JP2014180148A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller capable of properly suppressing the pulsation torque of an AC motor.SOLUTION: A motor controller 3 comprises: a current reproduction processing unit 301 and a three-phase/two-axis converter 302 for calculating the dc-axis current and qc-axis current of an AC motor 5; a voltage command arithmetic unit 315 for calculating a dc-axis voltage command and qc-axis voltage command corresponding to a voltage command for an inverter 1; signal preproduction processing units 303, 304 equipped with a correction function for correcting the phase value and/or amplitude value of at least one of the dc-axis current, qc-axis current, dc-axis voltage command, and qc-axis voltage command of the AC motor 5; an axis error estimator 305 for estimating an axis error between the real axis and control axis of the AC motor 5; and a pulsation torque suppression controller 306 for calculating a corrected current command so as to cancel the axis error and suppressing the pulsation torque of the AC motor 5.

Description

  The present invention relates to a motor control device that controls driving of an AC motor without a position sensor.

  Position sensorless control is known in which the position of the rotor of the AC motor is estimated using a current detection value of an inverter and the like, and the driving of the AC motor is controlled based on the estimated position. An AC motor driven by position sensorless control has excellent environmental resistance, and is particularly useful when driving a compressor.

  By the way, when the compressor is driven by controlling the AC motor, the load torque of the AC motor pulsates in synchronization with the compression stroke. Therefore, it is necessary to perform a pulsating torque suppression control that suppresses fluctuations in the speed of the AC motor by applying a current so as to cancel the pulsation of the load torque.

  For example, Patent Document 1 describes a control device for a synchronous motor that detects a pulsation component of a load torque generated in synchronization with a rotor position from an axis error obtained by calculation in the control device. The control device described above obtains a pulsating torque suppression current for correcting the pulsating component by integral control, and adds this to the average torque current command value to suppress the speed fluctuation of the rotor.

Further, Patent Document 2 estimates an axis error using the resistance value / inductance value of an AC motor, a voltage command value / frequency command value obtained by a control calculation, and a current detection value based on the concept of an extended induced voltage. A control device for a synchronous motor is described. The extended induced voltage described above will be described in the embodiment of the present invention.
Patent Document 2 discloses a case where an axial error is calculated with high accuracy using an equation including a differential term of a current value, a case where an axial error is calculated using an equation in which a differential term of a current value is omitted, Is described.

JP 2005-198402 A JP 2001-251889 A

  By the way, when the position sensorless control is performed, the above-described axis error itself includes an error. In the invention described in Patent Document 1, overcorrection is added due to the influence of the error, and vibration and noise of the AC motor may not be sufficiently reduced.

The invention described in Patent Document 2 that uses the concept of the extended induced voltage also has the following problems.
That is, since the motor current is intentionally changed during the pulsating torque suppression control, the differential value (L differential value) of the inductance L always changes in an analog manner, but it is difficult to accurately calculate the L differential value. Yes (problem in formula including differential term).
Further, when the L differential value is omitted, an error may occur in the calculation result of the axis error due to the effect of 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).

  Then, this invention makes it a subject to provide the motor control apparatus which can suppress appropriately the pulsation torque of an AC motor.

In order to solve the above problems, a motor control device according to the present invention includes a current calculation unit that calculates 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 detection unit. And a voltage command calculating means for calculating a dc-axis voltage command and a qc-axis voltage command corresponding to a voltage command to the inverter that drives the AC motor, and the actual axis and control of the AC motor based on the concept of the expansion induced voltage A shaft error estimating means for estimating a shaft error with respect to the shaft, and a pulsating torque suppression control for calculating a correction current command so as to cancel the shaft error estimated by the shaft error estimating means and suppressing the pulsating torque of the AC motor And at least one phase value and / or amplitude value of the dc axis current, qc axis current, dc axis voltage command, and qc axis voltage command of the AC motor is corrected. Correction means, and the axis error estimation means 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. The axis error is estimated.
Details will be described in an embodiment for carrying out the invention.

  ADVANTAGE OF THE INVENTION According to this invention, the motor control apparatus which suppresses appropriately the pulsation torque of an AC motor can be provided.

