JP2009038867A - Motor drive controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for motor, which starts a motor surely even in such a state that the motor is rotating in its normal direction or its reverse direction, while influenced by a headwind or a tailwind, etc., when stating the motor. <P>SOLUTION: A motor drive controller 1 is equipped with a drive voltage output part 10, a power source 11, and a drive voltage regulator 6. The drive voltage output part 10 outputs drive voltages SU1, SV1 and SW1 for driving the motor 51 to the motor 51. The power source 11 supplies the drive voltage output part 10 with power voltage Vcc. The drive voltage regulator 6 regulates the drive voltages SU1, SV1 and SW1 at start of the motor 51, so that the power voltage Vcc may be boosted by the regeneration operation of the motor 51, in the case where the motor 51 is rotating just before it starts. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motor drive control device.

  In recent years, in an air conditioner provided with devices such as a compressor and a fan, a motor is often used as a power source of these devices. The air conditioner further includes a drive device that drives the motor.

  Here, the case where a motor is used, for example as a power source of an outdoor fan is demonstrated. When the driving device tries to start the motor, if an external force in the reverse rotation direction is applied to the outdoor fan due to the influence of a reverse wind or the like, the motor rotates in the reverse rotation direction. When the motor is started in this state, a larger current flows through the motor than when the motor starts normally when no external force is applied to the outdoor fan as in the case of no wind. In particular, this current increases as the rotational speed of the motor toward the reverse rotation side increases. As described above, when the current flowing through the motor increases, the amount of heat generated in the output circuit in the drive device driving the motor increases, and for example, the switching elements constituting the output circuit may be destroyed.

Therefore, in Patent Document 1, an upper limit value of the rotation speed at the time of reverse rotation of the motor is provided, and when the rotation speed when the motor rotates in the reverse rotation direction exceeds this upper limit value, the rotation of the motor is stopped. Is disclosed.
JP-A-8-303386

  However, in Patent Document 1, for example, when the back wind is strong before the motor is started, the rotational speed of the motor in the reverse rotation direction exceeds the upper limit value before the start, and the motor may not be started. Also, for example, when two fans are arranged side by side in one air flow path in the air conditioner, if one fan is driven in the normal rotation direction, the other fan It may rotate in the reverse rotation direction due to the influence. This phenomenon is likely to occur particularly when the static pressure difference between the inside and outside of the air conditioner is high. However, even in such a case, when starting the other fan, if the other fan is strongly influenced by one fan and is rotating in the reverse direction, the motor for driving the other fan There is a possibility that the number of rotations exceeds the upper limit before starting. As a result, this motor cannot be started.

  On the other hand, when an external force is applied in the forward rotation direction of the fan due to the influence of forward wind, etc., and the motor is rotating in the forward rotation direction from before starting, the motor is rotating in the reverse rotation direction from before starting. As in the case of starting the motor, there may be a case where a larger current flows through the motor than when the motor is started in a state where no external force is applied to the outdoor fan.

  Therefore, according to the present invention, when starting the motor, the motor can be reliably started even when the motor is rotating in either the forward direction or the reverse direction due to the influence of the reverse wind or the forward wind. An object of the present invention is to provide a motor drive control device that can be used.

  A motor drive control device according to a first aspect includes a drive voltage output unit, a power supply unit, and a drive voltage adjustment unit. The drive voltage output unit outputs a drive voltage for driving the motor to the motor. The power supply unit supplies a power supply voltage to the drive voltage output unit. The drive voltage adjusting unit adjusts the drive voltage at the time of starting the motor so that the power supply voltage is boosted by performing the regenerative operation when the motor is rotating immediately before starting.

  When the motor has already been rotated before starting, the motor drive control device causes the motor to perform a regenerative operation immediately after starting the motor to boost the power supply voltage. As a result, when the motor is started, the rotational energy of the motor is regenerated to the power source, and thus a torque that reduces the rotational speed is applied to the motor. Therefore, an increase in the current supplied to the motor immediately after the start is suppressed. . Therefore, the motor can be started reliably.

  A motor drive control device according to a second aspect of the present invention is the motor drive control device according to the first aspect of the present invention, wherein the drive voltage adjusting unit adjusts the drive voltage so as to reduce the rotation speed of the motor.

  As a result, when the motor is started, the number of rotations of the motor is reduced, so that the current supplied to the motor at the time of starting the motor does not need to increase. Therefore, the motor can smoothly accelerate.

  A motor drive control device according to a third aspect of the present invention is the motor drive control device according to the first or second aspect of the present invention, wherein the drive voltage adjusting unit is driven such that a torque is generated in a direction opposite to the rotational direction immediately before the start of the motor. The voltage is determined and the drive voltage is set to a predetermined drive voltage or less.

  This motor drive control device outputs a drive voltage that generates torque in a direction opposite to the rotational direction immediately before the start of the motor and that is equal to or lower than a predetermined drive voltage to the motor. In this case, the motor performs a regenerative operation at the time of start-up, and the power supply voltage rises. Therefore, the rotational energy of the motor is converted into electric energy, and the rotational speed of the motor decreases. Therefore, an increase in the amount of current energized to the motor immediately after startup can be suppressed.

  A motor drive control device according to a fourth aspect of the present invention is the motor drive control device according to claim 3, wherein the drive voltage adjustment unit has a predetermined amount of deviation between the phase of the current flowing through the motor and the phase of the induced voltage generated in the motor. As described above, the driving voltage is determined so that torque in the direction opposite to the rotation direction immediately before the motor is started is generated.

  If there is a discrepancy between the phase of the current applied to the motor and the phase of the induced voltage generated in the motor, the power supply can be used to generate torque in the direction opposite to the rotational direction immediately before starting the motor. The voltage may be boosted. When the motor generates torque in the direction opposite to the rotational direction immediately before startup, the power supply voltage is more likely to be boosted as the phase shift increases. Therefore, this motor drive control device has a torque in the direction opposite to the rotational direction immediately before the start of the motor so that the deviation between the phase of the current applied to the motor and the phase generated in the motor is a predetermined amount or more. The generated drive voltage is output to the motor. Thereby, the motor drive control device can boost the power supply voltage.

  A motor drive control device according to a fifth aspect of the present invention is the motor drive control device according to the third or fourth aspect of the present invention, wherein the predetermined drive voltage is increased when the motor is started from the rotational state of the motor immediately before the motor is started. The voltage value is less than or equal to.

  A voltage to be applied to the motor in order to boost the power supply voltage has a critical value, and when a driving voltage lower than the critical value is applied to the motor, a boosting operation of the power supply voltage occurs. Here, this critical value is referred to as a voltage value at which the power supply voltage is boosted. Since this motor drive control device applies a drive voltage that is equal to or lower than the voltage value at which the power supply voltage is boosted to the motor, The voltage can be boosted.

  A motor drive control device according to a sixth aspect of the present invention is the motor drive control device according to the third or fourth aspect, wherein the predetermined drive voltage is smaller than an induced voltage generated in the motor.

