JP6489142B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device that controls the rotation of a motor by a rotation command from a microcomputer (hereinafter referred to as a microcomputer).

  The sensor-equipped three-phase brushless DC motor has a Hall element, a control and a drive IC and is driven. For example, when the space is limited and the microcomputer cannot be placed near the motor due to the power supply configuration on the primary side and the secondary side, such as an indoor fan of an air conditioner, the motor control IC drives the motor. The motor control IC receives a rotation command from the microcomputer and supplies a motor drive signal corresponding to the rotor position recognized by the magnetic element to the drive IC.

  The drive IC and the output transistor amplify the motor drive signal and supply electric power for driving the motor to the motor. The motor control IC feeds back the motor rotation speed signal recognized by the magnetic element to the microcomputer through an insulated photocoupler or the like. The microcomputer adjusts so as to eliminate the difference between the rotation speed signal and the rotation command, thereby realizing closed loop control.

  In brushless DC motors, mechanical angles and electrical angles are properly used in considering the rotation angle. As shown in FIG. 8, when the horizontal axis is an electrical angle and the vertical axis is a three-phase current, one cycle of a sine wave is called an electrical angle of 360 °. Since there is a relationship of mechanical angle = electrical angle / number of pole pairs between mechanical angle and electrical angle, the mechanical angle is 360 ° for one pole pair and 180 ° for two pole pairs with respect to 360 ° electrical angle. For a 4-pole pair, the angle is 90 °. When the air conditioner indoor fan is a 4-pole pair, a sine wave with an electrical angle of 4 to 1440 ° is required to make a mechanical angle of 1 to 360 ° (equal to a human rotor with a visual angle). It is necessary to supply the motor.

  On the other hand, there is an agreement in the motor rotation number signal. FIG. 9 shows the magnetic signal and rotation speed signal FG output.

  There are a case where three times of signals are output as the rotation number signal FG for one electrical angle-360 °, and a case where one rotation number signal FG is output for one rotation of the electrical angle-360 °. is there. These are selected according to the microcomputer of each company. For example, when the FG1 pulse is selected with a four-pole motor, when the microcomputer detects four rotation speed signals FG, it is recognized that the mechanical angle one-round motor has rotated. On the other hand, when the FG3 pulse is selected, in the same situation, it is determined that the rotation angle signal FG is 12 rounds and the mechanical angle is one round.

上式は、排他的論理和を示している。

The above formula represents exclusive OR.

      FG1 pulse FG = magnetic element U... U-phase signal is output as it is.

  In many cases, the number of rotations of the motor is expressed in units of rpm. The conversion formula is as follows.

When FG3 pulse is selected Motor speed (rpm) = FG frequency (Hz) x 1 / (3 x number of pole pairs) x 60 (min)
When FG1 pulse is selected Motor speed (rpm) = FG frequency (Hz) x 1 / (1 x number of pole pairs) x 60 (min)
Since such an arrangement is widely spread in the market, the microcomputer is standardized with respect to a series of flows of the receiving portion of the rotation signal FG of the 4-pole pair and the output of the rotation command, and cannot be easily changed.

  On the other hand, in the market of air conditioners and the like, with an increase in load, there is a demand for motors having a large motor torque with an emphasis on motor torque. In order to increase the motor torque, the number of poles may be increased to 5 pole pairs or the like.

  As a prior art, for example, a brushless motor driving method and a brushless motor drive control device described in Patent Document 1 are known.

JP 2005-192338 A

  However, as described above, it is difficult to change the microcomputer. If the microcomputer receives the rotation speed signal FG as it is without adjusting the microcomputer, when the FG1 pulse and FG = 10 Hz, the motor rotation speed is originally 120 rpm for the 5-pole pair, Since the 4-pole pair setting remains, the microcomputer misunderstands that the motor rotation speed is 150 rpm.

  In addition, when the microcomputer is changed, a dedicated microcomputer is required for control, and management becomes complicated.

  An object of the present invention is to provide a motor control device that can simplify management without requiring a dedicated computer for control.

