JP6753326B2 - Motor control device - Google Patents

Description

The present invention relates to a motor control device.

In a synchronous motor, it is known that the torque ripple caused by the harmonic component of the armature interlinkage magnetic flux based on the basic current flowing through the synchronous motor and the permanent magnet is large. That is, it is known that the 5th and 7th order torque ripples are larger than the fundamental frequency Finv of the fundamental current flowing through the synchronous motor. Therefore, the 5th and 7th order torque ripples caused by the harmonic component of the armature interlinkage magnetic flux due to the basic current and the permanent magnet are calculated, and the U-phase compensation voltage value which is the opposite component to the calculated 5th and 7th order torque ripples, Calculate the V-phase compensation voltage value and W-phase compensation voltage value, and use the calculated U-phase compensation voltage value, V-phase compensation voltage value, and W-phase compensation voltage value to obtain the U-phase voltage command value and V-phase voltage command value. By controlling the W-phase voltage command value, the fifth-order and seventh-order torque ripples caused by the harmonic component of the armature interlinkage magnetic flux due to the basic current and the permanent magnet are reduced.

For example, Patent Document 1 and the like are disclosed as a technique for reducing torque ripple.

JP-A-2004-064909

However, in a synchronous motor, there is also torque ripple due to pulse width modulation (PWM) for the inverter circuit that drives the synchronous motor, so it is a harmonic component of the armature interlinkage magnetic flux due to the basic current and the permanent magnet. Reducing the resulting 5th and 7th torque ripples is not sufficient as a measure to reduce the torque ripples. Torque ripple caused by PWM is generated by the influence of the switching signal (square wave) used in PWM and the synchronous motor (inductive load), and is generated in the frequency band higher than the 5th and 7th frequency bands with respect to the fundamental frequency Finv. To do. When the synchronous motor has a low rotation speed, it has sufficient resolution for the period of the fundamental frequency Finv, so torque ripple caused by PWM is not a concern, but when the synchronous motor has a high rotation speed, the fundamental frequency Finv has a sufficient resolution. Since sufficient resolution cannot be secured for the period, torque ripple due to PWM tends to increase.

An object of one aspect of the present invention is to provide a motor control device capable of reducing torque ripple caused by PWM in a synchronous motor.

A motor control device including an inverter circuit for driving a motor and a control circuit for controlling the inverter circuit, which is one embodiment of the present invention, includes a harmonic compensator, a first adder, and a second adder in the control circuit. It has an adder.

The harmonic compensator calculates the order of torque ripple caused by pulse width modulation with respect to the basic frequency using the basic frequency of the basic current flowing through the motor and the switching frequency when pulse width modulation is performed on the inverter circuit. Is used to obtain the d-axis compensation voltage value and the q-axis compensation voltage value, which are the opposite components of the torque ripple caused by the pulse width modulation.

The first adder adds the d-axis compensation voltage value to the d-axis voltage command value, and the second adder adds the q-axis compensation voltage value to the q-axis voltage command value.
Further, a motor control device including an inverter circuit for driving a motor and a control circuit for controlling the inverter circuit, which is another embodiment of the present invention, includes a harmonic compensation unit and a first adder in the control circuit. , A second adder, a third adder.

The harmonic compensator uses the basic frequency of the basic current flowing through the motor and the switching frequency of each of the three phases when pulse width modulation is applied to the inverter circuit to determine the order of torque ripple caused by pulse width modulation with respect to the basic frequency. Calculate for each switching frequency and use the order to obtain the U-phase compensation voltage value, V-phase compensation voltage value, and W-phase compensation voltage value, which are the opposite components of torque ripple caused by pulse width modulation of each of the three phases. ..

The first adder adds the U-phase compensation voltage value to the U-phase voltage command value, the second adder adds the V-phase compensation voltage value to the V-phase voltage command value, and the third adder is the W-phase. The W phase compensation voltage value is added to the voltage command value.

Torque ripple caused by PWM can be reduced in a synchronous motor.

It is a figure which shows one Example of Embodiment 1. It is a figure which shows one Example of the harmonic compensation part of the modification 1. It is a figure which shows one Example of Embodiment 2. It is a figure which shows one Example of the harmonic compensation part of the modification 2. It is a figure which shows one Example of the modification 3. It is a figure which shows one Example of the modification 4. It is a figure which shows one Example of the harmonic compensation part of the modification 4.

Hereinafter, embodiments will be described in detail with reference to the drawings.
<Embodiment 1>
FIG. 1 is a diagram showing an embodiment of the first embodiment. The motor control device shown in FIG. 1 includes a control circuit 1 (subtractor 2, subtractor 3, PI control unit 4, PI control unit 5, adder 6, adder 7, non-interference voltage compensation unit 8, adder 9 ( (First adder), adder 10 (second adder), harmonic compensation unit 11, adder 12, adder 13, harmonic compensation unit 14, coordinate conversion unit 15, PWM control unit 16, coordinate conversion A unit 17), an inverter circuit 18, a current sensor 19, a current sensor 20, a position detection unit 21, and the like, and controls the motor 22.

The control circuit 1 controls the inverter circuit 18. The control circuit 1 is, for example, a circuit using a CPU (Central Processing Unit), a multi-core CPU, a programmable device (FPGA (Field Programmable Gate Array), PLD (Programmable Logic Device), or the like). Further, the control circuit 1 has a storage unit.

The subtractor 2 subtracts the d-axis actual current value id from the d-axis current command value id * to calculate the d-axis current deviation value id_dev (= id * -id). The subtractor 3 subtracts the q-axis actual current value iq from the q-axis current command value iq * to calculate the q-axis current deviation value iq_dev (= iq * -iq).

The PI (Proportional Integral) control unit 4 calculates the d-axis voltage command value V'd * by performing PI control using the d-axis current deviation value id_dev. The PI control unit 5 calculates the d-axis voltage command value V'd * by performing PI control using the q-axis current deviation value iq_dev.

The adder 6 adds the d-axis voltage command value V'd * and the d-axis compensation voltage value Vod to calculate the d-axis voltage command value V "d * (= V'd * + Vod). Calculates the q-axis voltage command value V "q * (= V'q * + Voq) by adding the q-axis voltage command value V'q * and the q-axis compensation voltage value Voq.

The non-interference voltage compensating unit 8 uses the d-axis real current value id, the q-axis real current value iq, and the electric angular velocity ωe of the motor 22, and the speed at which they interfere with each other in the d-axis q-axis coordinate system. The d-axis compensation voltage value Vod and the q-axis compensation voltage value Vox that compensate for the electromotive force are calculated.

The adder 9 adds the d-axis voltage command value V ″ d * and the d-axis compensation voltage value Vd_sw to calculate the d-axis voltage command value V ″ ′ d * (= V ″ d * + Vd_sw). 10 calculates the q-axis voltage command value V ″ q * (= V ″ q * + Vq_sw) by adding the q-axis voltage command value V ″ q * and the q-axis compensation voltage value Vq_sw.

The harmonic compensation unit 11 uses the fundamental frequency Finv of the fundamental current flowing through the motor 22 and the switching frequency Fsw when performing PWM control on the inverter circuit 18 to set the order N of the torque ripple caused by PWM with respect to the fundamental frequency Finv. Using the calculated order N, the d-axis compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw, which are the inverse components of the torque ripple caused by PWM, are obtained.

The adder 12 adds the d-axis voltage command value V ″'d * and the d-axis compensation voltage value Vd_mtr to calculate the d-axis voltage command value Vd * (= V ″ ′ d * + Vd_mtr). The adder 13 adds the q-axis voltage command value V ″'q * and the q-axis compensation voltage value Vq_mtr to calculate the q-axis voltage command value Vq * (= V ″ ′ q * + Vq_mtr).

The harmonic compensation unit 14 uses the phase θe (phase or electric angle of the basic current) of the motor 22 and the electric angular velocity ωe of the motor 22 to harmonize the basic current flowing through the motor 22 with the armature interlinkage magnetic flux by the permanent magnet. The d-axis compensation voltage value Vd_mtr and the q-axis compensation voltage value Vq_mtr, which are the opposite components of the fifth-order and seventh-order torque ripples caused by the wave component, are obtained.

The coordinate conversion unit 15 uses the d-axis voltage command value Vd * and the q-axis voltage command value Vq * with the d-axis voltage command value Vd *, the q-axis voltage command value Vq *, and the phase θe to form the d-axis q. The axis coordinate system is converted into a three-phase AC coordinate system, and the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw * are obtained.

The PWM control unit 16 generates a signal (square wave) for PWM control of the inverter circuit 18 by using the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw *. Then, the voltage is output to the inverter circuit 18.

