JP2003033068A - Motor control device and electric drive device using the same - Google Patents

Abstract

(57) [Problem] To provide a torque (output) command type motor control device that can always drive a motor at the time of startup. Also, a motor control configuration for controlling the rotation speed so as not to exceed the rotation speed limit value of the system is provided. An adjusting mechanism for increasing a motor applied voltage until a required torque can be output at the time of starting is introduced. A rotation speed limit value is provided, and the torque current command or the rotation speed command is corrected so that the rotation speed does not exceed the above speed limit value. Any of a torque current command, a torque command, and an output command and a rotation speed limit value are calculated from an external signal related to the motor output. [Effect] In a motor control device using only a position detection sensor, a torque (output) command type motor control device that can always drive a motor can be realized. Further, in the torque command type motor control device, the rotation speed can be controlled so as not to exceed the rotation speed limit value of the motor or the system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device control method for driving a permanent magnet synchronous motor by 180 ° energization (sinusoidal wave) using a position detection sensor, and more particularly to a motor output command such as a torque command. The present invention relates to a control method for controlling a motor output torque or the like without detecting a current or the like.

[0002]

2. Description of the Related Art Many motor control devices have been announced for driving a permanent magnet synchronous motor through 180 degrees by using a position sensor such as a magnetic pole position sensor. Among them, in the paper “Development of a fully automatic washing machine with inverter control” of the 1999 Ibaraki branch research conference of the Institute of Electrical Engineers of Japan, we adopted vector control with a motor current sensorless, low-resolution position sensor to control 180-degree energization. It describes the details of achieving low noise.

The motor control configuration described in the above paper is as shown in FIG.

In the motor control configuration of FIG. 8, a speed calculation unit 4 for calculating the rotational speed ω _r of the permanent magnet synchronous motor using the position signals U, V, W of the magnetic pole position sensor, and the position signal of the magnetic pole position sensor. U, V, W obtains the magnetic pole reference phase theta _dps of the permanent magnet synchronous motor from the magnetic pole reference phase theta _dps
A phase error between the control unit and the internal phase θ _d of the control device and outputs a correction signal Δω _pll ;
_The phase updating unit 6 that calculates the internal phase θ _d from _r and the correction signal Δω _pll, and the speed control unit 13 that calculates the torque current command I _q ^* from the rotation speed command ω _r ^* and the rotation speed ω _r.
And a vector operation unit 1 for calculating the voltage commands V _q ^* and V _d ^* to the permanent magnet synchronous motor from the rotation speed ω _r and the motor current commands I _q ^* and I _d ^*, and the voltage commands V _q ^* and V. It is composed of an applied voltage generator 2 which calculates applied voltages Vu, Vv, Vw from _d ^* and the internal phase θ _d . Here, the model formula used in the vector operation unit 1 is shown in Formula (1).

[0005]

[Formula 1] V _d ^* = where ^{_{r · I d * -ω r ·}} L · I q * V q * = ω r · L · I d * + r · I q * + k E · ω r, V d * : D-axis voltage command, I _d ^* : Excitation current command V _q ^* : q-axis voltage command, I _q ^* : Torque current command, r: Winding resistance L _q : q-axis inductance, L _d : d-axis inductance k _E : Power generation constant, ω _r : rotation speed.

The magnetic pole position sensor for detecting the magnetic pole position of the permanent magnet motor is attached at an electrical angle of 120 degrees. Therefore, the magnetic pole position signal can be used to grasp the position for each 60 electrical degrees.

[0007]

The above-mentioned method uses the speed control unit 13 to change the torque current command I _q ^* with respect to the rotation speed command ω _r ^* input from the upper (external) device. The speed is controlled. Therefore, at the time of startup (acceleration / deceleration), the voltage applied to the permanent magnet synchronous motor 3 can be increased (increased or decreased) by increasing (increasing or decreasing) the rotation speed command ω _r ^* above the steady state. Therefore, the required torque can be output at the time of starting (acceleration / deceleration), and the permanent magnet synchronous motor 3 can be smoothly driven (acceleration / deceleration) In other words, the torque current command I _q ^* is determined by the speed controller 13. Since it can be (changed), the permanent magnet synchronization 3
The motor can be reliably driven and controlled.

