JP5866785B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device.

  Patent Document 1 describes that, in a brushless DC motor, the coefficient circuit of the optimum phase angle setting voltage generation means calculates the coefficient for the input speed command voltage and outputs the optimum phase angle setting voltage to the logic circuit. Yes. Specifically, an approximate straight line indicating the relationship between the speed command voltage and the optimum phase angle setting voltage is created in advance, and the coefficient circuit is configured so that the coefficient circuit has a coefficient corresponding to the slope of the approximate straight line. Thus, according to Patent Document 1, if the speed command voltage changes, the optimum phase angle setting voltage output from the coefficient circuit changes correspondingly, so that the optimum speed suitable for the motor speed and load torque is obtained. It is said that the phase angle can be set and the efficiency of the motor can be improved.

JP 2003-189666 A

  In the technique described in Patent Document 1, the speed (number of revolutions) at which the value of the speed command voltage is actually commanded due to variations in power supply voltage, characteristics of components (electronic components, motor windings, etc.), disturbance noise, etc. When it deviates from (varies), the optimum phase angle setting voltage also fluctuates following the value of the deviated speed command voltage. As a result, the set phase angle deviates from the one corresponding to the actually commanded speed, and the phase angle may not be an appropriate value, so that the motor efficiency tends to deteriorate.

  In the technique described in Patent Document 1, the load torque is increased in a quadratic function as the motor rotation speed increases. However, when the motor load (rotation speed) becomes unstable, the speed command is increased. Since the voltage fluctuates (varies), the set phase angle also fluctuates and may not be an appropriate value, so the motor efficiency tends to deteriorate.

  Further, when there is no load (such as when an abnormality occurs), there is a possibility that the phase angle will advance too much and abnormal rotation will occur.

  The present invention has been made in view of the above, and it is possible to improve the efficiency of a motor even when the command speed voltage varies, and to perform stable control even when the command speed voltage varies more than expected. The object is to obtain a control device.

  In order to solve the above-described problems and achieve the object, a motor control device according to the present invention is a motor control device that controls a motor to operate at a command speed, and a drive unit that drives the motor And an advance control unit that controls the advance amount of the phase stepwise according to the command speed, and a drive that controls the drive unit using the phase advanced by the controlled advance amount. A controller, and the advance angle controller increases the advance amount from the first value to the first value when the command speed voltage corresponding to the command speed increases beyond a first threshold. When the command speed voltage is changed to a larger second value and becomes smaller than a second threshold value that is smaller than the first threshold value, the advance amount is changed from the second value to the first value. It is characterized by changing to.

  Further, in the motor control device according to the present invention, in the above invention, the advance angle control unit compares the command speed voltage with the threshold value, and outputs the advance angle amount according to the comparison result. And a low-pass filter that selectively passes a low-frequency component of the output of the comparison unit and outputs the low-frequency component to the drive control unit.

  In the motor control apparatus according to the present invention, in the above invention, the comparison unit includes a first input terminal to which the command speed voltage is supplied, a second input terminal, and an output terminal. A first resistor connected between the second input terminal of the comparator and a reference potential, and a second resistor connected between the second input terminal of the comparator and a ground potential A third resistor having one end connected to the output terminal of the comparator, a fourth resistor connected between the reference potential and the output terminal of the comparison unit, a ground potential, and the comparison unit A fifth resistor connected between the output terminal, a sixth resistor connected between the other end of the third resistor and the second input terminal of the comparator, and the third resistor. A seventh terminal connected between the other end of the resistor and the reference potential; And an eighth resistor having one end connected to the output terminal of the comparison unit, a gate arranged on the third resistor side, one of the source and the drain connected to the ground potential, and the other of the source and the drain And a transistor connected to the other end of the eighth resistor.

  In the motor control device according to the present invention as set forth in the invention described above, the comparison unit further includes a buffer amplifier connected between the other end of the third resistor and the gate of the transistor. And

  The motor control apparatus according to the present invention is characterized in that, in the above invention, the motor is a fan motor.

  The motor control device according to the present invention has an effect that the efficiency of the motor can be improved even when the command speed voltage varies.

FIG. 1 is a diagram illustrating a configuration of a motor control device according to the first embodiment. FIG. 2 is a diagram illustrating a configuration and an operation of the comparison unit in the first embodiment. FIG. 3 is a diagram illustrating a configuration of the comparison unit in the first embodiment. FIG. 4 is a diagram illustrating an effect according to the first embodiment. FIG. 5 is a diagram illustrating a configuration and an operation of a comparison unit in a modification of the first embodiment. FIG. 6 is a diagram illustrating the configuration and operation of the comparison unit in the second embodiment. FIG. 7 is a diagram illustrating the effect of the second embodiment. FIG. 8 is a diagram illustrating the configuration and operation of the comparison unit in a modification of the second embodiment.

  Embodiments of a motor control device according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment.

(First embodiment)
A control device 1 for a motor M according to the first embodiment will be described with reference to FIG. FIG. 1A is a diagram illustrating the configuration of the control device 1 for the motor M.

