JP2008005592A - Motor drive device and storage device with the motor drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive device which enables the stoppage of the inverter output to a motor by recognizing the abnormal stoppage of the motor instantly even if it stops abnormally by the factor other than an overcurrent. <P>SOLUTION: When the drive device determines a motor to be stopping by the comparison among the present PWM output duty value, the PWM output duty value before one carrier stored in a PWM storage 18, and the reference PWM output duty value V_min, and the comparison between the rotor rotational phase Δθ of the motor estimated by a phase estimation formula based on a voltage equation and the reference rotor rotational phase Δθ0 of the motor, receiving the voltage rectified from AC power 1 as the input of the inverter 5, it stops the generation of the PWM output duty to a PWM generator 111 and also stops the revolution command to a revolution setting means 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor drive device that drives and controls a brassless motor by an inverter, and a storage device such as a refrigerator that includes the motor drive device.

  Conventionally, a motor drive device that drives and controls this type of brassless motor by an inverter has been disclosed (for example, see Patent Document 1).

  Moreover, in the motor drive device, a device that does not use a position sensor is desired from the viewpoint of wireless wiring and cost reduction. Using the motor current, the voltage applied to the brushless motor at that time, and the motor constants such as the resistance and inductance of the brushless motor, the rotor position of the motor was estimated by a phase estimation calculation formula based on the voltage equation (for example, Non-Patent Document 1).

  In addition to downsizing the motor drive device, it is possible to cope with either a configuration using a position sensor and a configuration without a position sensor, and even if the input voltage of the inverter pulsates greatly, There has also been proposed a motor drive device that can be stably driven without a position sensor without stopping the application of voltage to the brushless motor (see, for example, Patent Document 2).

  FIG. 9 is a block diagram showing a configuration of a conventional motor driving apparatus for driving a brushless DC motor.

  In FIG. 9, an AC power source 101, a rectifier diode 102, an inverter 103, a brushless motor 104, a current detection unit 105, and an inverter control unit 106 are configured.

  The AC power source 101 is converted into DC power having pulsation by a rectifier diode 102 and input to the inverter 103. The inverter 103 converts the rectified DC power into AC power and applies a desired voltage to the brushless motor 104.

  The inverter control unit 106 calculates the phase instantaneous currents Iu, Iv, and Iw flowing into the brushless motor based on the information on the instantaneous current Iin detected by the current detection unit 105 by calculation. A dq conversion unit 108 that converts a three-phase AC coordinate system of Iu, Iv, and Iw into a two-phase rotation orthogonal coordinate system of a d-axis current detection value Id and a q-axis current detection value Iq, an external rotation speed command, torque command, etc. The d-axis PI controller 109 for generating an d-axis voltage command value Vd by PI control of an error between the d-axis current command value Id * calculated based on the Id and the Id output by the dq conversion unit 108, rotation from the outside The q-axis voltage command value Vq is generated by PI control of an error between the q-axis current command value Iq * calculated based on the number command, the torque command, and the like and the Iq output from the dq conversion unit 108. PI controller 110, PWM generator for generating PWM output duty values Vu, Vv, Vw for driving the brushless motor by energizing 180 degrees from d-axis voltage command value Vd, q-axis voltage command value Vq, and input voltage detection value Vpn 111. Here, “*” attached to the previous current command value is for distinguishing from the driving currents Id and Iq, and the specific current values are also different.

  In the conventional inverter configuration, since the motor is driven by energization at 180 degrees, the input to the inverter 103 is based on the instantaneous current detected by one current detection means 105 and the input voltage detection value to the inverter 103. By controlling the inverter 103 while maintaining the voltage phase of the voltage applied to the brushless motor 104 when the voltage value is smaller than the voltage value to be applied, the brushless motor 104 can be supplied even when the DC side voltage of the inverter 103 is low. A voltage is continuously applied without stopping the voltage application, and stable driving is realized even when a large pulsating voltage is input to the inverter 103, thereby reducing the size of the motor driving device.

