JP5910757B2 - Electric motor control device - Google Patents

Description

  The present invention relates to a control device that controls the operation of a permanent magnet motor.

  For example, Patent Documents 1 and 2 disclose control devices that estimate the output torque of a synchronous motor and perform vector control of the synchronous motor based on the estimated output torque and a torque command supplied from outside.

  FIG. 5 is a block diagram showing a configuration of an electric motor control system including the control device of Patent Document 1. In the control device of Patent Document 1, first, the power consumption of the synchronous motor is calculated from the phase voltages supplied to the synchronous motor and the phase currents of the synchronous motor detected by the current detector. Next, the rotational angular velocity is calculated from the rotational angle of the rotor of the synchronous motor detected by the rotational angle detector, and the estimated value of the output torque of the synchronous motor is obtained by dividing the power consumption of the synchronous motor by the rotational angular velocity. Then, the torque command for determining each phase current of the synchronous motor is adjusted so that the estimated value of the output torque is equal to the torque command for instructing the target value of the output torque.

  FIG. 6 is a block diagram showing a configuration of an electric motor control system including the control device of Patent Document 2. In the control device of Patent Document 2, an interlinkage magnetic flux vector representing the interlinkage magnetic flux interlinking to the armature winding of the synchronous motor is obtained from each phase voltage supplied to the synchronous motor, and the interlinkage magnetic flux vector and the electric motor An outer product with a current vector representing the current flowing in the child winding as a vector is obtained. Also, the amount of change in the inner product of the flux linkage vector and the current vector with respect to the amount of change in the magnetic pole position of the rotor per unit time is obtained. The output torque is estimated from the outer product of the flux linkage vector and the current vector and the amount of change in the inner product of the flux linkage vector and the current vector. Then, the output torque is corrected using the estimated value of the output torque.

  In this way, the control devices of Patent Documents 1 and 2 prevent the output torque from deviating from the torque command.

JP 2006-31770 A JP 2009-268268 A

  However, the electric motor control devices of Patent Documents 1 and 2 both have two problems. The first problem is that it is impossible to prevent a shift between the operating point of the synchronous motor and the optimum operating point, and the synchronous motor cannot be operated with high efficiency.

  This first problem will be described in detail. Generally, in the vector control, means for calculating a current command from a torque command is provided. In the means for calculating the current command from the torque command, the current phase angle and the current amplitude are determined from the torque command so as to minimize the current amplitude, and the current having this phase angle is represented by the d axis in the dq axis coordinate system. And d-axis current command and q-axis current command are calculated by projecting on the q-axis. The current phase angle and current amplitude determined from the torque command are referred to as an operating point, and the current phase angle when the current amplitude is minimized is referred to as an optimal operating point. Further, in the means for calculating the current command from the torque command, the current command is calculated with a constant indicating the characteristic (for example, inductance) of the synchronous motor being determined and fixed in advance.

  When a synchronous motor is connected to such a conventional motor control device and the synchronous motor is overloaded, magnetic saturation may occur in the magnetic circuit inside the synchronous motor. In particular, in a permanent magnet type motor designed as an electric motor for driving an electric vehicle, since the motor is designed in a compact manner, magnetic saturation is likely to occur. When magnetic saturation occurs in the synchronous motor, the constant of the synchronous motor changes (particularly, the q-axis inductance changes), and the output torque changes due to the change of the constant of the synchronous motor. Further, when the constant of the synchronous motor changes, the optimum operating point at which the current with respect to the torque command is minimized changes. On the other hand, since the means for calculating the current command from the torque command calculates the current command with the constant of the synchronous motor as a fixed value, the change in the constant of the synchronous motor is not reflected in the current command. That is, the operating point determined by setting the constant of the synchronous motor as a fixed value and the optimum operating point changed due to the change in the constant of the actual synchronous motor will deviate. As a result, since the synchronous motor is operated at an operating point different from the actual optimal operating point, a current more than necessary must flow through the synchronous motor, and the synchronous motor cannot be operated with high efficiency. .

  The second problem is that the output torque cannot be accurately estimated when the rotational angular velocity of the rotor of the synchronous motor is low. In particular, when the rotational angular velocity is a value near zero, the output torque cannot be estimated. For this reason, in the case of the low rotational angular velocity, it is not possible to accurately correct the output torque so as to eliminate the difference between the estimated value of the output torque and the torque command.

  The present invention has been made in view of the circumstances as described above. The first object of the present invention is to provide a control device capable of operating a synchronous motor with high efficiency. The rotational angular velocity of the rotor of the synchronous motor is A second object is to provide a control device that can correct the output torque with high accuracy even in a low case.

  The present invention provides a current for calculating a current command for instructing a current to be supplied to the permanent magnet type motor based on a torque command for instructing an output torque of the permanent magnet type motor and a constant indicating a characteristic of the permanent magnet type motor. Command calculating means, current control means for adjusting a voltage command for instructing a voltage to be supplied to the permanent magnet type motor so that a current flowing through the permanent magnet type motor follows the current command, and a permanent magnet type motor. There is provided a motor control device comprising constant estimation means for estimating the constant based on a given current and voltage.

  According to the present invention, the constant of the permanent magnet type motor is estimated, and the current command is calculated using the estimated value of the constant, so that the operating point of the permanent magnet type motor is prevented from deviating from the optimum operating point. And the permanent magnet motor can be operated with high efficiency.

  The present invention further includes constant storage means for storing the constant estimated by the constant estimation means and a torque deviation coefficient of the permanent magnet type electric motor, and a rotational angular velocity of a rotor of the permanent magnet type electric motor is predetermined. When the rotational angular velocity is equal to or higher than the rotational angular velocity, the constant estimated by the constant estimating unit and the torque deviation coefficient of the permanent magnet type motor are stored in the constant storage unit and supplied to the current command calculation unit, and the permanent magnet type motor When the rotational angular velocity of the rotor is less than a predetermined rotational angular velocity, operation determining means for supplying the current command calculating means with the constant stored in the constant storage means and the estimated value of the torque deviation coefficient of the permanent magnet type motor. Furthermore, the present invention provides an electric motor control device.

  According to the present invention, when the rotational angular velocity of the permanent magnet type motor is less than the predetermined rotational angular velocity, the estimation of the constant of the permanent magnet type motor and the estimation of the torque divergence coefficient are not performed, but the permanent magnet type motor estimated at the high rotational angular velocity is used. Since the constant and the torque deviation coefficient are supplied to the current command calculation means to calculate the current command, the output torque can be corrected with high accuracy even at a low rotational angular velocity.