  For example, the control device 1 controls the motor M so as to operate at a preset command speed (command rotation speed). The motor M is, for example, a fan motor, and its rotor is connected to the rotation shaft of the fan by a shaft, and rotates the fan. The motor M may be a motor of components other than the fan in the air conditioner, or may be a motor for rotating an impeller or the like in the water pump.

  The control device 1 includes a driver circuit 10 and an advance angle control unit 20. The driver circuit 10 includes a drive unit 15 and a drive control unit 16.

  The drive unit 15 drives the motor M by outputting, for example, three-phase AC power to the motor M. Specifically, the drive unit 15 includes an inverter 11. The inverter 11 receives a control signal (for example, a PWM signal) from the drive control unit 16, and generates 3 DC power (motor power supply) Vm supplied from an external DC power supply (not shown) according to the control signal. It is converted into phase AC power and output to the motor M. The inverter 11 has, for example, an upper arm and a lower arm, and each of the upper arm and the lower arm has three switching elements corresponding to three phases (for example, U phase, V phase, and W phase).

  The advance angle control unit 20 controls the advance amount of the phase stepwise according to the command speed. Specifically, the advance angle control unit 20 receives a command speed voltage Vsp corresponding to the command speed from an external controller (not shown). The advance angle control unit 20 determines the advance amount LA as the first value LA1 when the command speed voltage Vsp is smaller than the threshold Va, and determines the advance amount LA when the command speed voltage Vsp is greater than the threshold Va. The second value LA2 is determined (see FIG. 2B). The second value LA2 is greater than the first value LA1. The advance angle control unit 20 supplies a signal φLA indicating the determined advance angle amount LA to the drive control unit 16.

  The drive controller 16 receives the signal φLA from the advance controller 20 and advances the phase by the advance amount indicated by the signal φLA. The drive control unit 16 controls the drive unit 15 using the advanced phase. Specifically, the drive control unit 16 includes a carrier generator 14, a comparison circuit 13, and a logic circuit 12.

  The carrier generator 14 generates a PWM carrier (for example, a triangular wave) and outputs it to the comparison circuit 13.

  Comparison circuit 13 receives command speed voltage Vsp from an external controller and receives a PWM carrier from carrier generator 14. As shown in FIG. 1B, the comparison circuit 13 performs a comparison operation between the command speed voltage Vsp and the PWM carrier, and outputs the calculation result to the logic circuit 12 as a signal for determining the modulation rate of the PWM signal.

  The logic circuit 12 receives a signal for determining the modulation rate of the PWM signal from the comparison circuit 13, receives the signal φLA from the advance angle control unit 20, and receives DC power (control power supply) Vcc from an external DC power supply (not shown). receive. The logic circuit 12 advances the phase of the PWM signal by the advance amount indicated by the signal φLA. As a result, the logic circuit 12 controls the on / off pattern of, for example, six switching elements in the inverter 11 using the phase advanced by the advance amount controlled by the advance controller 20.

  Thus, for example, when the command speed voltage Vsp is smaller than the threshold value Va, the drive control unit 16 advances the periodic control by the advance amount of the first value LA1 determined by the advance angle control unit 20. The drive unit 15 is controlled by a signal, and when the command speed voltage Vsp is larger than the threshold value Va, the drive unit 15 is driven by a periodic control signal advanced by the advance amount of the second value LA2 determined by the advance angle control unit 20. The unit 15 is controlled. As a result, the advance angle control unit 20 can perform advance angle control so as to improve the efficiency of the motor M according to the load (rotation speed), and the drive control unit 16 can improve the efficiency of the motor M according to the control of the advance angle control unit 20. The drive unit 15 can be driven and controlled.

  Next, the internal configuration of the advance angle control unit 20 will be described with reference to FIG.

  The advance angle control unit 20 includes a comparison unit 21 and a low pass filter (LPF) 22.

  The comparison unit 21 receives a command speed voltage Vsp corresponding to the command speed from an external controller (not shown). The comparison unit 21 compares the command speed voltage Vsp with the threshold value Va, and outputs a signal φLAi indicating the comparison result to the low-pass filter 22 as an advance amount. For example, the comparison unit 21 outputs a signal φLAi having a stepped waveform as shown by a solid line in FIG. 2B to the low-pass filter 22 when the command speed voltage Vsp exceeds the threshold value Va.

  The low-pass filter 22 receives the output of the comparison unit 21, that is, the signal φLAi indicating the comparison result from the comparison unit 21. The low-pass filter 22 selectively passes a low-frequency component of the signal φLAi indicating the comparison result, and generates a signal φLA indicating the advance amount LA. For example, the low-pass filter 22 generates a signal φLA having a time constant as shown by a one-dot chain line in FIG. 2B from a step-like waveform as shown by a solid line in FIG. The low pass filter 22 outputs the generated signal φLA to the logic circuit 12 of the drive control unit 16.

  Next, the internal configuration of the comparison unit 21 will be described with reference to FIGS. 2A and 3 are circuit diagrams showing the internal configuration of the comparison unit 21. FIG.

  As illustrated in FIG. 2A, the comparison unit 21 includes a comparator CM1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a resistor R5.

