor switching element 16a to 16f of the inverter circuit 16. A drive signal to be generated is generated and output to the drive circuit 28. That is, the drive control unit 22 functions as a PWM control unit.

  Further, the rotation speed signal detected by the rotation speed detection unit 21 is also used for abnormality determination related to driving of the compressor motor. For example, when the motor 10 stops due to an abnormality such as step-out, the abnormality determination unit 23 detects the number of rotations of the motor 10 because the motor 10 stops despite the output of the drive signal from the PWM control unit 22. The abnormality can be determined.

  Moreover, the abnormality determination part 23 can be performed also based on the current signal from the current detection part 25 provided with the shunt resistor 27 provided between the rectifier circuit 14 and the inverter circuit 16. The abnormality determination unit 23 can determine from the current value obtained by the current detection unit 25 whether the motor 10 is normally driven or is in an abnormal stop state such as a motor lock. Alternatively, the abnormality determination unit 23 is based on a signal from the current detection unit 25, and since the applied voltage is too large with respect to the speed, a delay control state in which the current phase is delayed with respect to the motor induced voltage or a load with respect to the speed. It is also possible to determine an abnormality such as whether the current phase with respect to the motor-induced voltage is greatly advanced, the control state is excessive, or the like.

  Moreover, in the abnormality determination part 23, as shown in Patent Document 1, an IPM (Intelligent Power Module) signal is input from a protection circuit (not shown) that detects overcurrent and overheating of the switching elements 16a to 16f of the inverter circuit 16. Can be determined as abnormal.

  Note that the above-described parameters acquired for determining an abnormality related to the driving of the compressor motor 10 are merely examples, and an abnormality determination can be made by combining these alone or in combination, or by further combining different types of parameters.

  The storage unit 24 stores the number of rotations of the compressor motor when an abnormality relating to compressor driving occurs and the compressor operating time until the abnormality occurs. The start of the compressor operation time stored in the storage unit 24 may be either when the compressor motor 10 is started or restarted, or when the compressor motor 10 is determined to be abnormal. In this example, since the compressor motor 10 is stopped by the abnormality determination of the compressor motor 10 and then restarted, the operation time of the compressor is stored starting from the start or restart of the compressor motor.

  Note that the elapsed time from the occurrence of abnormality is not counted when the compressor operation is stopped, but only during the compressor operation, thereby calculating the time the compressor has actually been operated. .

  The drive control unit 22 sets a time limit corresponding to the compressor operation time stored in the storage unit 24 in the next and subsequent operations when an abnormality related to the drive of the compressor occurs, and the compressor motor stored in the storage unit 24 similarly. The drive control is performed by limiting the number of rotations so that an abnormality does not easily occur according to the number of rotations.

Specifically, when the rotation speed of the compressor motor 10 at the time of occurrence of an abnormality is in the high rotation speed range of the use range rotation speed, the drive control unit 22 prevents the compressor from rising in the vicinity of the rotation speed. The number of rotations of the motor 10 is limited. When the rotation speed at the time of occurrence of an abnormality is in the low rotation speed range of the use range rotation speed, the rotation speed of the compressor motor 10 is limited so as not to decrease near the rotation speed. Further, when the rotation speed at the time of occurrence of abnormality is in the middle rotation speed range of the use range, the drive control is performed by limiting the rotation speed of the compressor motor 10 so that it does not stay in the vicinity of the rotation speed.

  The time limit at this time is set to a compressor operating time stored in the storage unit 24 or a time longer than the compressor operating time by a predetermined ratio (for example, 1.1 times).

  The drive control unit 22 limits the rotation speed of the compressor motor 10 after occurrence of an abnormality in the compressor motor, and if no abnormality occurs even after the limit time has elapsed, The time limit may be stored in the storage unit 24, and the operation may be performed according to the limit condition stored in the storage unit 24 during the next and subsequent operations.

  FIG. 3 is a flowchart regarding drive control of the compressor motor of this example. Based on this flowchart, the drive control of the compressor motor 10 will be described. During the operation of the compressor (step S1), the compressor motor 10 is stopped when an abnormality relating to the compressor drive occurs.

  At this time, the timer 28 starts counting the elapsed time from the occurrence of the abnormality, stores the rotation speed when the abnormality occurs, and stores the compressor operating time when the abnormality occurs. The elapsed time from the occurrence of the abnormality is not counted when the compressor operation is stopped, but only during the operation.