Further, when the instantaneous current Iin detected by the current detection unit 105 is an overcurrent, the overcurrent detection unit 112 stops the output from the PWM generation unit 111, thereby destroying the inverter 103 due to the overcurrent, the brushless motor 104 prevents abnormal heating and prevents performance deterioration of the permanent magnet used in the rotor.
JP 2005-304176 A Japanese Patent Laid-Open No. 2005-20986 Takeshita, Ichikawa, Lee, Matsui, “Sensorless salient pole type brushless DC motor control based on speed electromotive force estimation”, IEEJ Transactions D, 1997, Vol. 117, No. 1, p. 98-104

  However, there is no problem if the current flowing through the motor generates an overcurrent when the motor stops abnormally, but the motor stops abnormally when the current flowing through the motor is less than the level at which the overcurrent is detected. In this case, the inverter control unit cannot recognize that the motor is stopped, and the inverter continues to apply the voltage to the brushless motor based on the detected current value. In the storage device equipped with the device, there has been a problem that it may cause a situation in which a desired capacity cannot be found.

  The present invention solves the above-described conventional problems. Even when the motor is abnormally stopped due to a factor other than an overcurrent, the abnormal stop of the motor is instantly recognized, and the inverter output to the motor is stopped, so that the early restart can be achieved. It is an object of the present invention to provide a motor drive device that can be activated and a storage device including the motor drive device.

  In order to solve the above-described conventional problems, a motor drive device according to the present invention includes a rectifier circuit that performs full-wave rectification using an AC power supply as an input, an inverter that receives an output voltage of the rectifier circuit with large pulsation, and an inverter. A brushless motor to be driven, an input voltage to the inverter, a motor current that flows to the brushless motor, and a motor current command value that indicates a value that should flow to the brushless motor are input, and the input voltage and the motor current are Based on the rotational phase of the brushless motor, and a controller that controls the inverter while maintaining the voltage phase of the voltage applied to the brushless motor, the controller based on the rotational phase and the applied voltage. It is a motor drive device characterized by determining an abnormal stop of the brushless motor.

  As a result, even when the motor is abnormally stopped due to a factor other than overcurrent, the motor drive device can recognize the abnormal stop of the motor instantly, and can be restarted early by stopping the inverter output to the motor. And the storage apparatus provided with the motor drive device is realizable.

  The motor drive device of the present invention can instantly recognize a motor abnormal stop even with factors other than overcurrent, and can stop the inverter output to the motor, so that it is possible to drive a brushless motor without using a position sensor. A low-cost and highly reliable motor driving device can be provided.

  In addition, the storage using such a motor drive device can be used as a compressor drive device as a motor drive device, and as a result, early restart is possible. A highly reliable storage device that eliminates losses such as corruption can be obtained.

  Furthermore, the storage using such a motor drive device can increase the volume in the storage with the miniaturization of the motor drive device as described above, and can improve the reliability of the storage.

  The invention described in claim 1 includes a rectifier circuit that performs full-wave rectification using an AC power supply as an input, an inverter that receives an output voltage of the rectifier circuit that has a large pulsation, a brushless motor that is driven by the inverter, and the inverter An input voltage, a motor current flowing through the brushless motor, and a motor current command value indicating a value to flow through the brushless motor are input, and the rotational phase of the brushless motor is determined based on the input voltage and the motor current. And a controller that controls the inverter while maintaining the voltage phase of the voltage applied to the brushless motor, and the controller determines an abnormal stop of the brushless motor from the rotation phase and the applied voltage. This is a motor drive device.

  With such a configuration, even when the brushless motor is abnormally stopped due to a factor other than an overcurrent, the abnormal stop of the brushless motor can be instantly recognized. Therefore, a highly reliable motor driving device can be provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the controller is configured to estimate the rotation of the brushless motor based on the motor current even when the voltage applied to the brushless motor becomes a predetermined value or less. The motor driving device is characterized in that when the state where the phase does not change continues for a certain period of time, the abnormal stop of the brushless motor is determined.

