JP6438226B2 - Motor control device and motor control method - Google Patents

Description

  The present invention relates to a motor control device and a motor control method.

  2. Description of the Related Art Conventionally, there is known a motor control device that controls a current supplied to a coil wound around a tooth of a permanent magnet synchronous motor using a d-axis current command value and a q-axis current command value based on vector control. For example, in Patent Document 1, the secondary component of the radial force is suppressed by correcting the d-axis current command value based on the ratio of the portion of the tooth surface through which the magnetic flux of the permanent magnet passes.

JP 2014-64400 A

  However, although the technique of the above-mentioned Patent Document 1 can be expected to suppress the electrical angular secondary radial force among the excitation forces that cause the vibration of the motor, it cannot suppress the electrical angular sixth-order radial force. There was a problem.

  The problem to be solved by the present invention is to provide a motor control device and a motor control method capable of suppressing the radial force of the sixth electrical angle.

  The present invention calculates a dq-axis current command value based on the rotational speed of the motor and the torque command value of the motor, and dq-axis current command value based on the sixth harmonic current of the sixth component of the dq-axis current flowing through the motor. The above problem is solved by correcting the above.

  According to the present invention, since there is a constant transmission characteristic between the sixth-order radial force and the sixth-order harmonic current, the electric angle is corrected by correcting the current command value using the sixth-order harmonic current. Sixth-order radial force can be suppressed.

FIG. 1 is a block diagram of a drive system according to an embodiment of the present invention. FIG. 2 is a graph for explaining the approximate model and the electromagnetic field analysis result. FIG. 3 is a graph for explaining the approximate model and the electromagnetic field analysis result. FIG. 4 is a graph for explaining the approximate model and the electromagnetic field analysis result. FIG. 5 is a flowchart showing a control flow of the drive system according to the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of a drive system according to an embodiment of the present invention. The motor control device according to the present embodiment is a device for controlling a motor provided in an electric vehicle or a hybrid vehicle. The motor control device is not limited to a vehicle drive motor, and may be a device that controls a motor provided in a device other than the vehicle (such as an air conditioner compressor or a vacuum cleaner).

  As shown in FIG. 1, the drive system includes a battery 1, an inverter 2, a motor 3, a current sensor 4, an acceleration sensor 5, a current command value calculation unit 6, a motor current control unit 7, a correction command value calculation unit 8, and a switch control. A unit 9 and an adder 10 are provided.

  The battery 1 is configured by connecting a secondary battery such as a lithium ion battery, for example. The inverter 2 is a device that converts DC power output from the battery 1 into AC power. The inverter 2 has a conversion circuit in which switching elements such as IGBTs are connected in a bridge shape so as to be three-phase, a smoothing circuit, and the like. The inverter 2 is connected between the battery 1 and the motor 3.

  The motor 3 is a permanent magnet synchronous motor. In the present embodiment, an interior permanent magnet synchronous motor (IPMSM) is used as the motor. The motor 3 is not limited to an embedded magnet synchronous motor, and may be another motor.

  The motor 3 has a stator and a rotor (rotor). The stator is provided with teeth, and a coil is wound around the side surface of the teeth. The teeth are arranged along the circumferential direction of the stator, with the U phase, the V phase, and the W phase as one set, forming a plurality of sets. A plurality of permanent magnets are embedded in the rotor.

  The motor 3 is driven by electric power output from the inverter 2. The motor 3 also functions as a generator, and the generated power is supplied to the battery 1 via the inverter 2.

  A current sensor 4 is connected between the inverter 2 and the drive motor 3. The current sensor 4 detects a current (motor current) flowing through the coil of the motor 3. The current sensor 4 is connected to the U phase and the V phase. The W-phase current is calculated based on the U-phase and V-phase currents. The current sensor 4 may also be provided in the W phase. The current sensor 4 outputs the detected current to the motor current control unit 7 and the correction command value calculation unit 8.

  The acceleration sensor 5 is a sensor that detects vibration of the motor 3 as acceleration. The acceleration sensor 5 is provided in the motor 3. The acceleration sensor 5 outputs the detected acceleration to the correction command value calculation unit 8 and the switch control unit 9.