  The comparator CM1 has a non-inverting input terminal T1, an inverting input terminal T2, and an output terminal T3. A speed command voltage Vsp is supplied to the non-inverting input terminal T1 from an external controller (not shown). The inverting input terminal T2 is connected to a node NVa between the resistors R1 and R2. The output terminal T3 is connected to one end of the resistor R3.

  Specifically, the comparator CM1 includes a comparison circuit 211 and a transistor Q1, as shown in FIG. The comparison circuit 211 has an inverting input terminal 211a, a non-inverting input terminal 211b, and an output terminal 211c. The inverting input terminal 211a is connected to the non-inverting input terminal T1 of the comparator CM1. The non-inverting input terminal 211b is connected to the inverting input terminal T2 of the comparator CM1. The output terminal 211c is connected to the base of the transistor Q1. The transistor Q1 is, for example, a bipolar transistor, and has a base connected to the output terminal 211c of the comparison circuit 211, a collector connected to the output terminal T3 of the comparator CM1, and an emitter connected to the ground potential.

  The resistor R1 is connected between the node NVa and the reference potential Vref. That is, the resistor R1 is connected between the inverting input terminal T2 of the comparator CM1 and the reference potential Vref.

  The resistor R2 is connected between the node NVa and the ground potential. That is, the resistor R1 is connected between the inverting input terminal T2 of the comparator CM1 and the ground potential.

  Note that when the resistance value of the resistor R1 is R1 and the resistance value of the resistor R2 is R2, the resistance value R1, the resistance value R2, and the reference potential Vref are, for example, the threshold value Va that is the potential of the node NVa, respectively. It is adjusted in advance so as to satisfy the following formula 1.

Va = {R2 / (R1 + R2)} × Vref Equation 1
That is, in the comparison unit 21, the resistance value R1, the resistance value R2, and the reference potential Vref are adjusted so that the threshold value Va is obtained by a predetermined value, that is, mainly by resistance voltage division.

  The resistor R3 is connected between the output terminal T3 of the comparator CM1 and the output terminal NLA of the comparison unit 21.

  The resistor R4 is connected between a node between the resistor R3 and the output terminal NLA of the comparison unit 21 and the reference potential Vref. That is, the resistor R4 is connected between the reference potential Vref and the output terminal NLA of the comparison unit 21.

  The resistor R5 is connected between a node between the resistor R3 and the output terminal NLA of the comparison unit 21 and the ground potential. That is, the resistor R5 is connected between the ground potential and the output terminal NLA of the comparison unit 21.

  Next, the operation of the comparison unit 21 will be described with reference to FIGS. 3 and 2B and 2C.

  When the command speed voltage Vsp is smaller than the threshold value Va, the comparator CM1 outputs a low level signal indicating that the command speed voltage Vsp is smaller than the threshold value Va. That is, since the threshold value Va is higher than the command speed voltage Vsp, the comparison circuit 211 outputs a high level signal indicating that the threshold value Va is higher than the command speed voltage Vsp to the base of the transistor Q1. Accordingly, the transistor Q1 is turned on, so that the potential of the output terminal T3 of the comparator CM1 becomes a low level.

  At this time, a current flows through the resistors R3 to R5 as indicated by the one-dot chain line arrows in FIG. 3, so that the resistance values of the resistors R3, R4, and R5 are R3, R4, and R5, respectively. For example, if the potential LA of the output terminal NLA is not affected by the comparator, the potential LA becomes a low level value represented by Equation 2 below, that is, the first value LA1.

LA = LA1
= {R3 * R5 / (R3 * R5 + R4 * (R3 + R5))} * Vref
... Formula 2

  On the other hand, when the command speed voltage Vsp is greater than the threshold value Va, the comparator CM1 outputs a high level signal indicating that the command speed voltage Vsp is greater than the threshold value Va. That is, since the threshold value Va is lower than the command speed voltage Vsp, the comparison circuit 211 outputs a Low level signal indicating that the threshold value Va is lower than the command speed voltage Vsp to the base of the transistor Q1. In response to this, the transistor Q1 is turned off, so that the potential of the output terminal T3 of the comparator CM1 becomes High level.

  At this time, current flows through the resistors R3 to R5 as indicated by solid arrows in FIG. 3 (current does not flow through the resistor R3), so that the resistance values of the resistors R3, R4, and R5 are set to R3, R4, and R5, respectively. Then, the potential LA of the output terminal NLA of the comparison unit 21 becomes, for example, a high level value such as Equation 3 below, that is, the second value LA2.

LA = LA2
= {R5 / (R4 + R5)} × Vref Equation 3
The second value LA2 shown in Equation 3 is larger than the first value LA1 shown in Equation 2.

  Here, suppose that the advance angle control is performed by linearly matching the speed command voltage and the advance amount to be controlled. In this case, if the value of the speed command voltage deviates (varies) from the actually commanded speed (rotation speed) due to variations in power supply voltage, characteristic variations of parts (electronic components, motor windings, etc.) or disturbance noise, etc. The optimum phase angle setting voltage also fluctuates following the value of the shifted speed command voltage.