  When the drive voltage applied to the motor is adjusted below the induced voltage generated in the motor, current flows from the motor to the power supply unit side. As a result, a so-called regenerative operation in which energy is supplied from the motor side to the power supply unit side occurs, so that the power supply voltage can be boosted.

  A motor drive control device according to a seventh aspect of the present invention is the motor drive control device according to any of the first to sixth aspects, wherein the drive voltage adjusting unit further adjusts the drive voltage based on the rotational speed of the motor.

  This motor drive control device further adjusts the drive voltage according to the number of rotations of the motor so that the boosted power supply voltage does not exceed the ratings of components such as switching elements in the drive voltage output section. Thereby, it can prevent that components, such as a switching element, are damaged from the boosted power supply voltage, and can ensure reliability.

  A motor drive control device according to an eighth aspect is the motor drive control device according to the first or second aspect, wherein the motor is a motor having two or more phases. The drive voltage output unit includes a plurality of upper switching elements respectively connected between the positive terminal of the power supply unit and each phase of the motor, and a plurality of each connected between the negative terminal of the power supply unit and each phase of the motor. And a lower switching element. Then, the drive voltage adjusting unit turns on and off the lower switching element for outputting at least one phase of the drive voltage output to each phase of the motor at a predetermined frequency.

  This motor drive control device chops at least one lower switching element at a predetermined frequency immediately after the motor is started. In this case, the motor performs a regenerative operation, and the rotational energy of the motor is converted into electric energy and regenerated on the power supply unit side, the power supply voltage is increased, and the rotational speed of the motor is reduced. Therefore, an increase in the current flowing to the motor immediately after startup is suppressed.

  A motor drive control device according to a ninth aspect of the present invention is the motor drive control device according to the eighth aspect of the present invention, wherein the drive voltage adjustment unit determines a ratio between an on time for turning on the lower switching element and an off time for turning off the motor. Determine based on the number.

  In this motor drive control device, the ratio of the on time and the off time of the lower switching element to be chopped is set so that, for example, the boosted power supply voltage does not exceed the rating of components such as the switching element in the drive voltage output unit. Determined according to the motor speed. Thereby, it can prevent that components, such as a switching element, are damaged from the boosted power supply voltage, and can ensure reliability.

  A motor drive control device according to a tenth aspect of the present invention is the motor drive control device according to any one of the first to ninth aspects, wherein the number of rotations in the rotational direction in which the motor is rotating immediately before the start after the motor is started is a predetermined number or less. In this case, the drive voltage adjustment unit changes the drive voltage to the drive voltage at the normal rotation of the motor.

  For example, when the motor is rotating in the reverse rotation direction immediately before starting, the motor drive control device can reduce the drive voltage during normal rotation when the number of rotations in the reverse rotation direction of the motor becomes less than a predetermined number after starting. Output to the motor. As a result, the motor can reliably perform normal rotation.

  A motor drive control device according to an eleventh aspect of the present invention is the motor drive control device according to any of the first to ninth aspects, wherein the rotation direction immediately before the start of the motor is reverse rotation, and the rotation direction of the motor after the start of the motor When becomes the forward rotation direction, the drive voltage adjustment unit changes the drive voltage to a drive voltage during normal rotation of the motor.

  According to this motor drive control device, when the rotation direction of the motor that has been rotating in the reverse rotation direction immediately before activation becomes the normal rotation direction, the drive voltage during normal rotation is output to the motor. As a result, the motor can reliably perform normal rotation.

  A motor drive control device according to a twelfth aspect of the present invention is the motor drive control device according to any of the first to ninth aspects of the present invention, further comprising a time measuring unit. The time measuring unit measures the time after the motor is started. And when the time currently measured by the time measurement part passes predetermined time, a drive voltage adjustment part changes a drive voltage into the drive voltage at the time of normal rotation of a motor.

  According to this motor drive control device, after a predetermined time has elapsed, the drive voltage during normal rotation is output to the motor. As a result, the motor can reliably perform normal rotation.

  A motor drive control device according to a thirteenth aspect of the present invention is the motor drive control device according to any of the first to twelfth aspects of the present invention, further comprising a current protection unit. The current protection unit protects the current flowing in the regeneration direction of the motor when the motor is performing the regeneration operation.

  As a result, it is possible to prevent the current flowing from the motor to the components such as the switching elements in the drive voltage output section from exceeding the ratings of these components and damaging the components during the regenerative operation of the motor.

  A motor drive control device according to a fourteenth aspect of the present invention is the motor drive control device according to any of the first to thirteenth aspects of the present invention, wherein the drive voltage adjusting unit is driven by the drive voltage output unit when the power supply voltage is equal to or higher than the first predetermined value. Stop driving voltage output.

  Here, as the first predetermined value, for example, a value determined according to the rating of a component such as a switching element in the drive voltage output unit can be cited. The motor drive control device stops the output of the drive voltage when the boosted power supply voltage exceeds the first predetermined value. Therefore, the boosted power supply voltage is rated for components such as switching elements in the drive voltage output section. It is possible to prevent the parts from being damaged.

  A motor drive control device according to a fifteenth aspect of the present invention is the motor drive control device according to any of the first to fourteenth aspects of the present invention, wherein the power supply unit has a charge storage unit capable of storing a charge corresponding to the boosted power supply voltage.

  As a result, the power supply unit can suppress an increase in the power supply voltage even when the boosting operation is performed. For example, the rating of the components such as the switching element in the drive voltage output unit is exceeded, and the components are damaged. Can be prevented.

  A motor drive control device according to a sixteenth aspect of the present invention is the motor drive control device according to the fifteenth aspect of the present invention, further comprising a discharge unit and a discharge control unit. The discharge part can discharge the charge accumulated in the charge accumulation part. The discharge control unit controls the discharge unit such that at least a part of the charge stored in the charge storage unit is discharged when the power supply voltage is equal to or higher than the second predetermined value.

  Here, as the second predetermined value, for example, a value determined according to a rating of a component such as a switching element in the drive voltage output unit can be cited. In such a case, when the boosted power supply voltage exceeds the second predetermined value, the motor drive control device discharges at least part of the charge accumulated in the charge accumulation unit. As a result, the number of rotations of the motor can be reduced, and the boosted power supply voltage can be prevented from exceeding the ratings of components such as switching elements in the drive voltage output section, for example, and damaging the components.

  According to the motor drive control device of the first aspect of the present invention, when the motor is started, the rotational energy of the motor is regenerated to the power source, so that a torque that reduces the rotational speed is applied to the motor. The increase in current is suppressed. Therefore, the motor can be started reliably.

  According to the motor drive control device of the second aspect of the present invention, the number of rotations of the motor decreases when the motor is started, so that the current supplied to the motor does not increase when the motor is started. Therefore, the motor can smoothly accelerate.

  According to the motor drive control device of the third aspect of the present invention, when the motor is started up, the power supply voltage is boosted, so that the rotational energy of the motor is converted into electrical energy, and the rotational speed of the motor is reduced. Therefore, an increase in the current flowing to the motor immediately after startup is suppressed.

  According to the motor drive control device pertaining to the fourth aspect of the present invention, the power supply voltage can be boosted.