  The current command value calculation unit 6 calculates the d-axis current command value and the q-axis current command value of the motor 3 based on the rotation speed and torque command value of the motor 3. The rotational speed of the motor 3 is detected by a rotational speed sensor such as a resolver. The rotational speed sensor is provided in the motor 3 although not shown in FIG. The torque command value is calculated based on the accelerator opening and the like.

  The current command value calculation unit 6 stores in advance a map indicating the correspondence relationship between the rotation speed of the motor 3, the torque command value, and the dq axis current command value. The current command value calculation unit 6 calculates the dq-axis current command value by referring to the map. The q-axis current command value is a command value of a current component (q-axis) in the direction coaxial with the rotation axis of the rotor having a permanent magnet. The d-axis current command value is a command value of a current component (d-axis) in a direction orthogonal to the rotation axis of the rotor.

  The motor current control unit 7 calculates a voltage command value for controlling the inverter 2 based on the dq axis current command value calculated by the current command value calculation unit 6 and the detected current of the current sensor 4. The motor current control unit 7 calculates the difference between the dq-axis current command value and the dq-axis current, and based on the difference, calculates a voltage command by PI control so that the dq-axis detected current matches the dq-axis current command value. Calculate the value. The dq-axis current is a current value obtained by converting the three-phase detected currents of the U, V, and W phases detected by the current sensor 4 into two phases of the dq axis. Note that the rotation speed of the motor 3 is used in the three-phase / two-phase conversion.

  Further, the motor current control unit 7 compares the calculated voltage command value with the carrier, generates a switching signal (PWM signal) of the inverter 2 by so-called PWM control, and outputs it to the inverter 2.

  Thereby, the current command value calculation unit 6 calculates the dq-axis current command value by vector control. Further, the motor current control unit 7 causes the dq-axis current to follow the dq-axis current command value with a predetermined response without a steady deviation by feedback control in which the detection current of the current sensor 4 is fed back. The motor 3 is controlled. The control of the motor 3 is not limited to the above configuration, and may include non-interference control, for example.

  The correction command value calculation unit 8 calculates a correction command value for suppressing the sixth-order radial force based on the dq axis current detected by the current sensor 4. The correction command value calculation unit 8 outputs the correction command value to the switch control unit 9. A specific calculation method of the correction command value by the correction command value calculation unit 8 will be described later.

  The switch control unit 9 compares the detection value of the acceleration sensor 5 with the vibration threshold value. The detection threshold value is a threshold value representing the magnitude of motor vibration in terms of acceleration, and is set in advance. When the detected value is larger than the detection threshold, the switch control unit 9 turns on the switch and outputs a correction command value to the adder 10. On the other hand, when the detected value is less than or equal to the detection threshold, the switch control unit 9 turns off the switch. The adder 10 adds the dq-axis current command value calculated by the current command value calculation unit 6 and the correction command value calculated by the correction command value calculation unit 8. Thereby, when the vibration of the motor 3 is large, the correction command value is added to the dq-axis current command value, and the dq-axis current command value is corrected. The corrected dq axis current command value is output from the adder 10 to the motor current control unit 7.

  By the way, for example, when the drive system according to the present embodiment is applied to a vehicle, when the motor 3 vibrates, the vibration of the motor 3 becomes a sound generation source, which may affect the quietness in the vehicle interior. . Further, when the drive system is applied not only to the vehicle but also to other devices, low vibration and low noise of the motor 3 are required.

  The vibration of the motor 3 is generated by an electromagnetic exciting force of the motor 3. The electromagnetic excitation force is a force generated between the permanent magnet of the motor 3 and the stator. When an alternating current is passed through the coil of the motor 3, a force for attracting the permanent magnet to the stator and a force for separating the permanent magnet from the stator are generated. These forces are electromagnetic excitation forces. Of the electromagnetic excitation force, a force acting in the radial direction of the motor 3 is referred to as a radial force.