 During the compressor operation (S1), the elapsed time after the abnormality exceeds the storage time (stored compressor operation time) (S2), or a predetermined time longer than the storage time (stored compressor operation time) ( For example, the number of rotations of the compressor motor 10 is limited until it exceeds 1.1 (S2-1) so that the same abnormality does not occur next time.

  If the time limit corresponding to the storage time (stored compressor operating time) is exceeded (S2: YES), the limitation on the rotational speed of the compressor motor is canceled (S3), and an abnormality relating to compressor driving occurs. (S4).

  In step 2 (S2), if the elapsed time after abnormality does not exceed the storage time (S2: NO), the threshold value is set in two stages of the high rotation determination value and the low rotation determination value as a limitation on the rotation speed. When the rotation speed at the time of occurrence is higher than the high rotation determination value (S5: YES), the rotation speed is limited with the upper limit being stored near the rotation speed at the time of occurrence of abnormality (for example, rotation speed at the time of occurrence of abnormality −50 rpm) ( S6).

  If the rotation speed at the time of occurrence of abnormality is lower than the low rotation determination value (S7: YES), the rotation speed is limited with the stored vicinity of the rotation speed at the time of occurrence of abnormality (for example, abnormality rotation speed +50 rpm) as a lower limit (S8).

  In other cases, that is, when the rotation speed at the time of occurrence of an abnormality is in the middle rotation speed range of the use range, the drive control is performed by limiting the rotation speed of the compressor motor 10 so that it does not stay in the vicinity of the rotation speed. . That is, the vicinity of the rotation speed at the time of occurrence of abnormality (for example, the rotation speed of occurrence of abnormality ± 50 rpm) is set as the stagnation prohibition rotation speed (S9), and control is performed so as not to stagnate near this rotation speed.

  Then, it is monitored whether an abnormality relating to the compressor drive occurs again (S4), and if an abnormality occurs (S4: YES), the elapsed time after the abnormality is started for the next time (S10), and the abnormality occurs. The number of rotations at the time is stored (S11), the compressor operation time at the time of occurrence of abnormality is stored (S12), and the process returns to step 2 to determine whether the elapsed time after abnormality has reached the time limit corresponding to the storage time. (S2).

  As described above, when an abnormality occurs in the compressor drive, the abnormality occurrence state such as the rotation speed of the compressor motor 10 at the occurrence of the abnormality related to the compressor drive and the compressor operation time until the abnormality occurs is stored in the storage unit 24. Thereafter, the drive control of the compressor motor 10 is performed in accordance with the stored time limit under the limit condition in which the abnormality is unlikely to occur. Therefore, it is possible to reduce the probability of motor stoppage due to the abnormality determination of the compressor motor 10.

  As another embodiment of the present invention, as shown in FIG. 4, the drive control unit 22 uses a predetermined ratio before and after the compressor operation time stored in the storage unit 24 as a time limit, and during the time limit, the storage unit 24. The drive control is performed so as to prohibit the operation of the compressor motor at a rotational speed of a predetermined width above and below the rotational speed of the compressor motor 10 when the abnormality is stored.

  A specific control flow is as shown in FIG. When an abnormality relating to compressor driving occurs during the compressor operation (S21) (S26: YES), the elapsed time from the occurrence of the abnormality is started (S27), and the rotation speed at the time of the abnormality is stored (S28). The compressor operating time from when the abnormality occurred is stored (S29). Note that the elapsed time count (S27) from the time of occurrence of abnormality is not performed when the compressor operation is stopped, but only during operation.

  When the compressor is in operation (S21), if the post-abnormal elapsed time is within a certain ratio before and after the storage time (for example, 0.9 to 1.1 times the storage time) (S22: NO, S23). : NO), the number of rotations of the compressor motor 10 is limited by that time. In this case, the rotational speed is limited to the vicinity of the rotational speed at the time of occurrence of abnormality (for example, abnormal rotational speed ± 50 rpm) (S24). If the time of 0.9 to 1.1 times the storage time has passed, the rotational speed restriction is canceled (S25), and it is determined whether or not the next compressor drive abnormality will occur (S26).

  As a result, the drive control time of the compressor motor 10 is limited to a time zone in which the compressor motor 10 is likely to be abnormal, and normal operation control is performed at other times, thereby preventing loss of comfort. it can.

