JP2001258286A - Controller for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller which enables low noise/low vibration and high-efficiency driving compatible by a driving wave form that has a low distortion factor which is comparable to that of a sinusoidal wave, and has high fundamental wave level effective for torque generation. SOLUTION: This motor controller comprises a position detecting part 50 which outputs a position signal which changes smoothly in response to the position of the rotor of a motor, and a driving waveform generating part 10 which has a differential part 11 having a nonlinear differential input/output characteristic due to a pair of differential transistor and receives the position signal as an input and generates a driving waveform signal for the windings of the motor by the output of the differential part 11, and a waveform controlling part 60 which controls the waveform of the driving waveform signal. The controlling part 60 changes the distortion factor and the fundamental wave level of the driving waveform signal by increasing/decreasing the crest value of the position signal to be inputted to the differential part which forms the generating part 10, and the purpose is accomplished by controlling the waveform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, a hot water supply device, an air purifier, a washing machine, a refrigerator, a vacuum cleaner in the home appliance field, or a document device such as a PPC, a facsimile, a printer, an LBP, and an optical disc in the information field. Media device such as hard disk, or F
A. The present invention relates to a control device for a widely used brushless DC motor or an induction motor, such as a semiconductor manufacturing apparatus, a component mounting machine, a robot, a sewing machine, and a general-purpose motor in the industrial field.

[0002]

2. Description of the Related Art In recent years, motors have been used in a very wide range as described above. In any field, however, demands for higher performance and lower cost of motors are only increasing.

In particular, increasing the efficiency of a motor is a very important performance in view of environmental issues and energy saving and responding to the spread of battery-powered portable devices. Reduction of noise and vibration is important for the living environment or work environment. This is a very important performance in terms of comfort and compatibility with high-density recording and reproduction of various information devices.

However, it is difficult to achieve both high motor efficiency and reduced noise and vibration, and it is very difficult to realize this at low cost.

FIG. 19 is a circuit configuration diagram of a motor control device in a general prior art.

In FIG. 19, reference numerals 1001 to 1003 denote windings of a motor. Although not shown, the motor is configured together with a mover. Reference numeral 1010 denotes an energization command unit which outputs signals UH, VH, WH, UL, VL, WL for sequentially energizing the windings 1001 to 1003 in accordance with the position of the mover in the case of a brushless DC motor. 1
Reference numeral 020 denotes a PWM modulator, which includes a triangular wave oscillator 1024 that generates a pulse signal pm having a pulse width corresponding to a speed command Vsp input from the outside and a comparator 1023;
It comprises AND gates 1031 to 1033 for pulse width modulating the signals UL, VL, WL with the signal pm. An output unit 1030 is a power MOSFET.
Output elements 1041 to 1046 and a gate driver 1040 for driving these input gates. The signal UH,
VH, WH and the output signal U from the PWM modulator 1020
Lpm, VLpm, WLpm are input, and the output element 1
The U-phase winding 1001 is connected to the source of the output element 1042 and the drain of the
A V-phase winding 1002 is connected to the drain of
And the drain of 1046 have a W-phase winding 100
3 are connected respectively.

The common drains of the output elements 1041 to 1043 are connected to the positive voltage Vdc of the DC main power supply, and the common sources of the output elements 1044 to 1046 are connected to the negative voltage PG of the DC main power supply.

FIG. 20 is an explanatory diagram of the operation of the motor control device according to the above-mentioned prior art.

FIG. 20A shows signals UH, VH, WH, UL, VL, WL output from energization command section 1010.
, The output signal Cy of the triangular wave oscillator 1024, the speed command Vsp, and the pulse signal pm.

The signals UH, VH, WH are output to output elements 1041, 1042, 104 via a gate driver 1040.
3, the U-phase winding 1001 and the V-phase winding 10
02, the W-phase winding 1003 is connected to the positive voltage Vdc of the DC main power supply.
Controls whether to connect to or not.

On the other hand, signals UL, VL and WL act on output elements 1044, 1045 and 1046 via a PWM modulator 1020 and a gate driver 1040, respectively.
Phase winding 1001, V-phase winding 1002, W-phase winding 1003
Is connected to the negative voltage PG of the DC main power supply.

As shown in the figure, signals UH, VH, WH are:
This signal is a signal that is at the “H” level for 120 electrical degrees and has a phase difference of 120 electrical degrees from each other. The same applies to the signals UL, VL, WL.

These signals UH, VH, WH (or UH
L, VL, WL) turn on the corresponding output element 1041, 1042, 1043 (or 1044, 1045, 1046) when it is at "H" level, and turn the corresponding phase winding 1001, 1002, 1003. Is connected to the voltage Vdc (or PG), and when the signal is at the “L” level, the corresponding output element is turned off so that the corresponding winding is not connected to Vdc (or PG).

The signals UL, VL and WL are subjected to pulse width modulation by the signal pm, and the pulse width modulation signal ULp
m, VLpm, and WLpm control on / off of the output elements 1044, 1045, and 1046 via the gate driver 1040.

The signal pm is a comparison signal between the speed command Vsp and the triangular wave signal (carrier signal) Cy, and is a signal in which the higher the speed command Vsp, the longer the "H" level period. The longer the "H" level period of the signal pm, the longer the time for connecting the motor winding to the PG, and the average value of the drive voltage to the motor winding increases.

Therefore, the drive voltage of the motor winding can be varied according to the speed command Vsp, and the speed of the motor can be controlled.

FIG. 20 (b) shows that when a certain value is given as the speed command Vsp and the motor is driven, the terminal voltage U of the U-phase winding, the neutral point voltage N, and the neutral point voltage N 3 shows the voltage waveform of the terminal voltage U, that is, the drive voltage waveform UN of the winding (all of them are average values). Although not particularly shown, the same applies to voltages of other phases.

The operation of the conventional motor control device has been described above.

[0019]

However, in the above prior art, the terminal voltage of the winding becomes high impedance during commutation for switching the phase of the winding to be driven (for example, in the case of the U phase, the signals UH and UL are output). Are both at the “L” level, the output elements 1041 and 1044 are both turned off and become high impedance.), And the winding current immediately before commutation is a body diode (drain-source) existing between the drain and source of the output element (power MOSFET). (Not shown).
As shown in FIG. 0 (b), a spike-like voltage is generated.

Driving to generate such a spike-like voltage is generally performed in many cases.
No. 60493, JP-A-7-123773, and the like.

The spike voltage due to this reflux is shown in FIG.
As shown in dV of (b), the drive voltage waveform UN of the winding
Causes a sudden change in This sudden change in the voltage waveform causes the winding current to suddenly change into excitation energy,
Resonance with the structural members of the motor causes noise to be generated.

The spike voltage increases the distortion rate of the winding drive voltage waveform UN and causes torque ripple. Moreover, when the load becomes heavy, the speed increases, or the electric time constant of the motor increases, the width of the spike voltage increases, and the distortion rate further increases, thereby further increasing the torque ripple. The torque ripple causes the motor to vibrate, and causes the device on which the motor is mounted to resonate, causing greater vibration.

In addition, the spike voltage also reduces the fundamental wave component included in the driving voltage waveform of the winding, that is, the component that can contribute to the motor output, and reduces the voltage Vdc supplied from the DC main power supply to an effective motor output. This hinders utilization and leads to a decrease in efficiency.

On the other hand, as a technique for driving a motor with low noise, low torque ripple and low vibration, there is a technique for driving a winding of a motor with a sine wave voltage.

Although the noise and vibration of the motor can be greatly improved by this kind of technology, this can be achieved by, for example, a ROM storing sinusoidal drive waveform data as disclosed in Japanese Patent Publication No. 2658085. Such a memory circuit is required, and a relatively large-scale circuit is required for the processing of reading this information, and the cost is inevitably increased.

Although a technique for improving the voltage utilization rate has been proposed for driving a motor by a sine wave, there are some places where the use of a voltage supplied from a DC main power supply is insufficient.

The main object of the present invention is to reduce noise and torque ripple / vibration, which are problems of the prior art, to a level comparable to an ideal sine wave drive, and in addition to the conventional drive technology including sine wave drive. It is an object of the present invention to provide a motor control device that can effectively utilize a voltage supplied from a DC main power supply, that is, can achieve both low noise and low vibration and high efficiency driving, and can be realized at low cost.

[0028]

In order to solve this problem, a motor control device according to a first embodiment of the present invention includes a drive waveform generator for generating a drive waveform signal for a winding of a motor; P for pulse width modulation of the drive waveform signal
A WM modulation unit; and an output unit that drives the winding based on the drive waveform signal pulse-width modulated by the PWM modulation unit.

At this time, the drive waveform signal is at the first level during the electrical angle θd of 180 degrees or less, and is at the second level during the electrical angle θz of 0 degrees or more (θz = 180 degrees−θd). A signal, wherein the winding is driven by a voltage of a desired magnitude determined by the first level during the electrical angle θd, and driven by a zero voltage determined by the second level during the electrical angle θz. And

As a result, generation of a spike voltage due to recirculation during commutation is eliminated, and motor noise is suppressed. Also, the distortion rate of the drive voltage waveform of the winding is improved, and torque ripple and vibration are reduced. In addition, the fundamental wave component included in the driving voltage waveform of the winding, that is, the component that can contribute to the motor output also increases, and the voltage of the DC main power supply can be effectively used, and the efficiency can be improved.