The coordinate conversion unit 17 acquires signals or information corresponding to the U-phase current value iu and the V-phase current value iv measured by the current sensors 19 and 20, calculates the W-phase current value iwa, and acquires the acquired U-phase current value. The d-axis real current value id and the q-axis real current value iq are calculated based on the signal or information corresponding to the iu and the V-phase current value iv and the calculated W-phase current value iwa. When a current sensor for measuring the W-phase current value iwa is provided, the coordinate conversion unit 17 acquires a signal or information corresponding to the W-phase current value iwa, and U-phase current value iu and V-phase current value iv. , The d-axis real current value id and the q-axis real current value iq may be calculated using the signal or information corresponding to the W-phase current value iwa.

The inverter circuit 18 has a switch element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), is PWM controlled by a PWM control unit 16, and has a U-phase current value iu and a V-phase in the motor 22. The current value iv and the W phase current value iwa are output.

The current sensor 19 measures the U-phase current value iu flowing in the U-phase output from the inverter circuit 18, and outputs a signal or information corresponding to the measured U-phase current value iu to the coordinate conversion unit 17. The current sensor 20 measures the V-phase current value iv flowing in the V-phase output from the inverter circuit 18, and outputs a signal or information corresponding to the measured V-phase current value iv to the coordinate conversion unit 17. Although FIG. 1 shows an example in which only the current sensors 19 and 20 are used, a current sensor for measuring the W-phase current value iw flowing in the W-phase output from the inverter circuit 18 is provided, and the measured W-phase current is measured. The signal or information corresponding to the value iwa may be output to the coordinate conversion unit 17.

The position detection unit 21 detects the phase θe and the electric angular velocity ωe of the motor 22 by, for example, an encoder or a resolver connected to the motor 22.
The motor 22 is controlled by the U-phase current value iu, the V-phase current value iv, and the W-phase current value iwa output from the inverter circuit 18. As the motor 22, for example, an embedded structure permanent magnet synchronous motor or the like can be considered.

The motor control device of the first embodiment will be described.
The d-axis current command value id * is input to the id * input terminal (+) of the subtractor 2, and the id input terminal and the coordinate conversion unit of the non-interfering voltage compensation unit 8 are input to the id input terminal (-) of the subtractor 2. The id output terminal of 17 is connected. The id_dev input terminal of the PI control unit 4 is connected to the id_dev output terminal of the subtractor 2.

The q-axis current command value iq * is input to the IQ * input terminal (+) of the subtractor 3, and the IQ input terminal and coordinate conversion unit of the non-interference voltage compensation unit 8 are input to the IQ input terminal (-) of the subtractor 3. The iq output terminal of 17 is connected. The IQ_dev input terminal of the PI control unit 5 is connected to the iq_dev output terminal of the subtractor 3.

The V'd * output terminal of the PI control unit 4 is connected to the V'd * input terminal (+) of the adder 6, and the Vod of the non-interference voltage compensation unit 8 is connected to the Vod input terminal (+) of the adder 6. The output terminal is connected. The V "d * input terminal (+) of the adder 9 is connected to the V" d * output terminal of the adder 6.

The V'q * output terminal of the PI control unit 5 is connected to the V'q * input terminal (+) of the adder 7, and the Voq of the non-interfering voltage compensation unit 8 is connected to the Voq input terminal (+) of the adder 7. The output terminal is connected. The V "q * output terminal of the adder 7 is connected to the V" q * input terminal (+) of the adder 10.

The Vd_sw output terminal of the harmonic compensation unit 11 is connected to the Vd_sw input terminal (+) of the adder 9, and the V "'d * input terminal of the adder 12 (V"'d * input terminal of the adder 9 is connected to the V "'d * output terminal of the adder 9. +) Is connected.

The Vq_sw output terminal of the harmonic compensation unit 11 is connected to the Vq_sw input terminal (+) of the adder 10, and the V "'q * input terminal of the adder 13 (V"'q * input terminal of the adder 13 is connected to the V "'q * output terminal of the adder 10. +) Is connected.

The Vd_mtr output terminal of the harmonic compensation unit 14 is connected to the Vd_mtr input terminal (+) of the adder 12, and the Vd * input terminal of the coordinate conversion unit 15 is connected to the Vd * output terminal of the adder 12.

The Vq_mtr output terminal of the harmonic compensation unit 14 is connected to the Vq_mtr input terminal (+) of the adder 13, and the Vq * input terminal of the coordinate conversion unit 15 is connected to the Vq * output terminal of the adder 13.

The Vu * input terminal of the PWM control unit 16 is connected to the Vu * output terminal of the coordinate conversion unit 15, and the Vv * input terminal of the PWM control unit 16 is connected to the Vv * output terminal of the coordinate conversion unit 15. The Vw * input terminal of the PWM control unit 16 is connected to the Vw * output terminal of the unit 15.

The output terminals corresponding to the U-phase, V-phase, and W-phase of the PWM control unit 16 are connected to the input terminals corresponding to the U-phase, V-phase, and W-phase of the inverter circuit 18.

The iu input terminal of the motor 22 is connected to the iu output terminal of the inverter circuit 18, the iv input terminal of the motor 22 is connected to the iv output terminal of the inverter circuit 18, and the iv output terminal of the motor 22 is connected to the iv output terminal of the motor 22. The iw input terminal is connected.

The iu input terminal of the coordinate conversion unit 17 is connected to the output terminal of the current sensor 19, and the iv input terminal of the coordinate conversion unit 17 is connected to the output terminal of the current sensor 20.

The position detection unit 21 is connected to the motor 22, and the θe input terminal of the harmonic compensation unit 11, the θe input terminal of the harmonic compensation unit 14, and the θe input terminal of the coordinate conversion unit 15 are connected to the θe output terminal of the position detection unit 21. And are connected. Further, the ωe input terminal of the non-interference voltage compensation unit 8 and the ωe input terminal of the harmonic compensation unit 14 are connected to the ωe output terminal of the position detection unit 21.

The harmonic compensation unit 11 of the first embodiment will be described.
First, the harmonic compensation unit 11 divides the switching frequency Fsw when PWM-controlling the inverter circuit 18 by the fundamental frequency Finv of the fundamental current flowing through the motor 22 to calculate the order N. That is, the harmonic compensation unit 11 calculates the order N using Equation 1.

N = Fsw / Finv Equation 1
Subsequently, the harmonic compensation unit 11 uses the order N calculated by the equation 1 and stores the d-axis compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw in association with the order N in the storage unit. With reference to the axis q-axis compensation voltage information, the d-axis compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw corresponding to the order N are obtained.

The d-axis q-axis compensation voltage information includes, for example, a degree N (a plurality of different order ranges “N1”, “N2” to “Nn”) and a d-axis compensation voltage value Vd_sw (order range “N1”) associated with the degree N. "Vd_sw_N1" corresponding to, "Vd_sw_N2" corresponding to the order range "N2" to "Vd_sw_Nn" corresponding to the degree range "Nn", and the q-axis compensation voltage value Vq_sw associated with the degree N (order range "N1"). Is a table associated with "Vq_sw_N1" corresponding to "Vq_sw_N1", "Vq_sw_N2" corresponding to the degree range "N2" to "Vq_sw_Nn" corresponding to the degree range "Nn", and n is a positive integer. is there.

For example, when the order N calculated by Equation 1 is included in the order range "N1" of the d-axis q-axis compensation voltage information, the d-axis compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw are in the order range "N1". It becomes "Vd_sw_N1" corresponding to "" and "Vq_sw_N1" corresponding to the degree range "N1".

The d-axis compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw associated with the order N are obtained in advance by using experiments and simulations.
Subsequently, the harmonic compensation unit 11 outputs the obtained d-axis compensation voltage value Vd_sw to the adder 9, and outputs the obtained q-axis compensation voltage value Vq_sw to the adder 10.

In this way, the d-axis compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw, which are the opposite components of the torque ripple caused by PWM, are obtained using the order N, and the d-axis voltage command value V ″ d * and the d-axis compensation voltage are obtained. The value Vd_sw is added by the adder 9 to calculate the d-axis voltage command value V ″'d *, and the q-axis voltage command value V ″ q * and the q-axis compensation voltage value Vq_sw are added by the adder 10. By calculating the q-axis voltage command value V ″'q *, the torque ripple caused by PWM in the motor 22 can be reduced.

Further, since the torque ripple caused by PWM can be reduced, the hearing noise of the motor 22 can be reduced.

Further, since the torque ripple caused by PWM can be reduced only by changing the software executed by the control circuit 1 without adding hardware, it is possible to suppress the price increase of the motor control device.

<Modification 1>
The harmonic compensation unit 11 of the first modification will be described.

FIG. 2 is a diagram showing an embodiment of the harmonic compensation unit 11 of the modified example 1. The harmonic compensation unit 11 of FIG. 2 includes a degree calculation unit 201, a U-phase compensation voltage calculation unit 202u, a V-phase compensation voltage calculation unit 202v, a W-phase compensation voltage calculation unit 202w, and a coordinate conversion unit 203.

