KR101485989B1 - Motor control device - Google Patents

Abstract

An object of the present invention is to provide a motor control device capable of appropriately suppressing the pulsating torque of an AC motor.
In order to solve such a problem, the motor control device 3 includes a current reproduction processing section 301 and a three-phase / two-axis converter 302 for calculating the dc axis current and the qc axis current of the AC motor 5, A qc axis voltage command, and a qc axis voltage command of the AC motor 5; a voltage command calculator 305 for calculating a qc axis voltage command and a dc axis voltage command corresponding to the voltage command for the AC motor 5; And an axial error estimator 305 for estimating an axial error between the real axis of the alternating-current motor 5 and the control axis, a signal processing unit 305 for correcting at least one phase value and / And a pulsating torque suppression controller 306 for calculating a correction current command so as to eliminate the shaft error and suppressing the pulsation torque of the AC motor 5.

Description

[0001] MOTOR CONTROL DEVICE [0002]

The present invention relates to a motor control device for controlling the driving of an AC motor by a position sensorless method.

A position sensorless control for estimating the position of a rotor of an AC motor using a current detection value of the inverter or the like and for controlling the drive of the AC motor based on the estimated position is also known. The AC motor driven by the position sensorless control is excellent in environmental resistance, and is particularly useful when driving a compressor.

However, when the compressor is driven by controlling the alternating-current motor, the load torque of the alternating-current motor pulsates in synchronization with the compression stroke. Therefore, it is necessary to control the pulsating torque so as to flow the current so as to eliminate the pulsation of the load torque and suppress the fluctuation of the speed of the AC motor.

For example, Patent Document 1 describes a control apparatus for a synchronous motor that detects a pulsating component of a load torque generated in synchronization with a rotor position from an axial error obtained by an operation in a control apparatus. The above control device suppresses the speed fluctuation of the rotor by obtaining the pulsating torque suppressing current for correcting the pulsating component by integrating control and adding this to the average torque current command value.

Patent Document 2 discloses a technique for estimating an axis error by using a resistance value / inductance value of an alternating-current motor, a voltage command value / frequency command value obtained by a control calculation, and a current detection value, A control device for an electric motor is described. The above-described extended organic voltage will be described in the embodiments of the present invention.

Patent Document 2 describes a case where an axial error is calculated with high precision using an equation including a differential term of a current value and a case where an axial error is calculated using an equation in which a differential term of a current value is omitted have.

Japanese Patent Application Laid-Open No. 2005-198402 Japanese Patent Application Laid-Open No. 2001-251889

Incidentally, when the position sensorless control is performed, the axis error itself also includes an error. In the invention described in Patent Document 1, excessive correction is applied due to the error, and vibration and noise of the AC motor may not be sufficiently reduced.

Also, the invention described in Patent Document 2 using the concept of the extended organic voltage described above has the following problems.

In other words, since the motor current is intentionally changed during the pulse torque restraining control, the differential value (L differential value) of the inductance L is always changed analogously, but it is difficult to accurately calculate the L differential value Problem in the formula).

In addition, when the L differential value is omitted, there is a possibility that an error occurs in the calculation result of the shaft error due to the omission, and the effect of the pulsating torque suppression control may be reduced (a problem in the equation in which the differential term is omitted) .

It is therefore an object of the present invention to provide a motor control device capable of appropriately suppressing the pulsating torque of an AC motor.

In order to solve the above problems, a motor control apparatus according to the present invention includes: current calculating means for calculating a dc axis current and a qc axis current of an AC motor based on a current value of the AC motor detected by a current detecting means; Voltage command calculating means for calculating a qc-axis voltage command and a dc-axis voltage command corresponding to a voltage command to the inverter for driving the alternating-current motor, based on the concept of the extended electromotive voltage, A pulse torque suppressing control means for calculating a correction current command to eliminate the shaft error estimated by the axial error estimating means and suppressing a pulsation torque of the AC motor; A correction process for correcting at least one phase value and / or amplitude value of the dc axis current of the alternating current motor, the qc axis current, the dc axis voltage command, and the qc axis voltage command Wherein the axis error estimating means estimates the axis error based on the dc axis current, the qc axis current, the dc axis voltage command, and the qc axis voltage command including the at least one corrected by the correction processing means Is estimated.