A motor control device according to the present invention generates a motor drive signal based on a rotation command from a computer that processes a first rotation speed signal when a motor having a permanent magnet of M pole pairs is used, and N A motor control device for driving a motor having a pole pair of permanent magnets, wherein the second rotation number signal of the motor having the N pole pair of permanent magnets is used as the first motor of the motor having the M pole pair of permanent magnets. A pole pair conversion circuit that converts the rotation number signal to output to the computer is provided , and the pole pair conversion circuit outputs an electric angle of 180 ° when the second rotation number signal outputs one pulse with respect to an electric angle of 360 °. When the second rotational speed signal is inverted at × N / M, and the second rotational speed signal outputs three pulses with respect to an electrical angle of 360 °, the second rotational speed signal at an electrical angle of 60 ° × N / M To reverse And converting.

According to the present invention, the pole pair conversion circuit converts the second rotation speed signal of the motor having the N pole pair permanent magnet into the first rotation speed signal of the motor having the M pole pair permanent magnet and outputs the first rotation speed signal to the computer. Therefore, the computer can process signals in the same manner as when using a motor having a permanent magnet of M pole pairs. The pole pair conversion circuit inverts the second rotational speed signal at an electrical angle of 180 ° × N / M when the second rotational speed signal outputs one pulse with respect to the electrical angle of 360 °, and the second rotational speed signal is When three pulses are output for an angle of 360 °, the signal can be converted so that the second rotational speed signal is inverted at an electrical angle of 60 ° × N / M.

  Therefore, it is not necessary to provide a dedicated computer for control, and management can be simplified.

It is a circuit block diagram of the motor control apparatus which concerns on Example 1 of this invention. It is a timing chart for demonstrating operation | movement of the motor control apparatus which concerns on Example 1 of this invention. It is a figure which shows time acquisition for every 60 degree | times of the magnetic signal and rotation speed signal output electrical angle in the motor control apparatus which concerns on Example 1 of this invention. It is a circuit block diagram of the motor control apparatus which concerns on Example 2 of this invention. It is a timing chart for demonstrating operation | movement of the motor control apparatus which concerns on Example 2 of this invention. It is a circuit block diagram of the motor control apparatus which concerns on Example 3 of this invention. It is a timing chart for demonstrating operation | movement of the motor control apparatus which concerns on Example 3 of this invention. It is a figure which shows an electrical angle and motor rotation. It is a figure which shows a magnetic signal and a rotation speed signal.

Hereinafter, a motor control device according to an embodiment of the present invention will be described in detail with reference to the drawings.
Example 1
FIG. 1 is a circuit configuration diagram of a motor control device according to a first embodiment of the present invention. The motor 6 is a brushless DC motor, and the U-phase magnetic element 7a, the V-phase magnetic element 7b, and the W-phase magnetic element 7c, which are Hall elements corresponding to the three phases of the UVW phase, are electrically angled. Are arranged at intervals of approximately 120 °. The magnetic elements 7 a to 7 c detect magnetic signals by the rotation of the motor 6 and output the detected magnetic signals to the motor control device 3.

  The motor control device 3 inputs the rotation command from the microcomputer 1 to the drive signal generation unit 42 via the photocoupler 2a and the drive command unit 41, and the drive signal generation unit 42 is recognized by the magnetic elements 7a to 7c based on the rotation command. A motor drive signal corresponding to the rotor position thus generated is generated and output to the motor drive circuit 4. The motor drive circuit 4 drives the motor 6 by turning on and off the output transistor 5 according to a motor drive signal.

  The motor control device generates a motor drive signal based on a rotation command from the microcomputer 1 that processes a first rotation number signal from a motor having a permanent magnet of four pole pairs (corresponding to the M pole pair of the present invention), and the motor The motor 6 having a permanent magnet of 5 pole pairs (corresponding to the N pole pair of the present invention) is driven by the drive signal. M may be other than 4, and N may be other than 5.

  The motor control device 3 converts the second rotation speed signal of the motor 6 having a 5-pole pair of permanent magnets into a first rotation speed signal of a motor having a 4-pole pair of permanent magnets and outputs the first rotation speed signal to the microcomputer 1. A circuit 30 is provided.

  The pole pair conversion circuit 30 inverts the second rotational speed signal at an electrical angle of 180 ° × 5/4 = electrical angle of 225 ° when the second rotational speed signal outputs one pulse with respect to the electrical angle of 360 °. When the 2-rotation speed signal outputs 3 pulses with respect to an electrical angle of 360 °, the signal is converted so that the second rotational speed signal is inverted at an electrical angle of 60 ° × 5/4 = electrical angle of 75 °.

