JP6319337B2 - Motor drive control device and air conditioner indoor unit - Google Patents

Description

  The present invention relates to start control in a motor drive control device that performs rotor position sensorless control.

  The rotor position sensorless control of the motor has an advantage that a magnetic sensor or the like for detecting the position of the rotor becomes unnecessary. Since the stop position of the rotor is unknown at the start, for example, there is a control method in which the rotor is held at a predetermined position by performing direct current excitation that causes a direct current to flow through the stator of the motor only at the start (for example, Patent Documents). 1). In addition, a technique for controlling the rotor to stop at a predetermined position when stopping is also proposed (for example, see Patent Document 2).

JP 2014-27735 A (paragraph [0097]) JP 2012-165612 A

  However, when the above-described DC excitation is performed on a motor that rotationally drives a rotating body (for example, a fan) having a large moment of inertia, the rotating body may vibrate. For example, in an indoor unit of an air conditioner that is suspended from the ceiling, when the fan vibrates, the housing may shake and generate abnormal noise.

  In view of such problems, the present invention provides a motor drive control device capable of preventing noise caused by vibrations of a rotating body such as a fan at the start and capable of performing a quiet start, and an indoor unit of an air conditioner including the motor drive control device. For the purpose.

  (1) The present invention is a motor drive control device that rotationally drives a motor having a rotor connected to a rotor, and an inverter that provides an output voltage to the stator of the motor; A control unit that controls the inverter to rotate the rotating body, and the control unit prevents the rotating body from reversing the acceleration rate of the fundamental frequency of the output voltage of the inverter and the amplitude of the output current. It is a motor drive control apparatus which has a function which makes the said inverter perform initial start control which suppresses and starts.

The control unit in such a motor drive control device suppresses the acceleration rate of the fundamental frequency of the output voltage and the amplitude of the output current at the time of starting, thereby reducing the rotational speed of the magnetic field and the rotational torque applied to the rotor from a very small level. It can be raised gradually. Thereby, no matter where the rotor stop position before starting is, the rotor and the rotating body do not reverse but begin to rotate normally slowly.
By performing such initial start control, even if a rotating body has a large moment of inertia, noises caused by vibrations of the rotating body at the time of starting and the housing that houses the rotating body are prevented, and a quiet start is performed. Can do. Further, suppressing the acceleration rate of the fundamental frequency of the output voltage and the amplitude of the output current also contributes to a reduction in reactive current at the time of starting. By reducing the reactive current, it is possible to start more silently.
In addition, the state of the rotor and the rotating body before starting includes not only the state of complete stop but also the state substantially equivalent to the stop, for example, the state of rotating at a very low speed less than a predetermined rotational speed. Can do.

(2) In the motor drive control device according to (1), the control unit performs start control for bringing the acceleration rate and the amplitude of the output current close to the steady operation state after the time of the initial start control. It may have a function to be performed.
In this case, after the initial start control time has elapsed, the control unit brings the acceleration rate of the fundamental frequency of the output voltage and the amplitude of the output current closer to the steady operation state and shifts to the steady operation state of the rotor position sensorless control. Can do.

(3) Further, in the motor drive control device of (2), a rotation detection unit that detects the rotation of the rotating body before starting is provided, and the rotating body in a state where drive control is not performed is less than a predetermined number of rotations It rotated forward or reverse at a rotational speed, or when they are stationary, the control unit performs the starting control, the rotating body in a state in which no drive control, and forward in the rotational speed more than a predetermined rotational speed In this case, the control unit may perform the rotor position sensorless control without performing the start control.
The start control can be performed when the rotating body in a state where drive control is not performed is rotating forward or reverse at a rotational speed less than a predetermined rotational speed or is stationary. Further, if the state where the rotation member by an external force convection, etc. inertia or air already forward at a predetermined rotational speed or more speed there is no need to perform the starting control, immediately rotor position is omitted this Sensorless control can be performed.