  According to the motor drive control device of the fifth aspect of the present invention, since the drive voltage that is equal to or lower than the voltage value at which the power supply voltage is boosted is applied to the motor, the power supply voltage is reliably boosted.

  According to the motor drive control device of the sixth aspect of the invention, a so-called regenerative operation in which energy is supplied from the motor side to the power supply unit side occurs, so that the power supply voltage can be boosted.

  According to the motor drive control device pertaining to the seventh aspect of the present invention, it is possible to prevent components such as switching elements from being damaged by the boosted power supply voltage, and to ensure reliability.

  According to the motor drive control device of the eighth aspect of the present invention, the power supply voltage rises when the motor is started. Therefore, the rotational energy of the motor is converted into electric energy and regenerated on the power supply unit side, and the rotational speed of the motor decreases. Therefore, an increase in the amount of current energized to the motor immediately after startup can be suppressed.

  In the motor drive control device according to the ninth aspect of the present invention, the ratio of the on-time and the off-time of the lower switching element to be chopped, for example, the boosted power supply voltage does not exceed the ratings of the components such as the switching element in the drive voltage output unit. Thus, it determines according to the rotation speed of a motor. Thereby, it can prevent that components, such as a switching element, are damaged from the boosted power supply voltage, and can ensure reliability.

  According to the motor drive control devices according to the tenth to twelfth aspects of the present invention, the motor can be reliably rotated normally.

  According to the motor drive control device pertaining to the thirteenth aspect of the present invention, during the regenerative operation of the motor, the current flowing from the motor to components such as switching elements in the drive voltage output section exceeds the ratings of these components, and the components are damaged. Can be prevented.

  The motor drive control device according to the fourteenth aspect of the present invention stops the output of the drive voltage when the boosted power supply voltage exceeds the first predetermined value, so that the boosted power supply voltage is a component such as a switching element in the drive voltage output unit. It is possible to prevent the parts from being damaged due to exceeding the ratings.

  According to the motor drive control device of the fifteenth aspect of the present invention, the power supply unit can suppress an increase in the power supply voltage even when the boosting operation is performed. For example, the power supply unit exceeds the rating of components such as switching elements in the drive voltage output unit. This can prevent the parts from being damaged.

  When the boosted power supply voltage exceeds the second predetermined value, the motor drive control device according to the sixteenth aspect of the invention discharges at least a part of the charge accumulated in the charge accumulation unit. As a result, the number of rotations of the motor can be reduced, and the boosted power supply voltage can be prevented from exceeding the ratings of components such as switching elements in the drive voltage output section, for example, and damaging the components.

(1) Overall and Motor Configuration FIG. 1 is an overall configuration diagram of a motor drive control system 100 including a motor 51 and a motor drive control device 1 for controlling the drive of the motor 51. Here, generally, a DC motor, an AC motor, a stepping motor, a brushless DC motor, or the like can be cited as the type of motor. In this embodiment, the motor 51 is a brushless DC motor.

  The motor 51 is a three-phase outdoor unit fan motor used as a drive source of the propeller fan 61 in the outdoor unit of the air conditioner, and includes a stator 52, a rotor 53, and three Hall elements 54a, 54b, 54c. I have.

  The stator 52 includes U-phase, V-phase, and W-phase drive coils Lu, Lv, and Lw that are star-connected. One end of each of the U-phase, V-phase and W-phase drive coils Lu, Lv and Lw is connected to the U-phase, V-phase and W-phase drive coil terminals TU, TV and TW, respectively. It is connected to the. These three-phase drive coils Lu, Lv, and Lw generate an induced voltage according to the rotational speed and the position of the rotor 53 as the rotor 53 rotates.

  The rotor 53 includes a two-pole permanent magnet composed of an N pole and an S pole, and rotates about the rotation axis with respect to the stator 52. The rotation of the rotor 53 is output to the propeller fan 61 via an output shaft (not shown) that is on the same axis as the rotation shaft.

  The three Hall elements 54a to 54c detect the position of the rotor 53 with respect to the stator 52 based on the polarity of the permanent magnet of the rotor 53, and position detection signals Hu and Hv indicating the position of the rotor 53 after detection. , Hw is output to the motor drive control device 1.

(2) Configuration of Motor Drive Control Device Next, the configuration of the motor drive control device 1 according to the present embodiment will be described. As shown in FIG. 1, the motor drive control device 1 of the present embodiment includes a rotation direction detection unit 2, a rotation number measurement unit 3, a timer 4 (corresponding to a time measurement unit), a control unit 5, a drive voltage output unit 10, A power supply unit 11, a discharge unit 12, a voltage detection unit 13, a current detection unit 14, and an overcurrent protection unit 15 are provided.

(Rotation direction detector)
The rotation direction detection unit 2 detects the rotation direction of the rotor 53 in the motor 51 using the position detection signals Hu, Hv, and Hw output from the hall elements 54a to 54c. Hereinafter, in order to simplify the description, the rotation direction of the rotor 53 in the motor 51 is simply referred to as “the rotation direction of the motor 51”.

  The detected rotation direction of the motor 51 is taken into the control unit 5.

[Rotation speed measurement unit]
The rotation speed measurement unit 3 measures the rotation speed of the rotor 53 in the motor 51 using the position detection signals Hu, Hv, Hw output from the hall elements 54a to 54c. Hereinafter, in order to simplify the description, the rotational speed of the rotor 53 in the motor 51 is simply referred to as “the rotational speed of the motor 51” as in the rotational direction of the motor 51.

  The measured number of rotations of the motor 51 is taken into the control unit 5.

[Timer]
The timer 4 measures the time after the motor 51 is started. The measured time is taken into the control unit 5 in the same manner as the rotation direction and the rotation speed of the motor 51.

(Control part)
The control unit 5 is a microcomputer composed of a CPU and a memory, and is connected to each function unit inside the motor drive control device 1 such as the rotation direction detection unit 2, the rotation number measurement unit 3, the timer 4, and the like. Each function unit is controlled. The control unit 5 will be described later.

[Drive voltage output section]
The drive voltage output unit 10 outputs drive voltages SU1, SV1, SW1 based on gate control voltages Gu, Gx, Gv, Gy, Gw, Gz output from a gate control voltage generation unit 8 (described later) in the control unit 5. In order to output, it includes insulated gate bipolar transistors Q1 to Q6 (corresponding to switching elements, hereinafter simply referred to as transistors) and reflux diodes D1 to D6.

  The transistors Q1 and Q2, Q3 and Q4, Q5 and Q6 are connected in series between the power supply line and the GND line. The connection points NU, NV, NW between the transistors Q1 and Q2, Q3 and Q4, Q5 and Q6 are connected to the U-phase, V-phase and W-phase drive coil terminals TU, TV and TW of the motor 51, respectively. Yes. The transistors Q1, Q3, and Q5 are so-called upper transistors that are connected between the positive terminal of the power supply unit 11 and the drive coil terminals TU, TV, and TW of the respective phases of the motor 51. The transistors Q2, Q4, and Q6 are so-called lower transistors that are connected between the negative terminal of the power supply unit 11 and the drive coil terminals TU, TV, and TW of each phase of the motor 51, respectively.

