JP2023007752A - Motor drive control device and method, and motor drive control system - Google Patents

Abstract

To provide a motor drive control device, a motor drive control method, and a motor drive control system, capable of more appropriately suppressing pulsation torque.SOLUTION: A motor drive control system S comprises a motor M and a motor drive control unit for controlling the motor M, the motor drive control unit comprising: a pulsation torque estimation unit PT that uses a pulsation model representing pulsation torque having torque magnitude increasing and decreasing according to a lapse of time to estimate pulsation torque to be generated at the next control timing; a compensation value generation unit CV for generating a compensation value for canceling the estimated pulsation torque; and a drive control unit DC for controlling and driving the motor M using a control command value based on the generated compensation value. The pulsation torque contains at least either of first pulsation torque caused by a spatial high frequency component in a magnetomotive force distribution in the circumferential direction of the motor M and second pulsation torque that is cogging torque.SELECTED DRAWING: Figure 1

Description

The present invention relates to a motor drive control device and a motor drive control method for controlling the drive of a motor. The present invention also relates to an electric motor drive control system including the electric motor drive control device.

2. Description of the Related Art Electric motors that convert electrical energy into mechanical energy are used for various purposes. It has a stator that magnetically interacts with a rotor, and rotates the rotor by a rotating magnetic field. When such an electric motor rotates, the positional relationship between the magnets of the stator and the magnets of the rotor changes, so torque may pulsate. In order to reduce such pulsating torque (torque pulsation), for example, Patent Document 1 and Patent Document 2 propose a control device.

The motor control device disclosed in Patent Document 1 includes a basic voltage command calculator that calculates a basic value of a voltage command, a current detector that detects the current flowing through the windings of the motor, and a current that is applied to the windings. a magnetic flux estimating unit for estimating a magnetic flux linkage interlinking with the winding based on the applied voltage and the detected value of the current; and based on the detected value of the current and the estimated value of the magnetic flux linkage, the motor a torque estimator for estimating the output torque of; a pulsation extractor for extracting a pulsation component from the estimated value of the output torque; a pulsation controller for calculating a voltage command correction value based on the extracted value of the pulsation component; a superimposing unit that superimposes the voltage command correction value on the basic value of the voltage command to calculate a voltage command after superimposition; and applying a voltage to the winding via an inverter based on the voltage command after superimposition. and a voltage applying unit for applying the voltage. The voltage application unit performs fixed coordinate transformation and two-phase three-phase transformation on the superimposed dq-axis voltage command based on the magnetic pole position, and calculates a three-phase voltage command. and a PWM controller for outputting a control signal corresponding to the rectangular pulse wave of each of the three phases by comparing each of the voltage commands of the three phases with the triangular wave of the carrier wave.

The motor control device disclosed in Patent Document 2 is connected to a power converter that performs power conversion from DC power to AC power, and is a motor control device that controls driving of an AC motor that is driven using the AC power. a current command generator that generates a current command; a current controller that generates a voltage command based on the current command; and a gate signal for controlling the operation of the power converter based on the voltage command. and a current command correction unit that corrects the current command by superimposing pulsation on the current command, wherein the current command correction unit corrects the pulsation based on the rotation speed of the AC motor. are changed in amplitude and phase, respectively.

JP 2020-178439 A JP 2020-188555 A

By the way, in Patent Document 1, the superimposed voltage command for suppressing pulsation is directly input to the PWM control unit without feedback control. Therefore, if the gain setting in the pulsation suppressor is not appropriate, the control system may become unstable.

On the other hand, in Patent Document 2, if the command current value output by the current command correction unit includes a frequency that exceeds the frequency response of the current control unit, current control that follows the command value cannot be performed. In other words, it is difficult for the motor control device disclosed in Patent Document 2 to suppress high-frequency pulsations that exceed the frequency response of the current control unit.

The present invention has been made in view of the circumstances described above, and an object of the present invention is to provide an electric motor drive control device, an electric motor drive control method, and an electric motor drive control system including the electric motor drive control device that can more appropriately suppress pulsating torque. is to provide

As a result of various studies, the inventors of the present invention have found that the above object can be achieved by the present invention described below. That is, an electric motor drive control device according to one aspect of the present invention is a device that controls an electric motor, and uses a pulsation model representing pulsation torque whose magnitude increases and decreases with the lapse of time, thereby controlling the following control timing: A pulsating torque estimating unit for estimating the generated pulsating torque, a compensation value generating unit for generating a compensation value for canceling the pulsating torque estimated by the pulsating torque estimating unit, and control based on the compensation value generated by the compensation value generating unit a drive control unit that controls and drives the electric motor with a command value, and the pulsating torque is a first pulsating torque resulting from a spatial high-frequency component of the magnetomotive force distribution in the circumferential direction of the electric motor, and a cogging torque. At least one of a certain second pulsating torque is included.

Such a motor drive control device estimates the pulsating torque generated at the next control timing and generates a compensation value for canceling the estimated pulsating torque. pulsating torque including at least one of can be suppressed more appropriately.

In another aspect, in the above-described electric motor drive control device, the drive control unit includes a current control system that controls the drive current of the electric motor and a speed control system that controls the speed of the electric motor, and the compensation value generation unit is the frequency of the pulsating torque, the first frequency band of the current control system in which the current control system can follow the pulsating torque, and the second frequency band of the speed control system in which the speed control system can follow the pulsating torque. determining whether to generate the compensation value based on the compensation value, and generating the compensation value if it is determined to generate the compensation value. Preferably, in the above-described electric motor drive control device, the compensation value generating section firstly detects when the frequency of the first pulsating torque in the pulsating torque exceeds a first frequency band and when the frequency of the second pulsating torque in the pulsating torque in none of the cases where the frequency of the torque exceeds the first frequency band, determining not to generate the compensation value; or at least one of the frequency of the second pulsating torque in the pulsating torque exceeds the first frequency band, and the first pulsation in the pulsating torque When neither the frequency of the torque exceeds the second frequency band nor the frequency of the second pulsating torque in the pulsating torque exceeds the second frequency band, the input side of the drive control unit and third, if the frequency of a first pulsating torque in the pulsating torque exceeds a first frequency band and if the frequency of a second pulsating torque in the pulsating torque exceeds the first at least one of the cases where the frequency exceeds one frequency band, and the frequency of the first pulsating torque in the pulsating torque exceeds the second frequency band; In at least one of the cases where the frequency of the pulsating torque exceeds the second frequency band, it is determined to generate the compensation value used for the output of the drive control section. Preferably, the drive control unit is a device that controls the electric motor by feedback control according to a control target, and is a current command generation unit that generates a d-axis current command value and a q-axis current command value based on the control target. and a deviation between the d-axis current command value and the q-axis current command value generated by the current command generation unit and the d-axis current value and the q-axis current value corresponding to the current value supplied to the motor. and a current control unit for generating a d-axis voltage command value and a q-axis voltage command value based on each deviation generated by the deviation generation unit, wherein the compensation value generation unit is on the input side of the drive control unit. When it is determined to generate the compensation value to be used, the compensation value is used for the input of the current control unit, and when it is determined to generate the compensation value to be used for the output of the drive control unit, the current control Said compensation value is used in the output of the section. Preferably, the motor is a permanent magnet type synchronous motor (PMSM), the d-axis control target is a constant 0, and the compensation value generator generates the compensation value used on the input side of the drive controller. When it is determined to generate the compensation value used for the output of the drive control unit, the compensation value is used only for the q-axis voltage. used against Preferably, the permanent magnet synchronous motor (PMSM) includes a surface permanent magnet synchronous motor (SPMSM).