1 is a block diagram showing a configuration of an electric motor control system A including an electric motor control device 50A according to a first embodiment of the present invention. It is a figure which shows operation | movement of the operation determination part 44 of 50 A of electric motor control apparatuses which are the same embodiment. It is a block diagram which shows the structure of the electric motor control system B containing the electric motor control apparatus 50B which is 2nd Embodiment of this invention. It is a block diagram which shows the structure of the motor control system C containing the motor control apparatus 50C which is 3rd Embodiment of this invention. It is a block diagram which shows the structure of the electric motor control system containing the control apparatus of patent document 1. FIG. It is a block diagram which shows the structure of the electric motor control system containing the control apparatus of patent document 2. FIG.

Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
FIG. 1 is a block diagram showing a configuration of an electric motor control system A including an electric motor control device 50A according to the first embodiment of the present invention. The motor control system A includes a PMSM (Permanent Magnet Synchronous Motor) 1, an inverter 12, a PWM (Pulse Width Modulation) circuit 11, current detectors 14 and 15, a position detector 2 and an electric motor. It has a control device 50A. The motor control device 50A according to the present embodiment operates the inverter 12 by controlling the PWM circuit 11, and controls the operation of the PMSM 1 with this.

  The inverter 12 includes a switching element such as an IGBT (Insulated Gate Bipolar Transistor), and turns on / off the switching element to convert a DC voltage into a three-phase AC voltage of U phase, V phase, and W phase. It is the power converter device which converts. The PMSM 1 is connected to the output terminals of the U phase, V phase, and W phase of the inverter 12. The PWM circuit 11 is a circuit that generates a PWM signal for turning on / off the switching element of the inverter 12 based on the U-phase voltage Vu, the V-phase voltage Vv, and the W-phase voltage Vw supplied from the motor control device 50A.

  The current detector 14 is a device that detects the V-phase current iv supplied from the inverter 12 to the PMSM1. The current detector 15 is a device that detects the W-phase current iw supplied from the inverter 12 to the PMSM1. The position detector 2 is a device that detects the position (rotation angle) θ of the rotor of the PMSM 1. Information on each of the V-phase current iv and W-phase current iw detected by the current detectors 14 and 15 and the rotor position θ detected by the position detector 2 is sent to the motor control device 50A.

  The motor control device 50A includes a current command calculation unit 20, an uvw → dq coordinate conversion unit 21, subtractors 22 and 23, current controllers (ACR: Automatic Current Regulator) 25 and 26, a dq → uvw coordinate conversion unit 28, and a differential calculation. The circuit 16, the constant estimation unit 43, the constant storage unit 42, and the operation determination unit 44 are included.

  For example, the current command calculation unit 20 uses a torque command Trq * supplied from the outside based on a known control law such as maximum torque / current control for controlling the PMSM 1 to generate the maximum torque with the minimum current. The d-axis current command id * and the q-axis current command iq * are respectively calculated. At this time, the current command calculation unit 20 uses the estimated value of the q-axis inductance Lq supplied from the constant storage unit 42 as the q-axis inductance Lq that is a constant of PMSM1. Further, the current command calculation unit 20 uses an estimated value of the torque deviation coefficient Ktrq supplied from the constant storage unit 42 as a coefficient indicating the relationship between the torque command Trq * and the output torque. A method for estimating the q-axis inductance Lq and the torque deviation coefficient Ktrq will be described later.

  The uvw → dq coordinate conversion unit 21 uses the rotor position θ detected by the position detector 2 to detect the V-phase current iv and the W-phase current detector 15 of the PMSM 1 detected by the V-phase current detector 14. The detected W-phase current iw of PMSM1 is coordinate-converted into a d-axis current id and a q-axis current iq in the dq-axis coordinate system. At this time, the uvw → dq coordinate conversion unit 21 uses the fact that the sum of the U-phase, V-phase, and W-phase currents is zero, so that the V-phase currents iv and W from the V-phase current detector 14 are zero. After calculating the U-phase current iu from the W-phase current iw from the phase current detector 15, the U-phase current iu, the V-phase current iv and the W-phase current iw are converted into a d-axis current id and a q-axis current iq. .

  The subtractor 22 subtracts the d-axis current id calculated by the uvw → dq coordinate conversion unit 21 from the d-axis current command id * calculated by the current command calculation unit 20, and the subtraction result is the current controller 25. Output to. Further, the subtracter 23 subtracts the q-axis current iq calculated by the uvw → dq coordinate conversion unit 21 from the q-axis current command iq * calculated by the current command calculation unit 20, and the subtraction result is subjected to current control. Output to the device 26.

  The current controller 25 adjusts and outputs the d-axis voltage command Vd * so that the subtraction result of the subtracter 22 (that is, the current difference between the d-axis current command id * and the d-axis current id) becomes zero. The current controller 26 adjusts and outputs the q-axis voltage command Vq * so that the subtraction result of the subtracter 23 (that is, the current difference between the q-axis current command iq * and the q-axis current iq) becomes zero. To do.

  The dq → uvw coordinate conversion unit 28 uses the rotor position θ detected by the position detector 2 to adjust the d-axis voltage command Vd * adjusted by the current controller 25 and the q adjusted by the current controller 26. The shaft voltage command Vq * is converted into a U-phase voltage command Vu *, a V-phase voltage command Vv *, and a W-phase voltage command Vw * in a three-phase (UVW) coordinate system. Then, dq → uvw coordinate conversion unit 28 outputs U-phase voltage command Vu *, V-phase voltage command Vv *, and W-phase voltage command Vw * as U-phase voltage Vu, V-phase voltage Vv, and W-phase voltage Vw, respectively.

  The differential operation circuit 16 performs differential operation on the position θ of the PMSM1 rotor detected by the position detector 2 to calculate the rotational angular velocity ω of the PMSM1 rotor.

  The constant estimation unit 43 uses the d-axis current id and q-axis current iq calculated by the uvw → dq coordinate conversion unit 21, the d-axis voltage command Vd * adjusted by the current controller 25, and the current controller 26. Using each information of the adjusted q-axis voltage command Vq *, the rotational angular velocity ω calculated by the differential calculation circuit 16 and the torque command Trq * supplied from the outside, the q-axis inductance Lq which is one of the constants of PMSM1. And the estimated value of the torque deviation coefficient Ktrq indicating the degree of deviation between the estimated value and the estimated value of the output torque and the torque command. In this specification, calculation of the estimated value of the q-axis inductance Lq may be referred to as estimation of the q-axis inductance Lq, and calculation of the estimated value of the torque deviation coefficient Ktrq may be referred to as estimation of the torque deviation coefficient Ktrq. In addition, the estimation of the q-axis inductance Lq and the torque deviation coefficient Ktrq is executed according to an instruction from the operation determination unit 44. The estimation of the q-axis inductance Lq and the torque deviation coefficient Ktrq will be described in detail later.