It is a block diagram containing the motor control apparatus which concerns on one Embodiment of this invention. It is a block diagram of the signal reproduction process part with a correction function regarding a dc axis voltage command. FIG. 6 is a waveform diagram showing a dc axis voltage command Vdc * output from a voltage command calculator and a dc axis correction voltage command Vdc * f output from a signal reproduction processing unit with a correction function. It is a block diagram of the signal reproduction process part with a correction function regarding dc-axis current.

  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.

<Embodiment>
<Configuration of motor control device>
FIG. 1 is a configuration diagram including a motor control device according to the present embodiment. The motor control system S shown in FIG. 1 is a system that rotates the rotor (not shown) of the AC motor 5 by controlling the output voltage of the inverter 1 and drives the compressor 6 (for example, a rotary compressor). is there. 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 that converts the DC voltage V0 input from the DC power supply 4 into a three-phase AC voltage and outputs the three-phase AC voltage to the AC motor 5. Here, the DC power source 4 is obtained by converting AC power input from the AC power source 41 into DC power by the rectifier 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 the switching elements ON / OFF according to the PWM signal input from the PWM signal generator 318. To do. In this way, a rotating magnetic field is generated by the AC motor 5 by applying a three-phase AC voltage, and the rotor (not shown) is rotated. As the AC motor 5, for example, a permanent magnet synchronous motor (PMSM) having saliency can be used.

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

  The motor control device 3 is a device that generates a PWM signal based on the current value Ist detected by the current sensor 2 and outputs the PWM signal to the inverter 1. The motor control device 3 is, for example, a microcomputer (not shown), reads a program stored in a ROM (Read Only Memory), develops it in a RAM (Random Access Memory), and various CPUs (Central Processing Units) are provided. Execute the process.

  In the following description, the d-axis is an axis corresponding to the magnetic flux direction of the AC motor 5. The q axis is an axis orthogonal to the d axis. When position sensorless control is performed, current control is performed on the dc axis as the estimated d axis and the qc axis as the estimated q axis. The d-axis and the q-axis are sometimes referred to as “real axes”, and the dc-axis and the qc-axis are sometimes referred to as “control axes”.

The motor control device 3 mainly includes a current reproduction processing unit 301, a three-phase / two-axis converter 302, signal reproduction processing units 303 and 304 with a correction function, an axis error estimator 305, and a pulsating torque suppression controller. 306, a voltage command calculator 315, a 2-axis / 3-phase converter 317, and a PWM signal generator 318.
The current reproduction processing unit 301 (current calculation means) reproduces the three-phase AC currents Iuc, Ivc, Iwc flowing through the AC motor 5 using the current value Ist, and outputs the three-phase AC currents Iuc, Ivc, Iwc to the three-phase / 2-axis converter 302.

  The three-phase / two-axis converter 302 (current calculation means) is configured based on the reproduced three-phase AC currents Iuc, Ivc, Iwc and the phase estimation value θdc input from the integrator 310, and the control system dc An axis current Idc and a qc axis current Iqc are calculated. The three-phase / two-axis converter 302 outputs the calculated dc-axis current Idc to the signal reproduction processing unit 304 with a correction function, and outputs the qc-axis current Iqc to the axis error estimator 305.

The signal reproduction processing unit 303 with correction function (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 analogizes the dc axis correction voltage command Vdc * f. Reproduce as a signal.
The signal reproduction processing unit 304 with correction function (correction processing means) corrects the phase value and the amplitude value with respect to the dc-axis current Idc input from the three-phase / two-axis converter 302, and uses the dc-axis correction current Idcf as an analog signal. Reproduce.
The phase correction process regarding the dc axis voltage command Vdc * and the dc axis current Idc will be described later.

The correction function-equipped signal reproduction processing units 303 and 304 output the reproduced dc axis correction voltage command Vdc * f and dc axis correction current Idcf to the axis 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 shown as the same signal line from the middle. A signal is output to the axis error estimator 305 (the same applies to Idcf and Iqc).

  The axis error estimator 305 (axis error estimating means) calculates the axis error Δθc between the real axis and the control axis of the AC motor 5, the dc axis correction voltage command Vdc * f, the qc axis voltage command Vqc *, and the dc axis correction. The estimation is based on the current Idcf, the qc-axis current Iqc, and the electrical angular frequency ω1c. Details of the estimation process will be described later. The axis error estimator 305 outputs the estimated axis error Δθc to the pulsation torque suppression controller 306 and the sign inverter 307.