(4) In the motor drive control device of (2), the control unit has a function of direct current excitation of the stator, and the rotation of the rotating body reaches a predetermined state even if the initial start control is performed. If not, the rotor position sensorless control may be performed after the DC excitation.
As a result, if the desired initial start control is not successful due to the reverse rotation of the rotating body, the rotor position sensorless control can be performed after DC excitation instead. Note that the reverse rotation referred to here is a reverse rotation at a rotational speed that is not considered to be a stop.

  (5) On the other hand, the present invention is an indoor unit of an air conditioner having a fan that is rotatably supported in a housing, and a motor drive control device that rotationally drives a motor having the fan connected to a rotor. The motor drive control device includes an inverter that provides an output voltage to the stator of the motor, and a control unit that rotates the fan by controlling the inverter by rotor position sensorless control in a steady operation state. The control unit has a function of causing the inverter to perform initial start control for starting by suppressing the acceleration rate of the fundamental frequency of the output voltage of the inverter and the amplitude of the output current so that the fan does not reverse.

In the motor drive control device included in such an indoor unit of an air conditioner, the control unit suppresses the acceleration rate of the fundamental wave frequency of the output voltage and the amplitude of the output current at the time of starting, so that the rotation speed of the magnetic field and the rotor Can be gradually increased from an extremely small level. As a result, the rotor and the fan do not reverse, regardless of the stop position of the rotor before starting, and gradually start to rotate normally.
By performing such initial start control, even an indoor unit fan with a large moment of inertia can prevent noise caused by vibration of the fan and the housing that houses the fan at the start, and perform a quiet start Can do. Further, suppressing the acceleration rate of the fundamental frequency of the output voltage and the amplitude of the output current also contributes to a reduction in reactive current at the time of starting. By reducing the reactive current, it is possible to start more silently.

(6) In the indoor unit of (5), the control unit performs start control on the inverter so as to bring the acceleration rate and the amplitude of the output current close to the steady operation state after the time of the initial start control. It may have a function.
In this case, after the initial start control time has elapsed, the control unit brings the acceleration rate of the fundamental frequency of the output voltage and the amplitude of the output current closer to the steady operation state and shifts to the steady operation state of the rotor position sensorless control. Can do.

  According to the present invention, it is possible to prevent abnormal noise caused by vibration of a rotating body (for example, a fan) at the time of starting and to perform a quiet start.

It is a circuit diagram which shows an example of the motor drive control apparatus which drives the fan (motor) about the indoor unit of a type of air conditioner suspended from a ceiling, for example. It is a graph which shows the starting control by direct current excitation which is one already known method for the comparison. It is a graph which shows the starting control of the soft start which concerns on 1st Example. It is a graph which shows an example of the time change of fundamental wave frequency [rpm] of the output voltage of an inverter in the case of performing start control. 5 is a flowchart of start control shown in FIG. 4. It is a flowchart of the starting control which concerns on 2nd Example.

<Circuit configuration, etc.>
FIG. 1 is a circuit diagram illustrating an example of a motor drive control device that drives a fan (motor) of an indoor unit of an air conditioner that is suspended from a ceiling, for example. In the figure, the motor drive control device 1 includes a rectifier 6, a smoothing capacitor 7, and an inverter 8 as main main circuit components. The rectifier 6 is configured by bridge-connected diodes 2, 3, 4, and 5 and is connected to an AC power supply 20. The capacitor 7 smoothes the output voltage of the rectifier 6.

  The inverter 8 provides an inverter main circuit unit 8M configured by switching elements Q1, Q2, Q3, Q4, Q5, and Q6 connected in a three-phase full bridge, a switching control voltage, and a PWM (Pulse Width Modulation) signal. And a gate drive circuit 8G. The switching elements Q1, Q2, Q3, Q4, Q5, and Q6 are, for example, IGBTs (Insulated Gate Bipolar Transistors), and diodes d1, d2, d3, d4, d5, and d6 are connected in antiparallel.

  The three-phase output voltages Vu, Vv, Vw of the inverter 8 are supplied to the three-phase (U, V, W) windings of the stator 13 s of the motor 13. The rotor 13r is made of, for example, an outer rotor type permanent magnet and is connected to the fan 14.