Details of the invention will be described in detail.

According to the present invention, it is possible to provide a motor control apparatus that appropriately suppresses the pulsating torque of an AC motor.

1 is a configuration diagram including a motor control device according to an embodiment of the present invention;
Fig. 2 is a configuration diagram of a signal reproduction processor with a correction function relating to the dc-axis voltage command. Fig.
3 is a waveform diagram showing the dc-axis voltage command Vdc * output from the voltage command calculator and the dc-axis correction voltage command Vdc * f output from the correction-function-provided signal reproduction processor.
4 is a configuration diagram of a signal reproduction processor with a correction function relating to the dc-axis current;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings as appropriate.

&Quot; Embodiments &

<Configuration of Motor Control Device>

1 is a configuration diagram including a motor control device according to the present embodiment. The motor control system S shown in Fig. 1 rotates the rotor (not shown) of the alternating-current motor 5 by controlling the output voltage of the inverter 1 and drives the compressor 6 (for example, a rotary compressor) . The motor control system S includes an inverter 1, a current sensor 2, and a motor control device 3. [

The inverter 1 is a power converter for converting a DC voltage V0 input from the DC power supply 4 into a three-phase AC voltage and outputting it to the AC motor 5. [ The DC power supply 4 converts AC power inputted from the AC power supply 41 into DC power by the rectifying circuit 42 and the smoothing capacitor 43.

The inverter 1 has a plurality of switching elements (not shown) and converts the DC voltage V0 into a three-phase AC voltage by switching ON / OFF of the switching element in accordance with the PWM signal input from the PWM signal generator 318 . As described above, by applying the three-phase AC voltage, a rotating magnetic field is generated in the AC motor 5, and the above-described rotor (not shown) is rotated. As the alternating-current motor 5, for example, a Permanent Magnet Synchronous Motor (PMSM) having a salient polarity can be used.

The current sensor 2 (current detecting means) is connected in series to the bus bar P of the inverter 1, detects a current value Ist flowing through the bus bar P, and outputs it to the motor control device 3.

The motor control device 3 is a device for generating a PWM signal based on the current value Ist detected by the current sensor 2 and outputting the PWM signal to the inverter 1. [ The motor control device 3 is a microcomputer (not shown), for example, reads a program stored in a ROM (Read Only Memory) and develops it in a RAM (Random Access Memory) Performs various processes.

In the following description, the d-axis is an axis corresponding to the magnetic flux direction of the alternating-current motor 5. The q-axis is an axis orthogonal to the d-axis. When the position sensorless control is performed, current control is performed on the estimated dc axis as the estimated d-axis and the qc axis as the estimated q-axis. It is assumed that the d axis and the q axis are referred to as &quot; dead axis &quot; and the dc axis and the qc axis are referred to as &quot; control axis &quot;.

The motor control apparatus 3 mainly includes a current reproduction processing section 301, a three-phase / two-axis converter 302, a signal processing reproduction processing section 303 and a correction function processing section 303, an axis error estimator 305, A pulsating torque suppression controller 306, a voltage command computing unit 315, a two-axis / three-phase converter 317, and a PWM signal generator 318. [

The current reproduction processing section 301 (current calculating means) reproduces the three-phase alternating currents Iuc, Ivc and Iwc flowing in the alternating-current motor 5 using the current value Ist described above, .