Since such a motor drive control device determines whether or not to generate the compensation value based on the frequency of the pulsating torque, the first frequency band, and the second frequency band, the compensation value is generated appropriately. can.

In another aspect, in the above-described electric motor drive control device, the compensation value generation unit may generate a voltage when a voltage value corresponding to a control command value based on the compensation value exceeds a predetermined output voltage value of a power supply that supplies power to the electric motor. do not generate the compensation value.

Since such a motor drive control device controls the motor within the rated voltage value of the power supply, it is possible to avoid destabilization of control.

An electric motor drive control method according to another aspect of the present invention is a method for controlling an electric motor, and uses a pulsation model representing a pulsation torque whose magnitude increases or decreases with the lapse of time so that at the next control timing, a pulsating torque estimating step of estimating the generated pulsating torque; a compensation value processing step of obtaining a compensation value for canceling the pulsating torque estimated in the pulsating torque estimating step; and a control command based on the compensation value obtained in the compensation value processing step. and a drive control step of controlling and driving the electric motor with a value, wherein the pulsating torque is a first pulsating torque resulting from a spatial high-frequency component of a magnetomotive force distribution in the circumferential direction of the electric motor, and a cogging torque. At least one of the second pulsating torques is included.

In such a motor drive control method, the pulsating torque generated at the next control timing is estimated, and a compensation value for canceling the estimated pulsating torque is generated. pulsating torque including at least one of can be suppressed more appropriately.

An electric motor drive control system according to another aspect of the present invention includes an electric motor and an electric motor drive control unit that controls the electric motor, and the electric motor drive control unit is any one of the electric motor drive control devices described above. .

According to this, it is possible to provide an electric motor drive control system including any one of the electric motor drive control devices described above. Since such an electric motor drive control system includes any one of the electric motor drive control devices described above, it is possible to more appropriately suppress pulsating torque including at least one of the first and second pulsating torques generated in the electric motor itself.

The electric motor drive control device and the electric motor drive control method according to the present invention can suppress pulsating torque more appropriately. According to the present invention, an electric motor drive control system including the electric motor drive control device can be provided.

1 is a block diagram showing the configuration of an electric motor drive control system in an embodiment; FIG. 3 is a circuit diagram showing the configuration of an inverter circuit in the motor drive control system; FIG. 3 is a block diagram of a current control system; FIG. 3 is a block diagram of a speed control system; FIG. 4 is a flowchart showing operations in the electric motor drive control system; 9 is a flow chart showing the operation of the motor drive control system in a modified form;

One or more embodiments of the invention are described below with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. It should be noted that the configurations denoted by the same reference numerals in each figure indicate the same configurations, and the description thereof will be omitted as appropriate. In the present specification, reference numerals with suffixes omitted are used when referring to generically, and reference numerals with suffixes are used when referring to individual configurations.

An electric motor drive control system according to an embodiment is a system that controls and drives an electric motor. For example, it includes an electric motor and an electric motor drive control unit that controls the electric motor. A pulsation torque estimator for estimating the pulsation torque generated at the next control timing by using a pulsation model representing the pulsation torque whose magnitude increases and decreases, and a compensation for canceling the pulsation torque estimated by the pulsation torque estimator. and a drive control unit that controls and drives the electric motor with a control command value based on the compensation value generated by the compensation value generation unit, wherein the pulsating torque is the It includes at least one of a first pulsating torque resulting from a spatial high-frequency component of the magnetomotive force distribution in the circumferential direction of the electric motor and a second pulsating torque that is a cogging torque. A motor drive control system including such a motor drive control unit will be described in more detail below.

FIG. 1 is a block diagram showing the configuration of an electric motor drive control system according to an embodiment. FIG. 2 is a circuit diagram showing the configuration of an inverter circuit in the motor drive control system. FIG. 3 is a block diagram of the current control system. FIG. 4 is a block diagram of the speed control system.

The electric motor drive control system S in the embodiment includes, for example, as shown in FIG. It comprises a phase-to-phase converter CV2, a rotational speed processor RSC, a current measuring section CS, a rotation angle measuring section VS, a pulsating torque estimating section PT, and a compensation value generating section CV.

The electric motor M is a motor connected to the inverter circuit IV and driven by the AC output of the inverter circuit IV. For example, the electric motor M is a synchronous motor driven by a U-phase, V-phase, and W-phase three-phase AC power output from an inverter circuit IV. (Surface mounted permanent magnet synchronous motor, SPMSM) and its speed control is the object. The electric motor M is not limited to this, and may be, for example, an induction motor (IM), an SR motor (Switched Reluctance motor, SRM), or another type.