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

The sign inverter 307 inverts the sign of the axis error Δθc input from the axis error estimator 305 (that is, subtracts the axis error Δθc from zero, which is the axis error command value), and outputs the result to the PLL circuit 308.
A PLL (Phase Locked Loop) circuit 308 performs PI (Proportional Integral) control using the value (−Δθc) input from the sign inverter 307 to calculate and add the angular frequency correction value Δω1 of the AC motor 5. Output to the device 309.
The adder 309 adds the electrical angular frequency command ω1 * input from the angular frequency command calculator 314 and the angular frequency correction value Δω1 input from the PLL circuit 308 to the integrator 310 as the electrical angular frequency ω1c. Output.

The integrator 310 integrates the electrical angular frequency ω1c input from the adder 309 to calculate a phase estimation value θdc, and outputs the phase estimation value θdc to the 3-phase / 2-axis converter 302 and the 2-axis / 3-phase converter 317.
The d-axis current command generator 311 calculates a d-axis current command Id * corresponding to the average torque according to a preset program, and outputs it to the voltage command calculator 315.
The q-axis current command generator 312 calculates a q-axis current command Iqb corresponding to the average torque based on the qc-axis current Iqc input from the three-phase / two-axis converter 302 and outputs it to the adder 313.

The adder 313 calculates a new q-axis current command Iq * by adding the pulsation torque suppression current IqSIN * input from the pulsation torque suppression controller 306 to the q-axis current command Iqb, thereby calculating a voltage command calculation. To the device 315.
The angular frequency command calculator 314 multiplies the angular frequency command ωr * input from the angular frequency command generator 316 (angular frequency command generation means) by the number of pole pairs (P / 2) and adds it as an electrical angular frequency command ω1 *. Output to the controller 309 and the voltage command calculator 315.

The voltage command calculator 315 (voltage command calculation means) is configured to use the dc axis voltage commands Vdc * and qc based on the d axis current command Id *, the q axis current command Iq *, and the electrical angular frequency command ω1 *. The shaft voltage command Vqc * is calculated. 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 that drives the AC motor 5.
The voltage command calculator 315 outputs the calculated dc-axis voltage command Vdc * and qc-axis voltage command Vqc * to the 2-axis / 3-phase converter 317. Further, the voltage command calculator 315 outputs the dc axis voltage command Vdc * to the signal reproduction processing unit 303 with a correction function, and outputs the qc axis voltage command Vqc * to the axis error estimator 305.

The 2-axis / 3-phase converter 317 is 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 θdc input from the integrator 310. Three-phase voltage commands Vu *, Vv *, and Vw * are calculated and output to the PWM signal generator 318.
A PWM (Pulse Width Modulation) signal generator 318 generates a PWM signal in accordance with the three-phase voltage commands Vu *, Vv *, Vw * input from the two-axis / three-phase converter 317, and switches the inverter 1 Output to.

(About axial error Δθc)
The load torque of the AC motor 5 pulsates in synchronization with the compression process. Due to the influence of such torque pulsation, the magnitude of the axis error Δθc estimated by the axis error estimator 305 periodically varies according to the mechanical angle of the rotor (not shown) of the AC motor 5.

The axis error estimator 305 shown in FIG. 1 calculates the axis error Δθc every predetermined time by using calculation formulas (Formulas 1 and 2 described later) based on the concept of the extended induced voltage.
Here, the “extended induced voltage” is a term that summarizes the terms specific to the salient pole machine depending on the rotor position and current value as a term representing the voltage induced by the permanent magnet magnetic flux or the reluctance magnetic flux. I mean.
Since the extended induced voltage is expressed as a vector that rotates in synchronization with the rotor, the position of the rotor (not shown) can be obtained based on the phase information of the extended induced voltage.

  For example, as the calculation of the axis error Δθc in the axis error estimator 305, the following (Formula 1) can be used. In Equation 1, r: resistance value of AC motor 5, s: differential operator, Ld: d-axis inductance, Lq: q-axis inductance, ω1c: electrical angular frequency of AC motor 5. In (Expression 1), subscripts (dc, qc, etc.) are represented by subscripts (the same applies to (Expression 2) described later). Since (Formula 1) can be derived by the same method as in Patent Document 2 described above, detailed description thereof is omitted.