  In the motor 3, it is known that the radial force of the electrical angle secondary and the electrical angle 6th as the time order contributes to the vibration of the motor 3, and the secondary radial force and the sixth radial force become the excitation force to the motor 3. It has been. Therefore, in the present embodiment, paying attention to the interlinkage magnetic flux of the motor 3, while deriving a radial force approximation model of the electrical angle sixth-order component, using the dq-axis harmonic current based on the radial force approximation model, Suppresses the next radial force.

  In modeling the radial force of the electrical angle sixth-order component, the relationship between the dq-axis current, the linkage flux, and the electromagnetic excitation force will be described. As a premise for modeling, it is premised that the time harmonic component of the radial force acting on the whole tooth becomes the vibration of the stator.

The total magnetic flux φ _u (t) penetrating the U phase 1 tooth is expressed by the equation (1) using the U phase interlinkage magnetic flux φ _u (t).

ただし、ｔは時間であり、Ｎは１相当たりのコイルの巻き数である。なお全てのコイルは直列に接続されているとする。

However, t is time and N is the number of coil turns per phase. It is assumed that all the coils are connected in series.

A circumferential component of magnetic flux density at time (t) (hereinafter referred to as circumferential magnetic flux distribution) is B _θ (t), and a radial component of magnetic flux density (hereinafter referred to as radial magnetic flux distribution) is B _r (t ). Assuming that the circumferential magnetic flux distribution B _θ (t) is very small, all the magnetic fluxes interlinking with the teeth become the radial magnetic flux distribution B _r (t), and the U-phase interlinkage magnetic flux ψ _u (t). Is represented by equation (2).

ただし、Ｓは空隙に対向するティース面積である。空隙はティースとロータとの間の隙間である。

However, S is the tooth area facing the gap. The air gap is a gap between the teeth and the rotor.

The radial force f _u (t) acting on the U phase 1 tooth is expressed by the equation (3) using the Maxwell stress equation.

ただし、μ_０は真空透磁率である。

However, μ ₀ is the vacuum permeability.

  Assuming that the magnetic flux distribution is uniform on the tooth area S, the equations (2) and (3) become equations (4) and (5), respectively.

  The speed condition of the motor 3 is constant speed. Then, Expression (6) and Expression (7) are obtained by substituting Expression (1) and Expression (4) into Expression (5) while expressing the radial force as a function of the electrical angle θ.

  Equation (6) is an approximate model of radial force.

Next, assumptions regarding the flux linkage will be described. The U-phase linkage magnetic flux ψ _um (θ) due to the permanent magnet and the U-phase linkage magnetic flux ψ _ui (θ) due to the current are treated as linearly independent. The U-phase interlinkage magnetic flux ψ _u (θ) is expressed by Expression (8).

In order to consider the 6 radial force, the U-phase interlinkage magnetic flux ψ _um (θ) is considered up to the 7th order component as shown in Equation (9).

The fifth linkage flux ψ _5m and the seventh linkage flux ψ _7m can take a negative value when the phase is reversed with respect to the fundamental wave flux. Because of the symmetry of the three phases, the radial force acting on each phase tooth of UVW has the same amplitude and the same phase, so only the U phase is handled.

  Next, the definition of the current command value will be described. The dq axis current is defined as in the following formulas (10) to (13).

  Hereinafter, the derivation process until the sixth-order radial force is derived from the dq-axis harmonic current by substituting the dq-axis current defined as described above into the radial force approximation formula will be described.

The transfer characteristics between the d-axis harmonic current and the sixth-order radial are expressed by the following equations (14) to (17). The U-phase interlinkage magnetic flux ψ _uih generated by the d-axis harmonic current i _d6 is expressed by Expression (14).

By substituting Equation (9) and Equation (14) into Equation (8), the total interlinkage magnetic flux ψ _u of the U phase is expressed by Equation (15).

  In this embodiment, absolute conversion is used for dq / UVW conversion. Substituting equation (15) into equation (6) and rearranging only the sixth-order radial force term generated by the d-axis harmonic current yields equation (16).

K _dr (I _d0 , I _q0 ) is represented by the following formula (17).