The three-phase / two-axis converter 302 (current calculating means) calculates the dc axis current Idc and the dc axis current Idc of the control system based on the reproduced three-phase alternating currents Iuc, Ivc and Iwc and the phase estimated value? Dc input from the integrator 310, the qc axis current Iqc is calculated. The three-phase / two-axis converter 302 outputs the calculated dc-axis current Idc to the correction function-equipped signal reproduction processor 304, and outputs the qc-axis current Iqc to the axis error estimator 305. [

The correction function-equipped signal reproduction processor 303 (correction processing means) corrects the phase value and the amplitude value with respect to the dc-axis voltage command Vdc * input from the voltage command calculator 315 and outputs the dc-axis correction voltage command Vdc * f As an analog signal.

The correction function-equipped signal reproducing processor 304 (correction processing means) corrects the phase value and the amplitude value with respect to the dc-axis current Idc input from the 3-phase / 2-axis converter 302 and outputs the dc- Signal.

The phase correction processing relating to the dc-axis voltage command Vdc * and the dc-axis current Idc will be described later.

The correction-function-provided signal reproduction processing units 303 and 304 output the reproduced dc-axis correction voltage command Vdc * f and the dc-axis correction current Idcf to the shaft error estimator 305, respectively.

In Fig. 1, the signal line of the dc-axis correction voltage command Vdc * f and the signal line of the qc-axis voltage command Vqc * are described as the same signal line in the middle, but actually they are outputted as the different signals to the shaft error estimator 305 (Idcf and Iqc are also the same).

The axial error estimator 305 (axial error estimating means) calculates the axial error ?? c between the real axis of the alternating-current motor 5 and the control axis based on the dc axis correction voltage command Vdc * f, the qc axis voltage command Vqc * The current Idcf, the qc axis current Iqc, and the electric angular frequency? Lc. Details of the estimation processing will be described later. The axial error estimator 305 outputs the estimated axial error ?? c to the pulsating torque suppression controller 306 and the sign inverter 307.

The pulsation torque suppression controller 306 (the pulsation torque suppression control means) calculates the pulsating torque suppression current IqSIN * based on the shaft error ?? c inputted from the shaft error estimator 305 and outputs it to the adder 313. The pulsating torque suppression current IqSIN * is added to the q-axis current command Iqb by the adder 313 so as to eliminate the fluctuation of the load torque (that is, the pulsation torque) applied to the AC motor 5. [

The sign inverter 307 inverts the sign of the shaft error ?? c input from the shaft error estimator 305 (i.e., subtracts the shaft error ?? c from zero, which is the shaft error command value), and outputs it to the PLL circuit 308 do.

The phase locked loop (PLL) circuit 308 performs PI (Proportional Integral) control using a value (-Δθc) input from the sign inverter 307 and outputs a frequency correction value Δωl And outputs it to the adder 309. [

The adder 309 adds the electric angle frequency command? L * input from the frequency command calculator 314 and each frequency correction value ?? l inputted from the PLL circuit 308 and outputs the electric angle frequency? Lc to the integrator 310, .

The integrator 310 integrates the electric angular frequency ωlc input from the adder 309 to calculate a phase estimated value θdc and outputs it to the 3-phase / 2-axis converter 302 and the 2-axis / 3-phase converter 317.

The d-axis current command generator 311 calculates the d-axis current command Id * corresponding to the average torque in accordance with the preset program and outputs it to the voltage command calculator 315. [

The q-axis current command generator 312 calculates the q-axis current command Iqb corresponding to the average torque on the basis of the qc-axis current Iqc input from the 3-phase / 2-axis converter 302 and outputs it to the adder 313 do.

The adder 313 calculates a new q-axis current command Iq * by adding the pulsating torque suppression current IqSIN * input from the pulsation torque suppression controller 306 to the q-axis current command Iqb, .

Each frequency command calculator 314 multiplies each frequency command? R * input from each frequency command generator 316 (each of the frequency command generating means) by the maximum number P / 2, To the adder 309 and the voltage command calculator 315 as the command? *.