  As control circuit elements, a voltage detection unit 11 that detects a voltage across the capacitor 7, a current detection unit 12 that detects a current supplied to the inverter main circuit unit 8M, and, for example, a U-phase of the stator 13s, W A rotation detector 9 connected to the phase is provided. The rotation detection unit 9 receives an induced voltage based on the rotation of the rotor 13r when the output of the inverter 8 is stopped. Based on this induced voltage, the rotation detector 9 can detect the rotation (rotation speed, rotation direction) of the rotor 13r due to rotation caused by the inertia of the fan 14 or an external force such as air convection. it can. When the inverter 8 stops outputting and the induced voltage cannot be detected, the rotor 13r is stopped.

  The detection outputs of the voltage detection unit 11, the current detection unit 12, and the rotation detection unit 9 are sent to the control unit 10. The control unit 10 controls the gate drive circuit 8G based on these detection outputs. The control unit 10 includes a CPU, a memory, and the like, and can perform rotor position sensorless control and start control described later. Note that the rotation detection unit 9 can be integrally configured as one function of the control unit 10.

  The motor drive control device 1 is housed in the housing 15 of the indoor unit together with the motor 13 and the fan 14. The fan 14 is rotatably supported in the housing 15.

<Normal operation state>
Next, control in the steady operation state of the motor drive control device 1 will be described. The AC voltage input from the single-phase AC power supply 20 is full-wave rectified by the rectifier 6 and further smoothed by the capacitor 7 to become a DC voltage. This DC voltage is supplied to the inverter main circuit unit 8M. Switching elements Q1 to Q6 constituting inverter main circuit unit 8M are PWM-controlled by gate drive circuit 8G based on voltage command value Vpwm instructed from control unit 10 that performs rotor position sensorless control. The output of the inverter 8 is supplied to the stator 13s as the voltage of the PWM pulse train for three phases.

  The rotor position sensorless control includes various parameters indicating the characteristics of the motor 13, the voltage Vfl detected by the voltage detection unit 11, the current Im detected by the current detection unit 12, a predetermined mathematical model related to the control of the motor 13, and the like. This is a known control method that performs estimation of the position of the rotor 13r, estimation of the rotational speed, PI control with respect to the rotational speed, PI control with respect to the current Im, and the like. Various parameters indicating the characteristics of the motor 13 include the winding resistance, inductance component, induced voltage, number of poles, and the like of the stator 13s. When the inverter 8 is switched, the control unit 10 estimates the position of the rotor 13r and the rotational speed of the fan 14, and outputs a voltage command value Vpwm corresponding to these estimation results. Since the rotor position sensorless control is a known control method, further detailed description is omitted here.

<Starting control by DC excitation>
Next, motor start control will be described. First, an image of start control will be described using a graph.
FIG. 2 is a graph showing start control by direct current excitation, which is one already known method, for comparison. FIG. 2A is a graph showing an example of a temporal change in output current applied to each of the U, V, and W phases of the motor 13 (stator 13s). Three-phase current is represented by a solid line, an alternate long and short dash line, and a dotted line. Although the output voltage is a PWM pulse, the output current is smoothed by the inductance of the stator 13s, and therefore can be represented by a smooth curve. FIG. 2B is a graph showing an example of a temporal change in the rotational speed [rpm] of the rotor 13r caused by passing a current as shown in FIG. The dotted line represents the rotational speed command value (the fundamental frequency of the output voltage), and the solid line represents the actual measurement value.

  In FIG. 2A, first, from time ta to tb, the rotor 13r whose stop position is unknown is guided to a predetermined position by direct current excitation. For example, if the U-phase current is represented by a solid line, the V-phase current is represented by a dotted line, and the W-phase current is represented by a one-dot chain line, the switching elements Q4 and Q5 in FIG. The current is as shown in FIG.

  In FIG. 2B, the command value for the rotation speed (rotation speed) is 0 until time tb, as indicated by the dotted line. However, the rotational speed of the actual measurement value repeats a process in which the rotor 13r is attracted to the guide position by direct current excitation, and is excessively attracted by the moment of inertia of the fan 14 and excessively attracted. Thus, the swing width of the rotor 13r gradually converges while repeating normal rotation and reverse rotation during direct current excitation.