The d-axis sixth-order harmonic current i _d6 is multiplied by K _dr (I _d0 , I _q0 ) without _causing a phase delay to be a sixth-order radial force, as shown by equations (16) and (17). . K _dr (I _d0 , I _q0 ) is obtained from the radial frequency analysis result analyzed as i _d6 = cos 6θ. As a model used for frequency analysis, the motor 3 is a concentrated winding IPMSM having 12 poles and 18 slots. The permanent magnet of the rotor is arranged in a V shape. As parameters of the IPMSM, the number of coil turns N is 120, the number of pole pairs (P) is 6, the area of the facing surface of the teeth is 413 (mm ² ), the fundamental interlinkage magnetic flux ψ _1m is 36.2 (mWb), d The axial inductance (L _d ) is 0.866 (mH), the q-axis inductance (L _q ) is 1.31 (mH), the air gap is 1 (mm), the outer diameter of the stator is 150 (mm), and the outer diameter of the rotor Is 100 (mm) and the stacking thickness is 30 (mm).

FIG. 2 and FIG. 3 show electromagnetic field analysis results obtained by evaluating the approximate accuracy of K _dr (I _d0 , I _q0 ) using the above model.

FIG. 2 is a graph showing the relationship between I _d0 and K _dr when I _q0 = 0. FIG. 3 is a graph showing the relationship between I _q0 and K _dr when I _d0 = 0. 2 and 3, the solid line graph is the value of the approximate model (approximate model) represented by the equation (17), and the value indicated by the cross is the result of the electromagnetic field analysis (frequency analysis). .

  As shown in FIGS. 2 and 3, the approximate model of the sixth-order radial force expressed by the above formula and the electromagnetic field analysis result are in good agreement.

Next, transfer characteristics between the q-axis harmonic current and the sixth-order radial are expressed by the following equations (18) to (20). The U-linkage magnetic flux ψ _uih generated by the q-axis harmonic current i _q6 is expressed by Expression (18).

While deriving total linkage flux [psi _u likewise U-phase and the formula (15), substituting the total linkage flux [psi _u of U-phase in equation (6). Then, when only the term of the sixth-order radial force generated by the q-axis harmonic current is arranged, Expression (19) is obtained.

K _qr (I _d0 , I _q0 ) is represented by the following formula (20).

FIG. 4 shows an electromagnetic field analysis result obtained by evaluating the approximate accuracy of K _qr (I _d0 , I _q0 ) using the above model. FIG. 4 is a graph showing the relationship between I _q0 and K _qr when I _d0 = 0. In FIG. 4, the solid line graph is the value of the approximate model (approximate model) represented by Expression (20), and the value indicated by the cross indicates the result of electromagnetic field analysis (frequency analysis).

From equation (20), the sixth-order radial force generated by the q-axis harmonic current i _q6 is proportional to the q-axis fundamental wave current. The approximate model matches the analysis result as shown in FIG.

Next, a control method for suppressing the sixth radial force will be described. When the sixth-order radial force to be suppressed is denoted by _{f base (I d0, I q0} ), all six primary radial force _{f r6 (i d, i q} ) is represented by the formula (21) and (22).

From Equation (21), the sixth-order radial force can be suppressed using the harmonic current of at least one of the d-axis and the q-axis. Assuming that F _base and θ _base are known by electromagnetic field analysis, the dq-axis harmonic current command value for suppression is expressed by equations (23) and (24).

Equation (23) shows the d-axis sixth harmonic current when the sixth radial force is suppressed using the d-axis harmonic current. In other words, it is the d-axis sixth-order harmonic current for setting the q-axis harmonic current i _q6 to zero while _{setting it} to zero in Equation (21). Moreover, Formula (24) has shown the q-axis 6th harmonic current in the case of suppressing 6th-order radial force using a q-axis harmonic current. In other words, it is the q-axis sixth-order harmonic current for setting the d-axis harmonic current i _d6 to zero while setting the zero in equation (21) to zero.

  When the dq-axis sixth-order harmonic current expressed by Equation (23) or Equation (24) is added to the dq-axis current command value, the dq-axis current command value is corrected to a command value that suppresses the sixth-order radial force. Is done. The motor 3 is driven based on the corrected dq axis current command value, so that vibration due to the sixth-order radial force is suppressed.