  For example, when the actually commanded speed (rotation speed) is the speed ωt1 shown in FIG. 4A, an external controller (not shown) generates a speed command voltage Vsp1 corresponding to the command speed ωt1. Output. However, the speed command voltage is supplied in the process of being supplied from the external controller to the comparison unit 21 of the advance angle control unit 20 due to variations in power supply voltage, characteristic variations of parts (electronic components, motor windings, etc.) or disturbance noise. The value of Vsp varies between Vsp1 and Vsp1a (see the arrow indicated by the broken line in FIG. 4A). In other words, the relationship between the speed ω and the speed command voltage Vsp tends to shift from the ideal relationship indicated by the solid line in FIG. 4A to the relationship indicated by the broken line. For example, when the value of the speed command voltage Vsp becomes Vsp1a, the amount of advance is controlled to correspond to the speed command voltage Vsp of the value Vsp1a. Therefore, as shown in FIG. 4A, the controlled speed is the speed ωt1. It will shift to faster speed ωt1a. As described above, the set advance angle amount deviates from the one corresponding to the actually commanded speed, and the advance angle amount may not be an appropriate value, so the motor efficiency tends to deteriorate. .

  On the other hand, in the first embodiment, the advance angle control unit 20 controls the advance amount of the phase stepwise according to the command speed. That is, the advance angle control unit 20 determines the advance amount LA as the first value LA1 when the command speed voltage Vsp is smaller than the threshold Va, and determines the advance amount LA when the command speed voltage Vsp is greater than the threshold Va. The second value LA2 is determined to be larger than the first value LA1.

  For example, when the actually commanded speed (number of revolutions) is the speed ωt1 shown in FIG. 4A, it is caused by variations in power supply voltage, characteristics of components (electronic components, motor windings, etc.), disturbance noise, etc. Even if the value of the speed command voltage Vsp varies from Vsp1 to Vsp1a, as shown in FIG. 4B, the set advance amount can be set to the first value LA1 corresponding to the speed ωt1 ( (See arrows shown by broken lines in FIG. 4B).

  Similarly, for example, when the actually commanded speed (number of revolutions) is the speed ωt2 shown in FIG. 4A, the power supply voltage varies, the characteristics of components (electronic components, motor windings, etc.), or the disturbance Even if the value of the speed command voltage Vsp fluctuates between Vsp2 and Vsp2a due to noise or the like, as shown in FIG. 4B, the set advance amount is set to the second value LA2 corresponding to the speed ωt2. (Refer to the arrow indicated by the broken line in FIG. 4B).

  As described above, according to the first embodiment, even when the command speed voltage varies due to variations in power supply voltage, variations in characteristics of components (electronic components, motor windings, etc.), disturbance noise, etc. ), The advance angle control can be performed with an advance amount such that the efficiency of the motor M is improved, so that the efficiency of the motor M can be improved. That is, the efficiency of the motor can be improved even when the command speed voltage varies.

  Further, when the advance angle control is performed by linearly matching the speed command voltage with the amount of advance angle to be controlled, the speed command voltage fluctuates (varies) when the load (rotational speed) of the motor M becomes unstable. Therefore, there is a possibility that the set phase angle also fluctuates and does not become an appropriate value. As a result, the set advance angle amount deviates from that corresponding to the actually commanded speed, and the advance angle amount may not be an appropriate value, so that the motor efficiency tends to deteriorate.

  On the other hand, in the first embodiment, as described above, even when the command speed voltage varies due to instability of the motor load (rotation speed), the motor M is controlled according to the load (rotation speed). Since the advance angle can be controlled with an advance angle amount that improves the efficiency, the efficiency of the motor M can be improved. That is, the efficiency of the motor can be improved even when the command speed voltage varies.

  Also, when the advance angle control is performed by linearly matching the speed command voltage and the advance amount to be controlled, the phase angle advances too much when there is no load (such as when there is an abnormality), causing the motor M to rotate abnormally. There is a possibility of waking up.

  On the other hand, in the first embodiment, the advance angle control unit 20 controls the advance angle amount stepwise, and the phase angle can be prevented from advancing beyond the upper limit of the step. For example, in the case shown in FIG. 4B, it is possible to suppress the advance amount from becoming larger than the second value LA2. Thereby, abnormal rotation of the motor M can be suppressed.

  Alternatively, suppose that the advance angle control unit 20 does not have the low-pass filter 22. In this case, for example, when the command speed voltage Vsp increases beyond the threshold value Va, the comparison unit 21 outputs a signal φLAi having a stepped waveform as shown by a solid line in FIG. Will be output to. Thus, if the advance amount LA is suddenly switched, the rotational speed of the motor M that is driven and controlled by the drive control unit 16 may also fluctuate rapidly, resulting in abnormal noise.