  In addition, when the rotor 13r stops at the guide position by accident, the forward / reverse vibration does not occur. On the other hand, when the rotor 13r is stopped at a position farthest from the guide position, the amplitude of the forward / reverse vibration becomes the largest. That is, as described as the problem of the prior art, the vibration at the time of direct current excitation becomes large depending on the case, and an abnormal noise may be generated.

  In this way, the rotor 13r is positioned by causing the rotor 13r to settle at the guide position, and the rotor position sensorless control is performed after time tb. In other words, as the rotational speed command value increases, the inverter 8 supplies a three-phase AC output to the stator 13s, and the fundamental frequency of the output voltage gradually increases. Thus, the rotational speeds of the rotor 13r and the fan 14 are increased.

  If the DC excitation as described above is not performed, the rotor 13r cannot be positioned. In the rotor position sensorless control method, since there is no sensor for detecting the position of the rotor 13r, the stop position of the rotor 13r is unknown when the motor is not driven.

<Starting control by synchronous operation>
The inventors of the present application have found for the first time that by controlling the rotor 13r and the fan 14 not to reverse, the generation of noise due to the vibration of the rotor 13r and the fan 14 can be prevented and a quiet start can be performed. It was. Hereinafter, an embodiment incorporating such control will be described.

<< First Example >>
FIG. 3 is a graph showing the soft-start start control according to the first embodiment. FIG. 3A is a graph showing an example of a temporal change in output current applied to the U, V, and W phases of the motor 13 (stator 13s) at the time of starting. Three-phase current is represented by a solid line, a one-dot chain line, and a dotted line. FIG. 3B is a graph showing an example of a temporal change in the rotational speed [rpm] of the rotor 13r caused by passing a current as shown in FIG. The dotted line represents the rotational speed command value (the fundamental frequency of the output voltage), and the solid line represents the actual measurement value.

  In FIG. 3A, first, when starting control is started at time t0, the control unit 10 causes the inverter 8 to start synchronous operation by output of three-phase alternating current. However, the control unit 10 performs control so that the amplitude of the output current of the inverter 8 and the fundamental frequency of the output voltage gradually increase from near zero over time. Although the initial value of the output current immediately after the start is near 0, it is not 0 or the same value for the three phases, but is an instantaneous value of a three-phase alternating current with very small amplitude and frequency. Thus, the amplitude of the current immediately after starting is set to be small, and the amplitude of the current is increased as the deviation between the rotation of the magnetic field and the position of the rotor 13r is reduced by the synchronous operation.

  When the fundamental frequency of the output voltage of the inverter 8 is rapidly increased from the state where the stop position of the rotor 13r is unknown, for example, after the time tb in FIG. 2A, the rotor 13r and the fan 14 are reversed. In some cases, the inversion can be suppressed by controlling the fundamental frequency of the output voltage to gradually increase from near zero over time. Further, by controlling the amplitude of the output current of the inverter 8 to gradually increase from near zero over time, it is possible to prevent a sudden large rotational torque from being applied to the rotor 13r at the start, and the rotor 13r and the fan 14 Reversal can be suppressed. Note that how to set the acceleration rate of the fundamental frequency of the output voltage and the amplitude of the output current is verified by an actual machine, and optimal values are selected so that the rotor 13r and the fan 14 do not reverse.

By such starting control, as shown in FIG. 3B, the rotor 13r and the fan 14 smoothly increase the rotational speed along the command value, and the amount of deviation and increase / decrease of the rotational speed viewed from the command value are increased. The vibration is clearly reduced as compared with FIG. Also, during start-up, the rotational speed is not negative. That is, the rotor 13r and the fan 14 are not reversed during startup.
Such a start enables a quiet start of the fan 14.