The PWM modulator PW is a circuit that outputs a rectangular wave with a variable pulse width, and the inverter circuit IV is a circuit that converts DC power to AC power. In this embodiment, the PWM modulator PW and the inverter circuit IV constitutes a so-called three-phase PWM inverter motor driver that drives a motor with three-phase AC power. These PWM modulator PW and inverter circuit IV are connected to a drive controller DC via a two-to-three phase converter CV1, and convert DC power from a DC power supply Vdc to a predetermined frequency according to the control of the drive controller DC. Convert to AC power. More specifically, the PWM modulator PW is a circuit that outputs a rectangular wave having a frequency and a pulse width controlled by the drive controller DC as a control signal (IV control signal) to the inverter circuit IV. The inverter circuit IV is a circuit that is connected to the PWM modulator PW and converts the DC power of the DC power supply Vdc into AC power of a predetermined frequency according to the IV control signal from the PWM modulator PW. For example, as shown in FIG. 2, the inverter circuit IV includes three sets Tr1, Tr4; Tr2, Tr5; Prepare. More specifically, the inverter circuit IV includes six first through sixth switches Tr1 through Tr6. These first to sixth switching elements Tr1 to Tr6 are power semiconductor elements, such as insulated gate bipolar transistors (IGBTs), which have switching functions to turn on and off. One terminal (for example, each collector terminal) of each of the first to third switching elements Tr1 to Tr3 is connected to one terminal of the DC power supply Vdc. The other terminal (for example, emitter terminal) of the first switching element Tr1 is connected to one terminal (for example, each collector terminal) of the fourth switching element Tr4. The other terminal (for example, emitter terminal) of the second switching element Tr2 is connected to one terminal (for example, each collector terminal) of the fifth switching element Tr5. The other terminal (for example, the emitter terminal) of the third switching element Tr3 is connected to one terminal (for example, each collector terminal) of the sixth switching element Tr6. The other terminals (for example, emitter terminals) of the fourth to sixth switching elements Tr4 to Tr6 are connected to the other terminal of the DC power supply Vdc. Control terminals (for example, gate terminals) to which IV control signals for turning on/off the switching elements Tr are input in the first to sixth switching elements Tr1 to Tr6 are connected to the PWM modulator PW. Diodes D1 to D6 having anode terminals connected to the other terminals are connected between the one terminals and the other terminals of the first to sixth switching elements Tr1 to Tr6, respectively. A first connection point that connects the first switching element Tr1 and the fourth switching element Tr4 is connected to an input terminal that outputs a U-phase alternating current and connects the U-phase of the electric motor M, for example. A second connection point connecting the second switching element Tr2 and the fifth switching element Tr5 outputs, for example, a V-phase alternating current and is connected to an input terminal to which the V-phase of the electric motor M is connected. A third connection point that connects the third switching element Tr3 and the sixth switching element Tr6 is connected to an input terminal that outputs a W-phase AC current and connects the W-phase of the electric motor M, for example. In such a configuration, the inverter circuit IV is a so-called two-level three-phase inverter circuit, and the switching elements Tr1, Tr2, and Tr3 on one side of each group and the switching elements Tr4, Tr5, and Tr6 on the other side are switched in opposite directions to each other. Control is performed according to the IV control signal from the PWM modulator PW so that when one is on, the other is off, and when one is off, the other is on. It converts the DC power and outputs AC current of three phases of U-phase, V-phase and W-phase to the electric motor M.

The current measurement unit CS is connected to the three-to-two phase conversion unit CV2, and measures the current flowing from the inverter circuit IV to the electric motor M, in this embodiment, the U-phase current, the V-phase current, and the W-phase current. This device outputs the measurement result to the three-to-two phase converter CV2. The current measuring unit CS is configured with an AC ammeter, for example.

The rotation angle measurement unit VS is connected to each of the two-to-three-phase conversion unit CV1, the three-to-two phase conversion unit CV2, the rotation speed processing unit RSC, and the pulsation torque estimation unit PT, and measures the magnetic pole position of the electric motor M in terms of angles, The measurement results (rotational angle, electrical angle (=mechanical angle/polar logarithm of electric motor M)) are converted to two-to-three-phase converter CV1, three-to-two-phase converter CV2, rotational speed processor RSC, and pulsating torque estimator PT, respectively. It is a device that outputs to The rotation angle measurement unit VS is configured including, for example, a rotary encoder (pulse generator), a Hall IC, and the like. In the sensorless case, the rotation angle measurement unit VS may use a model of the electric motor M to obtain the rotation angle of the electric motor M from the current and voltage.

The two-to-three phase conversion unit CV1 is connected to the drive control unit DC, and receives the measurement result (rotation angle) input from the rotation angle measurement unit VS and the voltage command values v _d ^* and v _q generated by the drive control unit DC. ^* , a ^control _signal ⁽ _PWM control signal), and outputs this PWM control signal to the PWM modulator PW.

The three-to-two phase conversion unit CV2 is connected to the drive control unit DC, and receives measurement results (U-phase current, V-phase current, and W-phase current) input from the current measurement unit CS and input from the rotation angle measurement unit VS. From the measurement result (rotation angle), the excitation current ( _d -axis current) id and the torque component current (q-axis current) _iq are obtained by the so-called Clarke transformation and Park transformation, and the obtained d-axis It outputs the current id and the _q -axis current _iq to the drive controller DC.

The rotation speed processing unit RSC is connected to the drive control unit DC, obtains the rotation speed ω _m of the electric motor M from the measurement result (rotation angle) input from the rotation angle measurement unit VS, and converts the obtained rotation speed ω _m It outputs to the drive control section DC. For example, the rotation speed _ωm can be obtained by time-differentiating the rotation angle _θe measured by the rotation angle measuring unit VS and multiplying it by the reciprocal of the number of pole pairs p of the motor M.

The drive controller DC controls and drives the electric motor M with a control command value based on the compensation value generated by the compensation value generator CV as described later. More specifically, the drive control unit DC is a device that controls the electric motor M by feedback control according to a control target, and is a current controller that generates a d-axis current command value and a q-axis current command value based on the control target. command generators GId and GIq, d-axis current command values and q-axis current command values generated by the current command generators GId and GIq, and d-axis current values and q-axis current values corresponding to the current values supplied to the motor M deviation generators SM2d and SM2q for generating deviations from current values by subtracting the d-axis current value and the q-axis current value from the d-axis current command value and the q-axis current command value, respectively; Current control units GVd and GVq are provided for generating a d-axis voltage command value and a q-axis voltage command value based on the deviations generated by the units SM2d and SM2q, for example, by so-called PI control. In this embodiment, the motor M is a permanent magnet synchronous motor (PMSM), more specifically a surface permanent magnet synchronous motor (SPMSM), so only the q-axis contributes to torque. , the d-axis control target is always constant 0, and the d-axis current command generator GId is omitted as shown in FIG. Therefore, this d-axis control target 0 is input to the d-axis deviation generator SM2d. As shown in FIG. 1, the q-axis current command generator GIq calculates the deviation between the control target ω _m ^* (k) and the rotation speed ω _m of the motor M obtained by the rotation speed processing unit RSC as the control target ω A deviation generator SM1q obtained by subtracting the rotation speed ω _m of the electric motor M from _m ^* (k), and a q-axis current command value corresponding to the deviation obtained by the deviation generator SM1q is generated by PI control, for example. and a generator PI.