  By adopting such a configuration, when the brushless motor is abnormally stopped due to a factor other than overcurrent, it is erroneously recognized that the rotational phase of the brushless motor estimated based on the motor current is excessively advanced with respect to the rotational phase of the predetermined brushless motor. Without stopping, the abnormal stop of the brushless motor can be recognized instantly. Therefore, it is possible to provide a motor driving device with higher reliability.

  According to a third aspect of the present invention, in the first aspect of the present invention, the controller is configured to estimate the rotation of the brushless motor based on the motor current even when a voltage applied to the brushless motor becomes a predetermined value or more. The motor driving device is characterized in that when the state where the phase does not change continues for a certain period of time, the abnormal stop of the brushless motor is determined.

  By adopting such a configuration, when the brushless motor is abnormally stopped due to a factor other than overcurrent, it is erroneously recognized that the rotational phase of the brushless motor estimated based on the motor current is too late with respect to the rotational phase of the predetermined brushless motor. Thus, an abnormal stop of the brushless motor can be instantly recognized and early restart can be performed, and an overcurrent caused by an increase in the voltage applied to the brushless motor can be prevented. Therefore, it is possible to provide a motor driving device with higher reliability.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the control unit determines that the brushless motor is abnormally stopped, the output from the inverter is stopped. This is a featured motor drive device.

  By adopting such a configuration, when the brushless motor is abnormally stopped due to a factor other than overcurrent, it is possible to restart early after stopping the inverter output to the motor. Accordingly, it is possible to realize driving of a brushless motor that does not use a position sensor, and to provide a small and low-cost and highly reliable motor driving device.

  The invention according to claim 5 is a storage device including the motor drive device according to any one of claims 1 to 4, and can be restarted early, resulting in non-cooling in the warehouse. Loss such as food spoilage can be eliminated and the reliability of the storage can be improved.

  Further, the storage using such a motor driving device can increase the volume in the storage as the motor driving device is downsized as described above, and the inside of the storage for storing food with the same appearance by downsizing the circuit. The volume of can be increased.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same reference numerals are given to the same configurations as those of the conventional examples or the embodiments described above, and detailed descriptions thereof will be omitted. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a block diagram of a motor drive apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, an AC power source 1 is a commercial power source, which is AC 100 V, 50 Hz, or 60 Hz in Japan and is connected to a rectifier circuit 2. The rectifier circuit 2 includes a rectifier diode 3 in which four diodes indicated by reference numerals 3a, 3b, 3c, and 3d are bridge-connected, and a smoothing capacitor 4 having a small capacitance, and is full-wave rectified by the rectifier diode 3. The voltage is input to the smoothing capacitor 4.

  The inverter 5 has a configuration in which six sets of circuits each including a diode 5g connected in the opposite direction to the switching element 5a are used and these are connected in a three-phase bridge. Here, the respective switching elements are indicated by symbols 5a, 5b, 5c, 5d, 5e, and 5f, and the diodes are indicated by symbols 5g, 5h, 5i, 5j, 5k, and 5l. In the first embodiment, an FET is used for the inverter 5, but an IGBT or a bipolar transistor may be used.

  The brassless motor 6 is driven by the three-phase output of the inverter 5. The stator of the brushless motor 6 is provided with a three-phase star-connected winding, and this winding method may be concentrated winding or distributed winding. The rotor of the brushless motor 6 has a rare earth permanent magnet, and the arrangement method may be a surface magnet type (SPM) or a magnet embedded type (IPM). The permanent magnet may be a ferrite magnet or a rare earth magnet.

  The compression element 7 is connected to the shaft of the rotor of the brushless motor 6 and has a known configuration that sucks refrigerant gas, compresses it, and discharges it. The brushless motor 6 and the compression element 7 are accommodated in the same sealed container 8 to constitute a compressor 9.

  The discharge gas compressed by the compressor 9 constitutes a refrigeration air-conditioning system that returns to the suction of the compressor 9 through the condenser 10, the decompressor 11, and the evaporator 12, and the condenser 10 performs heat dissipation, Since the evaporator 12 absorbs heat, it can be cooled and heated.