  The constant storage unit 42 stores the q-axis inductance Lq and the torque deviation coefficient Ktrq estimated by the constant estimation unit 43 according to an instruction from the operation determination unit 44. Further, the constant storage unit 42 receives the q-axis inductance Lq and the torque deviation coefficient Ktrq estimated by the constant estimation unit 43 or the q-axis inductance Lq and torque stored in the constant storage unit 42 according to an instruction from the operation determination unit 44. One of the deviation coefficients Ktrq is supplied to the current command calculation unit 20. The operation of the constant storage unit 42 will be described in detail later.

Whether or not the motion determination unit 44 calculates the q-axis inductance Lq and the torque deviation coefficient Ktrq in the constant estimation unit 43 based on whether or not the rotational angular velocity ω calculated by the differential calculation circuit 16 is equal to or greater than a predetermined rotational angular velocity. And the constant storage unit 42 determines whether to store the q-axis inductance Lq and the torque deviation coefficient Ktrq, and instructs the constant estimation unit 43 and the constant storage unit 42 based on these determination results. The determination performed by the operation determination unit 44 will be described in detail later.
The above is the configuration of the motor control device 50A according to the present embodiment and the motor control system A including the motor control device 50A.

  Next, estimation of the q-axis inductance Lq in the constant estimation unit 43 will be described. When magnetic saturation occurs in the internal core of the motor by passing a current through PMSM1, the constant of PMSM1 changes and the current of PMSM1 changes. For example, the current changes due to a change in the q-axis inductance Lq, and an error occurs between the d-axis current id and the d-axis current command id *. In the motor control device 50A according to the present embodiment, as shown in FIG. 1, an error generated between the d-axis current id and the d-axis current command id * is calculated in the subtractor 22, and the d-axis is calculated in the current controller 25. The d-axis voltage command Vd * is adjusted and output so that there is no error between the current id and the d-axis current command id * (in other words, the d-axis current id follows the d-axis current command id *. ) For this reason, the d-axis voltage command Vd * output from the current controller 25 reflects an error between the d-axis current id and the d-axis current command id *. As a result, the q-axis inductance of PMSM1 The change of Lq is reflected. By calculating using this d-axis voltage command Vd *, it is possible to estimate the q-axis inductance Lq of PMSM1 after changing due to magnetic saturation. If the q-axis inductance Lq of PMSM1 after the change can be estimated, it is possible to prevent the operating point from deviating from the optimal operating point by calculating the current command using the estimated value. Therefore, in the motor control device 50A according to the present embodiment, the d-axis voltage command Vd * is supplied to the constant estimation unit 43, and the constant estimation unit 43 performs arithmetic processing using the d-axis voltage command Vd *, thereby obtaining PMSM1. The q-axis inductance Lq that is a constant of is estimated. The reason why the q-axis inductance Lq is estimated among the constants of PMSM1 is that the influence of the operating point deviating from the optimum operating point when magnetic saturation occurs is larger than the other PMSM1 constants.

ここで、ＲａはＰＭＳＭ１の電機子抵抗（巻き線抵抗）、Ψａは永久磁石による磁束成分、ωはＰＭＳＭ１の回転子の回転角速度、Ｌｄはｄ軸インダクタンス、Ｌｑはｑ軸インダクタンス、ｉｄはｄ軸電流、ｉｑはｑ軸電流、Ｖｄはｄ軸電圧、Ｖｑはｑ軸電圧である。The estimation of the q-axis inductance Lq will be described in detail. The voltage equation of PMSM1 in the dq axis coordinate system can be expressed by the following equations (1A) and (1B).

Here, Ra is the armature resistance (winding resistance) of PMSM1, Ψa is the magnetic flux component by the permanent magnet, ω is the rotational angular velocity of the rotor of PMSM1, Ld is the d-axis inductance, Lq is the q-axis inductance, and id is the d-axis Current, iq is a q-axis current, Vd is a d-axis voltage, and Vq is a q-axis voltage.

When PMSM1 rotates stably, assuming that the change in d-axis current (did / dt) and the change in q-axis current (diq / dt) are zero, the above formulas (1A) and (1B) are expressed by the following formula (2A ) And (2B).

式（３）に示すように、ｑ軸インダクタンスＬｑは、電機子抵抗Ｒａ、回転角速度ω、ｄ軸電流ｉｄ、ｑ軸電流ｉｑおよびｄ軸電圧Ｖｄから求めることができる。このため、本実施形態による電動機制御装置５０Ａの定数推定部４３では、上記式（３）に基づいて電機子抵抗Ｒａ、回転角速度ω、ｄ軸電流ｉｄ、ｑ軸電流ｉｑおよびｄ軸電圧Ｖｄからｑ軸インダクタンスＬｑを推定する。And the said Formula (2A) can be deform | transformed like following formula (3) about the q-axis inductance Lq.

As shown in Expression (3), the q-axis inductance Lq can be obtained from the armature resistance Ra, the rotational angular velocity ω, the d-axis current id, the q-axis current iq, and the d-axis voltage Vd. Therefore, in the constant estimation unit 43 of the motor control device 50A according to the present embodiment, from the armature resistance Ra, the rotational angular velocity ω, the d-axis current id, the q-axis current iq, and the d-axis voltage Vd based on the above equation (3). The q-axis inductance Lq is estimated.

  More specifically, the armature resistance Ra in the equation (3) uses a value measured in advance, and the rotational angular velocity ω uses a value obtained by differentiating the detection result of the position detector 2. Further, as the d-axis current id and the q-axis current iq in the expression (3), values obtained by converting the detection results of the current detectors 14 and 15 into dq coordinates are used. Further, the d-axis voltage command Vd * that is the output of the current controller 25 is used as the d-axis voltage Vd in the expression (3).