The drive control section DC having such a configuration includes a current control system for controlling the drive current of the electric motor M and a speed control system for controlling the speed of the electric motor M. FIG.

The pulsating torque estimating unit PT is connected to the compensation value generating unit CV, and estimates the pulsating torque generated at the next control timing by using a pulsating torque representing the pulsating torque whose magnitude increases or decreases with the passage of time. be. The pulsating torque includes, for example, at least one of a first pulsating torque caused by a spatial high-frequency component of the magnetomotive force distribution in the circumferential direction of the electric motor M and a second pulsating torque that is a cogging torque. In this embodiment, the pulsating torque T _dist is modeled so as to include both the first and second pulsating torques p _n and T _cog as shown in Equation 1 below. etc., one of them may be omitted and the pulsating torque T _dist may be modeled.

where i _d (k) is the d-axis current in the k-th control, i _q (k) is the q-axis current in the k-th control, and θ _e (k) is the k-th control is the rotation angle of the electric motor M at . φ _dh (θ _e ) is the harmonic component of the flux linkage on the d-axis, and φ _qh (θ _e ) is the harmonic component of the flux linkage on the q-axis. The first term of Equation 1 represents the first pulsating torque _pn , and the second term of Equation 1 represents the second pulsating torque T _cog . This first pulsating torque _pn is generated, for example, by a deviation from an ideal state in which the magnetomotive force distribution in the circumferential direction of the electric motor M is a sine curve.

φ _dh (θ _e ) and φ _qh (θ _e ) at the first pulsating torque p _n are obtained by detecting back electromotive force values ν _d and ν _q obtained by driving the motor M with no load, for example. is obtained by using the following equation 2, thereby obtaining the first pulsating torque _pn . Ψ is the cross flux of the permanent magnets in the motor M; Alternatively, for example, φ _dh (θ _e ) and φ _qh (θ _e ) can be obtained by simulation simulating similar driving conditions or by so-called FEM analysis.

This second pulsating torque T _cog can be obtained, for example, by similarly detecting the thrust value obtained by driving the electric motor M with no load. Alternatively, for example, the second pulsating torque T _cog can be obtained by a simulation simulating a similar drive state, or by so-called FEM analysis.

In this embodiment, the pulsating torque T _dist that varies depending on the rotational angle θ _e (k) of the electric motor M is estimated by the pulsating model of the above equation 1, and a compensation value that cancels out the estimated pulsating torque T _dist is determined. By adding it to the control command, the pulsating torque T _dist is suppressed. Here, the pulsating torque T _dist estimated from the rotation angle θ _e (k) detected by the rotation angle measuring unit VS is an estimated value of the pulsating torque T _dist generated at the current rotation angle θ _e (k), Actually, since a processing time is required to generate the compensation value, since the processing time of at least one control cycle has elapsed, the estimated value of the pulsating torque T _dist and the actually generated pulsating torque T _dist The processing time delay occurs between the two, and a mismatch occurs between them due to this delay. In particular, when rotating at high speed, this mismatch greatly affects the control, making it difficult to suppress the pulsating torque T _dist . In order to suppress the pulsating torque T _dist , it is necessary to compensate for this delay, and in this embodiment, the delay in the rotation angle θ _e (k) used for estimating the pulsating torque T _dist is compensated. In the present embodiment, the delay (the processing time) is set to the time of one control cycle T _s , and the rotation angle θ _e (k+1) after the time of one control cycle T _s has elapsed is estimated by the following equation 3, and this rotation By using the angle estimate θ _e (k+1) to estimate the pulsating torque T _dist , the lag is compensated. In the case of the k-th control, (k+1), (k+2), (k+3), . . . represent predicted values.

Therefore, in the present embodiment, the pulsating torque estimator PT is connected to the rotation angle measurement unit VS, and based on the rotation angle θ _e (k) of the electric motor M measured by the rotation angle measurement unit VS, one control period T _s a rotation angle estimating unit DA for estimating the rotation angle _{θ e} (k+1) after a period of time has passed using the above equation 3; A first pulsating torque estimating unit PN corresponding to the first term of the above equation 1 for estimating the first pulsating torque _pn based on the subsequent rotational angle θ _e (k+1) and the rotational angle estimating unit DA. , the second pulsation corresponding to the second term of the above equation 1, which estimates the second pulsation torque T _cog based on the rotation angle θ _e (k+1) after one control period T _s estimated by the rotation angle estimator DA a torque estimating section TC; and an adding section SM for adding the first pulsating torque _pn estimated by the first pulsating torque estimating section PN and the second pulsating torque T _cog estimated by the second pulsating torque estimating section TC. Prepare.

The compensation value generator CV generates a compensation value for canceling the pulsating torque estimated by the pulsating torque estimator PT.

In this embodiment, when the frequency of the pulsating torque T _dis is low, the pulsating torque T _dis can be canceled by the drive control unit DC itself. Generate no value. More specifically, each closed-loop transfer function is obtained by inputting the control command values of the current and speed control systems in the drive control unit DC, and the compensation value is determined according to each of these cutoff frequencies. Whether or not to generate the compensation value and where to input the compensation value are determined. That is, the compensation value generation unit CV is configured to generate the frequency of the pulsating torque, the first frequency band of the current control system in which the current control system of the drive control unit DC can follow the pulsating torque, and the speed control system of the drive control unit DC determines whether to generate the compensation value based on the second frequency band of the speed control system that can follow the pulsating torque, and generates the compensation value when it is determined to generate the compensation value.

_More ^specifically , the current control _system is approximated, for example, as shown in FIG. a subtractor 11 obtained by subtracting the _q -axis current iq of the electric motor M from the current _iq ^* ; a controller 12 for feedback-controlling the electric motor M based on the deviation obtained by the subtractor 11; an electric circuit 13 of the electric motor M controlled by 12; The controller 12 is for example k _Pi +k _Ii /s and the electric circuit 13 of the motor M is for example 1/(Ls+R).