Now, consider a case where a torque current command I _q ^* (or torque command τ ^* , motor output Pm ^*, etc.) is input as the upper (external) command instead of the rotation speed command ω _r ^* . In other words, consider a torque (output) command type motor control configuration instead of a speed command type motor control configuration. In this case, a motor control configuration in which the speed control unit 13 is not provided and the directly input torque current command I _q ^* is input to the vector calculation unit 1 is conceivable.

However, this configuration does not always enable activation. Because the input torque current command I
_{Since q} ^* is constant irrespective of the rotation of the permanent magnet synchronous motor 3, the motor applied voltage calculated by the input torque current command _Iq ^* is a value that cannot generate an output torque that is equal to or greater than the starting torque required at the time of starting. This is because the motor cannot be started forever. That is, there is no configuration for increasing the voltage applied to the motor until the required output torque can be output at startup.

In view of the above, the first object of the present invention is to provide a torque (output) at which a motor can be driven in response to any command in a motor control device using only a position detection sensor (without a motor current sensor). An object is to provide a command type motor control device.

Further, in the torque command type motor control device, the rotation speed of the motor is determined by the relationship between the output torque of the motor and the load torque. In other words, there is no control structure for controlling the rotation speed of the motor. Therefore, the rotation speed may exceed the rotation speed limit value of the motor or the system. Therefore, a second object of the present invention is to provide, in a torque command type motor control device, a motor control configuration for limiting the rotation speed so as not to exceed the rotation speed limit value of the motor or the system.

[0012]

In order to achieve the first object, it is necessary to provide an adjusting mechanism for increasing the voltage applied to the motor until the torque required at the start can be output.

Here, paying attention to the arithmetic expression (equation (1)) of the vector arithmetic unit 1, the motor applied voltage can be increased by setting an appropriate value for the rotational speed value ω _r . And, as means for that purpose, the present invention uses the following two means.

First, as a first means, a means for providing a speed value setting section for setting an arbitrary value to the rotation speed value ω _r used in the vector operation section 1 was used. That is, at startup, a value other than the actual rotation speed is set as the rotation speed value ω _r shown in the equation (1).

Specifically, (a) input a predetermined value at the time of starting, (b) switch to a rotation speed when the rotation speed reaches a preset limit value, and (c) rotate after a predetermined time elapses. Switching to speed, (d) changing the content ratio of the predetermined value and the actual rotation speed according to the rotation speed,
(E) In (a) to (c) above, the predetermined value is increased with time, (f) In (a) to (c) above, the predetermined value is input from the outside. It is conceivable to change according to the command value related to the output.

As a second means, a means for using a speed control unit so as to change the torque current command I _q ^* and introducing a rotation speed command calculation unit for producing a rotation speed command ω _r ^* is used.

Specifically, the motor control device is provided with a rotation speed command calculation unit for calculating the rotation speed command so that the internal status value matches the internal status command value input from the outside. This can be solved by adopting a configuration in which the rotation speed control is performed according to. The internal state value, which is a value related to the motor output, is the motor output, output torque, or torque current of the permanent magnet synchronous motor.

In the above structure, the rotation speed command value can be used for the calculation of the vector calculation section.

Therefore, by using the first and second means, it is possible to provide a torque (output) command type motor control device which can drive the motor without fail by using only the position detection sensor (without the motor current sensor). You can

Next, in order to achieve the second object, it is necessary to set a limit value for the rotation speed and to control the speed so that it does not exceed the limit value.

However, since the first means for achieving the first object has no speed control section, the rotation speed of the permanent magnet synchronous motor is set to a predetermined speed limit value for this means. It is necessary to provide a torque current correction unit that corrects the torque current command so as not to exceed the limit.

Further, since the second means has the speed control unit, the speed can be controlled by the speed limit value, and the rotation speed command calculation is performed so that the rotation speed command does not exceed the predetermined rotation speed limit value. It is necessary to deal with this by providing a rotation speed limit value in the section.