FIG. 4 is a graph showing an example of a temporal change in the fundamental wave frequency [rpm] (hereinafter also referred to as inverter output frequency) of the output voltage of the inverter 8 when starting control is performed. Note that the lengths of the vertical and horizontal axes are not necessarily proportional to actual numerical values.
For example, if the engine is started at time t0, from 0 to N1 [rpm], the acceleration rate of the fundamental frequency of the output voltage is A1 [rpm / s] as the initial start control until time t1 (t1-t0). During this period, the inverter output frequency, that is, the rotational speed of the rotating magnetic field of the stator 13s is increased at a very slow pace. Next, from time t1 to t2, the acceleration rate is set to A2 [rpm / s], and the inverter output frequency is increased from N1 [rpm] to N2 [rpm] (t2-t1).

  Thereafter, similarly, the acceleration rate is A3 [rpm / s] from time t2 to t3, and the inverter output frequency is increased from N2 [rpm] to N3 [rpm] (t3-t2). Further, the acceleration rate is set to A4 [rpm / s] from time t3 to t4, and the inverter output frequency is increased from N3 [rpm] to N4 [rpm] (t4-t3). Up to this point, the start control is performed, and after time t4, the inverter output frequency is increased to a predetermined frequency by setting the acceleration rate to A5 [rpm / s] in a steady state.

  The above initial start control means a part of the initial start control, but the time t0 to t1 is an example, and the initial start is from t0 to t2 or from t0 to t3. It can also be considered as control.

  FIG. 5 is a flowchart of the start control shown in FIG. The execution subject of the flowchart is the control unit 10 (FIG. 1). In FIG. 5, for example, it can be said that steps S1 to S5 are start control. During start control, the amplitude of the output current of the inverter 8 gradually increases from near zero.

  When the start control is started, the control unit 10 determines whether or not the start is from a state where the rotor 13r and the fan 14 are stopped (step S1). At this time, the control part 10 can grasp | ascertain whether the rotor 13r and the fan 14 have stopped by the detection signal of the rotation detection part 9 (FIG. 1). That is, when the inverter 8 is not operating and the rotor 13r is rotated by an inertia or an external force such as air convection, the induced voltages Viu and Viw are generated. The rotation of the rotor 13r can be detected.

  Note that “stop” includes not only a complete stop but also a state substantially equivalent to the stop, for example, rotation at a very low speed (for example, less than N1 [rpm]) (forward rotation / reverse rotation). In addition, the state which is doing can also be included (the same applies hereafter).

  In the case of starting from the stop, the control unit 10 performs initial start control for increasing the inverter output frequency from 0 to N1 [rpm] at the acceleration rate A1 [rpm / s] (step S2). Subsequently, the inverter output frequency is increased from N1 to N2 [rpm] at an acceleration rate A2 [rpm / s] (step S3). Further, the inverter output frequency is increased from N2 to N3 [rpm] at the acceleration rate A3 [rpm / s] (step S4). Then, the inverter output frequency is increased from N3 to N4 [rpm] at an acceleration rate A4 [rpm / s] (step S5).

  When the start control is completed, the control unit 10 increases the speed to a desired number of revolutions at A5 [rpm / s], which is a steady-state acceleration / deceleration rate, and enters a steady operation state (step S6). Thereafter, when a stop command is issued while performing acceleration / deceleration as necessary (step S7), the operation of the inverter 8 is stopped.

  In step S1, when the engine is not started from the stop, that is, the rotor 13r and the fan 14 are rotated (forward rotation) at a rotational speed equal to or higher than a predetermined rotational speed (for example, N4 [rpm]) by inertia or external force. In some cases, start control is not required. Therefore, the control unit 10 skips the start control (steps S2 to S5) and performs steady operation at the steady-state acceleration / deceleration rate (step S6). In short, it is not necessary to perform start control if the fan 14 in a state where drive control is not performed is rotating forward at a rotational speed of a predetermined rotational speed or more by an external force such as inertia or air convection. The controller 10 can omit this and immediately perform rotor position sensorless control.