  In the present embodiment, when the sixth-order radial force is suppressed using the d-axis sixth-order harmonic current, the correction command value calculation unit 8 uses the d-axis sixth-order harmonic current command represented by Expression (23). The value is calculated as a correction command value (d-axis). Further, when the sixth-order radial force is suppressed using the q-axis sixth-order harmonic current, the correction command value calculation unit 8 sets the d-axis sixth-order harmonic current command value represented by the equation (24) as Calculation is performed as a correction command value (q-axis).

  In the present embodiment, the correction command value is not limited to any one of the d-axis sixth harmonic current or the q-axis sixth harmonic current, but the d-axis sixth harmonic current and the q-axis sixth harmonic current. Both command values of wave current may be used. When the d-axis current and the q-axis current are used as the correction command values, the d-axis sixth harmonic current and the q-axis sixth harmonic are set so that the value represented by the upper side of the equation (21) becomes zero. Wave current is calculated.

As shown in the equation (17), the sixth-order radial force generated by the d-axis sixth harmonic current is a coefficient (depending on the fundamental magnetic flux of the permanent magnet (the magnetic flux of the fundamental component)) and the d-axis fundamental current ( K _dr ). Then, if the d-axis fundamental wave current is calculated from the d-axis current detected by the current sensor 4, the d-axis sixth-order harmonic current command value for suppressing the sixth-order radial force is calculated from the equation (23). Can be calculated.

The correction command value calculation unit 8 records the relationship of the equation (23) including the coefficient (K _dr ) in advance using a map. The correction command value calculation unit 8 calculates the d-axis fundamental wave current based on the detection current of the current sensor 4, and refers to the map to determine the d-axis sixth harmonic corresponding to the d-axis fundamental wave current and the electrical angle (θ). The wave current command value is calculated as a correction command value. In addition, what is necessary is just to calculate an electrical angle ((theta)) from the detected value of a rotation speed sensor.

Further, as shown in the equation (20), the sixth-order radial force generated by the q-axis harmonic current is expressed by a coefficient (K _qr ) depending on the q-axis fundamental current, and the fundamental wave magnetic flux of the permanent magnet and It is independent of the d-axis fundamental wave current. Therefore, similarly to the d-axis sixth harmonic current, the q-axis sixth harmonic current command value for suppressing the sixth radial force can be calculated from the map.

The correction command value calculation unit 8 records the relationship indicated by the equation (24) including the coefficient (K _qr ) in advance using a map. The correction command value calculation unit 8 calculates the q-axis fundamental wave current based on the detection current of the current sensor 4, and refers to the map to determine the q-axis sixth harmonic corresponding to the q-axis fundamental wave current and the electrical angle (θ). The wave current command value is calculated as a correction command value.

  When the detected value of the acceleration sensor 5 is larger than the vibration threshold value, the switch control unit 9 turns on the switch, and the correction command value calculation unit 8 outputs the correction command value to the adder 10. At this time, the correction command value is a command value of either the d-axis sixth harmonic current or the q-axis sixth harmonic current.

  Adder 10 adds the dq-axis current command value calculated by current command value calculation unit 6 and the correction command value, and outputs the added dq-axis current command value to motor current control unit 7. The added dq-axis current command value becomes the corrected dq-axis current command value. As a result, the dq-axis current command value is corrected based on the sixth-order harmonic current of the sixth-order component of the dq-axis current.

  Next, the control flow of the drive system in the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing a control flow of the drive system. Note that the control flow shown in FIG. 5 is repeatedly executed at a predetermined cycle.

  In step S1, the current command value calculation unit 6 acquires a torque command value and a motor rotation speed. In step S <b> 2, the current sensor 4 detects the motor current and outputs it to the motor current control unit 7 and the correction command value calculation unit 8.

  In step S <b> 3, the acceleration sensor 5 detects acceleration and outputs the detected acceleration to the switch control unit 9. In step S4, the current command value calculation unit 6 calculates a dq axis current command value based on the torque command value and the motor rotation speed, and outputs the dq axis current command value to the adder 10.