Thus, in the torque command type motor control device, it is possible to provide a motor control structure for limiting the rotation speed so as not to exceed the rotation speed limit value of the motor or the system.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a control block diagram for realizing the first means described in the means for solving the problems. This control is realized by using, for example, a microcomputer. The permanent magnet synchronous motor is a three-phase eight-pole salient-pole motor, and three magnetic pole position sensors are attached at 120 electrical angle intervals.

FIG. 2 is a diagram showing the relationship between the induced voltage of the permanent magnet synchronous motor and the position signal from the magnetic pole position sensor.
The relationship when rotated in the W) direction is shown. The magnetic pole position sensor is attached so as to have the relationship shown in FIG. The first embodiment is an example in which the control configuration shown in FIG. 1 is applied to a motor drive device of an electric drive device such as a washing machine. The washing mode of the washing machine shown here is not a constant speed control during operation, but a characteristic that the speed decreases with an increase in load (laundry) is desirable, and constant torque or constant output control is suitable.

First, the control configuration shown in FIG. 1 will be described in detail.

In the control configuration of FIG. 1, the torque command τ ^* and the limiting rotation speed command ω _rLMT are calculated based on a command (here, a washing force command) related to the motor output input from the upper circuit of the electric drive device. Command conversion unit 7 and torque command τ
^Using the torque current command conversion unit 8 for calculating the external torque current command I _q ^** based on ^* , and the position signals U, V, W of the magnetic pole position sensor attached to the permanent magnet synchronization motor 3, the permanent magnet synchronization is performed. The speed calculation unit 4 that calculates the rotation speed ω _{r of the} motor, the limit rotation speed command ω _rLMT, and the rotation speed ω _r
A torque current correction unit 9 that corrects the external torque current command I _q ^** based on the above to calculate the torque current command I _q ^* ,
The magnetic pole reference phase θ _dps of the permanent magnet synchronous motor is obtained from the position signals U, V, W of the magnetic pole position sensor, and the correction signal Δω is obtained from the phase error between the magnetic pole reference phase θ _dps and the internal phase θ _d of the control configuration (device). _The phase correction unit 5 that outputs _pll and the internal phase θ _d based on the rotation speed ω _r and the correction signal Δω _pll
And a speed value setting unit 10 that sets either the rotation speed ω _r or the value _obtained by multiplying the limit rotation speed command ω _rLMT by a coefficient as the rotation speed command value ω _r ^* used in the vector calculation unit 1. And a maximum torque control unit 11 that calculates an exciting current command I _d ^* that maximizes the output torque of the motor based on the torque current command I _q ^* , and a motor current command (exciting current command I _d ^* , torque current command I _q ^* ) and the rotational speed command ω _r ^* , for example, according to the model formula shown in Formula (2), the vector operation unit 1 for calculating the voltage commands V _q ^* and V _d ^* to the permanent magnet synchronous motor, and the voltage Applied voltages Vu, Vv, Vw based on the commands V _q ^* , V _d ^* and the internal phase θ _d.
It is configured to have an applied voltage generation unit 2 for calculating
In the actual circuit configuration, the voltage is applied from the applied voltage generator 2 to the motor 3 via the inverter main circuit, but this is omitted in the first embodiment. Further, the following expression (2) is a model expression used in the vector operation unit 1.

[0028]

[Equation 2] ^{_{V d * = r · I d}} * -ω r * · L · I q * V q * = ω r * · L · I d * + r · I q * + k E · ω r * Then, The operation of each element of the control configuration shown in FIG. 1 will be described in detail.

The command conversion unit 7 outputs a torque command τ ^* and a limit rotation speed command ω _rLMT according to the washing force command from a preset table. The torque current command conversion unit 8 also uses preset table data to calculate the external torque current command I _q ^** from the torque command τ ^* . The command conversion unit 7 may directly calculate the external torque current command I _q ^** . Further, it is also possible to calculate the relational expression between the torque and the torque current instead of the table data.