A motor control device according to a second embodiment of the present invention is a position detecting unit that outputs a position signal that changes smoothly for each phase according to the position of the mover with respect to the winding of each phase of the motor. A drive waveform generator that generates a drive waveform signal for the winding, a PWM modulator that performs pulse width modulation on the drive waveform signal, and the drive waveform signal that is pulse width modulated by the PWM modulator. An output unit for driving the winding.

At this time, the driving waveform generating section includes at least a differential section having a differential characteristic by a differential transistor pair, and the differential section is provided corresponding to each position output of the position signal. The drive waveform signal has a desired peak value (or amplitude) and has a waveform shape obtained by subtracting the output of each of the differential sections corresponding to the adjacent phase of the position signal which changes smoothly. A signal comprising:
It is configured to be driven by a voltage having a magnitude determined by the desired peak value (or amplitude) and a voltage waveform having a shape determined by the waveform shape.

As a result, there is no sudden change in the drive voltage waveform of the winding, and the noise can be further reduced.
Further, the distortion rate of the drive voltage waveform is further reduced, so that the torque ripple can be further reduced and the vibration can be suppressed. Further, a memory circuit or the like for storing the drive waveform data is not required, the configuration can be simplified, and the cost can be reduced.

A motor control device according to a third embodiment of the present invention includes a position detection unit that outputs a position signal that smoothly changes in accordance with the position of a mover of a motor, and a drive waveform signal for a winding of the motor. A driving waveform generator for generating
A PWM modulator for pulse width modulating the drive waveform signal;
An output unit for driving the winding based on the drive waveform signal pulse-width modulated by the PWM modulation unit.

At this time, the drive waveform generation section includes at least a differential section having a differential characteristic by a differential transistor pair, and the drive waveform signal has a desired peak value (or amplitude) and changes smoothly. The position signal is a signal having a waveform shape obtained through the differential section having the differential characteristic, the winding is a voltage having a magnitude determined by the desired peak value (or amplitude), and It is configured to be driven by a voltage waveform having a shape determined by the waveform shape.

As a result, a sharp change in the driving voltage waveform of the winding is eliminated, and the distortion factor is also reduced, thereby making it possible to significantly reduce noise, torque ripple and vibration. In addition, the fundamental wave component of the driving voltage waveform of the winding can be further increased, and high-efficiency driving can be realized by further effectively utilizing the voltage of the DC main power supply. Further, a memory circuit or the like for storing the drive waveform data is not required, the configuration can be simplified, and the cost can be reduced.

A motor control device according to a fourth embodiment of the present invention includes a drive waveform generator for generating a drive waveform signal for the winding of the motor, a PWM modulator for pulse width modulating the drive waveform signal, An output unit that drives the winding based on the drive waveform signal pulse-width modulated by the PWM modulation unit, and a waveform shape control unit that controls a waveform shape of the drive waveform signal.

At this time, the winding has a voltage of a magnitude determined by the peak value (or amplitude) of the drive waveform signal.
The drive waveform signal is driven by a voltage waveform determined by the waveform shape of the drive waveform signal, and the waveform shape of the drive waveform signal is configured such that the distortion factor and the fundamental wave level can be varied by the waveform shape control unit.

Thus, the drive voltage waveform can be varied according to the use condition of the motor, and the low-noise and low-vibration drive equivalent to the sine-wave drive and the high-efficiency drive using the drive voltage waveform having a high fundamental wave level can be selectively used. In addition, flexible motor performance can be utilized.

A motor control device according to a fifth embodiment of the present invention includes a position detecting section that outputs a position signal that smoothly changes in accordance with the position of a mover of a motor, and a non-linear position detecting section using a differential transistor pair. A drive waveform generating unit including at least a differential unit having differential input / output characteristics, wherein the position signal is input to the differential unit, and a drive waveform signal for a winding of the motor is generated by an output of the differential unit; A PWM modulator for pulse width modulating the drive waveform signal;
An output unit that drives the winding based on the drive waveform signal pulse width modulated by the modulation unit, and a waveform shape control unit that controls the waveform shape of the drive waveform signal.

At this time, the winding has a voltage determined by the peak value (or amplitude) of the drive waveform signal.
The drive waveform signal is driven by a voltage waveform having a shape determined by the waveform shape of the drive waveform signal, and the waveform shape of the drive waveform signal is applied to the differential unit having the nonlinear differential input / output characteristics forming the drive waveform generation unit. The peak value or amplitude value of the input position signal is increased or decreased by the waveform shape control unit,
The distortion factor and the fundamental wave level of the drive waveform signal can be varied.

As a result, the drive voltage waveform of the winding of the motor can be varied only by increasing or decreasing the peak value or amplitude value of the position signal, and the motor performance can be varied by using the drive voltage waveform according to the use condition of the motor. Can be easily used flexibly.

A motor control device according to a sixth embodiment of the present invention includes a position detection unit that outputs a position signal that smoothly changes in accordance with the position of a mover of a motor, and a non-linear control unit using a differential transistor pair. A drive waveform generating unit including at least a differential unit having differential input / output characteristics, wherein the position signal is input to the differential unit, and a drive waveform signal for a winding of the motor is generated by an output of the differential unit; A PWM modulator for pulse width modulating the drive waveform signal;
An output unit that drives the winding based on the drive waveform signal pulse width modulated by the modulation unit, and a waveform shape control unit that controls the waveform shape of the drive waveform signal.

At this time, the winding has a voltage determined by the peak value (or amplitude) of the drive waveform signal.
The drive waveform signal is driven by a voltage waveform having a shape determined by the waveform shape of the drive waveform signal, and the drive waveform signal has a non-linear differential input / output characteristic that constitutes the drive waveform generation unit. The input sensitivity is increased or decreased by the waveform shape control unit, and the distortion factor and the fundamental wave level of the drive waveform signal can be varied.

As a result, the drive voltage waveform of the motor winding can be varied only by increasing or decreasing the input sensitivity of the differential unit, and the motor performance can be flexibly changed by selectively using the drive voltage waveform according to the use condition of the motor. Can be easily used.

In each of the above-described fourth to sixth embodiments, the peak value (or amplitude) and waveform shape of the drive waveform signal may be varied according to the motor speed or the speed command.

In this case, the motor is driven by a drive voltage waveform having a small distortion rate at the time of low speed driving where low vibration and low noise are desired, and the voltage of the DC main power supply can be effectively utilized at the time of high speed driving where high efficiency driving is desired. By driving the motor with a drive voltage waveform having a fundamental wave level, it is possible to make maximum use of the motor performance.

In each of the fourth to sixth embodiments, the peak value (or amplitude) and waveform shape of the drive waveform signal
It may be configured to be variable according to the torque (load) of the motor or the torque command.

In this case, when the load is light and the torque is not required, the motor is driven with low noise and low vibration by the driving voltage waveform having a small distortion rate, and when the load is heavy and the torque is required, the voltage of the DC main power supply is effective. The motor performance can be effectively utilized by driving the motor with high efficiency using a drive voltage waveform having a high fundamental wave level that can be utilized for the motor.

In each of the first to sixth embodiments, the drive waveform signal is output in accordance with the winding of each phase of the motor, and the signal of the lowest level among the drive waveform signals of each phase is determined. A configuration may be adopted in which the terminal voltage of the winding of the phase corresponding to the reference level is the lowest potential that can be output by the output unit.

Alternatively, the drive waveform signals are output corresponding to the windings of each phase of the motor, and the highest level signal among the drive waveform signals of each phase is used as a constant reference level.
The terminal voltage of the phase winding corresponding to the reference level may be set to the highest potential that the output unit can output.

In this case, the utilization of the voltage of the DC main power supply is increased, and the effect of reducing the switch loss of the output power element during PWM driving is added.

[0053]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a configuration diagram of a motor control device according to Embodiment 1.

In FIG. 1, reference numerals 1 to 3 denote windings of a star-connected motor. Although not shown, the motor is configured together with a mover. Reference numeral 10 denotes a drive waveform generator, which is a drive waveform signal Uf for driving the windings 1 to 3.
Vf and Wf are generated. A speed command Vsp is input to the drive waveform generator 10, and the peak values (or amplitudes) of the signals Uf, Vf, Wf are configured to be increased or decreased by the speed command Vsp.

Reference numeral 20 denotes a PWM modulator, which outputs a triangular wave oscillator 24 for outputting a carrier signal Cy having a triangular waveform for pulse width modulation, and compares the carrier signal Cy with the drive waveform signals Uf, Vf, Wf to generate a pulse. Width modulation signal Up
Comparators 21 to 23 that output m, Vpm, and Wpm.