  On the other hand, in the first embodiment, the advance angle control unit 20 includes a low-pass filter 22. That is, the comparison unit 21 outputs a signal φLAi having a stepped waveform as indicated by a solid line in FIG. The low-pass filter 22 generates a signal φLA having a time constant as indicated by a one-dot chain line in FIG. 2B from a step-like waveform as indicated by a solid line in FIG. The low pass filter 22 outputs the generated signal φLA to the drive control unit 16. In this manner, when the command speed voltage Vsp increases beyond the threshold value Va by the low-pass filter 22, the signal φLA indicating the advance amount LA is supplied to the drive control unit 16 so as to be slow step-up. Thereby, since the advance amount LA can be switched slowly, the rotational speed of the motor M that is driven and controlled by the drive control unit 16 can also be changed slowly, and abnormal noise can be reduced.

  In the first embodiment, the comparison unit 21 includes a comparator CM1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a resistor R5. The comparator CM1 has a non-inverting input terminal T1, an inverting input terminal T2, and an output terminal T3 to which the command speed voltage Vsp is supplied. The resistor R1 is connected between the inverting input terminal T2 of the comparator CM1 and the reference potential Vref. The resistor R2 is connected between the inverting input terminal T2 of the comparator CM1 and the ground potential. The resistor R3 is connected between the output terminal T3 of the comparator CM1 and the output terminal NLA of the comparison unit 21. The resistor R4 is connected between the reference potential Vref and the output terminal T3 of the comparison unit 21. The resistor R5 is connected between the ground potential and the output terminal NLA of the comparison unit 21.

  In this configuration, for example, by dividing the value of the reference potential Vref with the resistors R1 and R2, the threshold value Va that is the potential of the node NVa can be supplied to the inverting input terminal T2 of the comparator CM1. In addition, since the way of current flow to the resistors R3 to R5 can be changed by the output according to the comparison result from the comparator CM1, the comparison unit 21 determines the comparison between the threshold value Va and the speed command voltage Vsp by the comparator CM1. The potential of the output terminal NLA can be changed stepwise.

  As described above, according to the first embodiment, the advance angle control unit 20 that controls the phase advance amount stepwise according to the command speed can be realized with a simple circuit configuration.

  In the first embodiment, the motor M is, for example, a fan motor. The fan motor operation mode is, for example, in two stages, a low wind operation mode and a strong wind operation mode. That is, the command speed in the low wind operation mode can be set to the speed ωt1 shown in FIG. 4A, and the command speed in the strong wind operation mode can be set to the speed ωt2 shown in FIG. In this case, even when the command speed voltage varies, as shown in FIG. 4 (b), it is possible to reliably control with an efficient advance amount in each of the weak wind operation mode and the strong wind operation mode.

  As shown in FIG. 5B, in the control device 1i, the comparison unit 21i of the advance angle control unit 20i may control the phase advance amount stepwise in multiple steps. For example, when the motor M is a fan motor and the operation mode of the fan motor is in three stages of a low wind operation mode, a medium wind operation mode, and a strong wind operation mode, the comparison unit 21i increases the phase advance amount in three stages. You may control in steps.

  In this case, the comparison unit 21i has a configuration corresponding to the resistors R1 to R3 and the comparator CM1 between the terminal to which the speed command voltage Vsp is supplied (the input terminal of the comparison unit 21i) and the output terminal NLA of the comparison unit 21i. The resistors R1 to R3 and the comparator CM1 may be additionally connected in parallel. That is, the comparison unit 21i further includes a comparator CM2, a resistor R6, a resistor R7, and a resistor R8 as illustrated in FIG.

  The comparator CM2 has a non-inverting input terminal T4, an inverting input terminal T5, and an output terminal T6. The non-inverting input terminal T4 is supplied with a speed command voltage Vsp from an external controller (not shown). The inverting input terminal T5 is connected to a node NVb between the resistor R6 and the resistor R7. The output terminal T6 is connected to one end of the resistor R8.

  The resistor R6 is connected between the node NVb and the reference potential Vref. That is, the resistor R6 is connected between the inverting input terminal T5 of the comparator CM2 and the reference potential Vref.

  The resistor R7 is connected between the node NVb and the ground potential. That is, the resistor R6 is connected between the inverting input terminal T5 of the comparator CM2 and the ground potential.

  The resistor R8 is connected between the output terminal T6 of the comparator CM2 and the output terminal NLA of the comparison unit 21i.

  In this configuration, for example, by dividing the value of the reference potential Vref by the resistors R6 and R7, the threshold value Vb that is the potential of the node NVb can be supplied to the inverting input terminal T5 of the comparator CM2. Further, since the way of current flow to the resistors R4, R5, and R8 can be changed by the output according to the comparison result from the comparator CM2, the comparison unit according to the comparison result of the threshold value Vb and the speed command voltage Vsp by the comparator CM2. The potential of the output terminal NLA of 21i can be changed stepwise. That is, as shown in FIG. 5B, in addition to stepwise changing the potential of the output terminal NLA of the comparator 21i in accordance with the comparison result of the threshold value Va and the speed command voltage Vsp by the comparator CM1, the comparator CM2 Since the potential of the output terminal NLA of the comparison unit 21i can be changed in steps according to the comparison result of the threshold value Vb and the speed command voltage Vsp, the potential of the comparison unit 21i can be changed in three steps.