The torque current correction unit 9 determines the rotation speed ω of the motor.
_This is a circuit unit that controls the torque current command I _q ^* so that _r does not exceed the limit rotation speed ω _rLMT , and is mainly performed using proportional- _plus- integral control. Here, when the rotation speed ω _r is below the limit rotation speed command ω _rLMT , the torque current correction value Δ
I _q ^* becomes zero, and the external torque current command I _q ^** and the torque current command I _q ^* have the same value. In other words, the rotation speed ω
_{When r} exceeds the limit rotation speed command ω _rLMT , the torque current command is corrected.

The speed value setting unit 10 has an initial state (at the time of startup).
Is set to a value _obtained by multiplying the limit rotation speed command ω _rLMT by a coefficient, and the rotation speed ω _r is set to the limit rotation speed command ω _rLMT.
If it is determined that the reached coefficient multiplied by the value, the rotation speed omega _r
Will be changed to. Here, the coefficient is 1/2, and the setting value is changed once after starting. In other words, after the change, the rotation speed ω _r is set until the rotation is stopped.

By the above operation, the necessary starting torque can be generated (applying a large voltage) at the time of starting, and reliable starting is possible. In the steady state, the motor speed can be controlled with the optimum current phase. In other words, the applied voltage can be increased by setting a relatively large value to the rotation speed command ω _r ^* of the vector calculation formula shown in Formula (2), and torque exceeding the torque required at the time of startup can be generated. it can. Then, in the steady state, vector control is performed using the actual rotation speed ω _r , which makes it possible to perform control at the optimum current phase.

Further, it is important to set the magnitude of the set value set at the time of startup and the timing of switching.
Methods other than the above will be described below.

First, as a method of giving the set value (rotational speed command value ω _r ^* ), the method is to increase it with the passage of time.

A method of changing the size of the set value according to the input value of the external input value (torque command τ ^* , torque current command I _q ^*, etc.). Can be considered.

As the switching timing, a method of switching to the rotation speed ω _r after a predetermined time has elapsed.

Depending on the rotation speed, the set value and the rotation speed ω
How to change the content ratio of _r . Can be considered.

Next, FIG. 3 shows the output characteristics of the motor when the control device illustrated in the first embodiment is used. FIG. 3 is a diagram showing the rotation speed with respect to the output torque, using the washing force command as a parameter.

The washing force command shown in FIG. 3 increases in the order of A → B → C. Further, it is a characteristic when an upper limit value is set for the input power. Therefore, the upper limit value of the rotation speed decreases as the washing force command increases. Since the output torque is small in the washing force commands A and B, the operation can be performed up to the high speed rotation range. However, in this region, the torque current correction unit 9 functions to reduce the torque current command and control the rotation speed to the limited rotation speed. In other words, the torque decreases while the rotation speed remains constant.

By using the control configuration of the first embodiment,
The motor can be reliably started and the output torque of the motor can be controlled to be constant. Also, the rotation speed can be suppressed by the rotation speed limit value.

(Second Embodiment) Next, a second embodiment will be described with reference to FIGS.

The second embodiment realizes the second means described in the means for solving the problems. FIG. 4 is a control configuration diagram according to the second embodiment, and FIG.
FIG. 7 is a diagram showing the output characteristics of the motor when the control configuration in the embodiment is used. The same reference numerals as in the first embodiment perform the same operations.

The main difference from the first embodiment is that the speed control unit 13 is used and the rotation speed command calculation unit 12A for calculating the rotation speed command ω _r ^* is introduced. Depending on the difference in the above configuration, a command conversion unit 7A that calculates the motor output command Pm ^* and the limit rotation speed command ω _rLMT based on the washing force command and a motor output calculation unit 14A that calculates the motor output Pm are added respectively. has been changed.

The configuration of the second embodiment is for creating a motor output command from the washing force command and controlling the motor output.

The rotation speed command calculator 12A calculates the rotation speed command ω _r ^* using proportional-plus-integral control so that the motor output Pm matches the motor output command Pm ^* .
The limit rotation speed command ω _rLMT is also input to the rotation speed command calculator 12A, and the calculated rotation speed command ω _r ^* is restricted so as not to exceed the limit rotation speed command ω _rLMT .

The speed controller 13 controls the rotation speed command ω _r ^*.
So that the actual rotation speed ω _r agrees with the torque current command I _q ^*
Is calculated.