  In addition, a heat exchanger may be further accelerated | stimulated using a fan etc. for the condenser 10 and the evaporator 12 as needed. Moreover, in this Embodiment 1, the said refrigeration air conditioning system is demonstrated by the case where it uses for the refrigerator 13 which is an example of a storage device, It is set as the structure which cools the inside 13a of the refrigerator 13 with the evaporator 12. FIG.

  The current detection circuit 14 is a circuit that detects a current flowing through the DC part of the inverter. In the first embodiment, the current detection circuit 14 is configured to detect using the shunt resistor 15, but a configuration using a current transformer may be used.

  The rotation speed setting means 16 sets the d-axis current command value Id * and the q-axis current command value Iq * calculated based on the rotation speed command, the torque command, and the like from input information such as outside temperature and switch input. The rotational speed at which the brushless motor 6 should be operated is set. Here, “*” attached to the previous current command value is for distinguishing from the driving currents Id and Iq, and the specific current values are also different.

  The first inverter control unit 17 controls the output of the inverter so as to drive the brushless motor 6 at the target rotational speed set by the rotational speed setting means 16.

  In the configuration of the first inverter control unit 17, the phase current calculation unit 107, the dq conversion unit 108, the d-axis PI controller 109, the q-axis PI controller 110, the PWM generation unit 111, and the overcurrent detection unit 112 are as follows. The configuration is exactly the same as that of the prior art, and detailed description thereof is omitted.

  The PWM storage unit 18 holds the PWM output duty values Vu, Vv, and Vw generated by the PWM generation unit 111 for a certain period, and sets the values at that time as Vu_z1, Vv_z1, and Vw_z1, respectively. When the overcurrent detection unit 112 detects an overcurrent, or the overcurrent detection unit 112 does not detect an overcurrent, the first stop determination unit 19 detects that the PWM output duty values Vu, Vv, Vw and the PWM storage unit 18 are Comparison between the stored Vu_z1, Vv_z1, Vw_z1 and the reference PWM output duty value V_min, and the motor current necessary for generating the PWM output duty value by the PWM generator 111, and the voltage applied to the brushless motor at that time The motor is stopped by comparing the rotor rotation phase Δθ of the motor estimated by the phase estimation calculation formula based on the voltage equation and the rotor rotation phase Δθ0 of the reference motor using the motor constant such as the resistance value and inductance of the brushless motor. Generates a PWM output duty to the PWM generator 111 when it is determined that To stop the bets stopping the rotation speed command to the rotational speed setting means 16. The first timer 20 is a timer that performs a count for the first stop determination unit 19 to determine the stop of the motor.

  The operation of the above configuration will be described below with reference to FIGS. 1, 2, 3 and 4. FIG.

  FIG. 2 is an operation flowchart of the motor driving apparatus according to the first embodiment, FIG. 3 is a timing chart showing the PWM signal operation according to the first embodiment, and FIG. 4 is a diagram showing a motor model for sensorless control according to the first embodiment. It is.

  Here, in FIG. 3, the inverter output U upper phase ON and OFF, U lower phase OFF and ON patterns are listed among the inverter PWM signal operation output patterns in one carrier, but the same applies to other patterns. And Also, in FIG. 4, the pattern when both the PWM output duty value Vu and Vu_z1 stored in the PWM storage unit 18 are smaller than the reference duty value V_min is cited, but the same applies to the other patterns. To do.

  In the flowchart of FIG. 2, in STEP 100, if the brushless motor 6 is not being driven, the first inverter control unit 17 returns to STEP 100 and waits until a rotation speed command is issued from the rotation speed setting means 16. When the rotational speed command is issued from the operation, the brushless motor 6 is regarded as being driven and the process proceeds to STEP 101.

  In STEP 101, if the first stop determination unit 19 determines that the overcurrent detection unit 112 has detected an overcurrent, the process proceeds to STEP 106, and if it is determined that the overcurrent detection unit 112 has not detected an overcurrent, the process proceeds to STEP 102.