  Thus, according to this modification, the advance angle control unit 20i that controls the phase advance amount stepwise in three steps according to the command speed can be realized with a simple circuit configuration.

(Second Embodiment)
Next, the control apparatus 100 for the motor M according to the second embodiment will be described. Below, it demonstrates centering on a different part from 1st Embodiment.

  In the first embodiment, the variation in the command speed voltage Vsp is caused only by, for example, characteristic variations of parts (electronic parts, motor windings, etc.) as shown by broken arrows in FIG. As shown in FIG. 7B, the phase advance amount can be stably controlled.

  However, the variation in the command speed voltage Vsp is caused by disturbances (strong winds, etc.) in addition to characteristic variations of parts (electronic parts, motor windings, etc.), for example, as shown by a one-dot chain line arrow in FIG. If it exceeds the predetermined allowable range, as shown in FIG. 7B, the advance amount LA is repeatedly switched before and after the threshold value Va. In this case, the advance amount LA is not stable, and the logic circuit 12 that receives the signal φLA indicating the advance amount LA may malfunction.

  Therefore, in the second embodiment, as shown in FIG. 6B, the advance angle control unit 120 gives hysteresis to the step advance angle control operation. That is, the advance angle control unit 120 changes the advance angle amount LA from the first value LA1 to the second value LA2 when the command speed voltage Vsp increases beyond the first threshold value Va1. The second value LA2 is larger than the first value LA1. Further, the advance angle control unit 120 changes the advance angle amount LA from the second value LA2 to the first value LA1 when the command speed voltage Vsp becomes smaller than the second threshold value Va2. The second threshold value Va2 is a threshold value that is smaller than the first threshold value Va1.

  Further, the internal configuration of the comparison unit 121 of the advance angle control unit 120 is different from that of the first embodiment as shown in FIG.

  Specifically, the comparison unit 121 further includes a resistor R111, a resistor R112, a resistor R113, a transistor M1, and a buffer amplifier BA1, and the connection destination on the input terminal side of the comparator CM1 is different.

  The inverting input terminal T1 of the comparator CM1 is connected to the node NVa, not the terminal to which the speed command voltage Vsp is supplied. The non-inverting input terminal T2 of the comparator CM1 is connected not to the node NVa but to a terminal to which the speed command voltage Vsp is supplied. Accordingly, the output of the comparator CM1 is based on the reverse of the first embodiment, that is, the step output shown in FIG. 2B is reversed left and right (see FIG. 6C).

  The resistor R111 is connected between the node between the resistor R3 and the buffer amplifier BA1 and the node NVa. That is, the resistor R111 is connected between the other end of the resistor R3 whose one end is connected to the comparator CM1 and the inverting input terminal T1 of the comparator CM1. The resistor R111 is provided to give hysteresis to the output of the comparator CM1. That is, the resistor R111 sets the potential of the node NVa as the threshold value Va1 when the speed command voltage Vsp exceeds the threshold value Va1, and sets the potential of the node NVa when the speed command voltage Vsp decreases beyond the threshold value Va2. The threshold Va2 (<Va1) is set.

  The resistor R112 is connected between the node between the resistor R3 and the buffer amplifier BA1 and the reference potential Vref. That is, the resistor R112 is connected between the other end of the resistor R3 whose one end is connected to the comparator CM1 and the reference potential Vref.

  The resistor R113 is connected between the drain of the transistor M1 and the output terminal NLA of the comparison unit 121. That is, the resistor R113 has one end connected to the output terminal NLA of the comparison unit 121 and the other end connected to the drain of the transistor M1.

  The transistor M1 is, for example, an NMOS transistor, the gate is arranged on the resistor R3 side, the source is connected to the ground potential, and the drain is connected to the other end of the resistor R113. The transistor M1 is connected to the output terminal of the buffer amplifier BA1. The transistor M1 inverts the step output of the comparator CM1. In other words, the transistor M1 horizontally inverts the output of the comparator CM1, which is the step output shown in FIG. 2B inverted horizontally, to obtain the same step output as that shown in FIG. .

  The transistor M1 may be a PMOS transistor, for example. In this case, the gate is arranged on the resistor R3 side, the drain is connected to the ground potential, and the source is connected to the other end of the resistor R113.

  The buffer amplifier BA1 has an input terminal connected to the other end of the resistor R3, and an output terminal connected to the gate of the transistor M1. That is, the buffer amplifier BA1 is connected between the other end of the resistor R3 and the gate of the transistor M1. The buffer amplifier BA1 performs impedance conversion so that the voltage level to be supplied to the gate of the transistor M1 is L level / H level according to the output of the comparator CM1.

  The buffer amplifier BA1 may be one in which two inverters are connected in series.