Reference numeral 30 denotes an output unit, which outputs signals Upm, Vp
m and Wpm are directly input to the on-delay circuits 34 and 3
5, 36 and on-delay circuits 37, 38, 39 input via inverter gates 31, 32, 33
, A gate driver 40 to which the outputs of the on-delay circuits 34 to 39 are input, and output elements 41 to 46 composed of power MOSFETs. The output of the gate driver 40 is input to each gate to drive the gates of the output elements 41 to 46 to turn these elements on and off. The source of the output element 41 and the drain of the output element 44 are the U-phase winding 1, the source of the output element 42 and the drain of the output element 45 are the V-phase winding 2, and the source of the output element 43 and the drain of the output element 46 are W
The phase windings 3 are respectively connected. The common drains of the output elements 41 to 43 are connected to the positive voltage Vdc of the DC main power supply, and the common sources of the output elements 44 to 46 are connected to the negative voltage PG of the DC main power supply.

The operation of the motor control device according to the present embodiment configured as described above will be described.

First, the operation of the output unit 30 will be described.

The pulse width modulation signals Upm, Vpm, Wpm, which are input signals to the output section 30, are signals having two values of "L" level or "H" level.

The output section 30 operates to turn on the output element 41 via the on-delay circuit 34 and the gate driver 40 when the signal Upm is at "H" level. At this time, the signal Upm is simultaneously logically inverted by the inverter gate 31, and the “L” level signal is transmitted to the output element 44 via the on-delay circuit 37 and the gate driver 40. As a result, the output element 44 operates to turn off. That is, when the signal Upm is at the “H” level, the output unit 30 turns on the output element 41 and turns on the output element 44.
Is turned off. Also, the signal Upm
Is low, the output element 41 is turned off and the output element 44 is turned on.

When the signal Upm switches from "H" level to "L" level or from "L" level to "H" level, the on-delay circuits 34 and 37 output the output elements 41 and 44. In order to prevent the voltage Vdc of the DC main power supply and the PG from being short-circuited simultaneously for a moment, the function of delaying the timing at which each element is turned on is performed.

As is apparent from the above description, the signal Up
Each time m alternates between “H” level and “L” level, the terminal voltage U of the U-phase winding 1 becomes the positive voltage Vd of the DC main power supply.
c and the negative voltage PG are alternately and repeatedly connected. The average value of the terminal voltage U of the winding 1 is determined by the connection time ratio, and can be controlled by the time ratio between the “H” level and the “L” level of the signal Upm, that is, the duty.

The above operation is the same for the signals Vpm and Wpm. The terminal voltage V of the V-phase winding 2 and the W-phase winding are determined by the time ratio between the "H" level and the "L" level of the signals Vpm and Wpm. The average value of the terminal voltage W of No. 3 can also be controlled.

Next, the overall operation of this embodiment will be described with reference to FIG.

The drive waveform signals Uf, Vf, Wf output from the drive waveform generator 10 have an electrical angle θd of 180 degrees or less.
, The first level and the electrical angle θz (θz
= 180 degrees-θd), the signal having the second level.

Hereinafter, the signal Uf will be described more specifically. (The signals Vf and Wf are not particularly described,
This is exactly the same as the signal Uf. FIG. 2A shows a signal Uf when θd is an electrical angle of 120 degrees and θz is an electrical angle of 60 degrees.

As shown in FIG. 2A, the drive waveform signal Uf output from the drive waveform generator 10 is compared with the carrier signal Cy in the PWM modulator 20. And the signal U
pulse width modulation signal U whose duty changes according to f
pm. The signal Upm is input to the output unit 30 described above, and the duty controls the average value of the terminal voltage U of the U-phase winding. As a result, the U-phase winding 1 is driven by the voltage waveform having the same shape as the drive waveform signal Uf.

Similarly, V-phase winding 2 and W-phase winding 3 are driven by voltage waveforms having the same shape as drive waveform signals Vf and Wf. The U-phase, V-phase, and W-phase drive waveforms have the same size and shape and have a phase difference of 120 electrical degrees from each other.

As described above, the terminal voltages U,
V and W are always controlled by the drive waveform signals Uf, Vf and Wf output from the drive waveform generator 10.

FIG. 2A shows the neutral point voltage N of each phase winding.
And the voltage waveform U of the U-phase terminal voltage U viewed from the voltage N
−N is also shown. Here, the voltage waveform UN is
3 shows a drive voltage waveform of the U-phase winding 1.

When this voltage waveform UN is compared with the waveform shown in the prior art (see FIG. 20B), FIG.
In the present embodiment shown in the waveform (a), there is no generation of a spike voltage due to recirculation during commutation unlike the prior art, and it can be seen that the change dV in the drive voltage UN of the winding is considerably suppressed. . Therefore, a sudden change in the winding current can be suppressed, and the excitation energy can be reduced to reduce noise.

The spike voltage is not generated because the output section does not become high impedance during commutation, and the output section is always controlled by the drive waveform signal.

The drive voltage waveform UN shown in FIG. 2A will be further described.

First, the distortion factor will be described.

The distortion rate of the drive voltage waveform affects the torque ripple and vibration during driving of the motor.

Generally, among the harmonic components of the drive voltage waveform, the fifth and seventh harmonic components greatly affect the torque ripple and vibration. Of course, higher-order harmonics such as the 11th and 13th-order also have effects, but these effects are relatively small.

In the case of the drive voltage waveform UN shown in FIG.
The ratio of the fifth and seventh harmonics to the fundamental wave, that is, the distortion factor, is about 24.6%. On the other hand, the conventional technology (FIG. 20)
The distortion rate of the drive voltage waveform UN shown in (b)) deteriorates due to the influence of the spike voltage due to the circulation, and is about 33.7.
% (When the spike voltage generation period is assumed to be 10 degrees in electrical angle).

From these numerical values, it can be seen that the drive voltage waveform shown in FIG. 2A has a small distortion rate and no effect on torque ripple and vibration because no spike voltage is generated.

Next, the fundamental wave level will be described.

In general, the output torque of the motor is greatly affected by the level of the fundamental wave component included in the driving voltage waveform of the winding. When the drive voltage waveform of the winding includes a harmonic, harmonic components other than the fundamental component only generate torque ripple, and do not contribute to torque generation on average.

Therefore, in order to effectively use the voltage of the DC main power supply provided to supply electric power to the motor,
An important point is how to apply a driving voltage waveform having a large fundamental wave level to the winding of the motor.

In the case of the drive voltage waveform UN shown in FIG.
The effective value of the fundamental wave when the output section outputs the maximum output within the range of the applied voltage Vdc of the DC main power supply is about 0.39 ×
Vdc. On the other hand, in the case of the drive voltage waveform UN shown in the prior art (FIG. 20 (b)), the fundamental wave effective value under the same condition is about 0.37 × Vdc (the spike voltage generation period is 10 degrees in electrical angle. Assuming).

From these numerical values, it can be seen that the drive voltage waveform shown in FIG. 2A utilizes the voltage Vdc of the DC main power supply more effectively, and is effective for high-efficiency driving.

Next, as drive waveform signals Uf, Vf and Wf, θd is set to an electrical angle of 150 degrees (or 149 degrees), θz
Is set as an electrical angle of 30 degrees (or 29 degrees) with reference to FIG.

FIG. 2B shows only the drive waveform signal Uf, but the same applies to the signals Vf and Wf. The basic operation is the same as that of FIG.

In the case of the drive voltage waveform UN shown in FIG. 2B, it can be seen that the sharp voltage change dV is further suppressed as compared with the waveform of FIG. 2A. Therefore, further low noise driving of the motor is possible.

The distortion rate of this waveform is as follows.
It is about 6.55% at 0 degree and about 6.51% at θd of 149 degrees electrical angle, and has the smallest value in this type of drive voltage waveform (so-called rectangular wave drive). Therefore, when the motor is driven by the drive voltage waveform shown in FIG. 2B, low-vibration drive can be performed with a very small torque ripple.

The effective value of the fundamental wave of this waveform is approximately 0.43 × Vdc when the output section outputs the maximum output within the range of the applied voltage Vdc of the DC main power supply. It can be seen that high-efficiency driving using Vdc more effectively than the waveform in FIG.

Next, FIG. 2C shows an example in which θd is an electrical angle of 180 degrees and θz is an electrical angle of 0 degrees (that is, there is no period of θz) as the drive waveform signals Uf, Vf, Wf.
This will be described with reference to FIG.

FIG. 2C shows only the driving waveform signal Uf, but the same applies to the signals Vf and Wf. The basic operation is the same as that of FIG.

In the case of the drive voltage waveform UN shown in FIG. 2C, the distortion factor is about 24.4%. This value is almost the same level as the waveform of FIG. 7A, and indicates that the motor can be driven with lower vibration than the waveform of the related art.

The effective value of the fundamental wave of this waveform is approximately 0.45 × Vdc when the output section outputs the maximum output within the range of the applied voltage Vdc of the DC main power supply. This value is the largest value in driving a three-phase motor, and FIG.
When the motor is driven by the drive voltage waveform shown in (c),
This shows that high-efficiency driving that most effectively utilizes the power supply voltage Vdc can be realized.

As described above, according to the present embodiment, generation of a spike voltage due to recirculation during commutation is eliminated, and noise of the motor is suppressed. Also, the distortion rate of the drive voltage waveform of the winding is improved, and torque ripple and vibration are reduced. In addition, the fundamental wave component included in the driving voltage waveform of the winding, that is, the component that can contribute to the motor output also increases, and the voltage of the DC main power supply can be effectively used, and the efficiency can be improved.