  The diodes D1 to D6 have such characteristics that they are turned on when a reverse voltage is applied to the transistors Q1 to Q6, and are connected in parallel to the transistors Q1 to Q6.

  The drive voltage output unit 10 having such a configuration is such that the transistors Q1 to Q6 are turned on and off based on the gate control voltages Gu, Gx, Gv, Gy, Gw, and Gz applied to the respective gate terminals. Drive voltages SU1, SV1, and SW1 having modulation rates determined by a PWM control unit 7 (described later) of the control unit 5 can be output to the drive coils Lu, Lv, and Lw.

〔Power supply part〕
The power supply unit 11 converts an alternating voltage into a direct current, and supplies the power supply voltage Vcc to the drive voltage output unit 10 through a power supply wiring. The power supply unit 11 includes therein a charge storage unit 11a capable of storing charges according to the boosted power supply voltage Vcc. Examples of the charge storage unit 11a include a capacitor and a battery. In the present embodiment, a case where a capacitor is used as the charge storage unit 11a is taken as an example.

[Discharge part]
The discharge part 12 is for discharging the electric charge accumulated in the capacitor 11a in the power supply part 11, and is connected in parallel to the capacitor 11a. The discharge unit 12 is controlled by a discharge control unit 9 (described later) of the control unit 5.

(Voltage detector)
The voltage detection unit 13 is connected in parallel to the power supply unit 11 and detects the power supply voltage Vcc output from the power supply unit 11. The value of the power supply voltage Vcc detected by the voltage detection unit 13 is taken into the control unit 5.

[Current detector]
The current detection unit 14 is connected in series between the negative terminal of the power supply unit 11 and the drive voltage output unit 10 and detects a current flowing from the power supply unit 11 to the motor 51 or from the motor 51 to the power supply unit 11. The current value detected by the current detection unit 14 is sent to the overcurrent protection unit 15.

[Overcurrent protection section]
The overcurrent protection unit 15 adjusts the amount of current flowing through the motor 51 based on the amount of current detected by the current detection unit 14. Specifically, the overcurrent protection unit 15 protects a current flowing in the power running direction when the motor 51 is performing a power running operation (that is, a normal rotation operation), or when the motor 51 is performing a regenerative operation. Protects current flowing in the regeneration direction. In particular, the overcurrent protection unit 15 protects the current flowing in the regeneration direction of the motor 51 so that the current flowing in the motor 51 when the motor 51 is performing the regeneration operation is changed to each of the transistors Q1 to Q1 of the drive voltage output unit 10. It is possible not to exceed the rating of Q6.

(2-1) Configuration of Control Unit The control unit 5 according to the present embodiment adjusts the drive voltages SU1, SV1, and SW1 for controlling the motor 51 and controls the discharge unit 12. In order to perform such an operation, the control unit 5 functions as the drive voltage adjustment unit 6 and the discharge control unit 9.

[Drive voltage adjustment section]
The drive voltage adjustment unit 6 includes a PWM control unit 7 and a gate control voltage generation unit 8, and adjusts the drive voltages SU1, SV1, and SW1 for controlling the motor 51 by PWM (Pulse-Width Modulation). In particular, the drive voltage adjustment unit 6 according to the present embodiment is affected by the propeller fan 61 under the influence of headwind and forward wind, and is rotated with an external force applied in the forward and reverse directions due to the influence of the propeller fan 61. When starting the motor 51, the drive voltages SU1, SV1, and SW1 at the time of starting the motor 51 are adjusted so that the power supply voltage Vcc is boosted by performing the regenerative operation of the motor 51.

[PWM control unit]
The PWM control unit 7 determines the modulation rate of the drive voltages SU1, SV1, SW1 applied to the drive coils Lu, Lv, Lw based on the rotation direction and the rotation speed of the motor 51, and corresponds to this modulation rate. The PWM voltage v-duty is output to the gate control voltage generator 8. Hereinafter, the operation performed by the PWM control unit 7 will be described separately for the operation for starting the motor 51 and the operation after starting the motor 51.

(A) Operation for starting the motor When the PWM control unit 7 starts the motor 51 that is already rotating in the forward direction or the reverse direction before the start, the motor 51 performs a regenerative operation so that the power supply voltage Vcc is The modulation factors of the drive voltages SU1, SV1, and SW1 when the motor 51 is started are determined so that the number of rotations of the motor 51 is reduced.

  As a method of boosting the power supply voltage Vcc by the regenerative operation of the motor 51, the drive voltages SU1, SV1, SW1 that generate torque in the direction opposite to the rotation direction immediately before the start, and not more than a predetermined drive voltage are used. A method of outputting such drive voltages SU1, SV1, and SW1 to the motor 51 can be given. According to such a method, when the motor 51 is started, torque is generated in the motor 51 in the forward rotation direction or the reverse rotation direction, and a regenerative operation is performed. Thereby, the rotational energy of the motor 51 is converted into electric energy, the power supply voltage Vcc is boosted, and the rotational speed of the motor 51 is reduced.

  Here, in the present embodiment, a description will be given of when the drive voltages SU1, SV1, and SW1 at which the regenerative operation is performed are output to the motor 51. FIG. 2 is a diagram for explaining conditions under which the power supply voltage Vcc is boosted when the motor 51 is started from the rotation state of the motor 51 immediately before the motor 51 is started. The horizontal axis indicates the number of rotations of the motor 51. The vertical axis represents the modulation rate of the drive voltages SU1, SV1, SW1. Graphs A, B, and C in FIG. 2 correspond to the critical values of the modulation rates of the drive voltages SU1, SV1, and SW1 when the boost operation occurs in the power supply voltage Vcc (that is, corresponding to the first and second predetermined drive voltages). (Hereinafter referred to as a step-up operation level) is shown for each phase shift between the induced voltage generated in each drive coil Lu, Lv, and Lw of the motor 51 and the motor current. In a region where the modulation factors of the drive voltages SU1, SV1, and SW1 are smaller than the values on the graphs A to C (that is, the boost operation level) (including values on the graphs A to C), the power supply voltage Vcc Boost operation occurs. Graphs A, B, and C in FIG. 2 respectively show a case where there is no phase shift, a phase shift is t1, and a phase shift is t2 (where t1 <t2). This phase shift is determined by applying a drive voltage to the motor 51 and causing a current to flow.