The motor output calculation unit 14A calculates the motor output Pm from the following equation 3 using the motor current command and voltage command handled by the vector calculation unit 1.

[0048]

[Equation 3] The ^{_{Pm = V d * · I d}} * + V q * · I q * output characteristics of the motor in the case of using the second embodiment shown in FIG. Similar to FIG. 3, FIG. 5 also takes the washing force command as a parameter and shows the rotation speed with respect to the output torque. In FIG. 5, as in FIG. 3, the washing force command increases in the order of A → B → C.

In the case of the second embodiment, since the motor output command is created from the washing force command, the motor output is controlled to be constant. Therefore, when the output torque is changed, the rotation speed also changes.

Further, since the motor output is constant, the motor operates up to the high speed rotation range in the low torque range, but as in the first embodiment, the limit rotation speed command is suppressed and the rotation speed does not increase.

By using the second embodiment, the motor can be surely started and the motor output can be controlled to be constant, as in the first embodiment. Also, the rotation speed can be suppressed by the rotation speed limit value.

The second embodiment is an example in which the motor output is controlled to be constant by using the above-mentioned second means, but the output is output in the same manner as the first embodiment by using the configuration of the second embodiment. The torque can be controlled to be constant, and can be realized by the control configuration shown in FIGS. 6 and 7, for example. The detailed operation is the same as the operation of each component in the first and second embodiments. Therefore, an outline will be described here.

FIG. 6 is a configuration diagram in which the motor output torque is controlled by inputting the torque command τ ^* , and FIG. 7 is a configuration diagram in the case where the motor output torque is controlled by inputting the external torque current command I _q ^** . is there.

In the case of FIG. 6, the torque τ is set as the internal state value.
Needs to be calculated. Therefore, the torque calculation unit 14B
Is used. The torque calculation unit 14B calculates the torque using the equation (4).

[0055]

[Formula 4]

Here, P is the number of pole pairs.

In FIG. 6, the motor output torque τ is calculated using the equation (4), but the same control can be performed by obtaining the motor output torque from the motor output and the rotation speed.

In the case of FIG. 7, the external torque current command I _q ^**
Is used as an input, the torque current command I _q ^* is used as it is.

In the first and second embodiments, the maximum torque control unit 11 is used to calculate the exciting current command I _d ^* that maximizes the motor output torque from the torque current command I _q ^*. Is shown in equation (5).

[0060]

[Formula 5]

In the first and second embodiments, equation (5)
Is used to determine the exciting current command I _d ^* so that the output torque of the motor is maximized. However, the present invention is not limited to this, and the exciting current command such as field weakening control is operated separately. It goes without saying that the control of is also applicable.

[0062]

As described above, when the motor control device of the present invention is used, in the motor control device using only the position detection sensor (without the motor current sensor), the torque (output) command type that can drive the motor is surely used. A motor control device can be realized.

Further, in the above torque command type motor control device, it is possible to limit the rotation speed so as not to exceed the rotation speed limit value of the motor or the system.

[Brief description of drawings]

FIG. 1 is a control configuration diagram of a motor control device showing a first embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the induced voltage and the position signal according to the first embodiment of the present invention.

FIG. 3 is a motor characteristic diagram of the first embodiment of the present invention.

FIG. 4 is a control configuration diagram of a motor control device showing a second embodiment of the present invention.

FIG. 5 is a motor characteristic diagram of the second embodiment of the present invention.

FIG. 6 is a control configuration diagram of another motor control device of the present invention.

FIG. 7 is a control configuration diagram of another motor control device of the present invention.