In particular, θd is set to an electrical angle of 150 degrees (or 1
(49 degrees), the distortion rate of the drive voltage waveform of the winding is the smallest, and the motor drive with small torque ripple and vibration can be realized.

If θd is an electrical angle of 180 degrees, the applied voltage of the DC main power supply can be used most effectively, and the motor can be driven with high efficiency.

In this embodiment, the speed control can be realized by increasing or decreasing the peak values or the amplitudes of the drive waveform signals Uf, Vf, Wf according to the speed command Vsp.

That is, by increasing / decreasing the first level of the drive waveform signals Uf, Vf, Wf according to the speed command Vsp, the voltage applied to the terminal voltages U, V, W of the windings can be increased / decreased. It is possible. The second level of the driving waveform signal gives the amplitude center level of the signals Uf, Vf, Wf, and is not particularly limited in value except that it is the same level in each of the signals Uf, Vf, Wf. , May be an arbitrary value. When the drive waveform signal is at the second level, the drive voltage waveform of the winding (for example, in the case of U phase, U
−N) is zero voltage. (See FIGS. 2A and 2B.) (Embodiment 2) FIG. 3 shows a configuration diagram of a motor control device according to Embodiment 2.

Referring to FIG. 3, the first embodiment shown in FIG.
The same reference numerals are given to the same parts as those of the motor control device in the above, and the detailed description is omitted.

In FIG. 3, reference numeral 50 denotes a position detecting unit.
It detects the position of the mover (not shown) of the motor and outputs position signals Ufo, Vfo, Wfo.

In the position detecting section 50, 54, 55, 5
Reference numeral 6 denotes a detection element for detecting the position of the mover with respect to each of the phase windings 1, 2, and 3, and is constituted by, for example, a Hall element. Power is supplied to the detection elements 54, 55, 56 via resistors 57, 58 to drive them. 51,5
Reference numerals 2 and 53 denote amplifiers for amplifying the output signals of the detecting elements 54, 55 and 56. The outputs of the amplifiers 51, 52 and 53 become the position signals Ufo, Vfo and Wfo of the position detecting section 50.

Reference numeral 10 denotes a drive waveform generator, which outputs a position signal U
fo, Vfo, and Wfo are input and drive waveform signals Uf,
Vf and Wf are output.

In the driving waveform generator 10, 11, 1
Numerals 2 and 13 are differential units, and 14, 15, and 16 are subtractors. Here, as shown in FIG. 4, the differential section 11 has an input section composed of a pair of differential transistors 75 and 76, and has a differential input / output characteristic as shown in FIG. The same applies to the differential units 12 and 13. The subtractor 14 calculates the difference between the outputs of the differentials 11 and 12, the subtractor 15 calculates the difference between the outputs of the differentials 12 and 13, and the subtractor 16 calculates the difference between the differentials 13 and 13. Output the difference between the output of the motive device 11 and
These outputs are output from the drive waveform signal U of the drive waveform generator 10.
f, Vf, and Wf.

The speed command Vsp acts on the differential units 11, 12, and 13 so that the gain of the differential unit can be increased or decreased. For example, in the case of the differential unit 11, as shown in FIG. , 76 to increase or decrease the output current value of the common current source 70 to change the gain.

The other configuration is the same as that of the first embodiment shown in FIG. 1, and the description is omitted.

The operation of the second embodiment configured as described above will be described below.

FIG. 5 is an explanatory diagram of the operation in the second embodiment of FIG. 3, and is a diagram mainly illustrating the U-phase. Although detailed description of the V phase and the W phase is omitted,
It is basically the same as the U phase.

The detection element 54 outputs a position detection signal of the mover with respect to the U-phase winding 1. When the detection element 54 is a Hall element, the position signal Ufo is an analog signal that changes relatively smoothly. can do. The signal can be made approximately sinusoidal in a relatively simple manner by devising the magnetization of the position detecting magnet (or the magnet for obtaining the main magnetic flux) provided on the mover.

In the following description, position signal Ufo
(Similarly, Vfo and Wfo) will be described as a substantially sinusoidal signal.

The differential section 11 is configured as shown in FIG. 4. The signal Ufo (Vfo, Wfo) input thereto is a signal centered on the bias voltage Bias0. However, after this embodiment, the description will be made without describing this bias voltage for the sake of simplicity.

FIG. 5A shows a state in which a substantially sinusoidal position signal Ufo is input to the differential section 11 of the drive waveform generating section 10 and a signal Uf1 is output from the differential section 11. Since the input / output characteristics of the differential section 11 are as shown in the figure, the signal Ufo having a substantially sinusoidal waveform becomes a signal Uf1 having a waveform in which the crest portion is distorted.

The same applies to the signal Vf1 output from the differential unit 12, which is a phase adjacent to the differential unit 11, and the signal Vf
1 is a signal whose electrical angle is delayed by 120 degrees with respect to the signal Uf1. This is because the U-phase, V-phase, and W-phase are mechanically arranged with a phase difference of 120 degrees in electrical angle from each other.

The output signal Uf1 of the differential section 11 and the output signal Vf1 of the adjacent differential section 12 are subtracted by the subtractor 14, and the driving waveform signal Uf for the U-phase winding 1 is converted to the driving waveform generating section. 10 is output. V-phase and W-phase winding 2
The same applies to the drive waveform signals Vf and Wf for and 3.

FIG. 5B shows the drive waveform signal Uf.

The signal Uf is PWM as in the first embodiment.
The terminal voltage U of the U-phase winding via the modulation unit 20 and the output unit 30
Control.

FIG. 5B shows the state, the neutral point voltage N of each phase winding, and the voltage waveform UN when the U-phase terminal voltage U is viewed from the neutral point voltage N. Is shown. here,
The voltage waveform UN is a drive voltage waveform of the U-phase winding.

The V-phase and W-phase voltage waveforms have a phase difference of 120 degrees in electrical angle from the U-phase waveform.

The driving voltage waveform U- of the winding shown in FIG.
N is the waveform U- shown in FIG.
N is much smoother and there is no sudden voltage change. The smoothness is close to that of a sine wave drive. Therefore, the motor can be driven with extremely low noise by the drive voltage waveform shown in FIG.

The distortion rate of the driving voltage waveform is small, and the motor can be driven with low torque ripple and low vibration.

As described above, according to the present embodiment, the drive voltage waveform of the winding does not suddenly change, and low-noise and low-vibration driving close to sine-wave driving becomes possible.

Further, in order to obtain a smooth drive voltage waveform close to such a sine wave drive, a smoothly changing position signal obtained by using a Hall element or the like usually used for a brushless DC motor is used. Neither a memory circuit such as a ROM for storing the driving waveform nor a peripheral circuit such as a reading circuit thereof is required. Therefore, it is possible to realize a motor control device that can be driven simply and at low cost with low noise and low vibration at a level comparable to sine wave drive.

In this embodiment, the speed control can be realized by increasing or decreasing the peak values or the amplitudes of the drive waveform signals Uf, Vf, Wf according to the speed command Vsp.

Specifically, the voltage applied to the terminal voltages U, V, W of the windings can be increased / decreased by increasing / decreasing the gains of the differential sections 11, 12, 13 in accordance with the speed command Vsp, thereby controlling the motor speed control. Is possible. As described with reference to FIG. 4, the gain of the differential units 11, 12, and 13 can be easily increased or decreased by increasing or decreasing the output current of the common current source 70 of the differential transistor pair 72, 73 by the speed command Vsp. .
Alternatively, instead of increasing or decreasing the gain of the differentials 11, 12, and 13, the subtractors 14, 15, and 16 may be provided with a gain, and the gain may be increased or decreased by the speed command Vsp.

(Embodiment 3) FIG. 6 shows a configuration diagram of a motor control device according to Embodiment 3.

In FIG. 6, the second embodiment shown in FIG.
The same reference numerals are given to the same parts as those of the motor control device in the above, and the detailed description is omitted.

In FIG. 6, the drive waveform generator 10 includes differential units 11, 12, and 13.

The differential units 11, 12, and 13 are similar to the differential units denoted by the same reference numerals in the second embodiment shown in FIG. 3, and the output is the drive waveform signal Uf of the drive waveform generation unit 10. , Vf, and Wf are different from the second embodiment.

The other parts are the same as those of the second embodiment shown in FIG.

The operation of the third embodiment configured as described above will be described below.

FIG. 7 is an explanatory diagram of the operation in the third embodiment of FIG. 6, and is a diagram mainly illustrating the U-phase. Although detailed description of the V phase and the W phase is omitted,
It is basically the same as the U phase.

As in the second embodiment, the position signal Ufo (V
fo and Wfo) are substantially sinusoidal signals.

FIG. 7A shows a state in which a substantially sinusoidal position signal Ufo is input to the differential section 11 of the drive waveform generating section 10 and a signal Uf is output from the differential section 11. Since the input / output characteristics of the differential section 11 are as shown in the figure, the substantially sinusoidal signal Ufo becomes a signal Uf having a waveform in which the crest portion is distorted. This signal Uf is output from the drive waveform generator 10 as a drive waveform signal for the U-phase winding 1. The same applies to drive waveform signals Vf and Wf for V-phase and W-phase windings 2 and 3.