The closed-loop transfer function G _iq (s) from the control target q-axis current i _q ^* to the actual current i _q in the current control system is expressed by the following equation 4, for example, k _Pi =ω _cfi ×L, When k _Ii =k _Pi ×(R/L), the following equation 5 is obtained.

ここで、Ｌは、電動機Ｍの巻線のインダクタンスであり、Ｒは、電動機Ｍの巻線の抵抗であり、ω_ｃｆｉは、前記電流制御系の遮断周波数である。ｓは、ラプラス変換の演算子である。上述のｋ_Ｐｉ＝ω_ｃｆｉ×Ｌとし、ｋ_Ｉｉ＝ｋ_Ｐｉ×（Ｒ／Ｌ）のゲイン設定は、一例であり、この他のゲイン設定でも、上記式４から遮断周波数は、求められ得る。

where L is the inductance of the windings of the motor M, R is the resistance of the windings of the motor M, and ω _cfi is the cut-off frequency of the current control system. s is the Laplace transform operator. The above gain setting of k _Pi =ω _cfi ×L and k _Ii =k _Pi ×(R/L) is an example, and the cutoff frequency can be obtained from Equation 4 above even with other gain settings.

From Equation 5 above, the current control system has a first-order lag of the cutoff frequency ω _cfi . Therefore, at frequencies equal to or lower than the cutoff frequency ω _cfi (first frequency band FW1; 0<FW1≦ω _cfi ), this current control system can follow the time change of the controlled object and can cancel the pulsating torque.

_Similarly , the ^speed control _system is _approximated , for example, as shown in FIG ^. A subtractor 21 obtained by subtracting the rotation speed ω _m of the electric motor M from and an electric circuit 23 of the electric motor M. The controller 22 is for example k _Ps +k _Is /s and the electric circuit 23 of the motor M is for example 1/Js. J is the moment of inertia of the electric motor M; The disturbance torque _Td is mixed (added) to the output of the controller 22 . However, the frequency response of the speed control system was assumed to be significantly smaller than that of the current control system.

The closed-loop transfer function G _is (s) from the control target rotation speed ω _m ^* to the actual rotation speed ω _m in the speed control system is expressed by the following equation 6. For example, if k _Ps =ω _cfs ×J , is expressed by the following equation 7. Furthermore, the transfer function from the disturbance torque _Td to the actual rotational speed _ωm is expressed by the following equation (8).

From the above equation 8, at frequencies below the cutoff frequency ω _cfs (second frequency band FW2; 0<FW2≦ω _cfs ), this speed control system can follow the time change of the controlled object, and the disturbance torque T _d , that is, In this embodiment, pulsating torque can be canceled.

On the other hand, the first and second pulsating torques p _n and T _cog are generated with a period dependent on the rotation speed of the electric motor M. The frequency f _mag of the first pulsating torque p _n is expressed by the following equation 9, where the principal component is mth order. It is generally known that m=6 in a concentrated winding surface permanent magnet synchronous motor (SPMSM). The rotation angle period at which the second pulsating torque T _cog is generated is expressed by the following equation 10, and the frequency f _cog of the second pulsating torque T _cog is expressed by the following equation 11 from the rotation speed. Note that ns is the number of slots of the electric motor M, and lcm(A, B) is an operator for obtaining the lowest common multiple with _AtoB .

From the above, when the frequency f _mag of the first pulsating torque _pn is equal to or lower than the cut-off frequency ω _cfi of the current control system (2πf _mag ≤ ω _cfi ), the first pulsating torque _pn can follow the current control system. , when the frequency f _mag of the first pulsating torque p _n exceeds the cut-off frequency ω _cfi of the current control system (2πf _mag >ω _cfi ), the first pulsating torque p _n is on the input side of the drive control unit DC, as shown in FIG. In the example shown in 1, the input of the current control unit GVq may be canceled using a compensation value. When the frequency f _cog of the second pulsating torque T _cog is equal to or lower than the cutoff frequency ω _cfi of the current control system (2πf _{cog ≤ω cfi} ), the second pulsating torque T _cog can follow the current control system, and the second When the frequency f _cog of the pulsating torque T _cog exceeds the cutoff frequency ω _cfi of the current control system (2πf _cog >ω _cfi ), the second pulsating torque T _cog is on the input side of the drive control section DC, shown in FIG. In the example, the input of the current control section GVq may be canceled using a compensation value. Similarly, when the frequency f _mag of the first pulsating torque _pn is equal to or lower than the cutoff frequency ω _cfs of the speed control system (2πf _{mag ≤ω cfs} ), the first pulsating torque _pn can follow the speed control system. , when the frequency f _mag of the first pulsating torque p _n exceeds the cutoff frequency ω _cfs of the speed control system (2πf _mag >ω _cfs ), the first pulsating torque p _n is the output of the drive control section DC, In the example shown in FIG. 2, the output of the current control section GVq may be canceled using a compensation value. When the frequency f _cog of the second pulsating torque T _cog is equal to or lower than the cutoff frequency ω _cfs of the speed control system (2πf _cog ≦ω _cfs ), the second pulsating torque T _cog can follow the speed control system, and the second When the frequency f _cog of the pulsating torque T _cog exceeds the cutoff frequency ω _cfs of the speed control system (2πf _cog >ω _cfs ), the second pulsating torque T _cog is the output of the drive control unit DC, the example shown in FIG. Then, the compensation value should be used to cancel the output of the current control unit GVq.

Therefore, more specifically, as shown in FIG. 1, the compensation value generation unit CV includes a first variable amplification unit VA1, a second variable amplification unit VA2, a first subtraction unit SM3, a second subtraction unit SM4, and a gain controller GC.

The first variable amplifying section VA1 is connected on the input side to the adding section SM of the pulsating torque estimating section PT, and amplifies the pulsating torque T _dis estimated by the pulsating torque estimating section PT with a gain K _TI to obtain the pulsating torque estimating section It generates a compensation value for the q-axis current command value for canceling the pulsating torque _Tdis estimated by the PT. The first variable amplification section VA1 is connected to the first subtraction section SB3 on the output side, and outputs a compensation value for the d-axis current command value to the first subtraction section SB3.

The second variable amplifying section VA2 is connected on the input side to the addition section SM of the pulsating torque estimating section PT, and amplifies the pulsating torque _Tdis estimated by the pulsating torque estimating section PT with a gain _KIV to obtain the pulsating torque estimating section It generates a compensation value for the q-axis voltage command value for canceling the pulsating torque _Tdis estimated by the PT. The second variable amplification section VA2 is connected to the second subtraction section SB4 on the output side, and outputs the compensation value for the q-axis voltage command value to the second subtraction section SB4.