In the harmonic compensation unit 11 of FIG. 2, first, the order calculation unit 201 calculates the order N by dividing the switching frequency Fsw by the fundamental frequency Finv. See Equation 1.
Subsequently, the U-phase compensation voltage calculation unit 202u acquires the order N, the phase θe, the U-phase initial phase θu, and the U-phase compensation voltage amplitude Ku.

The U-phase compensation voltage amplitude Ku is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The U-phase compensation voltage calculation unit 202u uses the order N to refer to the compensation voltage amplitude information stored in the storage unit in which the U-phase compensation voltage amplitude Ku is associated with the order N and refers to the U-phase corresponding to the order N. The compensation voltage amplitude Ku is obtained.

The compensated voltage amplitude information corresponds, for example, to a degree N (plurality of different order ranges “Nu1”, “Nu2” to “Nun”) and a U-phase compensated voltage amplitude Ku (order range “Nu1”) associated with the degree N. It is a table associated with "Ku_Nu1", "Ku_Nu2" corresponding to the degree range "Nu2" to "Ku_Nun" corresponding to the degree range "Nun"). Further, n is a positive integer. For example, when the order N calculated by the equation 1 is included in the order range "Nu1" of the compensation voltage amplitude information, the U-phase compensation voltage amplitude Ku is "Ku_Nu1" corresponding to the order range "Nu1". The U-phase compensation voltage amplitude Ku is obtained in advance by experiments and simulations.

Further, the U-phase compensation voltage calculation unit 202u acquires the U-phase initial phase θu from the storage unit. The U-phase compensation voltage calculation unit 202u uses the order N to refer to the initial phase information stored in the storage unit in which the U-phase initial phase θu is associated with the order N and refers to the U-phase initial phase corresponding to the order N. Find θu.

The initial phase information includes, for example, the order N (plurality of different order ranges “Nθu1”, “Nθu2” to “Nθun”) and the U-phase initial phase θu (θu_Nθu1) corresponding to the order N (order range “Nθu1”). , And "θu_Nθu2" corresponding to the degree range "Nθu2" to "θu_Nθun" corresponding to the degree range "Nθun"). Further, n is a positive integer. For example, when the order N calculated by the equation 1 is included in the order range “Nθu1” of the initial phase information, the U-phase initial phase θu becomes “θu_Nθu1” corresponding to the order range “Nθu1”. The U-phase initial phase θu is obtained in advance by experiments and simulations.

Subsequently, the U-phase compensation voltage calculation unit 202u calculates the U-phase compensation voltage value Vu_sw using Equation 2.
Vu_sw = Ku × sin (N × θe + θu) Equation 2
Further, the V-phase compensation voltage calculation unit 202v acquires the order N, the phase θe, the V-phase initial phase θv, and the V-phase compensation voltage amplitude Kv.

The V-phase compensation voltage amplitude Kv is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The V-phase compensation voltage calculation unit 202v uses the order N to refer to the compensation voltage amplitude information stored in the storage unit in which the V-phase compensation voltage amplitude Kv is associated with the order N and refers to the V-phase corresponding to the order N. The compensation voltage amplitude Kv is obtained.

The compensated voltage amplitude information corresponds, for example, to a degree N (plurality of different order ranges “Nv1”, “Nv2” to “Nvn”) and a V-phase compensated voltage amplitude Kv (order range “Nv1”) associated with the degree N. It is a table in which "Kv_Nv1" and "Kv_Nv2" corresponding to the degree range "Nv2" to "Kv_Nvn" corresponding to the degree range "Nvn") are associated with each other. Further, n is a positive integer. For example, when the order N calculated by the equation 1 is included in the order range “Nv1” of the compensation voltage amplitude information, the V-phase compensation voltage amplitude Kv is “Kv_Nv1” corresponding to the order range “Nv1”. The V-phase compensation voltage amplitude Kv is obtained in advance by experiments and simulations.

Further, the V-phase compensation voltage calculation unit 202v acquires the V-phase initial phase θv from the storage unit. The V-phase compensation voltage calculation unit 202v uses the order N to refer to the initial phase information stored in the storage unit in which the V-phase initial phase θv is associated with the order N and refers to the V-phase initial phase corresponding to the order N. Find θv.

The initial phase information includes, for example, a degree N (plurality of different order ranges “Nθv1”, “Nθv2” to “Nθvn”) and a V-phase initial phase θv (θv_Nθv1) corresponding to the order N (order range “Nθv1”). , And "θv_Nθv2" corresponding to the degree range "Nθv2" to "θv_Nθvn" corresponding to the degree range "Nθvn"). Further, n is a positive integer. For example, when the order N calculated by the equation 1 is included in the order range “Nθv1” of the initial phase information, the V-phase initial phase θv becomes “θv_Nθv1” corresponding to the order range “Nθv1”. The initial phase θv of the V phase is obtained in advance by experiments and simulations.

Subsequently, the V-phase compensation voltage calculation unit 202v calculates the V-phase compensation voltage value Vv_sw using Equation 3.
Vv_sw = Kv × sin (N × θe + θv) Equation 3
Further, the W phase compensation voltage calculation unit 202w acquires the order N, the phase θe, the W phase initial phase θw, and the W phase compensation voltage amplitude Kw.

The W-phase compensation voltage amplitude Kw is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The W phase compensation voltage calculation unit 202w uses the order N to refer to the compensation voltage amplitude information stored in the storage unit in which the W phase compensation voltage amplitude Kw is associated with the order N and refers to the W phase corresponding to the order N. The compensation voltage amplitude Kw is obtained.

The compensated voltage amplitude information corresponds to, for example, a degree N (plurality of different order ranges “Nw1”, “Nw2” to “Nwn”) and a W-phase compensation voltage amplitude Kw (order range “Nw1”) associated with the degree N. It is a table in which "Kw_Nw1" and "Kw_Nw2" corresponding to the degree range "Nw2" to "Kw_Nwn" corresponding to the degree range "Nwn") are associated with each other. Further, n is a positive integer. For example, when the order N calculated by the equation 1 is included in the order range “Nw1” of the compensation voltage amplitude information, the W phase compensation voltage amplitude Kw is “Kw_Nw1” corresponding to the order range “Nw1”. The W-phase compensation voltage amplitude Kw is obtained in advance by experiments and simulations.

Further, the W phase compensation voltage calculation unit 202w acquires the W phase initial phase θw from the storage unit. The W-phase compensation voltage calculation unit 202w uses the order N to refer to the initial phase information stored in the storage unit in which the W-phase initial phase θw is associated with the order N and refers to the W-phase initial phase corresponding to the order N. Find θw.

The initial phase information includes, for example, the order N (plurality of different order ranges "Nθw1", "Nθw2" to "Nθwn") and the W phase initial phase θw associated with the order N (the order range "Nθw1", "θw_Nθw1". , And "θw_Nθw2" corresponding to the degree range "Nθw2" to "θw_Nθwn" corresponding to the degree range "Nθwn"). Further, n is a positive integer. For example, when the order N calculated by the equation 1 is included in the order range “Nθw1” of the initial phase information, the W phase initial phase θw becomes “θw_Nθw1” corresponding to the order range “Nθw1”. The W phase initial phase θw is obtained in advance by experiments and simulations.

Subsequently, the W-phase compensation voltage calculation unit 202w calculates the W-phase compensation voltage value Vw_sw using Equation 4.
Vw_sw = Kw × sin (N × θe + θw) Equation 4
Subsequently, the coordinate conversion unit 203 converts the U-phase compensation voltage value Vu_sw, the V-phase compensation voltage value Vv_sw, and the W-phase compensation voltage value Vw_sw from the three-phase AC coordinate system to the d-axis q-axis coordinate system, and performs d-axis compensation. The voltage value Vd_sw and the q-axis compensation voltage value Vq_sw are obtained.

In this way, the order is obtained by referring to the compensation voltage amplitude information using the order N and obtaining the U-phase compensation voltage amplitude Ku, the V-phase compensation voltage amplitude Kv, and the W-phase compensation voltage amplitude Kw corresponding to the order N. Since the U-phase compensation voltage amplitude Ku, the V-phase compensation voltage amplitude Kv, and the W-phase compensation voltage amplitude Kw corresponding to N can be obtained in a timely manner, torque ripple caused by PWM in the motor 22 can be further reduced as compared with the first embodiment.

Further, since the torque ripple caused by PWM can be further reduced as compared with the first embodiment, the hearing noise of the motor 22 can be further reduced.
Further, since the torque ripple caused by PWM can be reduced only by changing the software executed by the control circuit 1 without adding hardware, it is possible to suppress the price increase of the motor control device.