FIG. 7B shows the drive waveform signal Uf.

The signal Uf is PWM as in the first embodiment.
The terminal voltage U of the U-phase winding via the modulation unit 20 and the output unit 30
Control.

FIG. 7B shows the state, the neutral point voltage N of each phase winding, and the voltage waveform UN when the U-phase terminal voltage U is viewed from the neutral point voltage N. Is shown. here,
The voltage waveform UN is a drive voltage waveform of the U-phase winding.

The V-phase and W-phase voltage waveforms have a phase difference of 120 degrees in electrical angle from the U-phase waveform.

The drive voltage waveform U- of the winding shown in FIG.
N is the same as in the second embodiment.
The waveform UN shown in (b) is much smoother, and there is no sudden voltage change. The smoothness is close to that of a sine wave drive. Therefore, the motor can be driven with extremely low noise by the drive voltage waveform shown in FIG.

The distortion rate is also at the same level as in the second embodiment, and the motor can be driven with low torque ripple and low vibration.

In addition, the drive voltage waveform of FIG. 7B has a high fundamental wave level, and is close to that shown in FIG. 2C in which the θd is 180 degrees in electrical angle in the first embodiment. Therefore, the voltage Vd of the DC main power supply is
c can be used effectively, and the motor can be driven with high efficiency.

As described above, according to the present embodiment, there is no sudden change in the drive voltage waveform of the winding, and low-noise and low-vibration drive close to sine-wave drive can be performed. In addition, the fundamental wave component of the drive voltage waveform of the winding increases, and high-efficiency drive can be realized by further utilizing the voltage of the DC main power supply. In addition, in order to obtain a smooth drive voltage waveform close to such a sine wave drive, a smoothly changing position signal obtained using a Hall element or the like normally used in a brushless DC motor is used, and the drive waveform is Neither a memory circuit such as a ROM for storing the data nor a peripheral circuit such as a read circuit thereof is required. Therefore, it is possible to realize a motor control device that can be driven simply and at low cost with low noise and low vibration at a level comparable to that of the sine wave drive, and that can also perform high-efficiency drive by effectively utilizing the voltage of the DC main power supply. .

In this embodiment, the speed control can be realized by increasing or decreasing the peak values or the amplitudes of the drive waveform signals Uf, Vf, Wf according to the speed command Vsp. The specific method is as described in the second embodiment.

(Embodiment 4) FIG. 8 shows a configuration diagram of a motor control device according to Embodiment 4.

In FIG. 8, reference numeral 60 denotes a waveform shape control unit which acts on the drive waveform generation unit 10 in accordance with the state of use of the motor and changes the waveform shape of the drive waveform signals Uf, Vf, Wf.

The drive waveform generator 10 can select and output the drive voltage waveform of each phase winding, which has been clarified in the above embodiments, by using a signal from the waveform shape controller 60.

That is, the drive waveform generator 10 sets the θd in the first embodiment to 150 degrees in electrical angle (or 1 degree) as the drive waveform signals Uf, Vf, Wf having a small distortion factor.
49 degrees) (see FIG. 2B), the waveform in Embodiment 2 (see FIG. 5B), or the waveform in Embodiment 3 (see FIG. 7B). Either one (hereinafter, referred to as a low distortion rate waveform) and a drive waveform signal Uf, Vf, Wf having a high fundamental wave level, for example, a waveform in which θd in the first embodiment is 180 degrees in electrical angle (FIG. c)) or one of the waveforms in Embodiment 3 (see FIG. 7B) (hereinafter referred to as a high fundamental wave level waveform). .

The other parts are the same as those described in the above embodiments.

The operation of the fourth embodiment configured as described above will be described below.

For example, when the speed command Vsp is a low speed command,
The control unit 60 detects this and acts on the generation unit 10, and the generation unit 10 converts the low distortion rate waveform into the drive waveform signals Uf and Vf.
Output as f and Wf. As a result, the motor has low noise,
It will be driven with low torque ripple and low vibration. When the speed command Vsp is a high-speed command, the control unit 60 detects this and acts on the generation unit 10, and the generation unit 10 converts the high fundamental wave level waveform into the drive waveform signals Uf, Vf, and Wf.
Output as f. As a result, the motor is driven with high efficiency by effectively utilizing the voltage Vdc of the DC main power supply.

In general, in the case of a motor having a wide variable speed range, the noise and vibration of the motor are conspicuous in a relatively low speed region, and it is often desired that the motor be driven with low noise and low vibration. In a high-speed region, it is often desired to drive the motor with the highest possible output.

In such a case, the drive waveform signal shown as the low distortion rate waveform as described above and the drive waveform signal shown as the high fundamental wave level waveform are adjusted by the waveform shape control unit 60 according to the use condition of the motor. The proper use of the motor will bring out the necessary motor performance when needed.
This is an effective method for improving the performance of the entire device on which the motor is mounted.

As described above, according to the present embodiment, the drive voltage waveform can be varied according to the use condition of the motor, and the drive voltage waveform having low noise, low vibration drive and high fundamental wave level equivalent to sine wave drive can be obtained. Can be used for high efficiency driving,
Flexible motor performance can be utilized.

In this embodiment, as in the previous embodiments, the speed control can be realized by increasing or decreasing the peak values or the amplitudes of the drive waveform signals Uf, Vf, Wf according to the speed command Vsp.

In this embodiment, the case where the drive voltage waveform is varied by the speed command has been described. Any information may be used as long as it can improve the performance of the motor and the entire device in which the motor is mounted.

(Embodiment 5) FIG. 9 shows a configuration diagram of a motor control device according to Embodiment 5.

In FIG. 9, position signals Ufo, Vfo,
Embodiment 3 shown in FIG. 6 except that a waveform shape control unit 60 to which Wfo is input is provided, and the gain of the position detection unit 50 is increased or decreased by the output of the control unit 60.
Is the same as that of the motor control device.

The operation of the fifth embodiment configured as described above will be described below.

The waveform shape control section 60 outputs the position signals Ufo,
Vfo and Wfo are input, and a peak value detecting section 61 for detecting the peak values of these signals, and a position detecting section 50 such that the peak value detected by the detecting section 61 becomes a preset reference level ref. And a controller 62 for adjusting the gains of the amplifiers 51, 52 and 53. Thus, the peak values of the position signals Ufo, Vfo, Wfo are controlled according to the reference level ref.

FIG. 11 is an overall operation explanatory diagram in the fifth embodiment of FIG. 9, and particularly illustrates the U-phase. The V phase and the W phase are not described in detail, but are basically the same as the U phase.

As in the third embodiment, the position signal Ufo (V
fo and Wfo) are substantially sinusoidal signals.

FIG. 11A shows a state in which a substantially sinusoidal position signal Ufo is input to the differential section 11 of the drive waveform generating section 10 and a signal Uf is output from the differential section 11.

The differential section 11 is configured as shown in FIG. 10 similarly to that shown in FIG. 4 in the second embodiment. This configuration is the same for the differential section 11 in the third embodiment shown in FIG. In addition, the other differential units 12 and 13
Has the same configuration.

The input / output characteristics of the differential section 11 are non-linear characteristics mainly determined by the differential transistor pairs 75 and 76, as shown in FIG. 10 or FIG.
The signal Ufo having a substantially sinusoidal shape becomes a signal Uf having a waveform whose peak portion is distorted when its peak value is large. When the peak value of the signal Ufo is small, the signal Uf is close to a sine wave. The signal Uf is appropriately amplified by the speed command Vsp, and then output from the drive waveform generator 10 as a drive waveform signal for the U-phase winding 1. The same applies to drive waveform signals Vf and Wf for V-phase and W-phase windings 2 and 3.

It should be noted that the driving waveform signal U
The waveform shape of f can be changed from a sinusoidal waveform to a trapezoidal waveform as shown in FIG. 11A by increasing or decreasing the peak value of the position signal Ufo. (The same applies to the signals Vf and Wf.) Therefore, the waveform signal control unit 60 described above controls the position signal U in accordance with the reference level ref.
By controlling the peak values of fo, Vfo, and Wfo, the waveform shapes of the drive waveform signals Uf, Vf, and Wf can be changed.

FIG. 11B shows the drive waveform signal Uf obtained when the peak value of the position signal Ufo is controlled to be large.
(C) shows the drive waveform signal Uf when the peak value of the position signal Ufo is controlled to be small.

The signal Uf is PWM as in the first embodiment.
The terminal voltage U of the U-phase winding via the modulation unit 20 and the output unit 30
Control.

FIGS. 11B and 11C show the state, the neutral point voltage N of each phase winding, and the voltage waveform when the U-phase terminal voltage U is viewed from the neutral point voltage N. UN is also shown. Here, the voltage waveform UN is a drive voltage waveform of the U-phase winding.

The V-phase and W-phase voltage waveforms have a phase difference of 120 degrees in electrical angle from the U-phase waveform.

When the peak value of the position signal Ufo is controlled to be large, the drive voltage waveform UN (see FIG. 11B) is a waveform having a high fundamental wave level, as in the third embodiment. Can be effectively utilized, and the motor can be driven with high efficiency. In addition, since the waveform UN at this time has no sharp voltage change and a small distortion rate, the motor can be driven with low noise and low vibration.