The voltage command calculator 315 (voltage command calculation means) calculates the dc axis voltage commands Vdc * and qc (q) based on the d-axis current command Id *, the q-axis current command Iq * Axis voltage command Vqc *. The dc-axis voltage command Vdc * and the qc-axis voltage command Vqc * correspond to the three-phase voltage commands Vu *, Vv * and Vw * to the inverter 1 for driving the alternating-current motor 5.

The voltage command calculator 315 outputs the calculated dc-axis voltage command Vdc * and the calculated qc-axis voltage command Vqc * to the 2-axis / 3-phase converter 317. The voltage command calculator 315 also outputs the dc-axis voltage command Vdc * to the correction function-equipped signal reproduction processor 303 and outputs the qc-axis voltage command Vqc * to the axial error estimator 305. [

Based on the dc-axis voltage command Vdc * and the qc-axis voltage command Vqc * input from the voltage command calculator 315 and the phase estimation value? Dc input from the integrator 310, the two-axis / three- Calculates the voltage commands Vu *, Vv * and Vw *, and outputs them to the PWM signal generator 318. [

The PWM (Pulse Width Modulation) signal generator 318 generates a PWM signal in accordance with the three-phase voltage commands Vu *, Vv *, and Vw * input from the two-axis / three-phase converter 317, And outputs it to the switching element.

(With respect to the axial error ?? c)

The load torque of the AC motor 5 pulsates in synchronization with the compression process. The magnitude of the axial error ?? c estimated by the axial error estimator 305 fluctuates periodically according to the mechanical angle of the rotor (not shown) of the AC motor 5 due to the influence of such torque pulsation.

The axial error estimator 305 shown in Fig. 1 calculates the axial error [Delta] [theta] c at predetermined time intervals by using an expression (Expressions 1 and 2 described later) based on the concept of the extended induced voltage.

Here, the term &quot; extended induced voltage &quot; means that the term specific to the rotor pole, which depends on the position and current value of the rotor, is organized as a term indicating the voltage induced by the permanent magnet flux or the reluctance flux.

Since the extended organic voltage appears as a vector rotating in synchronism with the rotor, the position of the rotor (not shown) can be obtained based on the phase information of the extended organic voltage.

For example, the following formula (1) can be used as the calculation of the axial error ?? c in the axial error estimator 305. In Equation 1, r is the resistance of the AC motor 5, s is the differential operator, Ld is the d-axis inductance, Lq is the q-axis inductance, and lc is the electrical angular frequency of the AC motor 5. In (Equation 1), the suffixes (dc, qc, etc.) are represented by subscripts (the same holds true in the latter equation (Equation 2)). (Formula 1) can be derived by the same method as in the above-described Patent Document 2, and therefore detailed description thereof will be omitted.

[Number 1]

Incidentally, during the pulsating torque suppression control, the q-axis current command Iq * is intentionally changed. Accordingly, since the differential term sLd of the d-axis inductance L always changes in an analog manner, it is difficult to accurately calculate the axis error ?? c using (Eq. 1).

In the present embodiment, the differential term is omitted in (Equation 1), and the shaft error ?? c is calculated by using (Equation 2) shown below.

[Number 2]

If the following correction process is not performed and the equation (2) is used as it is, there is a possibility that an error occurs in the calculation result of the axial error ?? c due to the omission of the differential term.

Therefore, in the present embodiment, the phase and amplitude of the dc-axis voltage command Vdc * and the dc-axis current Idc are corrected (corrected) by the correction function-equipped signal reproduction processing units 303 and 304 so as to reduce the shaft error ?? . Thereby, it is possible to reduce the error of the shaft error ?? c itself and effectively suppress the pulsation torque while calculating the shaft error ?? c at a high speed and at a high speed.

(Signal reproduction processor with correction function)

Fig. 2 is a configuration diagram of a signal-reproduction processing section provided with a correction function relating to the dc-axis voltage command.

The correction-function-provided signal reproduction processing section 303 mainly has a Fourier transformer 303a, first order delay filters 303b, 303c, and 303d, and a Fourier inverse transformer 303f.