  In STEP102, the first stop determination unit 19 compares the PWM output duty values Vu_z1, Vv_z1, and Vw_z1 one carrier before stored in the PWM storage unit 18 with the reference duty value V_min, and all are equal to or higher than the reference duty value V_min. If there is, proceed to STEP 107, and if any one is smaller, proceed to STEP 103. Here, in the first embodiment, only Vu_z1 is in a state of Vu_z1 <V_min.

  In STEP 103, the current PWM output duty values Vu, Vv, Vw generated by the PWM generation unit 111 by the first stop determination unit 19 are compared with the reference duty value V_min. Proceed to STEP 107, and if any one is smaller, proceed to STEP 104. Here, in the first embodiment, only Vu is in a state of Vu <V_min. The state (Vu_z1 <V_min and Vu <V_min) in the first embodiment in STEP102 and STEP103 is shown in the timing chart showing the PWM signal operation in FIG.

  In STEP 104, the motor current necessary for generating the PWM output duty value in the PWM generation unit 111 with respect to the rotor rotation phase Δθ0 of the reference motor by the first stop determination unit 19 and the voltage applied to the brushless motor at that time If the motor rotor rotational phase Δθ estimated by the phase estimation calculation formula based on the voltage equation is delayed using the value and the motor constant such as the resistance value and the inductance of the brushless motor, the process proceeds to STEP 107, and if advanced, the process proceeds to STEP 105 move on. The state in STEP 104 is shown in a diagram showing a motor model of sensorless control in FIG. Here, the state in the first embodiment is a state in which the estimated rotor rotation phase Δθ of the motor is advanced with respect to the rotor rotation phase Δθ0 of the reference motor.

  In STEP 105, it is determined by the first timer 20 whether an arbitrary set time (t1 sec in the first embodiment) has elapsed. If not, the process proceeds to STEP 107, and if it has elapsed, the process proceeds to STEP 106.

  In STEP 106, the output from the inverter 5 to the brushless motor 6 is stopped by stopping the generation of the PWM output duty values Vu, Vv, Vw of the PWM generator 111 by the first stop determination unit 19, and the rotation speed setting means 16 The rotation speed command is stopped and the process returns to STEP 100.

  In STEP 107, the current PWM output duty values Vu, Vv, Vw generated by the PWM generator 111 by the PWM storage unit 18 are updated from the PWM output duty values stored one carrier before, and the values at that time are updated. After returning to Vu_z1, Vv_z1, and Vw_z1, respectively, the process returns to STEP 100.

  As described above, according to the first embodiment, the brushless motor 6 may be caused by factors other than overcurrent from comparison with the reference PWM output duty value V_min, comparison with the rotor rotation phase Δθ0 of the reference motor, and time safety. Therefore, it is possible to determine that the rotation of the brushless motor is abnormally stopped without erroneously recognizing that the rotation phase of the brushless motor estimated based on the motor current has advanced too much with respect to the rotation phase of the predetermined brushless motor. Can recognize instantly. Therefore, a highly reliable motor driving device can be provided.

  In addition, when it is determined that the brushless motor has stopped abnormally, it is possible to stop the output from the inverter and to send an early notification that the brushless motor has also stopped to the rotation speed setting means. Even when an abnormal stop occurs, early restart after stopping the inverter output to the motor becomes possible.

  Accordingly, it is possible to realize driving of a brushless motor that does not use a position sensor, and to provide a small and low-cost and highly reliable motor driving device.

  In addition, by applying the motor driving device described above to a refrigerator, it is possible to eliminate waste due to abnormal shutdown of the motor and a delay in detection thereof, and food corruption, etc. By downsizing, the volume of the food storage part in the storage can be increased even with the same appearance, and a refrigerator with high internal volume efficiency can be provided.

(Embodiment 2)
FIG. 5 is a block diagram of a motor drive device according to Embodiment 2 of the present invention.

  In addition, about the same structure as FIG. 1 in the component in FIG. 5, since it has already demonstrated, it abbreviate | omits.