When the peak value of the position signal Ufo is controlled to be small, the drive voltage waveform UN (see FIG. 11C)
Is almost a sine wave. Therefore, the above signal Uf
Lower vibration of the motor than when the peak value of o is large,
The noise can be reduced, and an ideal low noise and low vibration motor drive at the same level as the so-called sine wave drive can be realized. that's all,
The waveform shape control unit 6 based on the third embodiment shown in FIG.
Although the example in which 0 is provided has been described, the second embodiment shown in FIG.
A similar effect can be obtained even if the waveform shape control means 60 is provided based on the above.

The operation in this case is as shown in FIG.

According to FIG. 12, when the crest value of the position signal Ufo is controlled to be large, the motor is driven by the same drive voltage waveform as that described in the second embodiment, as shown in FIG. Is possible. That is, similarly to the second embodiment, the motor can be driven with low noise and low vibration. When the crest value of the position signal Ufo is controlled to be small, the motor can be driven by a low distortion driving voltage waveform having the same level as the sine wave, as shown in FIG.
That is, it is possible to drive the motor with low noise and low vibration at a more ideal level.

FIG. 13A shows that the position signals Ufo, V are obtained by changing the reference level ref in the waveform shape control section 60.
drive voltage waveform U when the peak values of fo and Wfo are increased or decreased
It shows distortion rates of -N, VN, and WN.
FIG. 13A also shows the distortion rate of the drive voltage waveform clarified in the above embodiments for reference.

As is clear from FIG. 13A, the distortion rate when the peak value of the position signal is controlled to be small is very small, and is the same level as the sine wave. Although the distortion rate when the crest value of the position signal is controlled to be large slightly increases, the distortion rate is smaller than the distortion rate of the driving waveform (see FIG. 20B) shown in the related art, and the motor has low noise and low vibration. It can be seen that it can be driven by

FIG. 13B shows the position signals Ufo,
It shows changes in the fundamental wave levels (fundamental wave effective values) of the drive voltage waveforms UN, VN, and WN when the peak values of Vfo and Wfo are increased and decreased. FIG. 13B also shows the fundamental wave level (fundamental wave effective value) of the drive voltage waveform clarified in the above embodiments for reference.

As is clear from FIG. 13B, the fundamental wave level when the peak value of the position signal is controlled to be small becomes the same level as when the drive waveform is a sine wave. Also, as the peak value of the position signal is controlled to be larger, the fundamental wave level increases.
It can be seen that the driving waveform approaches the level equivalent to the driving waveform (see FIG. 2C).

As can be seen from FIGS. 13 (a) and 13 (b), the driving voltage waveform obtained by varying the peak value of the position signal is the same as that of the prior art for any of the position signal peak values. The distortion rate is smaller than the drive voltage waveform, and the fundamental wave level is higher. That is, it is understood that the driving voltage waveform is more excellent for low noise, low vibration, and high efficiency driving.

By changing the shape of the drive voltage waveform superior to that of the prior art as described above, the optimum drive voltage waveform can be selected according to the use condition of the motor, and low noise and low vibration can be obtained. Motor driving that achieves both driving and high-efficiency driving becomes possible.

In the above description, the waveform shape controller 60
Is configured to control the peak values of the position signals Ufo, Vfo, Wfo, but it is also possible to vary the waveform shape of the drive waveform signals Uf, Vf, Wf by controlling the amplitudes of the signals Ufo, Vfo, Wfo. Not even.

Further, as shown in FIG.
The drive waveform signals Uf, Vf, Wf
Can be varied. The input / output sensitivity of the differential unit is increased or decreased, for example, by the diodes 71 to 74 in FIG.
It can be realized by a known technique such as switching the number of stages.

As described above, according to the present embodiment, the driving voltage waveform of the motor winding is changed from the low noise and low vibration driving by the low distortion driving voltage waveform of the same level as the sine wave driving to the high fundamental wave level. It is possible to arbitrarily change the drive voltage waveform with high drive efficiency, and the drive voltage waveform can be selectively used according to the use state of the motor, and the motor performance can be flexibly utilized.

[0181] The motor drive that achieves both low noise, low vibration drive, and high efficiency drive becomes possible.

The drive voltage waveform can be varied only by increasing or decreasing the peak value or amplitude value of the position signal, and does not require particularly complicated control. In order to obtain such a drive voltage waveform, a smoothly changing position signal obtained by using a Hall element or the like usually used in a brushless DC motor is used, and a memory circuit such as a ROM for storing the drive waveform is used. And peripheral circuits such as a readout circuit thereof are unnecessary. Therefore, the effects of the above-described embodiment can be realized at very low cost.

In this embodiment, the speed control can be realized by increasing or decreasing the peak values or the amplitudes of the drive waveform signals Uf, Vf, Wf according to the speed command Vsp. The specific method is as described in the second embodiment.

(Embodiment 6) FIG. 15 shows a configuration diagram of a motor control device according to Embodiment 6.

In FIG. 15, except that a speed command Vsp is input and a waveform shape command unit 80 for giving a reference level ref to the waveform shape control unit 60 as a waveform shape command is provided. This is the same as the motor control device according to the fifth embodiment.

The operation of the sixth embodiment configured as described above will be described below with reference to FIG.

The waveform shape command section 80 operates to change the reference level ref according to the value of the speed command Vsp.

FIG. 16 shows some examples of the operation.

The first example is shown in FIG. In the case of this example, the command unit 80 sets a certain speed command value as a threshold value and gives a hysteresis characteristic near the threshold value,
The reference level ref is set to a relatively small value Ref1 for Vsp of a low-speed command, and the reference level ref is set to a relatively large value Ref2 for Vsp of a high-speed command. ing.

By operating the command section 80 in this manner, the drive voltage waveforms UN, V-
N and WN can be almost sinusoidal waves, and the driving voltage waveform can be a waveform having a high fundamental wave level at the time of high-speed command. This is shown in FIG.

In general, in the case of a motor having a wide variable speed range, the noise and vibration of the motor are conspicuous in a relatively low speed region, and it is often desired that the motor be driven with low noise and low vibration. In a high-speed region, it is often desired to drive the motor with the highest possible output.

In such a case, by varying the drive voltage waveform of the winding as described above, it becomes possible to drive the motor appropriately in accordance with the state of the speed command Vsp.

In FIG. 16A, the reason why the hysteresis characteristic is provided is to prevent the drive voltage waveform from frequently changing near the threshold value, thereby preventing the operation from becoming unstable.

A second example of the operation of the waveform shape command unit 80 is shown in FIG. In this example, the reference level ref is set to a relatively small value Ref1 for the low-speed command Vsp, and the reference level ref is set to a relatively small value Ref1 for the low-speed command Vsp. Is
The reference level ref is operated to have a relatively large value Ref2.

Thus, the same operation as the operation of FIG. 16A described above can be performed by operating the command section 80. In particular, in this case, there is an advantage that the shape of the drive voltage waveform can be continuously varied, and the transition from the waveform having a low distortion rate to the waveform having a high fundamental wave level is more natural and smooth.

A third example of the operation of the waveform shape command unit 80 is shown in FIG. In this example, as the speed command Vsp changes from a low speed command to a high speed command, the reference level ref is operated so as to change from a relatively small value Ref1 to a relatively large value Ref2.

As described above, even when the command section 80 is operated, the same operation as the operation of FIG. 16A described above can be performed. Also in this case, since the driving voltage waveform can be continuously varied, there is an advantage that the transition of the driving voltage waveform can be naturally and smoothly performed, similarly to the operation of FIG.

As described above, according to the present embodiment, the waveform shape of the drive waveform signal is varied according to the motor speed command. In other words, at a relatively low speed command where it is often desired to be driven with low noise and low vibration, the drive voltage waveform of the winding is almost sinusoidal, and it is often desirable to drive the motor with the highest possible output. At the time of a high-speed command, the drive voltage waveform is a waveform having a high fundamental wave level. As a result, the motor performance can be flexibly utilized, and both low noise, low vibration driving and high efficiency driving, which have been difficult so far, can be achieved.

In this embodiment, the speed control can be realized by increasing or decreasing the peak values or the amplitudes of the drive waveform signals Uf, Vf, Wf according to the speed command Vsp. The specific method is as described in the second embodiment.

In this embodiment, the case where the drive voltage waveform is varied by the speed command has been described. However, there is no particular need for the speed command, and the speed, the motor current, the torque (load), the torque command, and the The drive voltage waveform may be varied according to various kinds of information that lead to an improvement in the performance of the motor and the entire device on which the motor is mounted.

For example, the torque is detected by a winding current or the like, and when the torque is not required, the motor is driven with low noise and low vibration by a drive voltage waveform having a small distortion, and when the motor is started or accelerated or decelerated. When torque is required or when the load is heavy, the reference level ref may be increased, and the motor may be driven with high output and high efficiency by using a drive voltage waveform having a high fundamental wave level.

(Seventh Embodiment) FIG. 17 shows a configuration diagram of a motor control device according to a seventh embodiment.