  The pole pair conversion circuit 30 includes differential comparators 31a to 31c, a time measurement unit 32, a counter 34, an exclusive OR circuit 35, a pulse selection unit 36, and a phase inversion unit 37.

  The differential comparators 31a to 31c are transmitted from the U-phase, V-phase, and W-phase magnetic elements 7a to 7c, and the magnetic signals HUP, HUN, HVP, and HVN shown in FIG. , HWP, HWN are amplified, and the amplified magnetic signals HU, HV, HW are output to the time measuring unit 32 and the exclusive logic circuit 35.

  The exclusive OR circuit 35 takes the exclusive OR of the magnetic signals HU, HV, HW shown in FIG. 2 that are sent from the differential comparators 31a to 31c and whose phases are shifted by 120 ° from each other. The rotation number signal FG′3 pulse of the FG3 pulse shown in FIG.

  The pulse selection unit 36 inputs the magnetic signal HU of the U-phase magnetic element 7a from the differential comparator 31a as the rotation number signal FG′1 pulse of the FG1 pulse shown in FIG. 2 and also from the exclusive OR circuit 35. The FG3 pulse rotation speed signal FG′3 pulse is input, the FG1 pulse rotation speed signal FG′1 pulse or the FG3 pulse rotation speed signal FG′3 pulse is selected and output to the phase inversion unit 37 and the counter 34.

  The time measuring unit 32 has an electrical angle 60 from the rising edge to the falling edge or from the falling edge to the rising edge between the phases based on the U-phase to W-phase magnetic signals HU, HV, HW from the differential comparators 31a to 31c. The motor drive signal for driving the motor 6 is output to the motor drive circuit 4 at the measured electrical angle of 60 °.

The time measuring unit 32 includes a T / 64 counter 33. The T / 64 counter 33 constitutes the first counter of the present invention, and the time of electrical angle 60 ° is divided by 64 (2 ⁶ = 64) to obtain the time of electrical angle 0.937 °, and the electrical angle 0 The time of 937 ° is output to the counter 34.

  The counter 34 constitutes a second counter of the present invention. When the rotation number signal FG′1 pulse of the FG1 pulse is sent from the pulse selector 36, the electrical angle 0 sent from the T / 64 counter 33 is zero. When the time of 937 ° is counted 240 times, that is, when the electrical angle reaches 225 °, a signal for inverting the phase is output to the phase inverting unit 37.

  When the counter 34 receives the FG3 pulse rotation number signal FG′3pulse from the pulse selector 36, the counter 34 counts the electrical angle of 0.937 ° 80 times, that is, the electrical angle becomes 75 °. A signal for inverting the phase is output to the phase inverting unit 37.

  The phase inversion unit 37 receives a signal indicating that the electrical angle is 225 ° from the counter 34 when the rotation number signal FG′1 pulse of the FG1 pulse is transmitted from the pulse selection unit 36. As shown in FIG. 2, the FG1 pulse rotation speed signal FG′1 pulse is converted into an FG1 pulse rotation speed signal FG1 pulse whose phase is inverted every 225 ° and output to the microcomputer 1 via the photocoupler 2b. To do.

  As shown in FIG. 2, the phase inversion unit 37 receives a signal indicating that the rotation angle signal FG′3 pulse of the FG3 pulse has been sent and that the electrical angle is 75 ° from the counter 34. In addition, the FG3 pulse rotation speed signal FG′3 pulse is converted into an FG3 pulse rotation speed signal FG3 pulse whose phase is inverted every 75 ° and output to the microcomputer 1 via the photocoupler 2b.

  The T / 64 counter 33, the counter 34, and the phase inverting unit 37 invert the second rotation number signal every 225 ° of electrical angle with reference to the time of the electrical angle of 60 ° measured by the time measuring unit 32. The rotational speed signal generation unit of the present invention that generates the first rotational speed signal is configured.

  Next, the operation of the motor control apparatus according to the first embodiment configured as described above will be described. First, it is assumed that the microcomputer 1 receives a 4-pole pair signal from the rotational speed signal FG, and the motor side is actually a 5-pole pair.

  When the rotation speed of the motor 6 is 120 rpm with the FG1 pulse, the rotation speed signal FG is output at 10 Hz because the motor 6 is a 5-pole pair. However, since the rotation speed signal FG is output to the microcomputer 1 corresponding to a 4-pole pair, the rotation speed signal FG needs to be output at 8 Hz.