Constants may be used for each of the U-phase compensation voltage amplitude Ku, the V-phase compensation voltage amplitude Kv, and the W-phase compensation voltage amplitude Kw. Further, constants may be used for each of the U-phase initial phase θu, the V-phase initial phase θv, and the W-phase initial phase θw.

Although the adder 9 is arranged between the adder 6 and the adder 12 in FIG. 1, the adder 9 may be arranged between the PI control unit 4 and the adder 6. It may be arranged between the adder 12 and the coordinate conversion unit 15. Further, although the adder 10 is arranged between the adder 7 and the adder 13 in FIG. 1, the adder 10 may be arranged between the PI control unit 5 and the adder 7. It may be arranged between the adder 13 and the coordinate conversion unit 15.

<Embodiment 2>
FIG. 3 is a diagram showing an embodiment of the second embodiment. The motor control device shown in FIG. 3 includes a control circuit 30 (subtractor 2, subtractor 3, PI control unit 4, PI control unit 5, adder 6, adder 7, non-interference voltage compensation unit 8, adder 12). Adder 13, harmonic compensation unit 14, coordinate conversion unit 15, PWM control unit 16, coordinate conversion unit 17, switching frequency calculation unit 31, harmonic compensation unit 32, adder 33 (first adder), adder It has 34 (second adder), adder 35 (third adder)), inverter circuit 18, current sensor 19, current sensor 20, position detection unit 21, and the like, and controls the motor 22.

The difference between the first embodiment and the second embodiment is that in the first embodiment, the adder 9, the adder 10, and the harmonic compensation unit 11 are used in the d-axis q-axis coordinate system, and the d-axis is the reverse component of the torque ripple caused by PWM. The compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw were calculated, and the d-axis compensation voltage value Vd_sw and the q-axis compensation voltage value Vq_sw were used to reduce the torque ripple caused by PWM. However, in the second embodiment, the switching frequency is reduced. The calculation unit 31, the harmonic compensation unit 32, the adder 33, the adder 34, and the adder 35 are used to reduce the torque ripple caused by PWM. That is, in the first embodiment, measures are taken to reduce the torque ripple caused by PWM in the d-axis q-axis coordinate system, but in the second embodiment, measures are taken to reduce the torque ripple caused by PWM in the three-phase AC coordinate system.

The adder 12 of the second embodiment adds the d-axis voltage command value V ″ d * and the d-axis compensation voltage value Vd_mtr to calculate the d-axis voltage command value Vd * (= V ″ d * + Vd_mtr). Further, the adder 13 of the second embodiment adds the q-axis voltage command value V "q * and the q-axis compensation voltage value Vq_mtr to calculate the q-axis voltage command value Vq * (= V" q * + Vq_mtr). ..

The switching frequency calculation unit 31 acquires the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw *, and U-phase switching frequency Fsw_u, V-phase switching frequency Fsw_v, and W-phase switching. The frequency Fsw_w is calculated.

The harmonic compensation unit 32 uses the switching frequencies Fsw_u, Fsw_v, and Fsw_w of the three phases when PWM-controlling the inverter circuit 18 and the basic frequency Finv of the basic current flowing through the motor 22, and the switching frequencies Fsw_u, Fsw_v, Fsw_w. Calculate the order Nu, Nv, Nw of the torque ripple caused by PWM for each basic frequency Finv, and use the order Nu, Nv, Nw to obtain the U-phase compensation voltage which is the reverse component of the torque ripple caused by the PWM of each of the three phases. The values Vu_sw, the V-phase compensation voltage value Vv_sw, and the W-phase compensation voltage value Vw_sw are obtained.

The adder 33 adds the U-phase voltage command value V'u * and the U-phase compensation voltage value Vu_sw to calculate the U-phase voltage command value Vu * (= V'u * + Vu_sw). The adder 34 adds the V-phase voltage command value V'v * and the V-phase compensation voltage value Vv_sw to calculate the V-phase voltage command value Vv * (= V'v * + Vv_sw). The adder 35 adds the W-phase voltage command value V'w * and the W-phase compensation voltage value Vw_sw to calculate the W-phase voltage command value Vw * (= V'w * + Vw_sw).

The motor control device of the second embodiment will be described.
The same part as in the first embodiment will be omitted.
The V "d * input terminal (+) of the adder 12 is connected to the V" d * output terminal of the adder 6. The V "q * input terminal (+) of the adder 13 is connected to the V" q * output terminal of the adder 7.

The Vd_mtr output terminal of the harmonic compensation unit 14 is connected to the Vd_mtr input terminal (+) of the adder 12, and the Vd * input terminal of the coordinate conversion unit 15 is connected to the Vd * output terminal of the adder 12. The Vq_mtr output terminal of the harmonic compensation unit 14 is connected to the Vq_mtr input terminal (+) of the adder 13, and the Vq * input terminal of the coordinate conversion unit 15 is connected to the Vq * output terminal of the adder 13.

The Fsw_u output terminal of the switching frequency calculation unit 31 is connected to the Fsw_u input terminal of the harmonic compensation unit 32, and the Fsw_v input terminal of the harmonic compensation unit 32 is connected to the Fsw_v output terminal of the switching frequency calculation unit 31. The Fsw_w output terminal of the switching frequency calculation unit 31 is connected to the Fsw_w input terminal of the compensation unit 32.

The Vu'* output terminal of the coordinate conversion unit 15 is connected to the Vu'* input terminal of the adder 33, and the Vu_sw output terminal of the harmonic compensation unit 32 is connected to the Vu_sw input terminal of the adder 33. The Vu * input terminal of the PWM control unit 16 is connected to the Vu * output terminal of.

The Vv'* output terminal of the coordinate conversion unit 15 is connected to the Vv'* input terminal of the adder 34, and the Vv_sw output terminal of the harmonic compensation unit 32 is connected to the Vv_sw input terminal of the adder 34. The Vv * input terminal of the PWM control unit 16 is connected to the Vv * output terminal of.

The Vw'* output terminal of the coordinate conversion unit 15 is connected to the Vw'* input terminal of the adder 35, and the Vw_sw output terminal of the harmonic compensation unit 32 is connected to the Vw_sw input terminal of the adder 35. The Vw * input terminal of the PWM control unit 16 is connected to the Vw * output terminal of.

The position detection unit 21 is connected to the motor 22, and the θe input terminal of the harmonic compensation unit 14, the θe input terminal of the harmonic compensation unit 32, and the θe input terminal of the coordinate conversion unit 15 are connected to the θe output terminal of the position detection unit 21. And are connected.

The switching frequency calculation unit 31 of the second embodiment will be described.
The switching frequency calculation unit 31 acquires, for example, the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw *, and the acquired U-phase voltage command value Vu * and the V-phase voltage. The switching frequency Fsw is calculated by referring to the signal (square wave) for PWM control generated based on the command value Vv * and the W phase voltage command value Vw *.

As a method of calculating the switching frequency Fsw, for example, the rise time t1 (the time when the low level is shifted to the high level) and the next rise time t2 of the signal for PWM control are detected, and the time t2 and the time t1 are set. Fsw is calculated based on the difference T1 (= t2-t1). Alternatively, the fall time t3 (time of transition from high level to low level) of the signal for PWM control and the next fall time t4 are detected, and the difference T2 (= t4-t3) between the time t4 and the time t3 is detected. ) May be used to calculate Fsw. Further, the average of the difference T1 and the difference T2 ((T1 + T2) / 2) may be calculated, and Fsw may be calculated based on the average. The switching frequency Fsw is obtained for each of the U phase, the V phase, and the W phase. That is, the U-phase switching frequency Fsw_u is obtained for the U-phase voltage command value Vu *, the V-phase switching frequency Fsw_v is obtained for the V-phase voltage command value Vv *, and the W-phase voltage command value Vw * is obtained. Finds the W-phase switching frequency Fsw_w.

The harmonic compensation unit 32 of the second embodiment will be described.
First, the harmonic compensation unit 32 sets the U-phase switching frequency Fsw_u, the V-phase switching frequency Fsw_v, and the W-phase switching frequency Fsw_w when performing PWM control on the inverter circuit 18, respectively, as the basic frequency Finv of the basic current flowing through the motor 22. Divide by, and calculate the U-phase order Nu corresponding to the U-phase switching frequency Fsw_u, the V-phase order Nv corresponding to the V-phase switching frequency Fsw_v, and the W-phase order Nw corresponding to the W-phase switching frequency Fsw_w. That is, the harmonic compensation unit 32 calculates the orders Nu, Nv, and Nw using the equations 5, 6, and 7.