  Here, the d-axis voltage command Vd * used as the d-axis voltage Vd in Expression (3) will be described in more detail. The d-axis voltage Vd in Expression (3) is a d-axis voltage obtained by converting each phase voltage input to the PMSM1 into the dq-axis coordinate system, and detects the input voltage of the PMSM1 as in the motor control system A according to the present embodiment. When no means is provided, the d-axis voltage command Vd * can be used as the d-axis voltage Vd in Equation (3). At this time, there is a possibility that an error exists between the d-axis voltage Vd and the d-axis voltage command Vd *. The main cause of this error is a so-called dead time inserted in the PWM signal in order to prevent a through current of the switching device of the inverter 12. In the motor control system A according to the present embodiment, the PWM circuit 11 includes means for correcting an error between the d-axis voltage Vd and the d-axis voltage command Vd * due to this dead time (not shown). Specifically, since the dead time is provided by shortening the pulse width for turning on the switching element of the inverter 12, the d-axis voltage Vd is equivalent to the voltage corresponding to the shortened pulse width as the d-axis voltage command Vd. * Lower than The PWM circuit 11 corrects the d-axis voltage Vd so as to eliminate this voltage drop, and generates a PWM signal that outputs the corrected d-axis voltage Vd. Accordingly, since the d-axis voltage command Vd * can be regarded as equivalent to the d-axis voltage Vd, the d-axis voltage command Vd * that is the output of the current controller 25 is directly used as the d-axis voltage Vd in the equation (3). be able to.

The q-axis inductance Lq estimated in this way is supplied to the current command calculation unit 20 and used for calculation of the current commands id * and iq *. Current commands id * and iq * are calculated using the estimated q-axis inductance Lq, and the current commands id * and iq * are used for controlling PMSM1, whereby PMSM1 is a constant (q-axis inductance after change due to magnetic saturation). It is possible to drive at an optimum operating point according to Lq).
The above is the details of the estimation of the q-axis inductance Lq.

  Next, estimation of the torque deviation coefficient Ktrq in the constant estimation unit 43 will be described. As described above, when magnetic saturation occurs in the internal iron core of the motor, the constant of PMSM1 changes and the output torque of PMSM1 also changes. For this reason, a divergence occurs between the output torque and the external torque command. In the motor control device 50A according to the present embodiment, as described above, the d-axis voltage command Vd * is set so that there is no error in the current controller 25 between the d-axis current id and the d-axis current command id *. Since the adjustment is performed, the change in the d-axis current id due to the change in the constant of PMSM1 is reflected in the d-axis voltage command Vd *. Similarly, in the motor controller 50A, the q-axis voltage command Vq * is adjusted in the current controller 26 so as to eliminate an error between the q-axis current iq and the q-axis current command iq *. The change in the q-axis current iq due to the change in the constant is reflected in the q-axis voltage command Vq *. By calculating using the d-axis voltage command Vd * and the q-axis voltage command Vq *, it is possible to estimate the output torque after the change. If the output torque can be estimated, the output torque can be corrected. Therefore, in the motor control device 50A according to the present embodiment, the constant estimation unit 43 estimates the output torque using the d-axis voltage command Vd * and the q-axis voltage command Vq *. In the motor control device 50A according to the present embodiment, the torque deviation coefficient Ktrq is estimated from the estimated output torque and the torque command Trq * input from the outside.

The estimation of the torque deviation coefficient Ktrq will be described in detail. The output torque of PMSM1 in the dq axis coordinate system can be expressed by the following equation (4).

回転角速度ωがゼロでないときに、上記式（５Ａ）および（５Ｂ）を上記式（４）に代入すると、ＰＭＳＭ１の出力トルクは、以下の式（６）で表すことができる。

式（６）に示すように、出力トルクＴは、電機子抵抗Ｒａ、回転角速度ω、ｄ軸電流ｉｄ、ｑ軸電流ｉｑ、ｄ軸電圧Ｖｄおよびｑ軸電圧Ｖｑから求めることができる。このため、本実施形態による電動機制御装置５０Ａの定数推定部４３では、上記式（６）に基づいて出力トルクを推定する。Here, Pn is the number of pole pairs of PMSM1, and the other variables are the same as in the above formulas (1A) and (1B) to (3). Also, the above formulas (2A) and (2B) can be organized into the following formulas (5A) and (5B).

If the above equations (5A) and (5B) are substituted into the above equation (4) when the rotational angular velocity ω is not zero, the output torque of PMSM1 can be expressed by the following equation (6).

As shown in Expression (6), the output torque T can be obtained from the armature resistance Ra, the rotational angular velocity ω, the d-axis current id, the q-axis current iq, the d-axis voltage Vd, and the q-axis voltage Vq. For this reason, the constant estimation unit 43 of the motor control device 50A according to the present embodiment estimates the output torque based on the above equation (6).

  More specifically, the d-axis voltage Vd in Expression (6) uses the d-axis voltage command Vd * that is the output of the current controller 25, and the q-axis voltage Vq is the q-axis that is the output of the current controller 26. The voltage command Vq * is used. Here, the d-axis voltage command Vd * and the q-axis voltage command Vq * can be used in the same manner as described in the calculation of the q-axis inductance Lq. Other variables are the same as the estimation of the q-axis inductance Lq.

このため、本実施形態による電動機制御装置５０Ａの定数推定部４３では、上記式（７）に基づいてトルク乖離係数Ｋｔｒｑを推定する。Further, the torque deviation coefficient Ktrq can be expressed by the following equation (7) from the estimated output torque obtained from equation (6) and the external torque command Trq *.

For this reason, the constant estimation unit 43 of the motor control device 50A according to the present embodiment estimates the torque deviation coefficient Ktrq based on the above equation (7).

The torque deviation coefficient Ktrq estimated in this way is supplied to the current command calculation unit 20 and used for calculation of the current commands id * and iq *. By correcting the current commands id * and iq * using the estimated torque deviation coefficient Ktrq, the PMSM 1 can be operated with the same output torque as the torque command.
The above is the details of the estimation of the torque deviation coefficient Ktrq.

  Next, the operation determination unit 44 and the constant storage unit 42 will be described. As shown in Equations (3) and (6) (Equation (7)), in estimating the q-axis inductance Lq and the output torque (torque divergence coefficient Ktrq), the rotational angular velocity ω of the PMSM1 rotor is given by In the denominator. Accordingly, when the rotational angular velocity ω is high, the q-axis inductance Lq and the torque deviation coefficient Ktrq can be accurately calculated and the calculation accuracy is high. However, when the rotational angular velocity ω is low, the q-axis inductance Lq In addition, the torque deviation coefficient Ktrq cannot be accurately calculated. In particular, when the rotational angular velocity ω is zero, that is, when the rotor of PMSM1 is stopped, the q-axis inductance Lq and the torque deviation coefficient Ktrq cannot be calculated. As described above, when the rotational angular velocity ω is low or zero, the estimation accuracy of the q-axis inductance Lq and the torque deviation coefficient Ktrq is lower than when the rotational angular velocity ω is high, and thereby the current commands id * and iq * are reduced. Calculation accuracy decreases. Therefore, in the motor control device 50A according to the present embodiment, in order to prevent the calculation accuracy of the current commands id * and iq * when the rotational angular velocity ω is low or zero, the operation determination unit 44 and the constant memory are stored. A portion 42 is provided.