The Fourier inverse transformer 303a calculates sin θr and cosθr calculated using the machine angular phase value θr of the rotor (not shown) at the time point detected by the current sensor 2 and the sin θr and cosθr calculated from the voltage command calculator 315 And the dc-axis voltage command Vdc * to be output to the first-order delay filter a2.

In addition, the mechanical angular phase value? R is a value obtained by converting the phase estimated value? Dc calculated by the integrator 310 (see FIG. 1) into the mechanical angle of the AC motor 5. The "mechanical angular phase value calculating means" for calculating the phase estimated value? Dc by integrating the electric angular frequency? C and calculating the mechanical angular phase value? R of the rotor by using the estimated phase value? Dc includes an integrator 310, And a correction function-equipped signal reproduction processor (303, 304).

The first-order delay filters 303b and 303c respectively remove the harmonic components from the signals input from the Fourier transformers 303a and extract the fluctuation components of the dc-axis voltage command Vdc *. The above-described fluctuation component means the difference between the time average value of the dc-axis voltage command Vdc * and the dc-axis voltage command value Vdc * fluctuating on the sinusoidal wave.

The first order delay filters 303b and 303c output the sin side scalar value Vldc _sin * and the cos side scalar value Vldc _cos * of this fluctuation component to the Fourier inverse transformer 303f. The time constants T ₁ of the first-order delay filters 303b and 303c are set in advance so that the variation component can be extracted while removing the harmonic components.

The first-order delay filter 303d performs filter processing so as to obtain an average value of the dc-axis voltage command Vdc * input from the voltage command calculator 315 within a predetermined time, and outputs the average voltage command Vdc_Base * . The time constant T ₂ of the first-order delay filter 303f is set in advance so that the average value of the dc-axis voltage command Vdc * can be calculated.

The adder 303e adds the machine angular phase value? R of the rotor (not shown) at the time point detected by the current sensor 2 and the phase correction value ?? com, and outputs it to the Fourier inverse transformer 303f. The phase correction value ?? com is set in advance based on an experiment to reduce an error caused by the use of (Expression 2) in the calculation processing of the axial error ?? c.

By using the dc-axis correction voltage command Vdc * corresponding to the phase value (? R +? Com) for the estimation of the axial error ??

It has also been found that the larger the rotational speed of the alternating-current motor 5, the smaller the error caused by the use of (Equation 2). Therefore, it is preferable that the phase correction value [Delta] [theta] com is made smaller (i.e., has a negative correlation with the rotational speed) as the rotational speed of the alternating-current motor 5 increases. Thus, the phase correction value [Delta] [theta] com can be adjusted so as to reduce the error according to the rotational speed of the AC motor 5. [

Also, the phase correction value ?? com may be a preset fixed value.

Fourier inverse converter (303f), the first-order lag filter sin side input from (303b) scalar Vldc _sin * and a primary delay filter cos side input from (303c) the scalar value Vldc _cos * and an adder (303e) (R + [Delta] [theta] com) inputted from the Fourier transformer.

That is, the Fourier inverse transformer 303f performs inverse Fourier transform so that the phase of the vector specified by the sin side scalar value Vldc _sin * and the cos side scalar value Vldc _cos * is shifted by the phase correction value ?? com, And outputs it to the computing unit 303g.

The proportional operator 303g multiplies the value input from the Fourier inverse transformer 303f (corresponding to a sinusoidal wave obtained by shifting the mechanical phase angle value? R of the rotor by the phase correction value ?? com) by a predetermined proportional gain Kp, (303h).

The magnitude of the proportional gain Kp is previously set based on experiments in the prior art, with the error in the case of using (Equation 2) being a value that can be reduced.

The adder 303h adds the variation input from the proportional operator 303g to the average voltage command Vdc_Base * input from the first-order delay filter 303d and outputs the dc-axis correction voltage command Vdc * f to the axis error estimator 305 (See Fig. 1).