<Summary>
As described above, the control unit 10 in the motor drive control device 1 performs the initial start control that suppresses the acceleration rate of the fundamental frequency of the output voltage of the inverter 8 and the amplitude of the output current at the start, thereby rotating the magnetic field. The speed and the rotational torque applied to the rotor 13r can be gradually increased from an extremely small level. Thereby, no matter where the stop position of the rotor 13r before starting is, the rotor 13r and the fan 14 do not reverse but start to rotate normally slowly. Thereafter, the control unit 10 can shift the acceleration rate of the fundamental frequency of the output voltage and the amplitude of the output current to the steady operation state and shift to the steady operation state of the rotor position sensorless control.

  By performing such start control, even if the fan 14 has a large moment of inertia, abnormal noise caused by vibration of the fan 14 at the time of start-up (particularly at the time of start-up by the initial start-up control) and the casing 15 housing the fan 14 is generated. It is possible to prevent and quiet start. In addition, by suppressing the acceleration rate of the fundamental frequency of the output voltage, the amplitude of the output current can be suppressed compared to the amplitude of the output current required for positioning by DC excitation, reducing the reactive current at the start Also contributes. Since the reactive current invites an excitation sound, if the reactive current at the time of starting is reduced, the excitation sound is reduced and a more quiet start can be performed.

  In addition, the output current required when the fan 14 is reversed compared to the amplitude of the output current required when starting from a state where the fan 14 is stopped (including extremely slow rotation) or rotating forward. The amplitude increases. Therefore, if the fan 14 does not substantially reverse due to the installation environment or the like, the output required when the fan 14 is stopped (including extremely slow rotation) or started from a normal rotation state. The amplitude of the output current may be suppressed so that it is equal to or greater than the amplitude of the current and less than the amplitude of the output current required when the fan 14 is reversed. By suppressing the amplitude of the output current in this way, the fan 14 can be started without any problem in practice, and the excitation sound caused by the reactive current can be further reduced.

<< Second Embodiment >>
The second embodiment is a start control that incorporates DC excitation while being based on the start control of the first embodiment.
FIG. 6 is a flowchart of start control according to the second embodiment. The execution subject of the flowchart is the control unit 10 (FIG. 1). In FIG. 6, for example, it can be said that the other steps excluding steps S6 and S7 are start control. When the operation is performed in the order of steps S1a, S2, S2a, S3, S4, and S5, the starting control is substantially the same as in FIG. Increase.

In FIG. 6, when starting control is started, the control unit 10 determines whether or not the rotor 13r and the fan 14 are rotating forward (step S1a). Forward rotation means a state in which the rotor 13r and the fan 14 are already rotating at a rotational speed that does not require starting control. The state that is not forward rotation includes stop and reverse rotation. The control unit 10 can grasp whether the rotor 13r and the fan 14 are in a stopped, normal rotation, or reverse rotation state from the detection signal of the rotation detection unit 9.
Since the start control is not required during normal rotation, the control unit 10 performs steady operation at a steady-state acceleration / deceleration rate (step S6).

On the other hand, in the case of starting from stop or reverse rotation, the control unit 10 increases the inverter output frequency from 0 to N1 [rpm] at the acceleration rate A1 [rpm / s] (step S2). Next, the control unit 10 checks whether the rotor 13r and the fan 14 have started normally as in step S2 (step S2a). For example, if the operation of the inverter 8 is stopped for a short time and the induced voltage from the stator 13s is detected by the rotation detector 9, the check can be performed based on the detection signal.
When the rotor 13r and the fan 14 are normally started, the processes in steps S3 to S7 are performed similarly to the case of FIG.

  On the other hand, if the rotor 13r and the fan 14 have not started normally in step S2a, the control unit 10 increments the number of events by 1 from the initial value 0 (step S8), and determines whether or not the predetermined number has been reached. Is determined (step S9). Until the predetermined number of times is reached, the process of step S2, step S2a, step S8, and step S9 is repeated. The case where the engine has not started normally is either (i) stopped, (ii) rotating forward but not reaching 16 [rpm], or (iii) rotating backward. is there.