Referring to FIG. 17, the driving waveform generator 10
Output signals Uf2, Vf2, W of differential sections 11, 12, 13
A minimum value detector 90 for detecting the signal fm having the smallest value of f2, subtractors 91, 92, 93 for subtracting the value of the signal fm from the values of the signals Uf2, Vf2, Wf2, and subtracters 91, 92, Of the 93 output signals, the maximum peak value fp
And a controller 101 that adjusts the gain of the differential units 11, 12, and 13 so that the peak value fp becomes the speed command Vsp.
Except that the output signals 2 and 93 are used as drive waveform signals Uf, Vf and Wf, the configuration is the same as that of the motor control device shown in each of the embodiments described above.

The operation of Embodiment 7 configured as described above will be described below.

FIG. 18 is an explanatory diagram of the operation in the seventh embodiment shown in FIG. 17, and FIG. 18 (a) shows an example of application to a representative one of the drive voltage waveforms clarified in the previous embodiments. ), (B), and (c) show three types of operations. In each case, the basic operation is the same, and the following description will focus on the one shown in FIG.

In FIG. 17 and FIG.
The output signals Uf2, Vf2, Wf2 of 1, 12, 13 are
In the above embodiments, the drive waveform signals Uf, V
f, Wf. In the present embodiment, the driving waveform signals Uf, Vf2 are newly added based on the signal having the smallest value among these signals Uf2, Vf2, Wf2.
f and Wf are generated. That is, in the present embodiment, Uf = Uf2-fm, Vf = Vf2-fm, Wf =
Wf2-fm, where fm is the signal Uf2, Vf2, W
(minimum value of f2).

The driving waveform signals Uf,
When the motor winding is driven by Vf and Wf, for example, the U-phase winding is driven by the voltage U shown in FIG.
Phase and W phase).

As is clear from FIG. 18, the voltage U is at a constant level during the period indicated by the symbol A.

This is because during the period of the symbol A, the signal Uf2 is
In this period, the switch loss of the output element can be reduced by continuously turning on the output element 44 of the output unit 30 during this period.

Since the neutral point voltage N changes as shown in FIG. 18, the voltage that can be applied to the winding per phase (the U-N voltage in the case of the U phase) increases, and the voltage of the DC main power supply increases. The utilization rate can be improved.

Note that such drive waveform signals Uf, V
f, Wf, the driving voltage waveform U
As shown in FIG. 18, -N (the same applies to VN and WN) does not differ from those described in the above embodiments, and does not change the respective effects.

In the present embodiment, speed control can be realized by increasing / decreasing the peak values of drive waveform signals Uf, Vf, Wf by speed command Vsp. Peak value detecting section 100 and controller 101 output signal Uf , Vf and Wf are accurately adjusted to the level of the speed command Vsp, which has the effect of stabilizing the rotational speed accuracy when controlling the speed of the motor by the speed command Vsp.

As described above, according to the present embodiment, the signal of the lowest level among the drive waveform signals Uf, Vf, Wf of each phase is set to a constant reference level fm, and the winding of the phase winding corresponding to the reference level fm is set. By driving the winding with the terminal voltage being the lowest potential that can be output by the output unit, the utilization rate of the voltage of the DC main power supply is increased, and the switching loss of the output element at the time of PWM driving can be further reduced. be able to.

The driving waveform signals Uf, V of each phase
Even if the signal of the highest level among f and Wf is set to a fixed reference level fm, and the terminal voltage of the winding of the phase corresponding to the reference level fm is set to the highest potential that can be output from the output unit, the winding is driven. Obviously, a similar effect can be obtained.

[0215]

According to the motor control device of the present invention,
As described in the first embodiment, during the electric angle θd of 180 degrees or less, the first level is set, and the electric angle θz of 0 degree or more is set.
(Θz = 180 degrees−θd), a drive waveform generation unit that generates a drive waveform signal of the second level, and based on the drive waveform signal, turns the motor winding to the first level during the electrical angle θd. Driven by a voltage of a desired magnitude determined by
By providing the output unit driven by the zero voltage determined by the second level during the electrical angle θz, generation of a spike voltage due to a circulating current during commutation is eliminated, and noise of the motor is suppressed. Also, the distortion rate of the drive voltage waveform of the winding is improved, and torque ripple and vibration are reduced. In addition, the fundamental wave component included in the driving voltage waveform of the winding, that is, the component that can contribute to the motor output also increases, and the voltage of the DC main power supply can be effectively used, and the efficiency can be improved.

Particularly, θd is set to an electrical angle of 150 degrees (or 1
(49 degrees), the distortion rate of the drive voltage waveform of the winding is the smallest, and the motor drive with small torque ripple and vibration can be realized.

If θd is an electrical angle of 180 degrees, the applied voltage of the DC main power supply can be used most effectively, and the motor can be driven with high efficiency.

The speed can be controlled by increasing or decreasing the peak value or the amplitude of the drive waveform signal.

Further, as described in the second embodiment, each of the transistors has a differential characteristic by a differential transistor pair, includes at least a differential section provided in correspondence with a position signal output of each phase, and has a desired peak value. (Or amplitude), and a drive waveform generation unit that generates a drive waveform signal having a waveform shape obtained by subtracting the outputs of the differential units corresponding to the adjacent phases of the position signal that smoothly changes. An output unit that drives a winding of the motor with a voltage having a magnitude determined by the desired peak value (or amplitude) based on the driving waveform signal and a voltage waveform having a shape determined by the waveform shape. , There is no sudden change in the driving voltage waveform of the winding,
Low noise due to smooth drive voltage waveform close to sine wave drive,
Low vibration driving becomes possible.

In order to obtain such a smooth drive voltage waveform, since a smoothly changing position signal output from a Hall element or the like usually used in a brushless DC motor is used, a memory such as a ROM for storing the drive waveform is used. No circuits or peripheral circuits are required. Therefore, it is possible to realize a motor control device that can be driven simply and at low cost with low noise and low vibration at a level comparable to sine wave drive.

The speed can be controlled by increasing or decreasing the peak value or the amplitude of the drive waveform signal.

As described in the third embodiment, at least a differential portion having a differential characteristic by a differential transistor pair is included, and a position signal having a desired peak value (or amplitude) and smoothly changing is provided. A drive waveform generating unit that generates a drive waveform signal having a waveform shape obtained through a differential unit having differential characteristics, and a motor winding are driven by a voltage having a magnitude determined by the desired peak value (or amplitude). And an output unit driven by a voltage waveform having a shape determined by the waveform shape, so that the motor has low noise and low noise at a level comparable to that of the sine wave drive at a level similar to that of the sine wave drive as in the second embodiment. Vibration drive becomes possible.

In addition, the fundamental wave component of the driving voltage waveform of the winding increases, and high-efficiency driving can be achieved by further effectively utilizing the voltage of the DC main power supply.

The speed can be controlled by increasing or decreasing the peak value or the amplitude of the drive waveform signal.

Also, as described in the fourth embodiment, the distortion factor of the drive waveform signal and the fundamental wave level are varied, and the waveform shape control unit for controlling the waveform shape is provided. The drive voltage waveform can be changed according to the drive voltage waveform, and low noise, low vibration drive equivalent to sine wave drive, and high efficiency drive using a drive voltage waveform with a high fundamental wave level can be used properly.
Flexible motor performance can be utilized.

As described in the fifth embodiment, at least a differential unit having a non-linear differential input / output characteristic by a differential transistor pair is included, and a smoothly changing position signal is input to the differential unit. A drive waveform generator that generates a drive waveform signal for the windings of the motor based on the output, and a crest value or amplitude value of the position signal input to the differential unit are increased or decreased to thereby reduce the distortion rate of the drive waveform signal By providing a waveform shape control unit for varying the fundamental wave level and controlling the waveform shape, the drive voltage waveform of the motor winding is reduced by the low distortion drive voltage waveform at the same level as the sine wave drive. The drive voltage can be changed arbitrarily from noise and low vibration drive to high-efficiency drive with a drive voltage waveform having a high fundamental wave level. It is possible to perform flexible use easily.

[0227] Then, it is possible to drive the motor while achieving both low noise, low vibration driving and high efficiency driving.

The drive voltage waveform can be varied only by increasing or decreasing the peak value or amplitude value of the position signal, and does not require particularly complicated control. Further, in order to obtain such a drive voltage waveform, since a smoothly changing position signal output by a Hall element or the like normally used in a brushless DC motor is used, a memory circuit such as a ROM for storing the drive waveform and its peripheral circuits are used. Is unnecessary. Therefore, the above effects can be realized very simply and at low cost.

The same effect can be obtained by controlling the waveform of the drive waveform signal by increasing or decreasing the input sensitivity of the differential section.

Also, as described in the sixth embodiment, the peak value (or amplitude) and waveform shape of the drive waveform signal are varied according to the motor speed or the speed command, whereby the waveform shape of the drive waveform signal is changed. The driving voltage waveform of the winding is almost sinusoidal at the time of low-speed command where it is desired to be driven with low noise and low vibration, and the driving voltage waveform is high at the time of high-speed command where it is desired to drive the motor with high output. It can be a waveform having a level. As a result, the motor performance can be flexibly used, and it is possible to achieve both low noise, low vibration driving and high efficiency driving, which have been difficult so far.