3 is a waveform diagram showing the dc-axis voltage command Vdc * output from the voltage command calculator and the dc-axis correction voltage command Vdc * f output from the correction-function-provided signal reproduction processor.

3, the phase of the dc-axis voltage command Vdc * is advanced by the phase correction value ?? com by the correction-function-signal-generating processor 303 and is converted into the dc-axis correction voltage command Vdc * f. In the example shown in Fig. 3, the proportional gain Kp used in the proportional operator 303g is set to '1'.

4 is a configuration diagram of a signal-reproduction-with-correction-function-processing section relating to the dc-axis current.

The correction function-equipped signal reproduction processing section 304 mainly has a Fourier transformer 304a, first order delay filters 304b, 304c and 304d, and a Fourier inverse transformer 304f.

4 are the same as those in the signal reproduction processor 303 (see Fig. 2) with the correction function relating to the dc-axis voltage command, and therefore the description thereof will be omitted.

<Effect>

The motor control apparatus 3 according to the present embodiment shifts the machine angular phase value? R at the point of time detected by the current sensor 2 by the phase correction value ?? com and changes the amplitude appropriately, The command Vdc * f, and the dc axis correction current Idcf.

The phase correction value ?? com and the proportional gain Kp are set in advance so as to reduce the error that can be caused by using the equation (2) in which the differential term is omitted (that is, an error caused when the present embodiment is not used) .

By using the expression (2) in which the differential term is omitted, the calculation load of the motor control device 3 at the time of calculating the axis error ?? c is reduced and the current detection value Ist is converted into the three-phase voltage commands Vu * and Vv * , And Vw * can be increased.

Based on the dc-axis correction voltage command Vdc * f and the dc-axis correction current command Idcf whose phase and amplitude are corrected by the correction-function-provided signal reproduction processing units 303 and 304, the axial error estimator 305 calculates an axial error & Respectively. Therefore, it is possible to reduce errors due to the use of the equation (2) in which the differential term is omitted, and to accurately calculate the axial error ??

Thus, by calculating the shaft error ?? c at high speed and accurately, the pulsation torque generated in the AC motor 5 can be effectively suppressed. As a result, vibration and noise of the compressor 6 (see Fig. 1) caused by periodic disturbance can be reduced.

Further, according to the present embodiment, since the pulsation torque is suppressed based on the above-mentioned axial error ?? c, the power required to eliminate the pulsation torque can be efficiently consumed. Therefore, the AC motor 5 can be driven with high efficiency.

"Variations"

As described above, the motor control apparatus 3 according to the present invention has been described with reference to the above embodiment, but the present invention is not limited to this, and various modifications can be made.

For example, in the above-described embodiment, the case where the correction-function-provided signal reproduction processing sections 303 and 304 calculate the dc-axis correction current Idcf and the dc-axis correction voltage command Vdc * f is described, . That is, the phase value correcting process and the amplitude value correcting process may be carried out with respect to at least one of the dc axis current, the qc axis current, the dc axis voltage command, and the qc axis voltage command of the AC motor 5.

In this case as well, by appropriately setting the phase correction value [theta] com and the proportional gain Gp, it is possible to reduce the error caused by the use of (Expression 2) in the calculation of the axial error [Delta] [theta] c.

In the above-described embodiment, the case where the correction-function-provided signal reproduction processing units 303 and 304 execute both the phase value correction process and the amplitude value correction is described, but either one may be performed.

In the above embodiment, the same value is used in the correction processing of the dc axis current Idc and the dc axis voltage command Vdc * as the phase correction value? Com and the proportional gain Gp, but the present invention is not limited to this. That is, the phase correction value? Com and the proportional gain Gp may be set to different values in the correction process for the dc-axis current Idc and the correction process for the dc-axis voltage command Vdc *.