  In step S5, the correction command value calculation unit 8 calculates a correction command value based on the dq-axis current, and outputs the correction command value to the switch control unit 9. The dq-axis current is a three-phase / two-phase converted current with respect to the UVW phase motor current detected by the current sensor 4. The correction command value is a command value for suppressing the sixth-order radial force, and is a d-axis sixth-order harmonic current expressed by Equation (23) or a q-axis sixth-order expressed by Equation (24). Harmonic current.

  In step S6, the switch control unit 9 compares the acceleration detected by the acceleration sensor 5 with the vibration threshold value. If the acceleration is larger than the vibration threshold value, the switching control unit 9 turns on the switch and outputs the correction command value to the adder 10 in step S7. In step S8, the adder 10 adds the correction command value to the dq-axis current command value. Thereby, the dq axis current command value is corrected. The corrected dq axis current command value is output to the motor current control unit 7. Then, the process proceeds to step S10.

  If the acceleration is equal to or less than the vibration threshold value in step S7, the process proceeds to step S9. In step S9, the switching control unit 9 turns off the switch. Since the correction command value is not output to the adder 10, the adder 10 outputs the dq axis current command value calculated by the current command value calculation unit 6 to the motor control unit 7 as it is. Then, the process proceeds to step S10.

  In step S <b> 10, the motor current control unit 7 generates a PWM signal by PWM control based on the dq axis current command value and the dq axis current output from the adder 10, and outputs the PWM signal to the inverter 2. The inverter 2 supplies current to the motor 3 based on the PWM signal, and the motor 3 is driven by the current supplied from the inverter 2. Thereby, when the vibration of the motor is large and the condition for suppressing the sixth-order radial force is satisfied (corresponding to “Y” in step S6), the dq-axis current command value is corrected based on the sixth-order harmonic current. Since the motor 3 is driven based on the corrected command value, the sixth radial force is suppressed.

  As described above, according to the present embodiment, the dq-axis current command value calculated based on the motor rotation speed and the torque command value is corrected based on the sixth harmonic current. The sixth-order radial force has a constant transfer characteristic with the sixth-order harmonic current. Therefore, the sixth-order radial force can be suppressed by correcting the dq-axis current command value based on the sixth-order harmonic current as in this embodiment.

  Further, according to the present embodiment, the correction command value that suppresses the sixth-order radial force is calculated, and the correction command value is added to the dq axis current command value, thereby correcting the dq axis current command. As shown in Expression (23) or Expression (24), the harmonic current command value for suppressing the sixth-order radial force can be calculated by an approximate model of the sixth-order radial force. Therefore, the sixth-order radial force can be suppressed by using the harmonic current command value calculated based on the equation (23) or the equation (24) as the correction command value.

According to the present embodiment, the d-axis sixth-order harmonic current command value for suppressing the sixth-order radial force is calculated as the correction command value by the equation (23) including the coefficient (K _dr ). Further, according to the present embodiment, the q-axis sixth-order harmonic current command value for suppressing the sixth-order radial force is calculated as the correction command value by the equation (24) including the coefficient (K _qr ). Thereby, the 6th-order radial force can be suppressed.

  The drive system shown in FIG. 1 is configured so that both the d-axis current command value and the q-axis current command value can be corrected, but only the d-axis current command value or only the q-axis current command value is corrected. You may comprise so that it can do. For example, when only the d-axis current command value is corrected, the q-axis signal line output from the correction command value calculation unit 8 to the adder 10 via the switching control unit 9 becomes unnecessary, and the switching control unit Nine q-axis side switches and the q-axis side adder of the adder 10 are unnecessary.

In a modification of this embodiment The correction command value calculating unit 8 calculates the coefficient _{(K dr)} and a coefficient _{(K qr)} based on the detection current of the current sensor 4, the coefficient _{(K dr)} and coefficient _{(K qr} ). When the coefficient (K _dr ) is larger than the coefficient (K _qr ), the d-axis sixth-order harmonic current command value calculated by the equation (23) including the coefficient (K _dr ) is output to the adder 10. To do. When the coefficient (K _dr ) is equal to or _smaller than the coefficient (K _qr ), the q-axis sixth-order harmonic current command value calculated by the equation (24) including the coefficient (K _qr ) is output to the adder 10. . Thereby, when the coefficient (K _dr ) is larger than the coefficient (K _qr ), the sixth-order radial force can be suppressed with a small current amplitude by using the d-axis harmonic current. Further, when the coefficient (K _qr ) is larger than the coefficient (K _dr ), the sixth-order radial force can be suppressed with a small current amplitude by using the q-axis harmonic current.