  It should be noted that the rotation speed to be limited is not a stagnation prohibition but a passage prohibition rotation speed. As a result, the number of rotations that are likely to cause an abnormality can be avoided, and the abnormal stop of the compressor can be minimized.

  In any of the above embodiments, if the compressor is abnormally stopped and the rotational speed is limited, and the abnormal stop does not occur even after the time limit has elapsed, the limiting condition (the rotational speed and time) is stored, Similarly, during the subsequent operation (in the case of restart after thermo-off), the rotational speed may be limited until the stored compressor operation time elapses from the start of the compressor. The thermo ON / OFF control is to stop the compressor when the room temperature reaches the set temperature (thermo OFF), and restart the compressor when the room temperature deviates from the set temperature (thermo ON). Control.

  In addition, when the air conditioner operation of the air conditioner is stopped by a remote controller or the like, the rotation speed limit may be canceled when the air conditioner operation is turned on next time. In this case, the abnormality occurrence state (rotation speed / operation time) stored in the storage unit is reset based on a stop command from a remote controller or the like.

  In the above-described embodiment, the compressor motor control of the air conditioner has been described. However, the present invention is not limited to this, and the compressor motor control of the present invention is also applied to electrical equipment using a compressor in a refrigeration cycle such as a freezer or a refrigerator. The device can be installed.

1 Compressor 2 Switching valve (4-way valve)
3 Outdoor Heat Exchanger 4 Throttle Device 5 Indoor Heat Exchanger 6 Refrigerant Pipe 7 Refrigeration Cycles 8 and 9 Blower 10 Compressor Motor 12 AC Power Supply 13 Reactor 14 Rectification Circuit 15 Smoothing Circuit 16 Inverter Circuits 16a to 16f Semiconductor Switching Element 21 Rotational Speed Detection unit 22 Drive control unit 23 Abnormality determination unit 24 Storage unit 25 Current detection unit

Claims (6)

A rotation number detection unit that detects the rotation number of the compressor motor, a drive control unit that drives and controls the compressor motor based on a signal from the rotation number detection unit, an abnormality determination unit that determines an abnormality related to the compressor drive, and a compression A storage unit for storing the number of rotations of the compressor motor when an abnormality relating to machine drive occurs and the compressor operating time until the occurrence of the abnormality;
The drive control unit sets a time limit according to the compressor operation time stored in the storage unit in the subsequent operation when an abnormality occurs, and if the elapsed time from the time of the abnormality is within the time limit , A compressor motor control device, wherein drive control is performed by limiting to a rotation speed at which an occurrence of abnormality is unlikely to occur according to a rotation speed of the compressor motor stored in the storage unit. The drive control unit limits the rotation speed of the compressor motor so that the rotation speed of the compressor motor at the time of occurrence of an abnormality does not increase in the vicinity of the rotation speed when the rotation speed is in the high rotation speed range. If the rotation speed at the time of abnormality is in the low rotation speed range of the operating range, limit the rotation speed of the compressor motor so that it does not fall near that rotation speed. 2. The compressor motor according to claim 1, wherein the compressor motor is controlled by limiting the number of revolutions of the compressor motor so that it does not stay in the vicinity of the number of revolutions in the range of the number of revolutions in the range. Control device. The said drive control part sets the said time limit to the compressor operation time memorize | stored in the said memory | storage part, or a time longer than the compressor operation time by a predetermined | prescribed ratio, The Claim 1 or 2 characterized by the above-mentioned. Compressor motor control device. The drive control unit sets a predetermined ratio before and after the compressor operation time stored in the storage unit as the time limit, and during the time limit, the rotation speed of the compressor motor at the time of occurrence of an abnormality stored in the storage unit is increased or decreased. 2. The compressor motor control device according to claim 1, wherein the drive control is performed so as to prohibit the operation of the compressor motor at a rotation speed of a predetermined width.   The drive control unit limits the number of rotations of the compressor motor after occurrence of an abnormality in the compressor motor, and if no abnormality occurs even after the time limit has elapsed, the number of rotations and the time limit that are the limiting conditions are set. The compressor motor control device according to any one of claims 1 to 4, wherein the controller motor is operated in accordance with the restriction condition stored in the storage unit and stored in the storage unit during the next and subsequent operations. An air conditioner comprising the compressor motor control device according to any one of claims 1 to 5.

Images