FIG. 8 is a control configuration diagram of a conventional motor control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vector calculation part, 2 ... Applied voltage creation part, 3 ... Permanent magnet synchronous motor, 4 ... Speed calculation part, 5 ... Phase correction part, 6 ...
Phase update unit, 7, 7A, 7B ... Command conversion unit, 8 ... Torque current command conversion unit, 9 ... Torque current correction unit, 10 ... Speed value setting unit, 11 ... Maximum torque control unit, 12A, 12B, 1
2C ... Rotation speed command calculation unit, 13 ... Speed control unit, 14A
... Motor output calculation unit, 14B ... Torque calculation unit.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihisa Iwaji             7-1-1, Omika-cho, Hitachi-shi, Ibaraki Prefecture             Inside the Hitachi Research Laboratory, Hitachi Ltd. F term (reference) 3B155 BA11 HB09 LA02 LA11 LB18                       LC12 LC13 MA05 MA08 MA09                 5H560 AA10 BB04 DA13 DB20 DC03                       DC07 DC12 DC13 EB01 GG04                       JJ02 JJ03 JJ05 SS03 XA04                       XA11 XA13                 5H576 AA12 BB06 CC01 DD02 DD07                       EE01 FF01 JJ25 LL14 LL22                       LL38 LL39

Claims (13)

[Claims] 1. A motor control device for controlling a motor based on an input from the outside, the motor rotating on the basis of an applied voltage, a magnetic pole position sensor for detecting a magnetic pole position of the motor, and the magnetic pole position. A speed calculation unit that calculates a rotation speed of the motor based on a position signal output from a sensor, a conversion unit that converts an input from the outside into a torque current command, a limiting rotation speed of the motor, and the speed calculation unit. A torque current correction unit that corrects the torque current command based on the calculated rotation speed of the motor, a vector calculation unit that calculates a voltage command using the corrected torque current command, and a voltage command based on the voltage command. And an applied voltage creating section for creating an applied voltage to the motor. 2. A permanent magnet synchronous motor, a magnetic pole position sensor for detecting a magnetic pole position of the permanent magnet motor, and a speed for calculating a rotation speed of the permanent magnet synchronous motor based on a position signal output from the magnetic pole position sensor. An arithmetic unit, a phase updating unit that obtains a rotational phase of the permanent magnet synchronous motor based on the rotational speed and the magnetic pole position signal, and a vector arithmetic unit that calculates a motor applied voltage based on a motor current command and a rotational speed value. A motor control device including a speed value setting unit that sets the rotation speed value to an arbitrary value. 3. The motor drive device according to claim 2, wherein the speed value setting unit sets a predetermined value. 4. The motor drive device according to claim 3, wherein the speed value setting unit sets the rotation speed when the rotation speed obtained by the speed calculation unit is equal to or more than a predetermined limit value. A motor control device characterized by the above. 5. The motor drive device according to claim 3, wherein the speed value setting unit sets the rotation speed obtained by the speed calculation unit after a predetermined time has elapsed. 6. The motor drive device according to claim 2, wherein the speed value setting unit includes a predetermined value based on a rotation speed of the permanent magnet synchronous motor and a rotation speed calculated by the speed calculation unit. A motor control device, characterized in that the rotation speed value is set by changing a ratio. 7. The motor control device according to claim 3, wherein the speed value setting section increases the predetermined value with time. 8. The motor control device according to claim 3, wherein the predetermined value in the speed value setting unit is a command value related to a motor output input from the outside. A motor control device characterized by being changed. 9. The motor control device according to claim 2, further comprising a torque current correction unit that corrects the torque current command so that the rotation speed of the permanent magnet synchronous motor does not exceed a predetermined speed limit value. A motor control device characterized by the above. 10. A permanent magnet synchronous motor, a magnetic pole position sensor for detecting a magnetic pole position of the permanent magnet motor, and a speed for calculating a rotational speed of the permanent magnet synchronous motor based on a position signal output from the magnetic pole position sensor. An arithmetic unit, a phase updating unit that obtains a rotational phase of the permanent magnet synchronous motor based on the rotational speed and the magnetic pole position signal, and a vector arithmetic unit that calculates a motor applied voltage based on a motor current command and a rotational speed value. And a rotation speed command calculation unit that calculates the rotation speed command so that the value of the internal state matches the internal state command value given from the outside. Control device. 11. The motor control device according to claim 10, wherein the internal state value is one of a motor output, a motor output torque, and a torque current. 12. The motor control device according to claim 10, wherein a rotation speed value used for the calculation of the vector calculation unit is the rotation speed command value. 13. The motor control device according to claim 10, wherein the rotation speed command is limited so that the rotation speed command does not exceed a predetermined rotation speed limit value. Motor control device.