The first subtractor SB3 is interposed between the deviation generator SM2q and the current controller GVq, and compensates the q-axis current command value generated by the first variable amplifier VA1 from the deviation generated by the deviation generator SM2q. It subtracts the value. By subtracting, the compensation value for the q-axis current command value generated by the first variable amplifier VA1 is added to the deviation generated by the deviation generator SM2q so as to cancel the pulsating torque _Tdis estimated by the pulsating torque estimator PT. be taken in.

The second subtraction unit SB4 is interposed between the current control unit GVq and the two-to-three phase conversion unit CV1, and the q-axis voltage command value generated by the current control unit GVq is the A compensation value for the d-axis voltage command value is subtracted. By subtracting, the compensation value for the q-axis voltage command value generated by the second variable amplifier VA2 cancels the pulsating torque T _dis estimated by the pulsating torque estimator PT. Incorporated into the voltage command value.

In this embodiment, the compensation value is directly input to the output of the current control unit GVq for the pulsating torque that cannot be compensated for by inputting the compensation value to the input of the current control unit GVq.

The gain controller GC is connected to each of the first and second variable amplifiers VA1 and VA2, and controls gains K _TI and K _IV of the first and second variable amplifiers VA1 and VA2.

More specifically, first, the gain control unit GC controls the frequency f _mag of the first pulsating torque p _n in the pulsating torque T _dis exceeding the first frequency band FW1 (2πf _mag >ω _cfi ). and when the frequency f _cog of the second pulsating torque T _cog in the pulsating torque T _dis exceeds the first frequency band FW1 (2πf _cog >ω _cfi ), the drive control unit DC follows Therefore, it is determined not to generate the compensation values (compensation value for the q-axis current command value and compensation value for the q-axis voltage command value). That is, the gain controller GC controls the gains K _TI and K _IV of the first and second variable amplifiers VA1 and VA2 to 0 (K _TI =0, K _IV =0).

Secondly, the gain control unit GC controls the pulsating torque T _dis when the frequency f _mag of the first pulsating torque p _n exceeds the first frequency band FW1 (2πf _mag >ω _cfi ) and the pulsating torque T _dis at least one of the cases where the frequency f _cog of the second pulsating torque T _cog exceeds the first frequency band FW1 (2πf _cog >ω _cfi ), and the pulsating torque T _dis When the frequency f _mag of the first pulsating torque p _n exceeds the second frequency band FW2 (2πf _mag >ω _cfs ) and the frequency f _cog of the second pulsating torque T _cog in the pulsating torque T _dis is in the second frequency band If FW2 is exceeded (2πf _cog >ω _cfs ), the compensation value (q axis Compensation value of current command value). That is, the gain controller GC controls the gain K _TI of the first variable amplifier VA1 to a value described later, and controls the gain K _IV of the second variable amplifier VA2 to 0 (K _TI ≠0, K _IV = 0). As a result, the compensation value of the q-axis current command value is used as an input to the current control section GVq, and the q-axis current generated by the first variable amplification section VA1 is calculated from the deviation generated by the deviation generation section SM2q by the first subtraction section SB3. A compensation value is subtracted from the command value.

Thirdly, the gain control unit GC controls the pulsating torque T _dis when the frequency f _mag of the first pulsating torque p _n exceeds the first frequency band FW1 (2πf _mag >ω _cfi ) and the pulsating torque T _dis at least one of the cases where the frequency f _cog of the second pulsating torque T _cog exceeds the first frequency band FW1 (2πf _cog >ω _cfi ), and the pulsating torque T _dis When the frequency f _mag of the first pulsating torque p _n exceeds the second frequency band FW2 (2πf _mag >ω _cfs ) and the frequency f _cog of the second pulsating torque T _cog in the pulsating torque T _dis is in the second frequency band If FW2 is exceeded (2πf _cog >ω _cfs ), the compensation value (q compensation value of the shaft voltage command value). That is, the gain controller GC controls the gain K _TI of the first variable amplifier VA1 to 0, and controls the gain K _IV of the second variable amplifier VA2 to values described later (K _TI =0, K _IV ≠ 0). As a result, the compensation value of the q-axis voltage command value is used for the output of the current control unit GVq, and the second subtraction unit SB4 generates the q-axis voltage command value generated by the current control unit GVq in the second variable amplification unit VA2. The compensation value of the q-axis voltage command value is subtracted.

Here, the gains K _TI and K _IV of the first and second variable amplifiers VA1 and VA2 may be obtained and set by tuning, for example. good. Equation 12 for obtaining the gain K _TI is based on the pulsating torque T _dis estimated by the pulsating torque estimating unit PT and the characteristic parameters p and Ψ of the electric motor M to obtain a current that cancels the pulsating torque T _dis estimated by the pulsating torque estimating unit PT. is set to require Equation 13 for the gain K _IV is set to convert the gain K _TI to a voltage. Here, k _TI and k _IV do not consider the difference between the design value and the actual machine value in the electric motor M and the inductance L of the winding when converting the gain K _TI into voltage. It is an adjustment parameter for adjusting the deviation, and is appropriately set in advance.

The pulsating torque estimator PT, the compensation value generator CV, the drive controller DC, the two-to-three-phase converter CV1, the three-to-two phase converter CV2, and the rotational speed processor RSC are implemented by a CPU (Central Processing Unit), It can be composed of a microprocessor comprising a memory and its peripheral circuits, and includes a pulsation torque estimator PT, a compensation value generator CV, a drive controller DC, a two-to-three-phase converter CV1, and a three-to-two phase converter. CV2 and rotation speed processing unit RSC are functionally configured in the CPU by executing a predetermined program. At this time, the rotation angle estimator DA, the first pulsating torque estimator PN, the second pulsating torque estimator TC and the adder SM in the pulsating torque estimator PT, the gain controller GC in the compensation value generator CV, the first variable Amplification section VA1, second variable amplification section VA2, first subtraction section SB3 and second subtraction section SB4, current command generation section GIq (deviation generation section SM1q, generation section PI) and deviation generation section SM2d in drive control section DC , SM2q and current controllers GVd and GVq are functionally configured in the CPU.

Next, the operation of this embodiment will be described. FIG. 5 is a flow chart showing the operation of the motor drive control system.