Nu = Fsw_u / Finv Equation 5
Nv = Fsw_v / Finv Equation 6
Nw = Fsw_w / Finv formula 7
Subsequently, the harmonic compensation unit 32 uses the U-phase order Nu, the V-phase order Nv, and the W-phase order Nw of each of the three phases calculated by Equations 5, 6, and 7 to obtain the U-phase. The U-phase compensation voltage value Vu_sw is associated with the order Nu, the V-phase compensation voltage value Vv_sw is associated with the V-phase order Nv, and the W-phase compensation voltage value Vw_sw is associated with the W-phase order Nw and stored in the storage unit. It corresponds to the U-phase compensation voltage value Vu_sw corresponding to the U-phase order Nu, the V-phase compensation voltage value Vv_sw corresponding to the V-phase order Nv, and the W-phase order by referring to the three-phase compensation voltage information. The W-phase compensation voltage value Vw_sw is obtained.

The three-phase compensation voltage information includes, for example, a U-phase table, a V-phase table, and a W-phase table. The U-phase table corresponds to the U-phase order Nu (several different degree ranges "Nu_u1" "Nu_u2" to "Nu_un") and the U-phase compensation voltage value Vu_sw associated with the degree Nu (order range "Nu_u1"). "Vu_sw_Nu1", "Vu_sw_Nu2" corresponding to the degree range "Nu_u2" to "Vu_sw_Nun" corresponding to the degree range "Nn_un") are associated with each other.

The V-phase table corresponds to the V-phase order Nv (several different order ranges "Nv_v1" "Nv_v2" to "Nv_vn") and the V-phase compensation voltage value Vv_sw (order range "Nv_v1") associated with the order Nv. "Vv_sw_Nv1", "Vv_sw_Nv2" corresponding to the degree range "Nv_v2" to "Vv_sw_Nvn" corresponding to the degree range "Nv_vn") are associated with each other.

The W-phase table corresponds to the W-phase order Nw (plurality of different order ranges "Nw_w1", "Nw_w2" to "Nw_wn") and the W-phase compensation voltage value Vw_sw associated with the order Nw (order range "Nw_w1"). "Vw_sw_Nw1", "Vw_sw_Nw2" corresponding to the degree range "Nw_w2" to "Vw_sw_Nwn" corresponding to the degree range "Nw_wn") are associated with each other.

Further, n is a positive integer.
For example, when the U-phase order Nu calculated by the equation 5 is included in the order range “Nu_u1” of the three-phase compensation voltage information, the U-phase compensation voltage value Vu_sw is “Vu_sw_Nu1” corresponding to the order range “Nu_u1”. ".

The U-phase compensation voltage value Vu_sw associated with the U-phase order Nu, the V-phase compensation voltage value Vv_sw associated with the V-phase order Nv, and the W-phase compensation voltage value associated with the W-phase order Nw. Vw_sw is obtained in advance by using experiments and simulations.

Subsequently, the harmonic compensation unit 32 outputs the obtained U-phase compensation voltage value Vu_sw to the adder 33, outputs the obtained V-phase compensation voltage value Vv_sw to the adder 34, and outputs the obtained W-phase compensation voltage value Vw_sw. Is output to the adder 35.

In this way, using the U-phase order Nu, the V-phase order Nv, and the W-phase order Nw, the U-phase compensation voltage value Vu_sw corresponding to the U-phase order Nu, which is the reverse component of the torque ripple caused by PWM, and , V-phase compensation voltage value Vv_sw corresponding to V-phase order Nv and W-phase compensation voltage value Vw_sw corresponding to W-phase order are obtained individually, and U-phase voltage command value V'u * and U-phase compensation voltage are obtained. The value Vu_sw is added by the adder 33 to calculate the U-phase voltage command value Vu *, and the V-phase voltage command value V'v * and the V-phase compensation voltage value Vv_sw are added by the adder 34 to calculate the V-phase voltage. The PWM in the motor 22 is calculated by calculating the command value Vv * and adding the W-phase voltage command value V'w * and the W-phase compensation voltage value Vw_sw with the adder 35 to calculate the W-phase voltage command value Vw *. The torque ripple caused by the voltage can be reduced.

Further, since the U-phase switching frequency Fsw_u, the V-phase switching frequency Fsw_v, and the W-phase switching frequency Fsw_w are used, torque ripple caused by PWM in the motor 22 can be accurately reduced.

Further, since the torque ripple caused by PWM can be reduced, the hearing noise of the motor 22 can be reduced.
Further, since the torque ripple caused by PWM can be reduced only by changing the software executed by the control circuit 30 without adding hardware, it is possible to suppress the price increase of the motor control device.

<Modification 2>
The harmonic compensation unit 32 of the second modification will be described.

FIG. 4 is a diagram showing an embodiment of the harmonic compensation unit 32 of the modification 2. The harmonic compensation unit 32 of FIG. 4 includes a U-phase order calculation unit 401u, a V-phase order calculation unit 401v, a W-phase order calculation unit 401w, a U-phase compensation voltage calculation unit 402u, a V-phase compensation voltage calculation unit 402v, and a W-phase compensation. It has a voltage calculation unit 402w.

In the harmonic compensation unit 32 of FIG. 4, first, the U-phase order calculation unit 401u divides the switching frequency Fsw_u by the fundamental frequency Finv to calculate the order Nu, and the V-phase order calculation unit 401v sets the switching frequency Fsw_v to the fundamental frequency Finv. The order Nv is calculated by dividing by, and the W phase order calculation unit 401w divides the switching frequency Fsw_w by the fundamental frequency Finv to calculate the order Nw. See Equation 5, Equation 6, and Equation 7.

Subsequently, the U-phase compensation voltage calculation unit 402u acquires the order Nu, the phase θe, the U-phase initial phase θu, and the U-phase compensation voltage amplitude Ku.
The U-phase compensation voltage amplitude Ku is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The U-phase compensation voltage calculation unit 402u uses the order Nu to refer to the U-phase compensation voltage amplitude information stored in the storage unit in which the U-phase compensation voltage amplitude Ku is associated with the order Nu and corresponds to the order Nu. The U-phase compensation voltage amplitude Ku is obtained.

The U-phase compensated voltage amplitude information is, for example, in the order Nu (plurality of different order ranges "Nuu1" "Nuu2" to "Nuun") and the U-phase compensated voltage amplitude Ku associated with the order Nu (order range "Nu1"). It is a table associated with the corresponding "Ku_Nuu1", the "Ku_Nuu2" corresponding to the degree range "Nu2" to the "Ku_Nuun" corresponding to the degree range "Nuun"). Further, n is a positive integer. For example, when the order Nu calculated by the equation 5 is included in the order range “Nuu1” of the U-phase compensation voltage amplitude information, the U-phase compensation voltage amplitude Ku is “Ku_Nuu1” corresponding to the order range “Nuu1”. Become. The U-phase compensation voltage amplitude Ku is obtained in advance by experiments and simulations.

Further, the U-phase compensation voltage calculation unit 402u acquires the U-phase initial phase θu from the storage unit. The U-phase compensation voltage calculation unit 402u uses the order Nu to refer to the U-phase initial phase information stored in the storage unit in which the U-phase initial phase θu is associated with the order Nu, and the U-phase corresponding to the order Nu. Find the initial phase θu.

The U-phase initial phase information corresponds to, for example, a degree Nu (plurality of different order ranges “Nθuu1”, “Nθuu2” to “Nθuuun”) and a U-phase initial phase θu (order range “Nθuu1”) associated with the order Nu. It is a table in which "θu_Nθuu1", "θu_Nθuu2" corresponding to the degree range "Nθuu2" to "θu_Nθuuun" corresponding to the degree range "Nθuuun") are associated with each other. Further, n is a positive integer. For example, when the order Nu calculated by the equation 5 is included in the order range “Nθuu1” of the U-phase initial phase information, the U-phase initial phase θu becomes “θu_Nθuu1” corresponding to the order range “Nθuu1”. The U-phase initial phase θu is obtained in advance by experiments and simulations.

Subsequently, the U-phase compensation voltage calculation unit 402u calculates the U-phase compensation voltage value Vu_sw using Equation 8.
Vu_sw = Ku × sin (Nu × θe + θu) Equation 8
Further, the V-phase compensation voltage calculation unit 402v acquires the order Nv, the phase θe, the V-phase initial phase θv, and the V-phase compensation voltage amplitude Kv.

The V-phase compensation voltage amplitude Kv is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The V-phase compensation voltage calculation unit 402v uses the order Nv to refer to the V-phase compensation voltage amplitude information stored in the storage unit in which the V-phase compensation voltage amplitude Kv is associated with the order Nv and corresponds to the order Nv. The V-phase compensation voltage amplitude Kv is obtained.