  If the initial start control in step S2 is tried a predetermined number of times in this manner, there is a possibility that the start is successful even if the start is from the reverse direction. On the other hand, if the initial start control in step S2 is repeatedly attempted and the engine does not start normally and reaches a predetermined number of times (Yes in step S9), the control unit 10 resets the count in step S10, Excitation is executed (step S11). After positioning the rotor 13r by direct current excitation, the control unit 10 performs steady operation at a steady-state acceleration / deceleration rate (step S6). The amplitude of the output current of direct current excitation (step S11) is made larger than the amplitude of the output current of initial start control (step S2).

  In this manner, when the soft start start control is not successful due to the reverse rotation of the fan 14, the rotor position sensorless control can be performed after positioning by DC excitation instead.

  In the flowchart of FIG. 6, an example is shown in which the initial start control is set to step S2 and the normal start is checked immediately after step S2 (step S2a). Depending on how far the start control is considered, a step for checking whether or not the engine is normally started can be provided immediately after step S3 or immediately after step S4.

<Others>
The motor drive control device 1 described above is described as an example that is mounted on an indoor unit of an air conditioner and rotates a fan. However, a motor drive control device that performs similar start control is a rotor position sensorless device. A synchronous motor that employs a control method is mounted, and the present invention can be applied to various electric devices that generate abnormal noise due to vibration at the time of starting on a rotating body such as a fan.

1: motor drive control device, 2-5: diode, 6: rectifier, 7: capacitor, 8: inverter, 8M: inverter main circuit unit, 8G: gate drive circuit, 9: rotation detection unit, 10: control unit, 11 : Voltage detector, 12: Current detector, 13s: Stator, 13r: Rotor, 13: Motor, 14: Fan, 15: Housing, 20: AC power supply, Q1-Q6: Switching element, d1-d6: Diode

Claims (6)

A motor drive control device (1) for rotationally driving a motor (13) having a rotor (14r) connected to a rotor (13r),
An inverter (8) for providing an output voltage to the stator (13s) of the motor (13);
In a steady operation state, the control unit (10) for rotating the rotating body (14) by controlling the inverter (8) by rotor position sensorless control,
The control unit (10) performs initial start control for starting by suppressing the acceleration rate of the fundamental frequency of the output voltage of the inverter (8) and the amplitude of the output current so that the rotating body (14) does not reverse. A motor drive control device having a function to be performed by the inverter (8).   The said control part (10) has a function which makes the said inverter (8) perform starting control which brings the acceleration rate and the amplitude of the said output current close to the said steady operation state through the time of the said initial starting control. The motor drive control device according to 1. A rotation detector (9) for detecting the rotation of the rotating body (14) before starting;
When the rotating body (14) in a state where drive control is not performed is rotated forward or reverse at a rotational speed less than a predetermined rotational speed , or is stationary, the control unit (10) performs the start control,
When the rotating body in a state where no drive control (14), which is forward in the rotational speed over the predetermined rotation speed, the control unit (10), without performing the starting control, the rotor position The motor drive control device according to claim 2 which performs sensorless control. The control unit (10) has a function of DC exciting the stator (13s),
3. The motor drive control according to claim 2, wherein if the rotation of the rotating body (14) does not reach a predetermined state even after the start control is performed, the rotor position sensorless control is performed after the DC excitation is performed. apparatus. A fan (14) rotatably supported in a housing (15), and a motor drive control device (1) that rotationally drives a motor (13) having the fan (14) connected to a rotor (13r). An indoor unit of an air conditioner having the motor drive control device (1)
An inverter (8) for providing an output voltage to the stator (13s) of the motor (13);
In a steady operation state, a controller (10) that controls the inverter (8) by rotor position sensorless control to rotate the fan (14), and
The control unit (10) performs initial start control for starting by suppressing an acceleration rate of a fundamental wave frequency of an output voltage of the inverter (8) and an amplitude of an output current so that the fan (14) does not reverse. An indoor unit of an air conditioner having a function to be performed in (8).   The said control part (10) has a function which makes the said inverter (8) perform starting control which brings the acceleration rate and the amplitude of the said output current close to the said steady operation state through the time of the said initial starting control. 5. An indoor unit of an air conditioner according to 5.

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