  As described above, in the second embodiment, the advance angle control unit 120 gives hysteresis to the stepwise advance angle control operation. That is, when the command speed voltage Vsp increases beyond the first threshold value Va1, the advance angle control unit 120 increases the advance amount LA from the first value LA1 to the second value LA2 that is larger than the first value LA1. Change to Further, when the command speed voltage Vsp becomes smaller than the second threshold value Va2 that is smaller than the first threshold value Va1, the advance angle control unit 120 changes the advance amount LA from the second value LA2 to the first value LA1. Change to

  For example, when the actually commanded speed (number of revolutions) is the speed ωt1 shown in FIG. 7A, for example, due to disturbances (strong winds, etc.) in addition to characteristic variations of parts (electronic parts, motor windings, etc.) Even if the value of the speed command voltage Vsp varies from Vsp1 to Vsp1b, as shown in FIG. 7C, the advance amount LA can be prevented from being repeatedly switched before and after the threshold value Va. As a result, the advance amount LA can be stabilized, and malfunction of the logic circuit 12 and the like in the drive control unit 16 that has received the signal φLA indicating the advance amount LA can be suppressed. In other words, in addition to the effect of the first embodiment, it is possible to obtain an effect that malfunction of the logic circuit 12 and the like in the drive control unit 16 can be suppressed.

  In the second embodiment, the comparison unit 121 further includes a resistor R111, a resistor R112, a resistor R113, and a transistor M1, and the connection destination on the input terminal side of the comparator CM1 is opposite to that in the first embodiment. ing. The resistor R111 has one end connected between the other end of the resistor R3 connected to the output terminal T3 of the comparator CM1 and the inverting input terminal T1 of the comparator CM1. The resistor R112 is connected between the other end of the resistor R3 and the reference potential Vref. One end of the resistor R113 is connected to the output terminal NLA of the comparison unit 121. The transistor M1 has a gate arranged on the resistor R3 side, a source connected to the ground potential, and a drain connected to the other end of the R113 resistor.

  In this configuration, when the resistance R111 increases when the speed command voltage Vsp exceeds the threshold value Va1, the potential of the node NVa is set to the threshold value Va1, and when the speed command voltage Vsp decreases beyond the threshold value Va2, the resistance of the node NVa The potential acts as a threshold value Va2 (<Va1). In addition, the transistor M1 horizontally inverts the output of the comparator CM1, which is obtained by horizontally inverting the step output shown in FIG. 2B, to obtain the same step output as that shown in FIG. (See FIG. 6 (c)). As a result, as shown by the solid line in FIG. 6B, the potential of the output terminal NLA of the comparison unit 121 can be changed stepwise in a form having hysteresis.

  In the second embodiment, the comparison unit 121 further includes a buffer amplifier BA1. The buffer amplifier BA1 has one end connected between the other end of the resistor R3 connected to the output terminal NLA of the comparison unit 121 and the gate of the transistor M1. In this configuration, for example, since the buffer amplifier BA1 has a large input impedance, the configuration on the left side of the buffer amplifier BA1 can be prevented from affecting the potential of the gate of the transistor M1, and the gate potential of the transistor M1 is attenuated. Can be suppressed. As a result, the operation of inverting the step output by the transistor M1 can be reliably performed.

  As shown in FIG. 8 (b), in the control device 100i, the comparison unit 121i of the advance angle control unit 120i has a phase advance amount with hysteresis and is stepped in multiple steps. You may control. For example, when the motor M is a fan motor and the operation mode of the fan motor is in three stages of a low wind operation mode, a medium wind operation mode, and a strong wind operation mode, the comparison unit 21i has a phase advance amount with hysteresis. It may be controlled in a stepwise manner in three stages.

  In this case, the comparison unit 121i includes resistors R1 to R3, R111 to R113, a comparator CM1, between a terminal to which the speed command voltage Vsp is supplied (an input terminal of the comparison unit 121i) and an output terminal NLA of the comparison unit 121i. A configuration corresponding to the buffer amplifier BA1 and the transistor M1 may be additionally connected in parallel to the resistors R1 to R3, R111 to R113, the comparator CM1, the buffer amplifier BA1, and the transistor M1. That is, as shown in FIG. 8A, the comparison unit 121i further includes a comparator CM2, a resistor R6, a resistor R7, a resistor R8, a resistor R121, a resistor R122, a resistor R123, a transistor M2, and a buffer amplifier BA2. The connection destination on the input terminal side of the comparator CM2 is different. Below, it demonstrates centering on a different part from the modification of 1st Embodiment, and 2nd Embodiment.

  The inverting input terminal T4 of the comparator CM2 is connected to the node NVb, not the terminal to which the speed command voltage Vsp is supplied. The non-inverting input terminal T5 of the comparator CM2 is connected not to the node NVb but to a terminal to which the speed command voltage Vsp is supplied. Thus, the output of the comparator CM2 is based on the reverse of the modification of the first embodiment, that is, the step output shown in FIG. 2B is reversed left and right (see FIG. 6C).

  The resistor R121 is connected between the node between the resistor R8 and the buffer amplifier BA2 and the node NVb. That is, the resistor R121 is connected between the other end of the resistor R8, one end of which is connected to the comparator CM2, and the inverting input terminal T4 of the comparator CM2. This resistor R121 is provided to provide hysteresis to the output of the comparator CM2. That is, the resistor R121 sets the potential of the node NVb as the threshold Vb1 when the speed command voltage Vsp exceeds the threshold Vb1, and sets the potential of the node NVb when the speed command voltage Vsp decreases beyond the threshold Vb2. The threshold Vb2 (<Vb1) is set.