Incidentally, the q-axis current command Iq * is intentionally changed during the pulsating torque suppression control. Along with this, the differential term sLd of the d-axis inductance L also always changes in an analog manner, so that it is difficult to accurately calculate the axis error Δθc using (Equation 1).
In the present embodiment, the differential term is omitted from (Formula 1), and the axial error Δθc is calculated using (Formula 2) shown below.

If (Formula 2) is used as it is without performing the correction processing described below, an error may occur in the calculation result of the axis error Δθc due to the effect of omitting the differential term.
Therefore, in this embodiment, the phase and amplitude of the dc-axis voltage command Vdc * and the dc-axis current Idc are changed by the signal reproduction processing units 303 and 304 with a correction function so as to reduce the axis error Δθc using (Equation 2). I decided to correct it. As a result, it is possible to reduce the error of the axis error Δθc itself while calculating the axis error Δθc simply and at high speed, and to effectively suppress the pulsation torque.

(Signal reproduction processing unit with correction function)
FIG. 2 is a configuration diagram of a signal reproduction processing unit with a correction function related to the dc-axis voltage command.
The signal reproduction processing unit 303 with a correction function mainly includes a Fourier forward transformer 303a, first-order lag filters 303b, 303c, and 303d, and a Fourier inverse transformer 303f.

The Fourier forward converter 303a receives sin θr and cos θr calculated using the mechanical angle phase value θr of the rotor (not shown) at the time point detected by the current sensor 2, and the dc input from the voltage command calculator 315. The shaft voltage command Vdc * and the shaft voltage command Vdc * are respectively multiplied and output to the first-order lag filter a2.
Incidentally, the mechanical angle phase value θr described above is a value obtained by converting the estimated phase value θdc calculated by the integrator 310 (see FIG. 1) into the mechanical angle of the AC motor 5. Further, the “mechanical angle phase value calculating means” for calculating the phase estimation value θdc by integrating the electrical angular frequency ω1c and calculating the mechanical angle phase value θr of the rotor using the phase estimation value θdc is an integrator. 310 and signal reproduction processing units 303 and 304 with a correction function.

Each of the first-order lag filters 303b and 303c removes a harmonic component from the signal input from the Fourier forward converter 303a, and extracts a fluctuation component of the dc-axis voltage command Vdc *. The above-mentioned fluctuation component means a difference between a temporal average value of the dc axis voltage command Vdc * and a dc axis voltage command value Vdc * that fluctuates in a sine wave shape.
The first-order lag filters 303b and 303c output the sin-side scalar value V1dc _sin * and the cos-side scalar value V1dc _cos * of the fluctuation component to the inverse Fourier transformer 303f. Incidentally, the first-order lag filter 303b, constant T ₁ when the 303c is previously set as extractable value fluctuation component while removing harmonic components.

The first-order lag filter 303d executes a filter process 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 value command Vdc_Base * to the adder 303h. To do. Incidentally, the constant T ₂ when the first-order lag filter 303f is preset average value of the dc axis voltage command Vdc * as calculated possible values.

The adder 303e adds the mechanical angle phase value θr of the rotor (not shown) at the time point detected by the current sensor 2 and the phase correction value Δθcom, and outputs the result to the inverse Fourier transformer 303f. The phase correction value Δθcom is set in advance based on prior experiments so as to reduce an error associated with the use of (Formula 2) in the calculation process of the axis error Δθc.
By using the dc axis correction voltage command Vdc * corresponding to the phase value (θr + Δθcom) for the estimation of the axis error Δθc, it is possible to reduce an error caused by using (Expression 2) in which the differential term is omitted.

It has also been found that the error associated with using (Equation 2) decreases as the rotational speed of the AC motor 5 increases. Therefore, it is preferable to decrease the phase correction value Δθcom (that is, to have a negative correlation with the rotation speed) as the rotation speed of the AC motor 5 increases. Accordingly, the phase correction value Δθcom can be adjusted so as to reduce the above-described error according to the rotational speed of the AC motor 5.
The phase correction value Δθcom may be a fixed value set in advance.

The inverse Fourier transformer 303f includes a sin-side scalar value V1dc _sin * input from the first-order lag filter 303b, a cos-side scalar value V1dc _cos * input from the first-order lag filter 303c, and a phase value input from the adder 303e. Based on (θr + Δθcom), inverse Fourier transform is performed.
That is, the Fourier inverse transformer 303f performs an inverse Fourier transform so that the phase of the vector specified by the sin side scalar value V1dc _sin * and the cos side scalar value V1dc _cos * is shifted by the phase correction value Δθcom, The result is output to the proportional calculator 303g.