  According to FIG. 2, in order to boost the power supply voltage Vcc when there is no phase shift (graph A), the driving voltage having a smaller modulation rate than when there is a phase shift (graphs B and C). SU1, SV1, and SW1 need to be output to the motor 51. In particular, in graph A, the power supply voltage Vcc is boosted only when the motor 51 rotates in the rotational direction immediately before the motor 51 is started. On the other hand, when the phase shift occurs (graphs B and C), when the phase shift does not occur (graph A), in the region where the power supply voltage Vcc is increased (that is, the motor 51 rotates immediately before the motor 51 is started). When rotating in the direction), the power supply voltage Vcc can be boosted by the drive voltages SU1, SV1, and SW1 having a modulation rate larger than that of the graph A. Further, as shown in graphs B and C, if the phase shift is equal to or greater than a predetermined amount, the power supply voltage Vcc is boosted even if torque in the direction opposite to the rotational direction immediately before the motor 51 is applied is applied to the motor 51. Occurs. Such a phase shift depends on, for example, inductance values in the drive coils Lu, Lv, and Lw of the motor 51. The larger the inductance of the drive coils Lu, Lv, and Lw, the easier the phase shifts. Conversely, the smaller the inductance of the drive coils Lu, Lv, Lw, the more difficult the phase shifts.

  Therefore, the PWM control unit 7 determines the modulation rate of the drive voltages SU1, SV1, SW1 based on FIG. Specifically, the PWM control unit 7 determines the modulation rate of the drive voltages SU1, SV1, and SW1 so that the boost operation is generated even if the phase shift does not occur, or the phase shift becomes a predetermined amount or more to boost the voltage. The modulation factors of the drive voltages SU1, SV1, and SW1 are determined such that an operation occurs and torque in the direction opposite to the rotation direction immediately before the start of the motor 51 is generated. 2 is stored in advance in the memory of the microcomputer.

  By the way, as described above, such drive voltages SU1, SV1, and SW1 are determined so as to satisfy a condition that the drive voltage SU1, SV1, and SW1 are not more than the predetermined drive voltage. In addition, a voltage value smaller than the induced voltage generated in the motor 51 can be mentioned. The PWM control unit 7 further adjusts the modulation rate of the drive voltages SU1, SV1, SW1 so that the drive voltages SU1, SV1, SW1 to be applied to the motor 51 have a voltage value smaller than the induced voltage generated in the motor 51. To do. As a result, a regenerative operation in which energy is supplied from the motor 51 side to the drive voltage output unit 10 side occurs, so that the power supply voltage Vcc is boosted and the rotational speed of the motor 51 is reduced.

  Further, as shown in FIG. 2, since the step-up operation level also depends on the number of rotations of the motor 51, the PWM control unit 7 determines the modulation rate of the drive voltages SU1, SV1, and SW to each transistor Q1 in the drive voltage output unit 10. Further adjustment is made based on the number of revolutions of the motor 51 so as not to exceed the ratings of components such as .about.Q6.

  Note that the modulation factors of the drive voltages SU1, SV1, and SW1 change linearly according to the number of rotations in FIG. 2, but are not limited to this, and may change stepwise in part or in the entire region. .

(B) Operation after motor startup Also, after the motor 51 is started, the PWM control unit 7 drives the drive voltage SU1 when the rotation number and direction of the motor 51 and the measurement time of the timer 4 satisfy predetermined conditions. , SV1 and SW1 are changed to the modulation rate of the drive voltage during normal rotation of the motor 51. In other words, the PWM control unit 7 changes the modulation rate of the drive voltage so that the motor 51 performs a power running operation when the motor 51 after activation satisfies a predetermined condition. Here, examples of the predetermined condition include the following.
(I) When the time measured by the timer 4 has passed a predetermined time (II) When the number of rotations in the direction of rotation in which the motor 51 was rotating immediately before starting is less than the predetermined number (III) Rotating in the reverse direction After the motor 51 is started, the motor 51 is rotated in the forward direction (that is, when the rotational speed is “0 rpm”).

  The modulation rate of the drive voltage during normal rotation is a modulation rate at which the motor 51 normally rotates in the normal rotation direction without causing a boosting operation to the power supply voltage Vcc. It is larger than the boosting operation level of graphs A to C. In the present embodiment, a case where predetermined conditions (I) and (II) are satisfied will be described below.

[Gate control voltage generator]
The gate control voltage generation unit 8 controls the drive voltage output unit 10 so that the drive voltages SU1, SV1, and SW1 having the modulation rates determined by the PWM control unit 7 are output from the drive voltage output unit 10 to the motor 51. To do. More specifically, the gate control voltage generation unit 8 controls the on / off of each of the transistors Q1 to Q6 based on the PWM voltage v-duty output from the PWM control unit 7. Generate Gx, Gv, Gy, Gw, Gz.

(Discharge control unit)
The discharge control unit 9 controls the discharge unit 12. Specifically, when the power supply voltage Vcc detected by the voltage detection unit 13 is equal to or higher than a predetermined value (corresponding to the second predetermined value), the discharge control unit 9 at least part of the charge accumulated in the capacitor 11a. Is controlled so that is discharged. For example, the discharge controller 9 determines the amount of charge to be discharged based on the difference between a predetermined value and the power supply voltage Vcc, and determines the time for the discharge unit 12 to discharge from the determined amount of charge. Here, the predetermined value is determined by the ratings of the transistors Q1 to Q6 in the drive voltage output unit 10.

  According to such a discharge control unit 9, when the power supply voltage Vcc is boosted and exceeds a predetermined value, the discharge by the discharge unit 12 is performed. As a result, the amount of charge accumulated in the capacitor 11a is reduced, so that the power supply voltage Vcc is suppressed to a value below the rating of each of the transistors Q1 to Q6 in the drive voltage output unit 10.

(3) Operation of Motor Drive Control Device (3-1) Flow of a Series of Operations FIG. 3 is a flowchart for explaining a flow of a sequence of operations performed by the motor drive control device 1.

  Steps S <b> 1 to S <b> 3: When the motor drive control device 1 obtains an activation instruction for the motor 51 from the outside of the motor drive control device 1 that is an outdoor unit or the like of the air conditioner (S <b> 1), the rotational speed measurement unit 3 (S2), and the rotation direction detector 2 detects the rotation direction of the motor 51 immediately before starting (S3).

  Step S4: If the motor 51 is in a stopped state in step S3 (NO in step S3), the drive voltage adjustment unit 6 determines the drive voltages SU1, SV1, SW1 when the motor 51 is normally started. The drive voltage output unit 10 outputs this to the motor 51. As a result, the motor 51 starts to rotate in the normal rotation direction from the stopped state and is started.

  Step S5: In step S3, when the motor 51 is already rotating in the reverse rotation direction or the forward rotation direction (YES in step S3), the PWM control unit 7 of the drive voltage adjusting unit 6 uses the rotation number measuring unit 3 to Based on the measured rotation speed and the graph of FIG. 2, the modulation factors of the drive voltages SU1, SV1, and SW1 are determined (S5).

  Step S6: The drive voltages SU1, SV1, and SW1 having the modulation factor determined in Step S5 are output to the drive coils Lu, Lv, and Lw in the motor 51 through the gate control voltage generator 8 and the drive voltage output unit 10. Is done. As a result, the motor 51 is started. Then, the timer 4 starts measuring time.