In such a motor drive control system S, when the power is turned on, each necessary part is initialized and started to operate. Then, for example, by executing a program, the CPU includes a pulsation torque estimator PT, a compensation value generator CV, a drive controller DC, a two-to-three-phase converter CV1, a three-to-two phase converter CV2, and a rotational speed processor. a rotation angle estimator DA, a first pulsation torque estimator PN, a second pulsation torque estimator TC, and an adder SM are functionally configured in the pulsation torque estimator PT; The compensation value generation unit CV is functionally configured with a gain control unit GC, a first variable amplification unit VA1, a second variable amplification unit VA2, a first subtraction unit SB3, and a second subtraction unit SB4. functionally includes a current command generator GIq (deviation generator SM1q, generator PI), deviation generators SM2d and SM2q, and current controllers GVd and GVq.

As for the control for canceling the pulsating torque, each process from process S1 to process S8 shown in FIG. 5 is repeatedly executed every predetermined control period _Ts until the driving of the electric motor M is stopped.

In FIG. 5, the electric motor drive control system S acquires the rotation angle θ _e (k) of the electric motor M from the rotation angle measurement unit VS by the rotation angle estimation unit DA of the pulsation torque estimation unit PT (S1).

Next, the electric motor drive control system S uses the rotation angle estimator DA to estimate the rotation angle θ _e (k+1) after the time of one control period T _s (the rotation angle θ _e (k+1) at the next control timing. (S2).

The electric motor drive control system S uses the first pulsation torque estimator PN of the pulsation torque estimator PT based on the rotation angle θ _e (k+1) after one control period T _s estimated by the rotation angle estimator DA in the process S2. The second pulsating torque estimating unit PN of the pulsating torque estimating unit PT estimates the second pulsating torque p _cog based on the rotation angle θ _e ( _k +1) to estimate the pulsating torque The adder SM of the part PT adds these first and second pulsating torques p _n and T _cog to estimate the pulsating torque T _dis (= _pn + T _cog ) (S3). The estimated pulsating torque is output from the adder SM to the first and second variable amplifiers VA1 and VA2 in the compensation value generator CV.

Next, when the frequency _fmag of the first pulsating torque _pn in the pulsating torque _Tdis exceeds the first frequency band FW1 ( 2πf _mag >ω _cfi ), or the frequency f _cog of the second pulsating torque T _cog in the pulsating torque T _dis exceeds the first frequency band FW1 (2πf _cog >ω _cfi ). (S4). As a result of this determination, if none of the above cases is true (No), the motor drive control system S next executes processing S5, and then terminates this processing at the current control timing. On the other hand, if the result of the determination is at least one of the above cases (Yes, 2πf _mag > ω _cfi , 2πf _cog > ω _cfi , 2πf _mag > ω _cfi and 2πf _cog > ω _cfi In any of the cases), the electric motor drive control system S next executes the process S6.

In this process S5, the motor drive control system S controls the gains K _TI and K _IV of the first and second variable amplifiers VA1 and VA2 to 0 by the gain controller GC of the compensation value generator CV (K _TI = 0, _KIV = 0). Therefore, the pulsating torque T _dis is reduced by the drive control section DC.

In the process S6, the electric motor drive control system S is controlled by the gain control unit GC when the frequency f _mag of the first pulsating torque p _n in the pulsating torque T _dis exceeds the second frequency band FW2 (2πf _mag >ω _cfs ) and the frequency f _cog of the second pulsating torque T _cog in the pulsating torque T _dis exceeds the second frequency band FW2 (2πf _cog >ω _cfs ). As a result of this determination, if none of the above cases is true (No), the motor drive control system S next executes processing S7, and then terminates this processing at the current control timing. On the other hand, if the result of the determination is at least one of the above cases (Yes, 2πf _mag > ω _cfs , 2πf _cog > ω _cfs , 2πf _mag > ω _cfs and 2πf _cog > ω _cfs In one of the cases), the electric motor drive control system S next executes the process S8, and then terminates the process at the current control timing.

In this process S7, the motor drive control system S obtains the gain KTI of the first variable amplifier section _VA1 by the gain control section GC according to the above equation 12, and the first variable amplifier section is adjusted to the obtained gain _KTI . VA1 is controlled, and the gain K _IV of the second variable amplifier VA2 is controlled to 0 (K _TI ≠0, K _IV =0). By executing this process S7, the compensation value of the q-axis current command value is used as the input of the current control unit GVq, and the first subtraction unit SB3 generates the deviation generated by the deviation generation unit SM2q in the first variable amplification unit VA1. Then, the compensation value of the q-axis current command value is subtracted, whereby the pulsating torque _Tdis is reduced by the compensation value of the q-axis current command value.

In the process S8, the motor drive control system S controls the gain KTI of the first variable amplification section _VA1 to 0 by the gain control section GC, and obtains the gain KIV of the second variable amplification section _VA2 by the above equation (13). , are controlled to values as described later (K _TI =0, K _IV ≠0). In order to obtain the gain K _IV from the above equation 13, the gain K _TI is obtained from the above equation 12. However, the gain K _TI of the first variable amplifying section VA1 is controlled to 0 as described above. By executing this process S8, the compensation value for the q-axis voltage command value is used for the output of the current control unit GVq, and the second subtraction unit SB4 performs the second variable amplification from the q-axis voltage command value generated by the current control unit GVq. The compensation value for the q-axis voltage command value generated in part VA2 is subtracted, whereby the pulsating torque T _dis is reduced by this compensation value for the q-axis voltage command value.

As described above, the electric motor drive control system S, the electric motor drive control device, and the electric motor drive control method implemented therein according to the present embodiment estimate the pulsation torque T _dis generated at the next control timing, and estimate the estimated pulsation torque T dis . Since the compensation value for canceling the torque T _dis is generated, the pulsating torque T _dis including at least one of the first and second pulsating torques p _n and T _cog generated in the electric motor M itself, and in the above description, both of them, is more appropriately can be suppressed. Therefore, the electric motor drive control system S, the electric motor drive control device, and the electric motor drive control method can achieve low vibration and low noise, and can follow the target speed and target position with high accuracy.

The electric motor drive control system S, the electric motor drive control device, and the electric motor drive control method are configured to control the pulsating torque T _dis , the first and second pulsating torques _pn described above, the respective frequencies f _mag and f _cog of T _cog , the first frequency Since it is determined whether or not to generate the compensation value based on the band FW1 and the second frequency band FW2, the compensation value can be generated appropriately.