  The current command value calculation unit 6 corresponds to the “current command value calculation unit” of the present invention, and the correction command value calculation unit 8, the switch control unit 9, and the adder 10 correspond to the “correction unit” of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Battery 2 ... Inverter 3 ... Motor 4 ... Current line sensor 5 ... Acceleration sensor 6 ... Current command value calculating part 7 ... Motor current control part 8 ... Correction command value calculating part 9 ... Switch control part 10 ... Adder

Claims (7)

In the motor control device that controls the current flowing in the coil of the permanent magnet synchronous motor,
Current command value calculation means for calculating a current command value including a d-axis current command value and a q-axis current command value based on the rotational speed of the motor and the torque command value of the motor;
Correction means for correcting the current command value based on the sixth harmonic current of the sixth component of the current flowing through the motor;
The correction means includes
By calculating a correction command value for suppressing the sixth-order radial force by an arithmetic expression including a first coefficient depending on the fundamental wave magnetic flux and the d-axis fundamental wave current, and adding the correction command value to the current command value, Correct the current command value,
The sixth-order radial force has an electric angle sixth-order frequency component, is a radial force of electromagnetic excitation force, and is a force generated by the sixth-order harmonic current,
The electromagnetic excitation force is a force generated between a permanent magnet of the motor and a stator of the motor,
The fundamental wave magnetic flux is a magnetic flux of the fundamental wave component of the permanent magnet,
The motor control device according to claim 1, wherein the d-axis fundamental wave current is a current of a fundamental wave component of the d-axis . In the motor control device that controls the current flowing in the coil of the permanent magnet synchronous motor,
Current command value calculation means for calculating a current command value including a d-axis current command value and a q-axis current command value based on the rotational speed of the motor and the torque command value of the motor;
Correction means for correcting the current command value based on the sixth harmonic current of the sixth component of the current flowing through the motor;
The correction means includes
The current command value is calculated by calculating a correction command value for suppressing the sixth-order radial force by an arithmetic expression including a second coefficient depending on the q-axis fundamental wave current, and adding the correction command value to the current command value. To correct
The sixth-order radial force has an electric angle sixth-order frequency component, is a radial force of electromagnetic excitation force, and is a force generated by the sixth-order harmonic current,
The electromagnetic excitation force is a force generated between a permanent magnet of the motor and a stator of the motor,
The motor control device according to claim 1, wherein the q-axis fundamental wave current is a current of a q-axis fundamental wave component . In the motor control device that controls the current flowing in the coil of the permanent magnet synchronous motor,
  Current command value calculation means for calculating a current command value including a d-axis current command value and a q-axis current command value based on the rotational speed of the motor and the torque command value of the motor;
  Correction means for correcting the current command value based on the sixth harmonic current of the sixth component of the current flowing through the motor;
The correction means includes
  A d-axis correction command value for suppressing the sixth-order radial force is calculated by an arithmetic expression including a first coefficient depending on the fundamental wave magnetic flux and the d-axis fundamental wave current,
  A q-axis correction command value for suppressing the sixth-order radial force is calculated by an arithmetic expression including a second coefficient that depends on the q-axis fundamental wave current,
  When the first coefficient is larger than the second coefficient, the current command value is corrected by adding the d-axis correction command value to the current command value,
  When the second coefficient is larger than the first coefficient, the current command value is corrected by adding the q-axis correction command value to the current command value,
The fundamental wave magnetic flux is a magnetic flux of the fundamental wave component of the permanent magnet of the motor,
The d-axis fundamental wave current is a current of a fundamental wave component of the d-axis,
The q-axis fundamental wave current is a current of a q-axis fundamental wave component,
The sixth-order radial force has an electric angle sixth-order frequency component, is a radial force of electromagnetic excitation force, and is a force generated by the sixth-order harmonic current,
The electromagnetic excitation force is a force generated between the permanent magnet of the motor and the stator of the motor.