  Steps S <b> 7 to S <b> 9: When the measurement time of the timer 4 and the rotation speed of the motor 51 satisfy predetermined conditions, the motor drive control device 1 controls the rotation speed of the motor 51. Thereby, the modulation rate of the drive voltages SU1, SV1, SW1 is determined to be the modulation rate of the drive voltage during normal rotation by the rotation speed control, and the drive voltages SU1, SV1 having the modulation rate thus determined , SW1 is output to the motor 51 (S9). Here, the predetermined conditions include “(I) When the measurement time of the timer 4 has passed the predetermined time (YES in S7)”, “(II) The number of rotations in the rotational direction that was rotating immediately before activation is “When the number is less than or equal to the predetermined number (YES in S8)”. When the measurement time of the timer 4 and the rotation speed of the motor 51 do not satisfy any of the predetermined conditions in step S7 or S8 (NO in S7 and S8), the motor drive control device 1 operates after step S7. repeat. Here, examples of the rotational speed control method include P (Proportional) control, PI (Proportional and Integral) control, and PID (Proportional, Integral and Derivative) control.

  Step S10: The motor drive control device 1 controls the rotation speed of the motor 51 until an instruction to stop the rotation of the motor 51 is acquired from the outside of the motor drive control device 1. When the motor drive control device 1 obtains an instruction to stop the rotation of the motor 51, the motor drive control device 1 stops the rotation of the motor 51 and ends the series of operations.

(3-2) Example of Modulation Rate of Adjusted Driving Voltage An example of the case where the motor drive control device 1 drives and controls the motor 51 in the above operation flow is shown in FIG. 4 and FIG. FIG. 4 is a diagram showing the modulation factors and the like of the drive voltages SU1, SV1, and SW1 that change with time when the motor 51 that is rotating in the reverse rotation direction is started before the start. FIG. 5 is a diagram showing the modulation factors and the like of the drive voltages SU1, SV1, and SW1 that change with time when the motor 51 that is rotating in the positive rotation direction is started before the start.

  In FIG. 4, the motor 51 is rotated in the reverse rotation direction from before the start due to the influence of the reverse wind or the like, and the motor drive control device 1 has a modulation rate such that torque is generated in the forward rotation direction of the motor 51. In addition, drive voltages SU1, SV1, and SW1 that are equal to or lower than a predetermined drive voltage are output to the motor 51, and the motor 51 is started. As a result, the drive voltages SU1, SV1, and SW1 having a smaller modulation rate than that during normal rotation are applied to the motor 51, and the power supply voltage Vcc is boosted. Then, the rotational speed of the motor 51 approaches 0 rpm, and the current that flows transiently in the motor 51 is suppressed.

  Here, in FIG. 4, the measurement time by the timer 4 elapses a predetermined time before the rotation number of the motor 51 to the reverse rotation side becomes the predetermined number A or less. Therefore, the motor drive control device 1 changes the modulation rate of the drive voltages SU1, SV1, SW1 to the modulation rate during normal rotation when a predetermined time has elapsed. Thereby, the motor 51 can perform a power running operation.

  Further, in FIG. 5, the motor 51 has rotated in the forward rotation direction before the start due to the influence of the wind and so on, and the motor drive control device 1 has a modulation rate so that torque is generated in the reverse rotation direction of the motor 51. In addition, driving voltages SU1, SV1, and SW1 that are equal to or lower than a predetermined driving voltage are output to the motor 51 to drive the motor 51. As a result, similarly to FIG. 4, the drive voltages SU1, SV1, and SW1 having a modulation rate smaller than that during normal rotation are applied to the motor 51, and the power supply voltage Vcc is boosted. Then, the rotational speed of the motor 51 approaches 0 rpm, and the current that flows transiently in the motor 51 is suppressed.

  Here, in FIG. 5, the number of rotations of the motor 51 in the forward rotation direction reaches the predetermined number B before the measurement time by the timer 4 elapses the predetermined time. Therefore, when the rotational speed of the motor 51 reaches the predetermined number B, the motor drive control device 1 changes the modulation rate of the drive voltages SU1, SV1, SW1 to the modulation rate during normal rotation. Thereby, the motor 51 can perform a power running operation.

(4) Effects (4-1)
When the motor 51 is already rotating in the reverse rotation direction or the forward rotation direction before starting, the motor drive control device 1 boosts the power supply voltage Vcc by performing a regenerative operation immediately after starting the motor 51. As a result, when the motor 51 is started up, the rotational energy of the motor 51 is regenerated to the power source, so that a torque that reduces the rotational speed is applied to the motor 51. Is suppressed. Therefore, the motor 51 can be reliably started.

(4-2)
Further, the drive voltage adjustment unit 6 of the motor drive control device 1 adjusts the drive voltages SU1, SV1, and SW1 so as to reduce the rotation speed of the motor 51. As a result, when the motor 51 is started, the number of rotations of the motor 51 is reduced, so that the current supplied to the motor 51 does not increase when the motor 51 is started. Therefore, the motor can smoothly accelerate.

(4-3)
Here, as a method for increasing the power supply voltage Vcc by performing the regenerative operation, the motor drive control device 1 generates a drive voltage in which torque is generated in a direction opposite to the rotation direction immediately before the motor 51 is started. A method of outputting the drive voltages SU1, SV1, and SW1 that are SU1, SV1, and SW1 and that are equal to or lower than a predetermined drive voltage to the motor 51 can be given. In this case, the motor 51 performs a regenerative operation at startup and the power supply voltage Vcc increases, so that the rotational energy of the motor 51 is converted into electric energy, and the rotational speed of the motor 51 decreases. Therefore, an increase in the amount of current that is supplied to the motor 51 immediately after startup is suppressed.

(4-4)
By the way, as shown in FIG. 2, if there is a difference between the phase of the current supplied to the motor 51 and the phase of the induced voltage generated in the drive coils Lu, Lv, and Lw of the motor 51, immediately before the start of the motor 51. The power supply voltage Vcc may also be boosted when the motor 51 generates torque in the direction opposite to the rotation direction at. When the motor 51 generates torque in the direction opposite to the rotation direction immediately before the start-up, the greater the phase shift, the easier the power supply voltage Vcc is boosted. Therefore, the motor drive control device 1 immediately before the start of the motor 51 so that the difference between the phase of the current supplied to the motor 51 and the phase generated in the drive coils Lu, Lv, Lw of the motor 51 is a predetermined amount or more. Drive voltages SU1, SV1, and SW1 that generate torque in a direction opposite to the rotation direction at are output to the motor 51. As a result, the motor drive control device 1 can boost the power supply voltage Vcc.

(4-5)
Here, the predetermined drive voltage is equal to or lower than a voltage value to which the power supply voltage Vcc is boosted when the motor 51 is started from the rotation state of the motor 51 immediately before the motor 51 is started. The voltage value at which the power supply voltage Vcc is boosted is a critical value of the voltage to be applied to the motor 51 in order to boost the power supply voltage Vcc (that is, the boosting operation level). When SV1 and SW1 are applied to the motor 51, a boosting operation occurs in the power supply voltage Vcc. Since the motor drive control device 1 applies the drive voltages SU1, SV1, and SW1 that are equal to or lower than the voltage value at which the power supply voltage Vcc is boosted to the motor 51, the power drive voltage Vcc can be reliably boosted.