  In FIG. 2, the magnetic signal HU, HV, HW of 5 pole pairs and the rotation speed signal FG output at that time (FG′3 pulse and FG′1 pulse are shown. FG′1 pulse in the case of a mechanical angle of 360 ° In this state, the microcomputer 1 mistakenly considers 120 rpm as 150 rpm.

  On the other hand, in the first embodiment, the microcomputer 1 can recognize the original number of rotations by setting the output to 4 times like the FG1 pulse when the motor makes one turn with 5 pole pairs. .

   That is, FG1 pulse = FG′1 pulse × (conventional microcomputer side assumed pole pair) ÷ (original motor pole pair). Regarding this calculation, if an operation is attempted while outputting all the data for one round of the motor mechanical angle, a delay occurs in the enormous logic control registers and output. Therefore, in the first embodiment, the output delay is also suppressed without greatly increasing the number of registers for this control.

  A control IC for a three-phase brushless DC motor with a sensor generally obtains a magnetic signal, that is, a position signal from a magnetic element, and divides an electrical angle of 360 ° into six states as shown in FIG. That is, there are six states for every 60 ° electrical angle. In order to generate a motor drive signal of the next electrical angle of 60 °, the time measuring unit 32 measures the time of the current electrical angle of 60 °.

Further, the T / 64 counter 33 divides the time of the electrical angle 60 ° by 64 (2 ⁶ = 64) to obtain the time of the electrical angle 0.937 °, and the time of the electrical angle 0.937 ° is the counter 34. Output to.

  Next, in the case of the FG′1 pulse, as shown in FIG. 2, the signal is inverted at an electrical angle of 360 ° / 2 = 180 °.

  On the other hand, in the first embodiment, when the counter 34 receives the FG1 pulse rotation number signal FG′1 pulse from the pulse selector 36, the electrical angle 0 sent from the T / 64 counter 33 is 0. When the time of 937 ° is counted 240 times, that is, when the electrical angle reaches 225 °, a signal for inverting the phase is output to the phase inverting unit 37.

  That is, the signal is inverted at an electrical angle of 225 ° by FG1 pulse = electrical angle 360 ° / 2 × (original motor pole pair) ÷ (conventional microcomputer side assumed pole pair).

  Since a signal with an electrical angle of 60 ° is measured, it is possible to output a rotational speed signal corresponding to a 4-pole pair by inverting the 5-pole pair rotational frequency signal every electrical angle of 225 °.

  Thus, according to the motor control device of the first embodiment, the pole pair conversion circuit 30 uses the second rotation number signal of the motor having the five-pole pair permanent magnet as the first rotation of the motor 6 having the four-pole pair permanent magnet. Since it is converted into a number signal and output to the microcomputer 1, the microcomputer 1 can process the signal in the same manner as when a motor having a quadrupole pair of permanent magnets is used.

Therefore, it is not necessary to provide a dedicated computer for control, and management can be simplified.
(Example 2)
FIG. 4 is a circuit configuration diagram of the motor control device according to the second embodiment of the present invention. The motor control device according to the second embodiment is different from the motor control device according to the first embodiment in the configuration of the T / 4 counter 33a and the counter 34a.

  The T / 4 counter 33a constitutes a third counter of the present invention. As shown in FIG. 5, the time of the electrical angle of 60 ° measured by the time measuring unit 32 is divided by 4 to obtain the time of the electrical angle of 15 °. Ask for. At this time, the division of a multiple of 2 of the logic signal can be realized with a very small number of logics.

  When the counter 34a constitutes the fourth counter of the present invention and outputs one pulse with respect to the electrical angle of 360 °, the electrical angle of 225 ° is counted when the time of the electrical angle of 15 ° from the T / 4 counter 33a is counted 15 times. The signal for inverting the phase is output to the phase inverting unit 37.

  When the counter 34a outputs three pulses with respect to an electrical angle of 360 °, the counter 34a outputs a signal that reverses the phase at an electrical angle of 75 ° when the time of the electrical angle of 15 ° from the T / 4 counter 33a is counted five times. It outputs to the phase inversion part 37.

Thus, the same effect as that of the motor control device according to the first embodiment can be obtained by the motor control device according to the second embodiment.
(Example 3)
FIG. 6 is a circuit configuration diagram of the motor control device according to the third embodiment of the present invention. The motor control device according to the third embodiment differs from the motor control device according to the first embodiment in the configuration of a T / 4 counter 33b and a counter 34b.