  The resistor R122 is connected between a node between the resistor R8 and the buffer amplifier BA2 and the reference potential Vref. That is, the resistor R122 is connected between the other end of the resistor R8, one end of which is connected to the comparator CM2, and the reference potential Vref.

  The resistor R123 is connected between the drain of the transistor M2 and the output terminal NLA of the comparison unit 121i. That is, the resistor R123 has one end connected to the output terminal NLA of the comparator 121i and the other end connected to the drain of the transistor M2.

  The transistor M2 is an NMOS transistor, for example, and has a gate arranged on the resistor R8 side, a source connected to the ground potential, and a drain connected to the other end of the resistor R123. The transistor M2 is connected to the output terminal of the buffer amplifier BA2. The transistor M2 inverts the step output of the comparator CM2. That is, the transistor M2 horizontally inverts the output of the comparator CM2, which is the one obtained by horizontally inverting the step output shown in FIG. 2B, to obtain the same step output as that shown in FIG. .

  In this configuration, when the resistance R121 increases when the speed command voltage Vsp exceeds the threshold value Vb1, the potential of the node NVb is set to the threshold value Vb1, and when the speed command voltage Vsp decreases beyond the threshold value Vb2, the resistance of the node NVb The potential acts as a threshold value Vb2 (<Vb1). In addition, the transistor M2 horizontally inverts the output of the comparator CM2, which is obtained by horizontally inverting the step output shown in FIG. 2B, to obtain the same step output as that shown in FIG. (See FIG. 6 (c)). As a result, as shown by the solid line in FIG. 8B, the potential of the output terminal NLA of the comparison unit 121i can be changed in a stepwise manner with a hysteresis. That is, as shown in FIG. 8B, the potential of the output terminal NLA of the comparison unit 121i is changed in a stepwise manner with hysteresis according to the comparison result of the threshold value Va and the speed command voltage Vsp by the comparator CM1. In addition, since the potential of the output terminal NLA of the comparison unit 21i can be changed in a stepped manner with hysteresis according to the comparison result of the threshold value Vb and the speed command voltage Vsp by the comparator CM2, the comparison unit 121i The potential can be changed stepwise in three stages in a form having hysteresis.

  As described above, according to this modification, the advance angle control unit 120i that controls the phase advance amount in accordance with the command speed in a stepped manner in three steps and has a simple circuit configuration. Can be realized.

  As described above, the motor control device according to the present invention is useful for controlling the fan motor.

1, 1i, 100, 100i Control device 15 Drive unit 16 Drive control unit 20, 20i, 120, 120i Advance angle control unit 21, 21i, 121, 121i Comparison unit 22 Low-pass filter BA1, BA2 Buffer amplifier CM1, CM2 Comparator M Motor M1, M2 Transistors R1-R8, R111-R113, R121-R123 Resistors

Claims (3)

A motor control device that controls a motor to operate at a command speed,
A drive unit for driving the motor;
An advance angle control unit for stepwise controlling the amount of advance of the phase according to the command speed;
A drive control unit that controls the drive unit using a phase advanced by the controlled advance amount;
With
When the command speed voltage corresponding to the command speed becomes larger than a first threshold, the advance angle control unit increases the advance amount from a first value to a second value greater than the first value. When the command speed voltage becomes smaller than a second threshold value smaller than the first threshold value, the advance amount is changed from the second value to the first value,
The command speed voltage is
A first command speed voltage having a first variation range;
A second command speed voltage having a second variation range that does not overlap the first variation range and exists at a higher speed than the first variation range;
Including
The first threshold value is determined to be a value between an upper limit of the first variation range and a lower limit of the second variation range;
The advance angle controller
A comparison unit that compares the command speed voltage including the first command speed voltage and the second command speed voltage with the threshold value, and outputs a comparison result as the advance amount;
A low pass filter that selectively passes a low frequency component of the output of the comparison unit and outputs the low frequency component to the drive control unit;
Have
The comparison unit includes:
A comparator having a first input terminal to which the command speed voltage is supplied, a second input terminal, and an output terminal;
A first resistor connected between the second input terminal of the comparator and a reference potential;
A second resistor connected between the second input terminal of the comparator and a ground potential;
A third resistor having one end connected to the output terminal of the comparator;
A fourth resistor connected between the reference potential and the output terminal of the comparator;
A fifth resistor connected between a ground potential and the output terminal of the comparator;
A sixth resistor connected between the other end of the third resistor and the second input terminal of the comparator;
A seventh resistor connected between the other end of the third resistor and the reference potential;
An eighth resistor having one end connected to the output terminal of the comparator;
A transistor having a gate disposed on the third resistor side, one of a source and a drain connected to a ground potential, and the other of the source and the drain connected to the other end of the eighth resistor;
Motor control device characterized by having a. The comparison unit, the motor control device according to claim 1, characterized by further comprising a connected buffer amplifiers between the gate of said third other terminal and said transistor of resistance. The motor, motor controller according to claim 1 or 2, characterized in that a fan motor.

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