(4-6)
Further, the predetermined drive voltage is smaller than the induced voltage generated in the motor 51. When the drive voltages SU1, SV1, SW1 applied to the motor 51 are adjusted to be equal to or lower than the induced voltage generated in the motor 51, current flows from the motor 51 to the power supply unit 11 side. As a result, a so-called regenerative operation in which energy is supplied from the motor 51 side to the power supply unit 11 side occurs, so that the power supply voltage Vcc can be boosted.

(4-7)
The modulation rate of the drive voltages SU1, SV1, and SW1 in FIG. 2 is set to the rotation speed of the motor 51 so that the boosted power supply voltage Vcc does not exceed the ratings of the transistors Q1 to Q6 in the drive voltage output unit 10. Adjusted accordingly. As a result, it is possible to prevent parts such as the transistors Q1 to Q6 from being damaged by the boosted power supply voltage Vcc and to ensure reliability.

(4-8)
In addition, after the motor 51 is started, when the rotation number in the rotation direction that the motor 51 was rotating immediately before the start is equal to or less than a predetermined number, the drive voltages SU1, SV1, and SW1 during normal rotation are output to the motor 51. Is done. As a result, the motor 51 can reliably perform normal rotation.

(4-9)
In addition, when the rotation direction of the motor 51 that has been rotating in the reverse rotation direction immediately before activation becomes the normal rotation direction, the drive voltages SU1, SV1, and SW1 during normal rotation are output to the motor 51. Thereby, the motor 51 can perform normal rotation reliably.

(4-10)
In addition, after a predetermined time has elapsed since the motor 51 was started, the drive voltages SU1, SV1, and SW1 during normal rotation are output to the motor 51. As a result, the motor 51 can reliably perform normal rotation.

(4-11)
Further, the motor drive control device 1 is provided with an overcurrent protection unit 15 for protecting a current flowing in the regeneration direction of the motor 51. As a result, during the regenerative operation of the motor 51, the current flowing from the motor 51 to the components such as the transistors Q1 to Q6 in the drive voltage output unit 10 exceeds the ratings of these components, and the components are damaged. Can be prevented.

(4-12)
Further, the power supply unit 11 includes a capacitor 11a capable of accumulating charges according to the power supply voltage Vcc. As a result, the power supply unit 11 can suppress an increase in the power supply voltage even when the boosting operation is performed. For example, the power supply unit 11 exceeds the rating of the component such as the switching element in the drive voltage output unit, and the component is damaged. Can be prevented.

(4-13)
As shown in FIG. 1, the motor drive control device 1 includes a discharge unit 12 that can discharge the charge in the charge storage unit 11 a and a discharge control unit 9 that controls the discharge unit 12. The discharge control unit 9 controls the discharge unit 12 so that when the power supply voltage Vcc exceeds a predetermined value, at least a part of the charge stored in the charge storage unit 11a is discharged. Here, if the predetermined value is a value determined according to the ratings of the components such as the transistors Q1 to Q6 in the drive voltage output unit 10, the motor drive control device 1 sets the rotation speed of the motor 51. In addition to reducing the voltage, the boosted power supply voltage Vcc can be prevented from exceeding the ratings of the components such as the transistors Q1 to Q6, and the components are damaged.

<Other embodiments>
(A)
In the above embodiment, the case where the motor is a three-phase motor has been described as an example. However, the motor drive control device according to the present invention is for driving a motor having two or more phases such as a two-phase motor and a four-phase motor. Can be applied.

(B)
In the above embodiment, as a method for preventing the boosted power supply voltage Vcc from exceeding the ratings of the transistors Q1 to Q6 in the drive voltage output unit 10, a method of discharging the charge in the capacitor 11a, an overcurrent, The method of providing the protection unit 15 and the method of adjusting the drive voltages SU1, SV1, SW1 according to the number of rotations of the motor 51 have been described as examples. As another method, when the boosted power supply voltage Vcc becomes a value different from the above predetermined value (corresponding to the first predetermined value) or more, the driving voltage SU1, SV1 generated by the driving voltage output unit 10 is used. Therefore, there is a method of stopping the output of SW1. As a method for stopping the output of the drive voltages SU1, SV1, SW1, the generation of the gate control voltages Gu, Gx, Gv, Gy, Gw, Gz is stopped, and the output of the PWM voltage v-duty of the PWM control unit 7 is stopped. Etc. As a result, since the drive voltages SU1, SV1, SW1 are not output to the motor 51, the motor 51 stops rotating, and the power supply voltage Vcc is not boosted. Therefore, it is possible to suppress the power supply voltage Vcc from exceeding the ratings of the transistors Q1 to Q6, and it is possible to prevent the transistors Q1 to Q6 from being destroyed.

  Note that the different value described above may be the same value as the predetermined value according to the embodiment. Another value is determined in consideration of the ratings of the transistors Q1 to Q6, similarly to the predetermined value.

(C)
In the above embodiment, as a method for boosting the power supply voltage Vcc by the regenerative operation of the motor 51, the method related to the torque generated in the motor 51 has been described as an example. As another method, lower transistors Q2, Q4, Q6 for outputting at least one phase of the drive voltages SU1, SV1, SW1 output to each phase of the motor 51 are provided. And a method of turning on and off (that is, chopping) at a predetermined frequency (FIG. 6). According to this method, as in the above embodiment, the motor 51 performs a regenerative operation at the time of start-up, the rotational energy of the motor 51 is converted into electric energy and regenerated to the power supply unit side 11, the power supply voltage Vcc is boosted, and the motor 51 The number of rotations decreases.

  Note that the ratio of the on time and the off time of the lower transistors Q2, Q4, Q6 to be chopped (specifically, the duty of the gate control voltages Gx, Gy, Gz) is driven by, for example, the boosted power supply voltage Vcc It is determined according to the number of rotations of the motor 51 so as not to exceed the ratings of the components such as the transistors Q1 to Q6 in the voltage output unit 10. As a result, the boosted power supply voltage Vcc does not exceed the ratings of the transistors Q1 to Q6 and the like, so that the transistors Q1 to Q6 can be prevented from being destroyed.

(D)
In the above embodiment, the case where the modulation rates of the drive voltages SU1, SV1, and SW1 are adjusted has been described. However, the present invention is not limited to this. The voltage values themselves of the drive voltages SU1, SV1, and SW1 may be adjusted.

(E)
In the above embodiment, the case where the motor drive control device 1 performs PWM control of the motor 51 has been described. However, the motor drive control device 1 performs so-called PAM (Pulse-Amplitude Modulation) control for controlling the amplitude of the drive voltage. Also good. Further, the motor drive control device 1 may perform rotation speed control such as P control and PI control for the motor 51.

(F)
In the above-described embodiment, the case where the drive voltage adjustment unit 6 and the discharge control unit 9 are included in the control unit 5 including one CPU has been described. Each may be constituted by a separate CPU.

(G)
In the above embodiment, the case where the motor 51 is a brushless DC motor has been described as an example, but the motor 51 may be another type of motor such as an induction motor. In particular, when the motor is a DC motor, the drive voltage during normal rotation can be a constant voltage.