  The T / 4 counter 33b constitutes the fifth counter of the present invention. As shown in FIG. 7, the time of the electrical angle of 60 ° measured by the time measuring unit 32 is divided by 4 to obtain the time of the electrical angle of 15 °. Is output five times at an electrical angle of 15 °. At this time, the division of a multiple of 2 of the logic signal can be realized with a very small number of logics.

  The counter 34 b constitutes a sixth counter of the present invention, and outputs a signal for inverting the phase to the phase inverting unit 37 when the time of the electrical angle of 15 ° from the T / 4 counter 33 b is counted five times.

  In this case, the fifth count uses a value of an electrical angle of 15 ° in advance. For this reason, the data in the shaded gray area is left over, so the data in this part is discarded.

  As described above, the motor control device according to the third embodiment can achieve the same effects as those of the motor control device according to the first embodiment.

DESCRIPTION OF SYMBOLS 1 Microcomputer 2a, 2b Photocoupler 3 Motor control circuit 4 Motor drive circuit 5 Output transistor 6 Motor 7a, 7b, 7c Magnetic element 31a, 31b, 31c Differential comparator 32 Time measurement part 33 T / 64 counter 33b T / 4 counter 34, 34b Counter 35 Exclusive OR circuit 36 Pulse selection unit 37 Phase inversion unit

Claims (5)

A motor drive signal is generated based on a rotation command from a computer that processes a first rotation speed signal when a motor having an M pole pair permanent magnet is used, and a motor having an N pole pair permanent magnet is generated by the motor drive signal. A motor control device for driving,
A pole pair conversion circuit for converting the second rotation speed signal of the motor having the N pole pair permanent magnet into the first rotation speed signal of the motor having the M pole pair permanent magnet and outputting the converted signal to the computer. ,
The pole pair conversion circuit inverts the second rotational speed signal at an electrical angle of 180 ° × N / M when the second rotational speed signal outputs one pulse with respect to an electrical angle of 360 °, and performs the second rotation. When the number signal outputs three pulses with respect to an electrical angle of 360 °, signal conversion is performed so that the second rotational speed signal is inverted at an electrical angle of 60 ° × N / M. The pole pair conversion circuit includes a time measuring unit that measures a time of an electrical angle of 60 ° of the second rotation number signal;
Based on the time of the electrical angle of 60 ° measured by the time measuring unit, when outputting one pulse, the second rotational speed signal is inverted every electrical angle of 180 ° × N / M, and the three-pulse output A rotation speed signal generating unit that generates the first rotation speed signal by inverting the second rotation speed signal every electrical angle of 60 ° × N / M.
The motor control device according to claim 1, further comprising: The M is 4, the N is 5,
The rotation number signal generation unit includes a first counter that obtains a time of electrical angle 0.937 ° by dividing the time of electrical angle 60 ° measured by the time measurement unit by 64;
When outputting the one pulse, when the time of the electrical angle of 0.937 ° from the first counter is counted 240 times, a signal for inverting the phase at the electrical angle of 225 ° is output, and when outputting the three pulses, the first pulse is output. A second counter that outputs a signal that inverts the phase at an electrical angle of 75 ° when the electrical angle of 0.937 ° from the counter is counted 80 times;
The motor control device according to claim 2, further comprising: The M is 4, the N is 5,
The rotation number signal generation unit divides the time of the electrical angle of 60 ° measured by the time measurement unit by 4 to obtain a time of the electrical angle of 15 °,
When outputting one pulse, when the time of the electrical angle of 15 ° from the first counter is counted 15 times, a signal for inverting the phase at an electrical angle of 225 ° is output, and when outputting the three pulses, the first counter A fourth counter that outputs a signal that inverts the phase at an electrical angle of 75 ° when the electrical angle of 15 ° is counted five times from
The motor control device according to claim 2, further comprising: The M is 4, the N is 5,
The rotation speed signal generation unit obtains a time of an electrical angle of 15 ° by dividing the time of the electrical angle of 60 ° measured by the time measurement unit by 4, and outputs the time of the electrical angle of 15 ° five times. A counter,
A sixth counter that outputs a signal that inverts the phase when the electrical angle of 15 ° from the first counter is counted five times;
The motor control device according to claim 2, further comprising:

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