  In FIG. 5, the second inverter control unit 21 controls the output of the inverter so as to drive the brushless motor 6 at the target rotational speed set by the rotational speed setting means 16.

  In the configuration of the second inverter control unit 21, the phase current calculation unit 107, the dq conversion unit 108, the d-axis PI controller 109, the q-axis PI controller 110, the PWM generation unit 111, and the overcurrent detection unit 112 are as follows. The configuration is exactly the same as that of the prior art, and detailed description thereof is omitted. Further, the PWM storage unit 18 has the same configuration as that of the first embodiment, and a detailed description thereof will be omitted.

  When the overcurrent detection unit 112 detects an overcurrent, or the overcurrent detection unit 112 has not detected an overcurrent, the second stop determination unit 22 detects that the PWM output duty values Vu, Vv, Vw and the PWM storage unit 18 are Comparison between the stored Vu_z1, Vv_z1, Vw_z1 and the reference PWM output duty value V_max, and the motor current necessary for generating the PWM output duty value by the PWM generator 111, and the voltage applied to the brushless motor at that time The motor is stopped by comparing the motor rotation phase Δθ estimated by the phase estimation calculation formula based on the voltage equation and the rotor rotation phase Δθ1 of the reference motor using the motor constants such as the resistance value and inductance of the brushless motor. Generates a PWM output duty to the PWM generator 111 when it is determined that To stop the bets stopping the rotation speed command to the rotational speed setting means 16. The second timer 23 is a timer that performs a count for the second stop determination unit 22 to determine the stop of the motor.

  In the above configuration, the operation will be described below with reference to FIG. 5, FIG. 6, FIG. 7, and FIG.

  FIG. 6 is an operation flowchart of the motor driving apparatus in the second embodiment, FIG. 7 is a timing chart showing the PWM signal operation in the second embodiment, and FIG. 8 is a diagram showing a sensor model of the sensorless control in the second embodiment. It is.

  Here, in FIG. 7, the inverter output U upper phase ON and OFF, U lower phase OFF and ON patterns are listed among the inverter PWM signal operation output patterns in one carrier, but the same applies to other patterns. And Also, in FIG. 8, the pattern when the PWM output duty value Vu and the Vu_z1 stored in the PWM storage unit 18 are both larger than the reference duty value V_max is cited, but the same applies to the other patterns. To do.

  In the flowchart of FIG. 6, STEP 100 is the same as in the first embodiment.

  In STEP 101, if the second stop determination unit 22 determines that the overcurrent detection unit 112 has detected an overcurrent, the process proceeds to STEP 106, and if it is determined that the overcurrent detection unit 112 has not detected an overcurrent, the process proceeds to STEP 202.

  In STEP 202, the PWM output duty values Vu_z1, Vv_z1, and Vw_z1 one carrier before stored in the PWM storage unit 18 by the second stop determination unit 22 are compared with the reference duty value V_max, and all are equal to or less than the reference duty value V_max. If there is, proceed to STEP 107, and if any one is larger, proceed to STEP 203. Here, in the second embodiment, only Vu_z1 is in a state of Vu_z1> V_max.

  In STEP 203, the current PWM output duty values Vu, Vv, Vw generated by the PWM generation unit 111 by the second stop determination unit 22 are compared with the reference duty value V_max. Proceed to STEP 107, and if any one is larger, proceed to STEP 204. Here, in the second embodiment, only Vu is in a state of Vu> V_max. The states (Vu_z1> V_max and Vu> V_max) in the second embodiment in STEP 202 and STEP 203 are shown in the timing chart showing the PWM signal operation in FIG.