  FIG. 2 is a diagram illustrating the operation of the operation determination unit 44. As shown in FIG. 2, when the rotational angular velocity ω is equal to or greater than a predetermined value ω0 (when the rotational angular velocity is higher than the predetermined rotational angular velocity ω0), the motion determining unit 44 determines the q-axis inductance Lq and torque divergence with respect to the constant estimating unit 43. An instruction to estimate the coefficient Ktrq is given. In this case, the operation determination unit 44 instructs the constant storage unit 42 to store the q-axis inductance Lq and the torque deviation coefficient Ktrq estimated by the constant estimation unit 43, and in addition to this estimation An instruction to output the q-axis inductance Lq and the torque deviation coefficient Ktrq to the current command calculation unit 20 is given.

  On the other hand, when the value of the rotational angular velocity ω is less than the predetermined value ω0 (when the rotational angular velocity is lower than the predetermined rotational angular velocity ω0), the motion determination unit 44 determines the q-axis inductance Lq and the torque deviation coefficient Ktrq from the constant estimation unit 43. Instructs not to perform estimation. In this case, the operation determination unit 44 instructs the constant storage unit 42 not to store the q-axis inductance Lq and the torque deviation coefficient Ktrq, and in addition, the rotational angular velocity ω is equal to or greater than the predetermined value ω0. An instruction to output the q-axis inductance Lq and the torque divergence coefficient Ktrq stored at times to the current command calculation unit 20 is given. As described above, in this embodiment, when the rotational angular velocity ω is lower than the predetermined rotational angular velocity ω0, the q-axis inductance Lq and the torque deviation coefficient Ktrq estimated at the high rotational angular velocity are output to the current command calculating unit 20.

  The reason why the torque deviation coefficient Ktrq estimated at the high rotation angular speed can be used even in the case of the low rotation angular speed is that the torque deviation coefficient Ktrq substantially depends only on the output torque and does not depend on the rotation angular speed. In the present embodiment, the estimated value of the output torque is not supplied to the current command calculation unit 20 as it is, but the torque deviation coefficient Ktrq is estimated from the estimated value of the output torque and then supplied to the current command calculation unit 20. This is because the result estimated at the high rotational angular velocity is used in the case of the low rotational angular velocity. Note that the q-axis inductance Lq is not dependent on the rotational angular velocity as is the case with the torque deviation coefficient Ktrq.

  In this way, the q-axis inductance Lq and the torque deviation coefficient Ktrq are not estimated at the low rotational angular velocity, but the estimation results of the q-axis inductance Lq and the torque deviation coefficient Ktrq at the high rotational angular velocity calculated with high accuracy are obtained at the low rotational angular velocity. By using this, the calculation accuracy of the current commands id * and iq * calculated by the current command calculation unit 20 is prevented from being lowered.

  Next, the constant storage unit 42 will be described. As described above, the constant storage unit 42 stores and outputs the q-axis inductance Lq and the torque deviation coefficient Ktrq estimated by the constant estimation unit 43 in accordance with the instruction of the operation determination unit 44. There are various ways of storing information indicating the q-axis inductance Lq and the torque deviation coefficient Ktrq as information. In addition to a mode in which the estimated q-axis inductance Lq and the torque deviation coefficient Ktrq are directly stored, a mode in which the estimated q-axis inductance Lq and the torque deviation coefficient Ktrq are indirectly stored as other parameters is also conceivable. As an aspect of indirectly storing, for example, there is an aspect of storing information indicating a q-axis inductance Lq and a torque deviation coefficient Ktrq as coefficients of an approximate equation.

ただし、ｉｑはｑ軸電流、Ｌｑ０はｑ軸電流がゼロの時のｑ軸インダクタンス、Ｋはｑ軸インダクタンスＬｑの変化を表すｑ軸磁気飽和係数である。In this embodiment, the q-axis inductance Lq is approximated to a first-order approximate equation, and the coefficient of the approximate equation is stored in the constant storage unit 42 as information indicating the q-axis inductance Lq. More specifically, the q-axis inductance Lq can be approximated by the following formula (8).

Here, iq is a q-axis current, Lq0 is a q-axis inductance when the q-axis current is zero, and K is a q-axis magnetic saturation coefficient representing a change in the q-axis inductance Lq.

  When the q-axis inductance Lq estimated by the constant estimation unit 43 is input, the constant storage unit 42 applies the estimated q-axis inductance Lq and the corresponding q-axis current iq to the above equation (8). The q-axis magnetic saturation coefficient K is calculated. The constant storage unit 42 stores the calculated q-axis magnetic saturation coefficient K as information indicating the q-axis inductance Lq. Thus, by storing the q-axis magnetic saturation coefficient K, the q-axis inductance Lq can be stored indirectly. Although the q-axis inductance Lq has been described, the torque deviation coefficient Ktrq can also be stored directly or indirectly.

  Further, in the motor control device 50A according to the present embodiment, the q-axis inductance Lq and the torque deviation coefficient at the start of the operation of the motor control system A so that the estimation of the q-axis inductance Lq and the torque deviation coefficient Ktrq is performed stably. The estimated value of Ktrq may be adjusted in advance. For example, the output torque corresponding to each torque command Trq * when the torque command Trq * is changed to 50%, 100%, 150%, 200%, etc. is estimated. That is, the torque deviation coefficient Ktrq is adjusted from the corresponding estimated value of the output torque. As a result, the estimation of the q-axis inductance Lq and the torque deviation coefficient Ktrq is stably performed, and the correction of the operating point and the correction of the output torque of the PMSM 1 are stably performed.