The V-phase compensation voltage amplitude information is, for example, in order Nv (plurality of different order ranges “Nvv1” “Nvv2” to “Nvvn”) and V-phase compensation voltage amplitude Kv (order range “Nvv1”) associated with the order Nv. It is a table in which the corresponding "Kv_Nvv1", the "Kv_Nvv2" corresponding to the degree range "Nvv2" to the "Kv_Nvvn" corresponding to the degree range "Nvvn") are associated with each other. Further, n is a positive integer. For example, when the order Nv calculated by the equation 6 is included in the order range "Nvv1" of the V-phase compensation voltage amplitude information, the V-phase compensation voltage amplitude Kv is "Kv_Nvv1" corresponding to the order range "Nvv1". Become. The V-phase compensation voltage amplitude Kv is obtained in advance by experiments and simulations.

Further, the V-phase compensation voltage calculation unit 402v acquires the V-phase initial phase θv from the storage unit. The V-phase compensation voltage calculation unit 402v uses the order Nv to refer to the V-phase initial phase information stored in the storage unit in which the V-phase initial phase θv is associated with the order Nv and refers to the V-phase corresponding to the order Nv. Find the initial phase θv.

The V-phase initial phase information corresponds to, for example, a degree Nv (several different order ranges “Nθvv1” “Nθvv2” to “Nθvvn”) and a V-phase initial phase θv (order range “Nθvv1”” associated with the order Nv. It is a table in which "θv_Nθvv1", "θv_Nθvv2" corresponding to the degree range "Nθvv2" to "θv_Nθvvn" corresponding to the degree range "Nθvvn") are associated with each other. Further, n is a positive integer. For example, when the order Nv calculated by the equation 6 is included in the order range “Nθvv1” of the V-phase initial phase information, the V-phase initial phase θv becomes “θv_Nθvv1” corresponding to the order range “Nθvv1”. The initial phase θv of the V phase is obtained in advance by experiments and simulations.

Subsequently, the V-phase compensation voltage calculation unit 402v calculates the V-phase compensation voltage value Vv_sw using Equation 9.
Vv_sw = Kv × sin (Nv × θe + θv) Equation 9
Further, the W phase compensation voltage calculation unit 402w acquires the order Nw, the phase θe, the W phase initial phase θw, and the W phase compensation voltage amplitude Kw.

The W-phase compensation voltage amplitude Kw is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The W-phase compensation voltage calculation unit 402w uses the order Nw to refer to the W-phase compensation voltage amplitude information stored in the storage unit in which the W-phase compensation voltage amplitude Kw is associated with the order Nw and corresponds to the order Nw. The W-phase compensation voltage amplitude Kw is obtained.

The W-phase compensation voltage amplitude information is, for example, in the order Nw (plurality of different order ranges "Nww1", "Nww2" to "Nwwn") and the W-phase compensation voltage amplitude Kw associated with the order Nw (order range "Nww1"). It is a table in which the corresponding "Kw_Nww1", the "Kw_Nww2" corresponding to the degree range "Nww2" to the "Kw_Nwwn" corresponding to the degree range "Nwwn") are associated with each other. Further, n is a positive integer. For example, when the order Nw calculated by the equation 7 is included in the order range "Nww1" of the W phase compensation voltage amplitude information, the W phase compensation voltage amplitude Kw is "Kw_Nww1" corresponding to the order range "Nww1". Become. The W-phase compensation voltage amplitude Kw is obtained in advance by experiments and simulations.

Further, the W phase compensation voltage calculation unit 402w acquires the W phase initial phase θw from the storage unit. The W phase compensation voltage calculation unit 402w uses the order Nw to refer to the W phase initial phase information stored in the storage unit in which the W phase initial phase θw is associated with the order Nw and refers to the W phase corresponding to the order Nw. Find the initial phase θw.

The W phase initial phase information corresponds to, for example, a degree Nw (a plurality of different order ranges “Nθww1”, “Nθww2” to “Nθwwn”) and a W phase initial phase θw (order range “Nθww1”) associated with the order Nw. It is a table in which "θw_Nθww1", "θw_Nθww2" corresponding to the degree range "Nθww2" to "θw_Nθwwn" corresponding to the degree range "Nθwwn") are associated with each other. Further, n is a positive integer. For example, when the order Nw calculated by the equation 7 is included in the order range “Nθww1” of the W phase initial phase information, the W phase initial phase θw becomes “θw_Nθww1” corresponding to the order range “Nθww1”. The W phase initial phase θw is obtained in advance by experiments and simulations.

Subsequently, the W-phase compensation voltage calculation unit 402w calculates the W-phase compensation voltage value Vw_sw using Equation 10.
Vw_sw = Kw × sin (Nw × θe + θw) Equation 10
In this way, using the orders Nu, Nv, and Nw, the U-phase compensation voltage amplitude information, the V-phase compensation voltage amplitude information, and the W-phase compensation voltage amplitude information are referred to, and the U-phase compensation voltage amplitude Ku corresponding to the order Nu is obtained. By obtaining the V-phase compensation voltage amplitude Kv corresponding to the order Nv and obtaining the W-phase compensation voltage amplitude Kw corresponding to the order Nw, the U-phase compensation voltage amplitude Ku corresponding to the order Nu and the V corresponding to the order Nv are obtained. Since the W-phase compensation voltage amplitude Kw corresponding to the phase compensation voltage amplitude Kv and the order Nw can be obtained in a timely manner, torque ripple caused by PWM in the motor 22 can be further reduced as compared with the second embodiment.

Further, since the torque ripple caused by PWM can be further reduced as compared with the second embodiment, the hearing noise of the motor 22 can be further reduced.
Further, since the torque ripple caused by PWM can be reduced only by changing the software executed by the control circuit 30 without adding hardware, it is possible to suppress the price increase of the motor control device.

<Modification example 3>
FIG. 5 is a diagram showing an embodiment of Modification 3. The motor control device shown in FIG. 5 includes a control circuit 50 (subtractor 2, subtractor 3, PI control unit 4, PI control unit 5, adder 6, adder 7, non-interference voltage compensation unit 8, adder 12). Adder 13, harmonic compensation unit 14, coordinate conversion unit 15, PWM control unit 16, coordinate conversion unit 17, switching frequency calculation unit 51, harmonic compensation unit 32, adder 33 (first adder), adder It has 34 (second adder), adder 35 (third adder)), inverter circuit 18, current sensor 19, current sensor 20, position detection unit 21, and the like, and controls the motor 22.

The difference between the third modification and the second embodiment and the second modification is that in the second embodiment and the second modification, the switching frequency calculation unit 31 is used to calculate the U-phase switching frequency Fsw_u from the U-phase voltage command value Vu *. The V-phase switching frequency Fsw_v was calculated from the V-phase voltage command value Vv *, and the W-phase switching frequency Fsw_w was calculated from the W-phase voltage command value Vw *. However, in the modified example 3, the switching frequency calculation unit 51 is used. , U-phase switching frequency Fsw_u is calculated from U-phase current value iu, V-phase switching frequency Fsw_v is calculated from V-phase current value iv, and W-phase switching frequency Fsw_w is calculated from W-phase current value iw.

The switching frequency calculation unit 51 acquires the U-phase current value iu, the V-phase current value iv, and the W-phase current value iwa, and the noise component of the U-phase current value iu, the noise component of the V-phase current value iv, and the W-phase current value. The noise component of iw is removed, the U-phase current value iu from which the noise component is removed is used to calculate the U-phase switching frequency Fsw_u, and the V-phase current value iv from which the noise component is removed is used to calculate the V-phase switching frequency Fsw_v. , The W-phase switching frequency Fsw_w is calculated using the W-phase current value iw from which the noise component has been removed. The W-phase current value iwa may be obtained based on the U-phase current value iu and the V-phase current value iv.

Further, as a method of removing the noise component, for example, a bandpass filter or an FFT (Fast Fourier Transform) may be used. The pass bandwidth is determined based on the PWM duty change rate.

In this way, using the U-phase current value iu, the V-phase current value iv, and the W-phase current value iwa from which the noise component has been removed, the U-phase switching frequency Fsw_u, the V-phase switching frequency Fsw_v, and the W-phase switching frequency Fsw_w are set. By calculating and obtaining the frequencies Nu, Nv, and Nw, it is possible to accurately obtain the U-phase compensation voltage value Vu_sw, the V-phase compensation voltage value Vv_sw, and the W-phase compensation voltage value Vw_sw. Therefore, torque ripple caused by PWM in the motor 22 can be reduced.

<Modification 4>
FIG. 6 is a diagram showing an embodiment of the modified example 4. The motor control device shown in FIG. 6 includes a control circuit 60 (subtractor 2, subtractor 3, PI control unit 4, PI control unit 5, adder 6, adder 7, non-interference voltage compensation unit 8, adder 12). Adder 13, harmonic compensation unit 14, coordinate conversion unit 15, PWM control unit 16, coordinate conversion unit 17, basic frequency calculation unit 61, harmonic compensation unit 62, adder 33 (first adder), adder It has 34 (second adder), adder 35 (third adder)), inverter circuit 18, current sensor 19, current sensor 20, position detection unit 21, and the like, and controls the motor 22.