Proportional calculator 303g is a predetermined proportional gain K _p to the value inputted from the inverse Fourier transformer 303f (corresponding to a sine wave and the mechanical angle phase value θr of the rotor is shifted by the phase correction value Δθcom min.) Multiply and output to adder 303h.
The size of the proportional gain K _p as capable of reducing the value of the error in the case of using (Equation 2) is set in advance based on prior experiments.

  The adder 303h adds the variation input from the proportional calculator 303g to the average voltage command Vdc_Base * input from the first-order lag filter 303d, and generates an axis error estimator 305 (FIG. 5) as a dc axis correction voltage command Vdc * f. 1).

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 signal reproduction processing unit with a correction function.
As shown in FIG. 3, the phase of the dc-axis voltage command Vdc * is advanced by the phase correction value Δθcom by the signal reproduction processing unit with correction function 303 and converted into the dc-axis correction voltage command Vdc * f. In the example shown in FIG. 3, it is set to a proportional gain K _p using a proportional calculator 303 g '1'.

FIG. 4 is a configuration diagram of a signal reproduction processing unit with a correction function related to the dc-axis current.
The signal reproduction processing unit with correction function 304 mainly includes a Fourier forward converter 304a, first-order lag filters 304b, 304c, and 304d, and an inverse Fourier transformer 304f.
4 is the same as that of the signal reproduction processing unit 303 with a correction function related to the dc-axis voltage command (see FIG. 2), the description thereof will be omitted.

<Effect>
In the motor control device 3 according to the present embodiment, the mechanical angle phase value θr at the time point detected by the current sensor 2 is shifted by the phase correction value Δθcom, and the amplitude is appropriately changed to change the dc axis correction voltage command Vdc * f. And dc axis correction current Idcf is calculated.
Moreover, the phase correction value Δθcom and the proportional gain K _p, as to reduce the error that may occur by using the omitted differential term (Equation 2) (that is, an error which occurs when not using the present embodiment), pre Is set.

  Thus, by using (Expression 2) in which the differential term is omitted, the calculation load of the motor control device 3 when calculating the axis error Δθc is reduced, and the current detection value Ist is set to the three-phase voltage commands Vu * and Vv *. , Vw * can be improved in response.

  The axis error estimator 305 estimates the axis error Δθc based on the dc axis correction voltage command Vdc * f and the dc axis correction current command Idcf whose phases and amplitudes are corrected by the signal reproduction processing units 303 and 304 with a correction function. To do. Therefore, it is possible to reduce the error associated with using (Expression 2) in which the differential term is omitted, and to accurately calculate the axial error Δθc that changes from moment to moment.

Thus, the pulsation torque generated in the AC motor 5 can be effectively suppressed by calculating the shaft error Δθc at high speed and accurately. As a result, the vibration and noise of the compressor 6 (see FIG. 1) due to periodic disturbance can be reduced.
Further, according to the present embodiment, since the pulsation torque is suppressed based on the above-described axis error Δθc, the electric power required to cancel the pulsation torque can be consumed efficiently. Therefore, the AC motor 5 can be driven with high efficiency.

≪Modification≫
As mentioned above, although the said embodiment demonstrated the motor control apparatus 3 which concerns on this invention, this invention is not limited to this, A various change can be performed.
For example, in the above-described embodiment, the case where the signal reproduction processing units 303 and 304 with the correction function calculate the dc-axis correction current Idcf and the dc-axis correction voltage command Vdc * f has been described, but the present invention is not limited thereto. That is, the phase value correction process and the amplitude value correction process may be executed on 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, by setting the phase correction value θcom and proportional gain G _p appropriately, it is possible to reduce the error associated with the use in the calculation of the axis error Δθc and (Equation 2).

In the above-described embodiment, the case where the signal reproduction processing units 303 and 304 with a correction function execute both the phase value correction processing and the amplitude value correction has been described, but either one may be executed.
In the above embodiment, as the phase correction value θcom and proportional gain G _p, descriptions have been given of the case using the same value dc-axis current Idc and the dc axis voltage command Vdc * of the correction process is not limited thereto. That is, the correction processing relating dc-axis current Idc, the correction processing relating dc axis voltage command Vdc *, in may be set phase correction value θcom and proportional gain G _p different values.