The speed control can be performed by increasing or decreasing the peak value or the amplitude of the drive waveform signal according to the speed command.

The peak value (or amplitude) and waveform shape of the drive waveform signal may be varied according to the torque (load) of the motor or the torque command.

In this case, when the torque is not required, the motor is driven with low noise and low vibration by the drive voltage waveform having a small distortion factor. When the motor is heavy, the motor can be driven with high output and high efficiency by the drive voltage waveform having a high fundamental wave level.

As described in the seventh embodiment, the drive waveform signals are output corresponding to the windings of each phase of the motor, and the lowest level signal among the drive waveform signals of each phase is fixed. By setting the terminal voltage of the winding of the phase corresponding to the reference level to the lowest potential that the output unit can output, the voltage utilization rate of the DC main power supply increases,
It is possible to further have an effect that the switch loss of the output element at the time of WM driving can be reduced.

The drive waveform signals are output corresponding to the windings of each phase of the motor, and the highest level signal among the drive waveform signals of each phase is set as a constant reference level, and corresponds to the reference level. The same effect can be obtained even if the terminal voltage of the phase winding is set to the highest potential that can be output by the output unit.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a motor control device according to a first embodiment.

FIGS. 2A, 2B, and 2C are explanatory diagrams of the operation of the motor control device according to the first embodiment;

FIG. 3 is a configuration diagram of a motor control device according to a second embodiment.

FIG. 4 is a specific configuration diagram of a differential unit.

FIGS. 5A and 5B are explanatory diagrams of the operation of the motor control device according to the second embodiment.

FIG. 6 is a configuration diagram of a motor control device according to a third embodiment.

FIGS. 7A and 7B are explanatory diagrams of the operation of the motor control device according to the third embodiment;

FIG. 8 is a configuration diagram of a motor control device according to a fourth embodiment.

FIG. 9 is a configuration diagram of a motor control device according to a fifth embodiment.

FIG. 10 is a configuration diagram of a differential section and peripheral sections according to the fifth embodiment.

11A, 11B, and 11C are explanatory diagrams of the operation of the motor control device according to the fifth embodiment.

FIGS. 12A, 12B, and 12C are diagrams illustrating a second operation according to the fifth embodiment;

FIGS. 13A and 13B are diagrams showing distortion factors and fundamental wave levels according to various drive voltage waveforms.

FIG. 14 is an operation explanatory diagram of another implementation method according to the fifth embodiment.

FIG. 15 is a configuration diagram of a motor control device according to a sixth embodiment.

FIG. 16 is an explanatory diagram of the operation of the motor control device according to the sixth embodiment.

FIG. 17 is a configuration diagram of a motor control device according to a seventh embodiment.

FIGS. 18 (a), (b), and (c) are explanatory diagrams of the operation of the motor control device according to the seventh embodiment.

FIG. 19 is a configuration diagram of a motor control device according to the related art.

20 (a) and (b) are explanatory diagrams of an operation of a motor control device according to a conventional technique.

[Explanation of symbols]

 1-3 winding 10 drive waveform generating section 11-13 differential section 20 PWM modulation section 30 output section 50 position detection section 60 waveform shape control section

Continued on the front page F-term (reference) 5H560 AA02 AA04 AA07 BB04 DA02 DC12 EB01 EC02 EC07 EC10 GG03 RR01 RR04 TT07 UA02 UA05 XA04 XA12 5H576 AA10 AA11 AA12 AA17 AA18 BB02 BB04 CC02 DD02 DD07 EJ08 FF03

Claims (10)

[Claims] 1. A drive waveform generator for generating a drive waveform signal for a winding of a motor, a PWM modulator for pulse width modulating the drive waveform signal, and the drive waveform signal pulse width modulated by the PWM modulator. And an output unit for driving the winding based on the driving waveform signal.
The electrical signal is a signal at the first level during an electrical angle θd of less than or equal to 0 degrees and at a second level during an electrical angle θz of 0 ° or more (θz = 180 degrees−θd). The motor control device is configured to be driven by a voltage of a desired magnitude determined by the first level during the electrical angle and to be driven by a zero voltage determined by the second level during the electrical angle θz. 2. A position detector for outputting a position signal that changes smoothly for each phase in accordance with a position of a mover with respect to a winding of each phase of a motor, and a driving waveform for generating a driving waveform signal for the winding. A generating unit, a PWM modulating unit for pulse width modulating the driving waveform signal, and an output unit for driving the winding based on the driving waveform signal pulse width modulated by the PWM modulating unit; The generating unit includes at least a differential unit having a differential characteristic by a differential transistor pair. The differential unit is provided corresponding to each phase output of the position signal. And a signal having a waveform shape obtained by subtracting the output of each of the differential sections corresponding to the adjacent phase of the position signal that smoothly changes and having the peak value (or amplitude) of Is the desired peak value (Or amplitude) and a motor control device configured to be driven by a voltage waveform having a shape determined by the waveform shape. 3. A position detecting section for outputting a position signal that smoothly changes in accordance with a position of a mover of a motor; a driving waveform generating section for generating a driving waveform signal for a winding of the motor; A PWM modulator for pulse width modulation; and an output unit for driving the winding based on the drive waveform signal pulse width modulated by the PWM modulator, wherein the drive waveform generator includes a differential transistor pair. The drive waveform signal includes at least a differential section having a differential characteristic, the drive waveform signal has a desired peak value (or amplitude), and the position signal that changes smoothly passes through the differential section having the differential characteristic. A signal having a waveform shape obtained, wherein the winding has a voltage having a magnitude determined by the desired peak value (or amplitude) and a voltage waveform having a shape determined by the waveform shape. A motor control device configured to be driven. 4. A drive waveform generator for generating a drive waveform signal for a winding of a motor, a PWM modulator for pulse width modulating the drive waveform signal, and the drive waveform signal pulse width modulated by the PWM modulator. And an output unit for driving the winding, and a waveform shape control unit for controlling a waveform shape of the drive waveform signal, wherein the winding has a size determined by a peak value (or amplitude) of the drive waveform signal. And the drive waveform signal is driven by a voltage waveform having a shape determined by the waveform shape of the drive waveform signal, and the waveform shape of the drive waveform signal can have its distortion factor and fundamental wave level variable by the waveform shape control unit. Motor control device. 5. At least a position detection unit that outputs a position signal that smoothly changes according to the position of a mover of a motor, and a differential unit having a non-linear differential input / output characteristic by a differential transistor pair, A driving waveform generating unit that receives the position signal to the differential unit and generates a driving waveform signal for a winding of the motor based on an output of the differential unit; and a PWM modulation unit that performs pulse width modulation on the driving waveform signal. , The PWM
An output unit that drives the winding based on the drive waveform signal that has been pulse width modulated by a modulation unit, and a waveform shape control unit that controls the waveform shape of the drive waveform signal, wherein the winding is The drive signal is driven by a voltage having a magnitude determined by the peak value (or amplitude) of the waveform signal and by a voltage waveform having a shape determined by the waveform shape of the drive waveform signal. A peak value or amplitude value of the position signal input to the differential unit having nonlinear differential input / output characteristics is increased or decreased by the waveform shape control unit, and a distortion factor and a fundamental wave of the drive waveform signal are increased. A motor control device with a variable level. 6. At least a position detection unit that outputs a position signal that smoothly changes according to the position of a mover of a motor, and a differential unit having a non-linear differential input / output characteristic by a differential transistor pair, A driving waveform generating unit that receives the position signal to the differential unit and generates a driving waveform signal for a winding of the motor based on an output of the differential unit; and a PWM modulation unit that performs pulse width modulation on the driving waveform signal. , The PWM
An output unit that drives the winding based on the drive waveform signal that has been pulse width modulated by a modulation unit, and a waveform shape control unit that controls the waveform shape of the drive waveform signal, wherein the winding is The drive signal is driven by a voltage having a magnitude determined by the peak value (or amplitude) of the waveform signal and by a voltage waveform having a shape determined by the waveform shape of the drive waveform signal. A motor control having a configuration in which the input sensitivity of the differential section having nonlinear differential input / output characteristics to be formed is increased or decreased by the waveform shape control section so that the distortion factor and the fundamental wave level of the drive waveform signal can be varied. apparatus. 7. The motor control according to claim 4, wherein a peak value (or amplitude) and a waveform shape of the drive waveform signal are varied according to a motor speed or a speed command. apparatus. 8. The configuration according to claim 4, wherein a peak value (or amplitude) and a waveform shape of the drive waveform signal are varied according to a torque (load) of the motor or a torque command. Motor control device. 9. A drive waveform signal is output corresponding to each phase winding of the motor, and a signal of the lowest level among the drive waveform signals of each phase is set as a constant reference level, The motor control device according to any one of claims 1 to 6, wherein the terminal voltage of the winding of the corresponding phase is set to the lowest potential that the output unit can output. 10. A drive waveform signal is output corresponding to each phase winding of a motor, and the highest level signal among the drive waveform signals of each phase is set to a constant reference level, and the drive waveform signal is output to the reference level. The motor control device according to any one of claims 1 to 6, wherein the terminal voltage of the winding of the corresponding phase is set to the highest potential that can be output by the output unit.