  Thus, in the motor drive device 50A according to the present embodiment, the constant estimation unit 43 estimates the q-axis inductance Lq and the torque deviation coefficient Ktrq, which are constants of PMSM1, and the estimated q-axis inductance Lq and the torque deviation coefficient Ktrq Is used to calculate the current commands id * and iq * in the current command calculation unit 20. As a result, even if magnetic saturation occurs in the motor internal core of PMSM1 and the q-axis inductance Lq, which is a constant of PMSM1, changes, the changed q-axis inductance Lq is estimated by the constant estimation unit 43, and the estimated q-axis inductance Since the current commands id * and iq * are calculated using Lq, changes in the q-axis inductance Lq can be reflected in the current commands id * and iq *. For this reason, it is possible to prevent the operating point of PMSM1 from deviating from the optimal operating point due to a change in q-axis inductance Lq, and PMSM1 can be operated with high efficiency. Further, even if the output torque changes, the changed output torque is estimated by the constant estimation unit 43 to estimate the torque deviation coefficient Ktrq, and the current commands id * and iq * are calculated using the estimated torque deviation coefficient Ktrq. In order to calculate, the torque deviation coefficient Ktrq can be reflected in the current commands id * and iq *. For this reason, the output torque can be prevented from deviating from the torque command Trq *, and the PMSM 1 can be operated with an appropriate output torque.

  Furthermore, in the motor drive device 50A according to the present embodiment, when the rotational angular velocity ω is high, the q-axis inductance Lq and the torque deviation coefficient Ktrq are estimated, and the estimated q-axis inductance Lq and the torque deviation coefficient Ktrq are stored in the constant storage unit 42. In addition, the current command calculation unit 20 calculates the current commands id * and iq * using the estimated q-axis inductance Lq and the torque deviation coefficient Ktrq. On the other hand, when the rotational angular velocity ω is low, the q-axis inductance Lq and the torque deviation coefficient Ktrq are not estimated, and the current command calculation unit 20 uses the q-axis inductance Lq and the torque deviation coefficient Ktrq stored at the high rotational angular velocity. Current commands id * and iq * are calculated. As a result, it is possible to prevent the calculation accuracy of the current commands id * and iq * calculated using the q-axis inductance Lq and the torque deviation coefficient Ktrq from being lowered when the rotational angular velocity is low. The output torque can be corrected with high accuracy over the entire operating range of angular velocity.

Second Embodiment
In the first embodiment, the voltage command is controlled by the current command in the dq axis coordinate system. On the other hand, in 2nd Embodiment, control of a voltage command is performed by the current command in a three phase (UVW) coordinate system. FIG. 3 is a diagram illustrating a configuration of an electric motor control system B including the electric motor control device 50B according to the present embodiment. In FIG. 3, the dq → uvw coordinate conversion unit 28 is deleted, the uvw → dq coordinate conversion unit 29, the dq → uvw coordinate conversion unit 30 and the current detector 13 are added, and the uvw is replaced with the uvw → dq coordinate conversion unit 21. → dq coordinate conversion unit 21A, subtracters 22A, 23A and 24A instead of subtractors 22 and 23, current controllers (ACR) 25A, 26A and current controllers (ACR) 25A, 26A and 27A This is different from the first embodiment (see FIG. 1).

  The current detector 13 is a device that detects the U-phase current iu supplied from the inverter 12 to the PMSM1.

  The uvw → dq coordinate conversion unit 21 </ b> A is detected by the U-phase current iu detected by the U-phase current detector 13 and the V-phase current detector 14 using the rotor position θ detected by the position detector 2. The V-phase current iv and the W-phase current iw detected by the W-phase current detector 15 are coordinate-converted into a d-axis current id and a q-axis current iq in the dq-axis coordinate system. The converted d-axis current id and q-axis current iq are sent to the constant estimation unit 43.

  The dq → uvw converter 30 uses the rotor position θ detected by the position detector 2 to convert the d-axis current command id * and the q-axis current command iq * output from the current command calculation unit 20 into three. It converts into the U-phase current command iu *, the V-phase current command iv *, and the W-phase current command iw * in the phase coordinate system.

  The subtractor 22A subtracts the U-phase current iu detected by the current detector 13 from the U-phase current command iu * supplied from the dq → uvw coordinate conversion unit 30, and outputs the subtraction result to the current controller 25A. . The subtractor 23A subtracts the V-phase current iv detected by the current detector 14 from the V-phase current command iv * supplied from the dq → uvw coordinate conversion unit 30, and the subtraction result is supplied to the current controller 26A. Output. The subtractor 24A subtracts the W-phase current iw detected by the current detector 15 from the W-phase current command iw * supplied from the dq → uvw coordinate conversion unit 30, and the subtraction result is sent to the current controller 27A. Output.

  The current controller 25A adjusts the U-phase voltage command Vu * so that the subtraction result of the subtractor 22A (that is, the current difference between the U-phase current command iu * and the U-phase current iu) becomes zero, thereby adjusting the U-phase voltage. Output as Vu. Further, the current controller 26A adjusts the V-phase voltage command Vv * so that the subtraction result of the subtracter 23A (that is, the current difference between the V-phase current command iv * and the V-phase current iv) becomes zero. Output as phase voltage Vv. The current controller 27A adjusts the W-phase voltage command Vw * so that the subtraction result of the subtractor 24A (that is, the current difference between the W-phase current command iw * and the W-phase current iw) becomes zero. Output as phase voltage Vw.

  The uvw → dq coordinate conversion unit 29 uses the rotor position θ detected by the position detector 2 to adjust the U-phase voltage Vu adjusted by the current controller 25A and the V-phase voltage adjusted by the current controller 26A. The W phase voltage Vw adjusted by Vv and the current controller 27A is coordinate-converted into a d-axis voltage Vd and a q-axis voltage Vq in the dq-axis coordinate system. In this embodiment, the current controllers 25A, 26A, and 27A adjust and output the U-phase voltage Vu, V-phase voltage Vv, and W-phase voltage Vw in the three-phase coordinate system, so that these voltages Vu, Vv, and The uvw → dq coordinate conversion unit 29 converts Vw from the voltage of the three-phase coordinate system to the voltage of the dq axis coordinate system, and then supplies the d-axis voltage Vd and the q-axis voltage Vq to the constant estimation unit 43.

  The constant estimator 43 in the present embodiment estimates the point of the q-axis inductance Lq using the equation (3) and the point of estimating the torque deviation coefficient Ktrq using the equation (7). This is the same as the unit 43. At this time, in the first embodiment, the d-axis voltage command Vd * and the q-axis voltage command Vq * are used in place of the d-axis voltage Vd and the q-axis voltage Vq in estimating the q-axis inductance Lq and the torque deviation coefficient Ktrq. However, in the present embodiment, the d-axis voltage Vd and the q-axis voltage Vq sent from the uvw → dq coordinate conversion unit 29 are used. Then, the q-axis inductance Lq and the torque deviation coefficient Ktrq are estimated as in the first embodiment.

  The constant storage unit 42 and the operation determination unit 44 in this embodiment are the same as those in the first embodiment.

  Also in this embodiment, the same effect as the first embodiment can be obtained.