In the above-described embodiment, the case has been described in which the corrected machine angular phase value (? R +? Com) is advanced to the original machine angular phase value? R (that is,? Com> 0). That is, the corrected machine angular phase value (? R +? Com) after the correction may be made to be slower than the original machine angular phase value? R (that is,? Com <0).

In the above-described embodiment, the case where the axial error estimator 305 estimates the axial error [Delta] [theta] c (Formula 2) is described, but the present invention is not limited to this. That is, if it is based on the extended organic voltage, an expression other than (Expression 2) may be used.

In the above embodiment, the rotary compressor is used as the compressor 6, but the present invention is not limited to this. That is, another type of compressor such as a reciprocating compressor may be used as the compressor 6.

In the above embodiment, the case where the shaft error ?? c is estimated using the current value Ist of the bus line P connected to the dc side of the inverter 1, is not limited to this. For example, the axial error [Delta] [theta] c may be estimated by detecting the current values iu and iw on the AC side of the inverter 1. [

In the above embodiment, the case where the synchronous motor is used as the AC motor 5 has been described, but the present invention is not limited thereto. That is, even if an induction motor is used as the alternating-current motor 5, high-precision pulsating torque suppression control can be performed in the same manner as in the above embodiment.

In the above embodiment, the case where the AC motor 5 driven by the motor control device 3 is installed in the compressor 6 has been described. However, the present invention is not limited to this. That is, if the AC motor 5 is driven by the position sensorless operation, it can be applied to all devices and systems.

S motor control system
1 inverter
2 Current sensor (current detection means)
3 Motor control unit
301 current reproduction processing section (current calculation means)
302 Three-phase / two-axis converter (current calculating means)
303, and 304 A signal reproduction signal processing section (correction processing means, machine angular phase value calculating means)
305 axis error estimator (axial error estimation means)
306 Pulse torque suppression controller (pulsation torque suppression control means)
310 integrator (mechanical phase value calculating means)
315 Voltage command calculator (voltage command calculation means)
316 Each frequency reference generator (each frequency reference generator)
317 Two-axis / three-phase converter
318 PWM Signal Generator
5 AC motors

Claims (4)

Current calculating means for calculating the dc axis current and the qc axis current of the alternating-current motor based on the current value of the alternating-current motor detected by the current detecting means,
Voltage command calculating means for calculating a qc-axis voltage command and a dc-axis voltage command corresponding to a voltage command to the inverter for driving the ac motor,
Axis error estimation means for estimating an axial error between the real axis and the control axis of the AC motor based on the concept of the extended electromotive voltage,
A pulsating torque suppression control means for calculating a correction current command to eliminate the shaft error estimated by the shaft error estimation means and suppressing a pulsation torque of the AC motor;
And correction processing means for correcting at least one phase value and / or amplitude value among the dc axis current, the qc axis current, the dc axis voltage command, and the qc axis voltage command of the alternating current motor,
Wherein the axis error estimation means comprises at least one value corrected by the correction processing means among the dc axis current, the qc axis current, the dc axis voltage command, and the qc axis voltage command and the at least one value corrected by the current calculation means and the voltage command calculation means And estimates the axis error based on the value input from
And the motor control device. The method according to claim 1,
And mechanical angular phase calculating means for calculating a phase estimation value by integrating the electric angular frequency of the AC motor and calculating a mechanical angular phase value of the rotor of the AC motor using the phase estimation value,
The correction processing means,
And correcting the at least one phase value by adding a predetermined correction phase value to the machine angular phase value calculated by the machine angular phase value calculating means
And the motor control device. The method according to claim 1,
The correction processing means,
Multiplying the at least one amplitude value by a predetermined proportional gain to correct the at least one amplitude value
And the motor control device. 4. The method according to any one of claims 1 to 3,
Wherein the axis error estimation means comprises:
And estimating the axial error using the following equation (2)
And the motor control device.
[Number 2]

Idc: dc axis current, Iqc: qc axis current, r: resistance value of the AC motor, Lq: q-axis inductance, ωc: electric current of the AC motor Each frequency.

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