(H)
In the embodiment described above, the case where the motor drive control device 1 is used as a fan motor for an outdoor unit of an air conditioner has been described as an example. However, the use of the motor drive control device 1 according to the present invention is not limited thereto. . In general, in the fan motor for outdoor units, disturbance due to headwinds and forward winds is large. However, by using the motor drive control device 1 according to the above embodiment, the outdoor unit can be used even when the disturbances are large. The fan motor can rotate reliably.

(I)
In the above embodiment, the case where the insulated gate bipolar transistors Q1 to Q6 are used as the switching elements in the drive voltage output unit 10 has been described. However, other types of elements such as MOSFETs may be used as the switching elements. In the above embodiment, the case where the Nch insulated gate bipolar transistors Q1 to Q6 are used is described, but a Pch transistor may be used.

  The motor drive control device according to the present invention has the effect of suppressing an increase in the current flowing to the motor immediately after startup, and starting the motor reliably, and controls the driving of the fan motor for the outdoor unit of the air conditioner. It is useful as a device.

The block diagram which showed the structure of the whole drive control system of the motor which concerns on this embodiment, and the internal structure of the motor drive control apparatus. The figure for demonstrating the conditions where a power supply voltage is boosted. The flowchart which shows the flow of a series of operation | movement which the motor drive control apparatus which concerns on this embodiment performs. The figure which showed an example of each signal which changes with time, when the motor drive control apparatus which concerns on this embodiment starts the motor rotating in the reverse direction. The figure which showed an example of each signal which changes with time, when the motor drive control apparatus which concerns on this embodiment starts the motor rotating in the positive direction. In the motor drive control device concerning other embodiments (C), an example of the gate control voltage by which at least 1 phase is chopped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor drive control apparatus 4 Timer 5 Control part 6 Drive voltage adjustment part 7 PWM control part 8 Gate control voltage generation part 9 Discharge control part 10 Drive voltage output part 11 Power supply part 11a Charge storage part 12 Discharge part 15 Overcurrent protection part 51 Motors 54a, 54b, 54c Position detection sensor 61 Propeller fan Vcc Power supply voltage SU1, SV1, SW1 Drive voltage

Claims (16)

A drive voltage output unit (10) for outputting a drive voltage (SU1 to SW1) for driving the motor (51) to the motor (51);
A power supply unit (11) for supplying a power supply voltage (Vcc) to the drive voltage output unit (10);
When the motor (51) is rotating immediately before starting, the motor (51) is driven when the motor (51) is started so that the power supply voltage (Vcc) is boosted by performing a regenerative operation. A drive voltage adjustment unit (6) for adjusting the voltages (SU1 to SW1);
A motor drive control device (1). The drive voltage adjustment unit (6) adjusts the drive voltage (SU1 to SW1) so as to reduce the rotational speed of the motor (51).
The motor drive control device (1) according to claim 1. The drive voltage adjustment unit (6) determines the drive voltage (SU1 to SW1) such that torque in a direction opposite to the rotation direction immediately before the motor (51) is started, and the drive voltage (SU1 to SW1). SU1 to SW1) are set to a predetermined driving voltage or less.
The motor drive control device (1) according to claim 1 or 2. The drive voltage adjusting unit (6) is configured to immediately before starting the motor so that a deviation between a phase of a current flowing through the motor (51) and a phase of an induced voltage generated in the motor (51) is a predetermined amount or more. The driving voltage (SU1 to SW1) is determined such that torque in the direction opposite to the rotation direction is generated.
The motor drive control device (1) according to claim 3. The predetermined drive voltage is equal to or lower than a voltage value at which the power supply voltage is boosted when the motor (51) is started from the rotational state of the motor (51) immediately before the motor (51) is started.
The motor drive control device (1) according to claim 3 or 4. The predetermined drive voltage is a voltage value smaller than an induced voltage generated in the motor (51).
The motor drive control device (1) according to claim 3 or 4. The drive voltage adjustment unit (6) further adjusts the drive voltage (SU1 to SW1) based on the rotational speed of the motor (51).
The motor drive control device (1) according to any one of claims 1 to 6. The motor (51) is a motor having two or more phases,
The drive voltage output unit (10) includes a plurality of upper switching elements (Q1, Q3, Q5) connected between a positive terminal of the power supply unit (11) and each phase of the motor (51), A plurality of lower switching elements (Q2, Q4, Q6) connected between the negative terminal of the power supply unit (11) and each phase of the motor (51),
The drive voltage adjustment unit (6) outputs the drive voltage (SU1 to SW1) of at least one phase among the drive voltages (SU1 to SW1) output to each phase of the motor (51). The lower switching elements (Q2, Q4, Q6) are turned on and off at a predetermined frequency.
The motor drive control device (1) according to claim 1 or 2. The drive voltage adjustment unit (6) determines a ratio between an on time for turning on the lower switching elements (Q2, Q4, Q6) and an off time for turning off the lower switching elements (Q2, Q4, Q6) based on the rotational speed of the motor (51). ,
The motor drive control device (1) according to claim 8. After the motor (51) is activated, when the rotational speed in the rotational direction in which the motor (51) is rotating immediately before the activation becomes equal to or less than a predetermined number, the drive voltage adjustment unit (6) (SU1 to SW1) is changed to the drive voltage during normal rotation of the motor (51).
The motor drive control device (1) according to any one of claims 1 to 9. When the rotation direction immediately before the start of the motor (51) is reverse rotation and the rotation direction of the motor (51) becomes a normal rotation direction after the start of the motor (51), the drive voltage adjustment unit ( 6) The drive voltage (SU1 to SW1) is changed to the drive voltage during normal rotation of the motor (51).
The motor drive control device (1) according to any one of claims 1 to 9. A time measuring unit (4) for measuring a time after the motor (51) is started;
When the time measured by the time measuring unit (4) has passed a predetermined time, the drive voltage adjusting unit (6) changes the drive voltage (SU1 to SW1) during normal rotation of the motor (51). Change to the drive voltage,
The motor drive control device (1) according to any one of claims 1 to 9. When the motor (51) is performing a regeneration operation, the motor (51) further includes a current protection unit (15) that protects a current flowing in the regeneration direction of the motor (51).
The motor drive control device (1) according to any one of claims 1 to 12. The drive voltage adjustment unit (6) stops the output of the drive voltages (SU1 to SW1) by the drive voltage output unit (10) when the power supply voltage (Vcc) is equal to or higher than a first predetermined value.
The motor drive control device (1) according to any one of claims 1 to 13. The power supply unit (11) includes a charge storage unit (11a) capable of storing charges according to the boosted power supply voltage (Vcc).
The motor drive control device (1) according to any one of claims 1 to 14. A discharge part (12) capable of discharging the charge accumulated in the charge accumulation part (11a);
Discharge control for controlling the discharge unit (12) so that at least a part of the charge stored in the charge storage unit (11a) is discharged when the power supply voltage (Vcc) is greater than or equal to a second predetermined value. Part (9);
The motor drive control device (1) according to claim 15, further comprising:

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