<Third Embodiment>
In the second embodiment, the q-axis inductance Lq and the torque are calculated using the d-axis current id and the q-axis current iq obtained by converting the detection results of the U-phase, V-phase, and W-phase current detectors from uvw → dq coordinates. The deviation coefficient Ktrq was estimated. In contrast, in the third embodiment, the q-axis inductance Lq and the torque deviation coefficient Ktrq are estimated using the d-axis current command id * and the q-axis current command iq *.

  FIG. 4 is a diagram illustrating a configuration of an electric motor control system C including the electric motor control device 50C according to the present embodiment. In FIG. 4, the uvw → dq coordinate conversion unit 21A is deleted, and instead of the d-axis current id and the q-axis current iq input to the constant estimation unit 43 from the uvw → dq coordinate conversion unit 21A, the current command calculation unit 20 The second embodiment is different from the second embodiment in that the d-axis current command id * and the q-axis current command iq * output from are input to the constant estimation unit 43 (see FIG. 3).

  The constant estimator 43 in the present embodiment is the point that obtains the q-axis inductance Lq using the equation (3) and the point that obtains the torque deviation coefficient Ktrq using the equation (7). It is the same. At this time, in the second embodiment, the d-axis current id and the q-axis current iq are used to obtain the q-axis inductance Lq and the torque deviation coefficient Ktrq. However, in this embodiment, the d-axis current id and the q-axis current iq are used. Instead, the d-axis current command id * and the q-axis current command iq * sent from the current command calculation unit 20 are used.

  Here, in the motor control device 50C according to the present embodiment, the current controller 25A functions so that the difference between the U-phase current iu and the U-phase current command iu * is zero, as in the second embodiment. U-phase current iu and U-phase current command iu * are equal. Similarly, the current controller 26A functions so that the difference between the V-phase current iv and the V-phase current command iv * becomes zero, so that the difference between the W-phase current iw and the W-phase current command iw * becomes zero. Since the current controller 27A functions, the V-phase current iv and the V-phase current command iv * are equal, and the W-phase current iw and the W-phase current command iw * are equal. That is, if the current controller is functioning, the output current and the current command are equal, the d-axis current id and the d-axis current command id * are equal, and the q-axis current iq and the q-axis current command iq. * Is equal. For this reason, in the present embodiment, in obtaining the q-axis inductance Lq and the torque deviation coefficient Ktrq, the d-axis current command id * is used instead of the d-axis current id, and the q-axis current command iq * is used instead of the q-axis current iq. Use. Then, the q-axis inductance Lq and the torque deviation coefficient Ktrq are estimated as in the first and second embodiments.

  The constant storage unit 42 and the operation determination unit 44 in this embodiment are the same as those in the first and second embodiments.

  Also in this embodiment, the same effect as the first and second embodiments can be obtained.

<Other embodiments>
Although the first to third embodiments of the present invention have been described above, other embodiments are conceivable for the present invention. For example:

(1) The constant estimation unit 43 according to the first to third embodiments estimates the q-axis inductance Lq as the constant of PMSM1. However, the constant of PMSM1 to be estimated is not limited to the q-axis inductance Lq, and other constants (for example, permanent magnet magnetic flux) of PMSM1 may be estimated. Then, the current command calculation unit 20 may calculate the d-axis current command id * and the q-axis current command iq * using the other constants of the estimated PMSM1.

(2) In the motor control systems A to C according to the first to third embodiments, the voltage commands Vd * and Vq * (voltages Vu, Vv and Vd) output from the current controllers 25 and 26 (25A, 26A and 27A) Vw) was used to estimate the q-axis inductance Lq and the torque deviation coefficient Ktrq. However, a means for detecting the voltage input to PMSM1 may be provided, and the q-axis inductance Lq and the torque deviation coefficient Ktrq may be estimated using the voltage detected by the voltage detection means.

(3) In the first to third embodiments, the position information θ is obtained by providing the position detector 2 for detecting the position of the rotor of the PMSM 1. However, instead of the position detector 2, position estimation means for estimating the position of the rotor of the PMSM 1 may be provided, and the position information θ of the rotor may be obtained using this position estimation means. In the first to third embodiments, the rotational angular velocity ω is obtained from the position information θ using the differential operation circuit 16. However, instead of the differential operation circuit 16, another speed estimation means may be provided, and the rotational angular speed ω may be obtained using this other speed estimation means.

(4) In the constant storage unit 42 according to the first to third embodiments, information indicating the q-axis inductance Lq is stored as the q-axis magnetic saturation coefficient K using a first-order approximation equation. However, the storage mode in the constant storage unit 42 is not limited to the first-order approximation equation. For example, a quadratic or higher approximation equation may be used.

  In the constant storage unit 42 according to the first to third embodiments, the q-axis magnetic saturation coefficient K is calculated by applying the estimated q-axis inductance Lq to the approximate equation. At this time, the calculated q-axis magnetic saturation coefficient K may be calculated using the latest estimated value of the q-axis inductance Lq, or may be calculated using the estimated value of the q-axis inductance Lq obtained in the past. good. As an example of the latter, it is possible to calculate the q-axis magnetic saturation coefficient K by applying the moving average value of the estimated value of the q-axis inductance Lq obtained in the past to an approximate equation.

  Further, the mode of storage in the constant storage unit 42 is not limited to the mode of storing as coefficients of the approximate equation. For example, the estimated value of the q-axis inductance Lq corresponding to the q-axis current iq is estimated in a plurality of q-axis current iq values, and stored as a table in which the q-axis current iq and the estimated value of the q-axis inductance Lq are associated with each other. You may do it.

(5) In the first embodiment, the current detectors 14 and 15 are used to detect the V-phase and W-phase currents, and the uvw → qd coordinate conversion unit 21 calculates the U-phase current. However, the acquisition mode of each current of U-phase, V-phase, and W-phase is not limited to this. For example, a U-phase current detector and a V-phase current detector may be provided to detect U-phase and V-phase currents, and the uvw → qd coordinate conversion unit 21 may calculate the W-phase current.

(6) In the motor control system A according to the first embodiment, the PWM circuit 11 includes means for correcting an error between the d-axis voltage Vd and the d-axis voltage command Vd * due to dead time. However, if this error correction means is not included in the PWM circuit 11, the constant estimation unit 43 performs a process of subtracting the voltage drop due to dead time from the d-axis voltage command Vd * which is the output of the current controller 25. You can do that. In this case, the q-axis inductance Lq and the torque deviation coefficient Ktrq may be estimated by regarding the result of subtracting the voltage drop from the d-axis voltage command Vd * as the d-axis voltage Vd input to the PMSM1.