In the above-described embodiment, the case where the corrected mechanical angle phase value (θr + Δθcom) is advanced from the original mechanical angle phase value θr (that is, θcom> 0) is described, but the present invention is not limited to this. That is, the corrected mechanical angle phase value (θr + Δθcom) may be delayed from the original mechanical angle phase value θr (that is, θcom <0).
In the above-described embodiment, the case where (Expression 2) is used when the axis error Δθc is estimated by the axis error estimator 305 is described, but the present invention is not limited to this. That is, any expression other than (Expression 2) may be used as long as it is based on the extended induced voltage.

Moreover, although the said embodiment demonstrated the case where a rotary compressor was used as the compressor 6, it is not restricted to this. That is, another type of compressor such as a reciprocating compressor may be used as the compressor 6.
Moreover, although the said embodiment demonstrated the case where axial error (DELTA) (theta) c was estimated using the electric current value Ist etc. of the bus-bar P connected to the direct current | flow side of the inverter 1, it is not restricted to this. For example, the axis error Δθc may be estimated by detecting the current values iu and iw on the AC side of the inverter 1.

Moreover, although the said embodiment demonstrated the case where a synchronous motor was used as the alternating current motor 5, it does not restrict to this. That is, even if an induction motor is used as the AC motor 5, highly accurate pulsating torque suppression control can be executed by the same method as in the above embodiment.
Moreover, although the said embodiment demonstrated the case where the AC motor 5 driven by the motor control apparatus 3 was installed in the compressor 6, it does not restrict to this. That is, as long as the AC motor 5 is driven without a position sensor, the present invention can be applied to all devices and systems.

S motor control system 1 inverter 2 current sensor (current detection means)
3 Motor control device 301 Current reproduction processing unit (current calculation means)
302 3-phase / 2-axis converter (current calculation means)
303, 304 Signal reproduction processing unit with correction function (correction processing means, mechanical angle phase value calculation means)
305 Axis error estimator (Axis error estimation means)
306 Pulsating torque suppression controller (Pulsating torque suppression control means)
310 integrator (mechanical angle phase value calculation means)
315 Voltage command calculator (voltage command calculation means)
316 Angular frequency command generator (angular frequency command generation means)
317 2-axis / 3-phase converter 318 PWM signal generator 5 AC motor

Claims (4)

Current calculating means for calculating the dc axis current and the qc axis current of the AC motor based on the current value of the AC motor detected by the current detecting means;
Voltage command calculation means for calculating a dc-axis voltage command and a qc-axis voltage command corresponding to a voltage command to the inverter that drives the AC motor;
An axis error estimating means for estimating an axis error between the real axis and the control axis of the AC motor based on the concept of the extended induced voltage;
A pulsation torque suppression control unit that calculates a correction current command so as to cancel the axis error estimated by the axis error estimation unit and suppresses the pulsation torque of the AC motor;
Correction processing means for correcting at least one phase value and / or amplitude value among the dc axis current, qc axis current, dc axis voltage command, and qc axis voltage command of the AC motor,
The axis error estimation means estimates the axis error based on a dc axis current, a qc axis current, a dc axis voltage command, and a qc axis voltage command including the at least one corrected by the correction processing means. A motor control device. A mechanical angle phase value calculating means for calculating a mechanical angle phase value of a rotor of the AC motor using the phase estimated value by calculating a phase estimated value by integrating the electrical angular frequency of the AC motor;
The correction processing means includes
2. The motor control according to claim 1, wherein the at least one phase value is corrected by adding a predetermined correction phase value to the mechanical angle phase value calculated by the mechanical angle phase value calculating unit. apparatus. The correction processing means includes
The motor control device according to claim 1, wherein the at least one amplitude value is corrected by multiplying the at least one amplitude value by a predetermined proportional gain. The axis error estimating means includes
Estimating the axis error using (Equation 2) shown below

The motor control device according to any one of claims 1 to 3, wherein:
However, Vdc *: dc axis voltage command, Vqc *: qc axis voltage command, Idc: dc axis current, Iqc: qc axis current, r: resistance value of AC motor, Lq: q axis inductance, ω1c: electricity of AC motor Angular frequency.

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