In the second embodiment, the second modification, and the third modification, the switching frequency calculation unit 31 or the switching frequency calculation unit 51 is used to set the U-phase switching frequency Fsw_u based on the U-phase voltage command value Vu * or the U-phase current value iu. The U-phase compensation voltage value Vu_sw was calculated using the harmonic compensation unit 32, but in the modified example 4, the U-phase fundamental frequency Finv_u was calculated using the fundamental frequency calculation unit 61, and the harmonic compensation unit 62 was used. The U-phase compensation voltage value Vu_sw is calculated based on the order Nu obtained from the U-phase fundamental frequency Finv_u and the U-phase switching frequency Fsw_u.

Further, in the second embodiment, the second modification, and the third modification, the switching frequency calculation unit 31 or the switching frequency calculation unit 51 is used, and the V-phase switching frequency is based on the V-phase voltage command value Vv * or the V-phase current value iv. Fsw_v was calculated, and the V-phase compensation voltage value Vv_sw was calculated using the harmonic compensation unit 32. In the modified example 4, the fundamental frequency calculation unit 61 was used to calculate the V-phase fundamental frequency Finv_v, and the harmonic compensation unit Using 62, the V-phase compensation voltage value Vv_sw is calculated based on the order Nvv obtained from the V-phase fundamental frequency Finv_v and the V-phase switching frequency Fsw_v.

Further, in the second embodiment, the second modification, and the third modification, the W phase switching frequency is used based on the W phase voltage command value Vw * or the W phase current value iw by using the switching frequency calculation unit 31 or the switching frequency calculation unit 51. Fsw_w was calculated, and the W-phase compensation voltage value Vw_sw was calculated using the harmonic compensation unit 32. In the modified example 4, the W-phase fundamental frequency Finv_w was calculated using the fundamental frequency calculation unit 61, and the harmonic compensation unit Using 62, the W-phase compensation voltage value Vw_sw is calculated based on the order Nww obtained from the W-phase fundamental frequency Finv_w and the W-phase switching frequency Fsw_w.

The fundamental frequency calculation unit 61 acquires the U-phase current value iu, the V-phase current value iv, and the W-phase current value iwa, and the noise component of the U-phase current value iu, the noise component of the V-phase current value iv, and the W-phase current value. The noise component of iw is removed, the U-phase fundamental frequency Finv_u is calculated using the U-phase current value iu from which the noise component is removed, and the V-phase fundamental frequency Finv_v is calculated using the V-phase current value iv from which the noise component is removed. , The W-phase fundamental frequency Finv_w is calculated using the W-phase current value iw from which the noise component has been removed.

The W-phase fundamental frequency Finv_w may be obtained from the W-phase current value iw obtained based on the U-phase current value iu and the V-phase current value iv.
Further, as a method of removing the noise component, for example, a bandpass filter or an FFT can be used. When the motor 22 has a low rotation speed, the center frequency of the pass bandwidth is changed according to the rotation speed. Further, when the motor 22 rotates at a high speed, the setting is made in consideration of the change in the current cycle, the error of the position detection unit 21, the responsiveness of the system, and the like.

The harmonic compensation unit 62 uses the basic frequency Finv_u of the U-phase basic current and the U-phase switching frequency Fsw_u when PWM-controlling the inverter circuit 18, and the order Nuu of the torque ripple caused by PWM with respect to the basic frequency Finv_u. Is calculated, and the U-phase compensation voltage value Vu_sw, which is the reverse component of the torque ripple caused by the U-phase PWM, is obtained by using the order Nu. Further, the harmonic compensation unit 62 uses the fundamental frequency Finv_v of the V-phase fundamental current and the V-phase switching frequency Fsw_v when PWM-controlling the inverter circuit 18 to generate torque ripple caused by PWM with respect to the fundamental frequency Finv_v. The order Nvv is calculated, and the order Nvv is used to obtain the V-phase compensation voltage value Vv_sw, which is the reverse component of the torque ripple caused by the V-phase PWM. Further, the harmonic compensation unit 62 uses the fundamental frequency Finv_w of the W-phase fundamental current and the W-phase switching frequency Fsw_w when PWM control is performed on the inverter circuit 18, and torque ripple caused by PWM with respect to the fundamental frequency Finv_w. The order Nww is calculated, and the W phase compensation voltage value Vw_sw, which is the reverse component of the torque ripple caused by the PWM of the W phase, is obtained by using the order Nww.

FIG. 7 is a diagram showing an embodiment of the harmonic compensation unit 62 of the modified example 4. The harmonic compensation unit 62 of FIG. 7 includes a U-phase order calculation unit 701u, a V-phase order calculation unit 701v, a W-phase order calculation unit 701w, a U-phase compensation voltage calculation unit 702u, a V-phase compensation voltage calculation unit 702v, and a W-phase compensation. It has a voltage calculation unit 702w.

In the harmonic compensation unit 62 of FIG. 7, first, the U-phase order calculation unit 701u divides the switching frequency Fsw_u by the fundamental frequency Finv_u to calculate the order Nu, and the V-phase order calculation unit 701v calculates the switching frequency Fsw_v by the fundamental frequency Finv_v. The order Nvv is calculated by dividing by, and the W phase order calculation unit 701w divides the switching frequency Fsw_w by the fundamental frequency Finv_w to calculate the order Nww. See Equation 11, Equation 12, and Equation 13.

Nu = Fsw_u / Finv_u Equation 11
Nvv = Fsw_v / Finv_v Equation 12
Nww = Fsw_w / Finv_w Equation 13
Subsequently, the U-phase compensation voltage calculation unit 702u acquires the order Nu, the phase θe, the U-phase initial phase θu, and the U-phase compensation voltage amplitude Ku.

The U-phase compensation voltage amplitude Ku is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The U-phase compensation voltage calculation unit 702u uses the order Nuu to refer to the U-phase compensation voltage amplitude information stored in the storage unit in which the U-phase compensation voltage amplitude Ku is associated with the order Nuu and corresponds to the order Nuu. The U-phase compensation voltage amplitude Ku is obtained.

The U-phase compensated voltage amplitude information includes, for example, the order Nuu (several different order ranges "Nuu1'" "Nuu2'" to "Nuun'") and the U-phase compensated voltage amplitude Ku associated with the order Nuu (order range "Nuu1'" It is a table in which "Ku_Nuu1'" corresponding to "Nu1'" and "Ku_Nuu2'" corresponding to the degree range "Nu2'" to "Ku_Nuun'" corresponding to the degree range "Nuun'") are associated with each other. Further, n is a positive integer. For example, when the order Nu calculated by Equation 11 is included in the order range "Nuu1'" of the U-phase compensation voltage amplitude information, the U-phase compensation voltage amplitude Ku corresponds to the order range "Nuu1'" "Ku_Nuu1". ′ ”. The U-phase compensation voltage amplitude Ku is obtained in advance by experiments and simulations.

Further, the U-phase compensation voltage calculation unit 702u acquires the U-phase initial phase θu from the storage unit. The U-phase compensation voltage calculation unit 702u uses the order Nuu to refer to the U-phase initial phase information stored in the storage unit in which the U-phase initial phase θu is associated with the order Nuu and refers to the U-phase corresponding to the order Nuu. Find the initial phase θu.

The U-phase initial phase information includes, for example, a degree Nu (a plurality of different order ranges “Nθuu1 ′” and “Nθuu2 ′” to “Nθuun ′”) and a U-phase initial phase θu (order range “Nθuu1 ′” associated with the order Nuu). It is a table in which "θu_Nθuu1'" corresponding to "" and "θu_Nθuu2'" corresponding to the degree range "Nθuu2'" to "θu_Nθuuun'" corresponding to the degree range "Nθuun'") are associated with each other. Further, n is a positive integer. For example, when the order Nu calculated by Equation 11 is included in the order range “Nθuu1 ′” of the U-phase initial phase information, the U-phase initial phase θu is “θu_Nθuu1 ′” corresponding to the order range “Nθuu1 ′”. It becomes. The U-phase initial phase θu is obtained in advance by experiments and simulations.

Subsequently, the U-phase compensation voltage calculation unit 702u calculates the U-phase compensation voltage value Vu_sw using Equation 14.
Vu_sw = Ku × sin (Nu × θe + θu) Equation 14
Further, the V-phase compensation voltage calculation unit 702v acquires the order Nvv, the phase θe, the V-phase initial phase θv, and the V-phase compensation voltage amplitude Kv.

The V-phase compensation voltage amplitude Kv is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The V-phase compensation voltage calculation unit 702v uses the order Nvv to refer to the V-phase compensation voltage amplitude information stored in the storage unit in which the V-phase compensation voltage amplitude Kv is associated with the order Nvv and corresponds to the order Nvv. The V-phase compensation voltage amplitude Kv is obtained.