The motor control apparatus characterized by the above-mentioned. In the motor control device according to any one of claims 1 to 3,
The correction means calculates the correction command value using at least one harmonic current of a d-axis sixth harmonic current or a q-axis sixth harmonic current,
The d-axis sixth harmonic current is a d-axis current of the sixth harmonic current,
The motor control device according to claim 1, wherein the q-axis sixth harmonic current is a q-axis current of the sixth harmonic current .   In the motor control method for controlling the current flowing in the coil of the permanent magnet synchronous motor,
  Based on the rotational speed of the motor and the torque command value of the motor, a current command value including a d-axis current command value and a q-axis current command value is calculated,
  Correcting the current command value based on the sixth harmonic current of the sixth component of the current flowing through the motor;
In the step of correcting the current command value,
  By calculating a correction command value for suppressing the sixth-order radial force by an arithmetic expression including a first coefficient depending on the fundamental wave magnetic flux and the d-axis fundamental wave current, and adding the correction command value to the current command value, Correct the current command value,
The sixth-order radial force has an electric angle sixth-order frequency component, is a radial force of electromagnetic excitation force, and is a force generated by the sixth-order harmonic current,
The electromagnetic excitation force is a force generated between the permanent magnet of the motor and the stator of the motor.
The fundamental wave magnetic flux is a magnetic flux of the fundamental wave component of the permanent magnet,
The d-axis fundamental wave current is a current of a fundamental wave component of the d-axis.
Motor control method.   In the motor control method for controlling the current flowing in the coil of the permanent magnet synchronous motor,
  Based on the rotational speed of the motor and the torque command value of the motor, a current command value including a d-axis current command value and a q-axis current command value is calculated,
  Correcting the current command value based on the sixth harmonic current of the sixth component of the current flowing through the motor;
In the step of correcting the current command value,
  The current command value is calculated by calculating a correction command value for suppressing the sixth-order radial force by an arithmetic expression including a second coefficient depending on the q-axis fundamental wave current, and adding the correction command value to the current command value. To correct
The sixth-order radial force has an electric angle sixth-order frequency component, is a radial force of electromagnetic excitation force, and is a force generated by the sixth-order harmonic current,
The electromagnetic excitation force is a force generated between a permanent magnet of the motor and a stator of the motor,
The q-axis fundamental wave current is a current of a q-axis fundamental wave component.
Motor control method. In the motor control method for controlling the current flowing in the coil of the permanent magnet synchronous motor,
  Current command value calculation means for calculating a current command value including a d-axis current command value and a q-axis current command value based on the rotational speed of the motor and the torque command value of the motor;
  Correction means for correcting the current command value based on the sixth harmonic current of the sixth component of the current flowing through the motor;
The correction means includes
  A d-axis correction command value for suppressing the sixth-order radial force is calculated by an arithmetic expression including a first coefficient depending on the fundamental wave magnetic flux and the d-axis fundamental wave current,
  A q-axis correction command value for suppressing the sixth-order radial force is calculated by an arithmetic expression including a second coefficient that depends on the q-axis fundamental wave current,
  When the first coefficient is larger than the second coefficient, the current command value is corrected by adding the d-axis correction command value to the current command value,
  When the second coefficient is larger than the first coefficient, the current command value is corrected by adding the q-axis correction command value to the current command value,
The fundamental wave magnetic flux is a magnetic flux of the fundamental wave component of the permanent magnet,
The d-axis fundamental wave current is a current of a fundamental wave component of the d-axis,
The q-axis fundamental wave current is a current of a q-axis fundamental wave component,
The sixth-order radial force has an electric angle sixth-order frequency component, is a radial force of electromagnetic excitation force, and is a force generated by the sixth-order harmonic current,
The electromagnetic excitation force is a force generated between the permanent magnet of the motor and the stator of the motor.
Motor control method.

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