In Patent Document 1, even when the pulsation frequency is low at low speeds and the pulsation can be suppressed only by the current control unit, the voltage command correction value is added to the basic value of the voltage command. is not appropriate, the voltage command correction value may become a disturbance. However, the electric motor drive control system S, the electric motor drive control device, and the electric motor drive control method described above perform the processing when neither 2πf _mag >ω _{cfi nor} 2πf _cog >ω _cfi in the processing S4 (No). Since S5 is executed and the gains K _TI and K _IV of the first and second variable amplifiers VA1 and VA2 are controlled to 0, the compensation value is not generated and the disturbance is prevented.

In the above-described embodiment, since the motor M is a surface type permanent magnet synchronous motor (SPMSM), a compensation value for canceling pulsating torque is introduced as necessary only for the q-axis that contributes to the torque. However, depending on the type of electric motor M, compensation values for canceling pulsating torque may be introduced for the q-axis and the d-axis.

Further, in the above-described embodiment, the compensation value generator CV generates the compensation value when the voltage value corresponding to the control command value based on the compensation value exceeds a predetermined output voltage value of the power supply that supplies power to the electric motor. It is preferable not to generate The predetermined output voltage value is appropriately set in advance, for example, in consideration of the specifications and operating conditions of the electric motor M and the inverter IV connected to the power supply. Since the electric motor drive control system S, the electric motor drive control device, and the electric motor drive control method described above control the electric motor M within the rated voltage value of the power supply, it is possible to avoid destabilization of the control. In particular, in Patent Document 1, as described above, the superimposed voltage command is directly input to the PWM control unit without feedback control, so that the voltage value corresponding to the superimposed voltage command is Exceeding the supply voltage can lead to difficulties in control, which is avoided in this variant.

FIG. 6 is a flow chart showing the operation of the motor drive control system in the modified form. As shown in FIG. 6, the electric motor drive control system in such a modification executes processing S11 before executing processing S8 described above with reference to FIG. That is, the motor drive control system in the modified form executes each of the processes S1 to S7 described above with reference to FIG. In (Yes), the motor drive control system S next executes processing S11.

In this process S11, the electric motor drive control system S feeds the electric motor M with the voltage values v _d ^* and v _q ^* corresponding to the control command value based on the compensation value by the gain control section GC of the compensation value generation section CV. It is determined whether or not the rated voltage value Vdc of the power supply is exceeded. More specifically, the gain controller GC determines whether or not the voltage values _vd ^* and _vq ^* corresponding to the control command values based on the compensation values are a times or less than the rated voltage value Vdc considering the margin a. (√(vd ^* + _vq ^*)≤a* _Vdc ). a is appropriately set in advance to be less than 1, and is set to any value in the range of 0.9<a<1, for example. As a result of this determination, if the v _d ^* and v _q ^* are equal to or less than a×Vdc (Yes), then the motor drive control system S executes the process S8 described above with reference to FIG. , the process at the current control timing ends. On the other hand, as a result of the determination, if the v _d ^* and v _q ^* are not equal to or less than a×Vdc (No), the motor drive control system S does not execute anything and executes the main control at the current control timing. End the process. This avoids destabilization of the control.

Although the present invention has been adequately and fully described above through embodiments with reference to the drawings in order to express the present invention, modifications and/or improvements to the above-described embodiments can easily be made by those skilled in the art. It should be recognized that it is possible. Therefore, to the extent that modifications or improvements made by those skilled in the art do not depart from the scope of the claims set forth in the claims, such modifications or improvements do not fall within the scope of the claims. is interpreted to be subsumed by

S Electric motor drive control system M Electric motor IV Inverter circuit PM PWM modulator DC Drive control section CS Current measurement section VS Rotation angle measurement section CV1 Two-phase three-phase conversion section CV2 Three-phase two-phase conversion section RSC Rotation speed processing section PT Pulsation torque estimation Section DA Rotation angle estimating section PN First pulsating torque estimating section TC Second pulsating torque estimating section SM Adding section CV Compensation value generating section VA1 First variable amplifying section VA2 Second variable amplifying section GC Gain control section SB3 First subtracting section SB4 second subtraction unit

Claims (5)

An electric motor drive control device for controlling an electric motor,
a pulsating torque estimating unit that estimates the pulsating torque generated at the next control timing by using a pulsating torque representing the pulsating torque whose magnitude increases or decreases with the lapse of time;
a compensation value generation unit that generates a compensation value for canceling the pulsation torque estimated by the pulsation torque estimation unit;
a drive control unit that controls and drives the electric motor with a control command value based on the compensation value generated by the compensation value generation unit;
The pulsating torque includes at least one of a first pulsating torque resulting from a spatial high-frequency component of the magnetomotive force distribution in the circumferential direction of the electric motor and a second pulsating torque that is a cogging torque.
Motor drive controller. The drive control unit includes a current control system that controls the drive current of the electric motor and a speed control system that controls the speed of the electric motor,
The compensation value generation unit is configured to provide a frequency of the pulsating torque, a first frequency band of the current control system in which the current control system can follow the pulsating torque, and a speed control system in which the speed control system can follow the pulsating torque. determining whether to generate the compensation value based on a second frequency band, and generating the compensation value if determined to generate the compensation value;
The electric motor drive control device according to claim 1. The compensation value generation unit does not generate the compensation value when a voltage value corresponding to the control command value based on the compensation value exceeds a predetermined output voltage value of a power supply that supplies power to the electric motor.
The electric motor drive control device according to claim 1 or 2. A motor drive control method for controlling a motor, comprising:
a pulsating torque estimating step of estimating the pulsating torque generated at the next control timing by using a pulsating torque representing the pulsating torque whose magnitude increases or decreases with the lapse of time;
a compensation value processing step of obtaining a compensation value for canceling the pulsating torque estimated in the pulsating torque estimating step;
a drive control step of controlling and driving the electric motor with a control command value based on the compensation value obtained in the compensation value processing step;
The pulsating torque includes at least one of a first pulsating torque resulting from a spatial high-frequency component of the magnetomotive force distribution in the circumferential direction of the electric motor and a second pulsating torque that is a cogging torque.
Electric motor drive control method. an electric motor;
and an electric motor drive control unit that controls the electric motor,
The electric motor drive control unit is the electric motor drive control device according to any one of claims 1 to 3,
Electric motor drive control system.

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