  In STEP 204, the motor current necessary for generating the PWM output duty value in the PWM generation unit 111 with respect to the rotor rotation phase Δθ1 of the reference motor by the second stop determination unit 22 and the voltage applied to the brushless motor at that time If the motor rotor rotational phase Δθ estimated by the phase estimation calculation formula based on the voltage equation is advanced using the value and the motor constant such as the resistance value and inductance of the brushless motor, the process proceeds to STEP 107, and if it is delayed, the process proceeds to STEP 205. move on. The state in STEP 204 is shown in a diagram showing a motor model of sensorless control in FIG. Here, the state in the second embodiment is a state in which the estimated rotor rotation phase Δθ of the motor is delayed with respect to the rotor rotation phase Δθ1 of the reference motor.

  In STEP 205, it is determined whether an arbitrary set time (t2 sec in the second embodiment) has elapsed by the second timer 23. If not, the process proceeds to STEP 107, and if it has elapsed, the process proceeds to STEP 106.

  STEP 106 and STEP 107 are the same as in the first embodiment.

  As described above, in the second embodiment, the brushless motor 6 can be detected by a factor other than the overcurrent from comparison with the reference PWM output duty value V_max, comparison with the rotor rotation phase Δθ1 of the reference motor, and time safety. Therefore, it is possible to determine that the rotation of the brushless motor has stopped abnormally without erroneously recognizing that the rotation phase of the brushless motor estimated based on the motor current is too late with respect to the predetermined rotation phase of the brushless motor. While being able to recognize instantly, the overcurrent caused by the increase in the applied voltage to a brushless motor can be prevented beforehand. Therefore, it is possible to provide a motor driving device with higher reliability.

  As described above, the motor driving apparatus of the present invention includes means that can determine that the motor is stopped abnormally even by a factor other than an overcurrent, thereby suppressing unnecessary inverter output when the brushless motor stops abnormally. The failure of the apparatus can be prevented, the size and cost can be reduced, and high reliability can be ensured. Therefore, the present invention can be widely applied to applications such as an AV device (particularly a small device) such as a device having a very small motor, which is difficult to attach a sensor, or a device whose circuit is very small.

1 is a block diagram of a motor drive device according to Embodiment 1 of the present invention. Operational Flowchart of Motor Drive Device in Embodiment 1 of the Present Invention Timing chart showing PWM signal operation in Embodiment 1 of the present invention The figure showing the motor model of sensorless control in Embodiment 1 of this invention Block diagram of a motor drive device in Embodiment 2 of the present invention Flowchart of operation of motor drive apparatus in Embodiment 2 of the present invention Timing chart showing PWM signal operation in Embodiment 2 of the present invention The figure showing the motor model of the sensorless control in Embodiment 2 of this invention Block diagram of a conventional motor drive device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectifier circuit 3 Rectifier diode 5 Inverter 6 Brushless motor 13 Refrigerator 17 1st inverter control part 19 1st stop determination part 21 2nd inverter control part 22 2nd stop determination part

Claims (5)

  A rectifying circuit that performs full-wave rectification using an AC power supply as an input, an inverter that receives an output voltage of the rectifying circuit having a large pulsation, a brushless motor driven by the inverter, an input voltage to the inverter, and the brushless motor And a motor current command value indicating a value that should flow to the brushless motor are input, the rotational phase of the brushless motor is estimated based on the input voltage and the motor current, and the brushless motor is supplied to the brushless motor. And a controller that controls the inverter while maintaining a voltage phase of an applied voltage, wherein the controller determines an abnormal stop of the brushless motor from the rotation phase and the applied voltage.   The control unit stops the brushless motor abnormally when a state in which the estimated rotation phase of the brushless motor does not change based on the motor current continues for a certain period of time even when the voltage applied to the brushless motor becomes a certain value or less. The motor driving device according to claim 1, wherein the motor driving device is determined.   The controller is configured to stop the brushless motor abnormally when a state where the estimated rotation phase of the brushless motor does not change based on the motor current continues for a certain period of time even when the voltage applied to the brushless motor exceeds a certain value. The motor driving device according to claim 1, wherein the motor driving device is determined.   4. The motor driving device according to claim 1, wherein when the control unit determines that the brushless motor is abnormally stopped, the output from the inverter is stopped. 5.   A storage device comprising the motor drive device according to any one of claims 1 to 4.

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