(7) In the motor control systems A to C according to the first to third embodiments, the constant estimation unit 43 estimates both the constant (q-axis inductance Lq) of the PMSM1 and the torque deviation coefficient Ktrq. It is not restricted to the aspect estimated. For example, the constant estimation unit 43 may be configured to estimate only the PMSM1 constant.

(8) A learning function may be given to the motor control devices 50A to 50C according to the first to third embodiments. For example, when the PMSM1 constant and the torque deviation coefficient Ktrq are estimated, the estimated value is stored in a memory (the constant storage unit 42 or the like) in association with the torque command Trq * at that time. By repeating this, a map of PMSM1 constants and torque deviation coefficients Ktrq for various torque commands Trq * can be generated. When a map of PMSM1 constants and torque deviation coefficient Ktrq corresponding to a sufficient number of types of torque commands Trq * is obtained, the PMSM1 constants corresponding to the torque commands Trq * and torque deviations are referred to thereafter by referring to the maps. The coefficient Ktrq is obtained and used to generate the current commands id * and iq *.

DESCRIPTION OF SYMBOLS 1 ... PMSM, 2 ... Position detector, 11 ... PWM circuit, 12 ... Inverter, 13,14,15 ... Current detector, 16 ... Differentiation calculation circuit, 20 ... Current command calculation unit 21,21A, 29 ... uvw-> dq coordinate conversion unit, 22, 23, 22A, 23A, 24A ... subtractor, 25, 26, 25A, 26A, 27A ... current controller, 28, 30 ... dq → uvw coordinate conversion unit, 42 ... constant storage unit, 43 ... constant estimation unit, 44 ... operation determination unit, 50A, 50B, 50C ... motor control device, A, B, C ... motor control system.

Claims (7)

Current command calculation means for calculating a current command for instructing a current to be supplied to the permanent magnet type motor based on a torque command for instructing an output torque of the permanent magnet type motor and a constant indicating a characteristic of the permanent magnet type motor; ,
Current control means for adjusting a voltage command for instructing a voltage to be supplied to the permanent magnet motor so that a current flowing through the permanent magnet motor follows the current command;
Constant estimation means for estimating the constant based on current and voltage applied to the permanent magnet type motor, wherein a torque deviation coefficient indicating a degree of deviation of the output torque of the permanent magnet type motor with respect to the torque command And a constant estimation means for estimating based on the d-axis voltage, d-axis current, q-axis voltage, q-axis current, armature resistance and rotational angular velocity of the rotor of the permanent magnet type motor. . Current command calculation means for calculating a current command for instructing a current to be supplied to the permanent magnet type motor based on a torque command for instructing an output torque of the permanent magnet type motor and a constant indicating a characteristic of the permanent magnet type motor; ,
Current control means for adjusting a voltage command for instructing a voltage to be supplied to the permanent magnet motor so that a current flowing through the permanent magnet motor follows the current command;
Constant estimation means for estimating the constant based on a current and a voltage applied to the permanent magnet motor, wherein the constant is a q-axis inductance of the permanent magnet motor and a d-axis voltage of the permanent magnet motor. Constant estimating means for estimating based on the d-axis current, the armature resistance, and the rotational angular velocity of the rotor,
The current command calculation means calculates the current command based on the torque command, the q-axis inductance of the permanent magnet type motor estimated by the constant estimation means, and the torque deviation coefficient of the permanent magnet type motor. An electric motor control device. The current command calculation means calculates the current command based on the torque command, the q-axis inductance of the permanent magnet type motor estimated by the constant estimation means, and the torque deviation coefficient of the permanent magnet type motor. The electric motor control device according to claim 1, wherein Current command calculation means for calculating a current command for instructing a current to be supplied to the permanent magnet type motor based on a torque command for instructing an output torque of the permanent magnet type motor and a constant indicating a characteristic of the permanent magnet type motor; ,
Current control means for adjusting a voltage command for instructing a voltage to be supplied to the permanent magnet motor so that a current flowing through the permanent magnet motor follows the current command;
Constant estimation means for estimating the constant based on current and voltage applied to the permanent magnet type motor;
Constant storage means for storing the constant estimated by the constant estimation means and a torque deviation coefficient of the permanent magnet type motor;
The constant estimated by the constant estimating means and the torque divergence coefficient of the permanent magnet type motor, or the constant stored in the constant storage means and the torque divergence coefficient of the permanent magnet type motor are supplied to the current command calculating means. An electric motor control device characterized by that. Current command calculation means for calculating a current command for instructing a current to be supplied to the permanent magnet type motor based on a torque command for instructing an output torque of the permanent magnet type motor and a constant indicating a characteristic of the permanent magnet type motor; ,
Current control means for adjusting a voltage command for instructing a voltage to be supplied to the permanent magnet motor so that a current flowing through the permanent magnet motor follows the current command;
Constant estimation means for estimating the constant based on a current and a voltage applied to the permanent magnet motor, wherein the constant is a q-axis inductance of the permanent magnet motor and a d-axis voltage of the permanent magnet motor. Constant estimating means for estimating based on the d-axis current, the armature resistance, and the rotational angular velocity of the rotor;
Constant storage means for storing the constant estimated by the constant estimation means and a torque deviation coefficient of the permanent magnet type motor;
The constant estimated by the constant estimating means and the torque divergence coefficient of the permanent magnet type motor, or the constant stored in the constant storage means and the torque divergence coefficient of the permanent magnet type motor are supplied to the current command calculating means. An electric motor control device characterized by that. Constant storage means for storing the constant estimated by the constant estimation means and the torque deviation coefficient of the permanent magnet type motor;
The constant estimated by the constant estimating means and the torque divergence coefficient of the permanent magnet type motor, or the constant stored in the constant storage means and the torque divergence coefficient of the permanent magnet type motor are supplied to the current command calculating means. The electric motor control device according to any one of claims 1 to 3, wherein the electric motor control device is provided. When the rotational angular velocity of the rotor of the permanent magnet type electric motor is equal to or higher than a predetermined rotational angular velocity, the constant storage unit stores the constant estimated by the constant estimation unit and the torque deviation coefficient of the permanent magnet type electric motor. When the rotational angular velocity of the rotor of the permanent magnet type electric motor supplied to the current command calculating means is less than a predetermined rotational angular velocity, the constant stored in the constant storage means and the estimation of the torque deviation coefficient of the permanent magnet type electric motor The motor control device according to any one of claims 4 to 6, further comprising operation determination means for supplying a value to the current command calculation means.

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