The V-phase compensated voltage amplitude information includes, for example, a degree Nvv (plurality of different order ranges "Nvv1'" "Nvv2'" to "Nvvn'") and a V-phase compensated voltage amplitude Kv associated with the degree Nvv (order range "Nvv1'"). It is a table in which "Kv_Nvv1'" corresponding to "Nvv1'" and "Kv_Nvvn'" corresponding to the degree range "Nvv2'" to "Kv_Nvvn'" corresponding to the degree range "Nvvn'") are associated with each other. Further, n is a positive integer. For example, when the order Nvv calculated by Equation 12 is included in the order range "Nvv1'" of the V-phase compensation voltage amplitude information, the V-phase compensation voltage amplitude Kv is "Kv_Nvv1" corresponding to the order range "Nvv1'". ′ ”. The V-phase compensation voltage amplitude Kv is obtained in advance by experiments and simulations.

Further, the V-phase compensation voltage calculation unit 702v acquires the V-phase initial phase θv from the storage unit. The V-phase compensation voltage calculation unit 702v uses the order Nvv to refer to the V-phase initial phase information stored in the storage unit in which the V-phase initial phase θv is associated with the order Nvv and refers to the V-phase corresponding to the order Nvv. Find the initial phase θv.

The V-phase initial phase information includes, for example, a degree Nvv (plurality of different order ranges "Nθvv1'" and "Nθvv2'" to "Nθvvn'") and a V-phase initial phase θv associated with the order Nvv (order range "Nθvv1'"). It is a table in which "θv_Nθvv1'" corresponding to "" and "θv_Nθvv2'" corresponding to the degree range "Nθvv2'" to "θv_Nθvvn'" corresponding to the degree range "Nθvvn'") are associated with each other. Further, n is a positive integer. For example, when the order Nvv calculated by Equation 12 is included in the order range "Nθvv1'" of the V-phase initial phase information, the V-phase initial phase θv is "θv_Nθvv1'" corresponding to the order range "Nθvv1'". It becomes. The initial phase θv of the V phase is obtained in advance by experiments and simulations.

Subsequently, the V-phase compensation voltage calculation unit 702v calculates the V-phase compensation voltage value Vv_sw using the equation 15.
Vv_sw = Kv × sin (Nvv × θe + θv) Equation 15
Further, the W phase compensation voltage calculation unit 702w acquires the order Nww, the phase θe, the W phase initial phase θw, and the V phase compensation voltage amplitude Kw.

The W-phase compensation voltage amplitude Kw is the amplitude of the inverse component for reducing the torque ripple caused by PWM, and is obtained as follows. The W-phase compensation voltage calculation unit 702w uses the order Nww to refer to the W-phase compensation voltage amplitude information stored in the storage unit in which the W-phase compensation voltage amplitude Kw is associated with the order Nww and corresponds to the order Nww. The W-phase compensation voltage amplitude Kw is obtained.

The W-phase compensated voltage amplitude information includes, for example, a degree Nww (a plurality of different order ranges "Nww1'" "Nww2'" to "Nwwn'") and a W-phase compensated voltage amplitude Kw (order range "Nww") associated with the degree Nww. It is a table in which "Kw_Nww1'" corresponding to "Nww1'" and "Kw_Nww2'" corresponding to the degree range "Nww2'" to "Kw_Nwwn'" corresponding to the degree range "Nwwn'") are associated with each other. Further, n is a positive integer. For example, when the order Nww calculated by the equation 13 is included in the order range "Nww1'" of the W phase compensation voltage amplitude information, the W phase compensation voltage amplitude Kw corresponds to the order range "Nww1'" "Kw_Nww1". ′ ”. The W-phase compensation voltage amplitude Kw is obtained in advance by experiments and simulations.

Further, the W phase compensation voltage calculation unit 702w acquires the W phase initial phase θw from the storage unit. The W phase compensation voltage calculation unit 702w uses the order Nww to refer to the W phase initial phase information stored in the storage unit in which the W phase initial phase θw is associated with the order Nww and refers to the W phase corresponding to the order Nww. Find the initial phase θw.

The W phase initial phase information includes, for example, a degree Nww (a plurality of different order ranges “Nθww1 ′” “Nθww2 ′” to “Nθwwn ′”) and a W phase initial phase θw associated with the order Nww (order range “Nθww1 ′”). It is a table in which "θw_Nθww1'" corresponding to "" and "θw_Nθww2'" corresponding to the degree range "Nθww2'" to "θw_Nθwwn'" corresponding to the degree range "Nθwwn'") are associated with each other. Further, n is a positive integer. For example, when the order Nww calculated by the equation 13 is included in the order range "Nθww1'" of the W phase initial phase information, the W phase initial phase θw is "θw_Nθww1'" corresponding to the order range "Nθww1'". It becomes. The W phase initial phase θw is obtained in advance by experiments and simulations.

Subsequently, the W-phase compensation voltage calculation unit 702w calculates the W-phase compensation voltage value Vw_sw using Equation 16.
Vw_sw = Kw × sin (Nww × θe + θw) Equation 16
In this way, using the orders Nuu, Nvv, and Nww, the U-phase compensation voltage amplitude information, the V-phase compensation voltage amplitude information, and the W-phase compensation voltage amplitude information are referred to, and the U-phase compensation voltage amplitude Ku corresponding to the order Nu is obtained. The V-phase compensation voltage amplitude Kv corresponding to the order Nvv is obtained, and the W-phase compensation voltage amplitude Kw corresponding to the order Nww is obtained to obtain the U-phase compensation voltage amplitude Ku corresponding to the order Nu and the V corresponding to the order Nvv. Since the W-phase compensation voltage amplitude Kw corresponding to the phase compensation voltage amplitude Kv and the order Nww can be obtained in a timely manner, torque ripple caused by PWM in the motor 22 can be further reduced as compared with the second embodiment.

Further, since the torque ripple caused by PWM can be further reduced as compared with the second embodiment, the hearing noise of the motor 22 can be further reduced.
Further, since the torque ripple caused by PWM can be reduced only by changing the software executed by the control circuit 60 without adding hardware, it is possible to suppress the price increase of the motor control device.

The switching frequency Fsw_u, the switching frequency Fsw_v, and the switching frequency Fsw_w in the modified example 4 may be obtained by using the switching frequency calculation unit 31 or the switching frequency calculation unit 51.

Further, the present invention is not limited to the embodiments of the first embodiment, the first modification, the second embodiment, the second modification, the third modification, and the fourth modification, and various aspects thereof are not deviated from the gist of the present invention. Can be improved and changed.

1, 30, 50, 60 Control circuits 2, 3 Subtractors 6, 7, 9, 10, 12, 13, 33, 34, 35 Adders 4, 5 PI control unit 8 Non-interference voltage compensation unit 11, 14, 32 , 62 Harmonic compensation unit 15, 17 Coordinate conversion unit 16 PWM control unit 18 Inverter circuit 19, 20 Current sensor 21 Position detection unit 22 Motor 31, 51 Switching frequency calculation unit 61 Basic frequency calculation unit 201 Order calculation unit 202u, 402u, 702u U-phase compensation voltage calculation unit 202v, 402v, 702v V-phase compensation voltage calculation unit 202w, 402w, 702w W-phase compensation voltage calculation unit 203 Coordinate conversion unit 401u, 701u U-phase order calculation unit 401v, 701v V-phase calculation unit 401w , 701w W phase order calculation unit

Claims (5)

The inverter circuit that drives the motor and
A control circuit that controls the inverter circuit and
It is a motor control device equipped with
The harmonic compensation unit of the control circuit
Using the fundamental frequency of the fundamental current flowing through the motor and the switching frequency when pulse width modulation is performed on the inverter circuit, the order of torque ripple caused by the pulse width modulation with respect to the fundamental frequency is calculated.
Using the following formula, the U-phase compensation voltage value Vu_sw, the V-phase compensation voltage value Vv_sw, and the W-phase compensation voltage value Vw_sw are obtained.
Vu_sw = Ku × sin (N × θe + θu)
Vv_sw = Kv × sin (N × θe + θv)
Vw_sw = Kw × sin (N × θe + θw)
N = Fsw / Finv
The U-phase compensation voltage value Vu_sw, the V-phase compensation voltage value Vv_sw, and the W-phase compensation voltage value Vw_sw are converted from the three-phase AC coordinate system to the d-axis q-axis coordinate system to obtain the torque ripple caused by the pulse width modulation. Obtain the d-axis compensation voltage value Vd_sw and the q- axis compensation voltage value Vq_sw, which are opposite components .
The order N is calculated by dividing the switching frequency Fsw by the fundamental frequency Finv.
The U-phase compensation voltage amplitude Ku, the V-phase compensation voltage amplitude Kv, and the W-phase compensation voltage amplitude Kw use the order N, and the U-phase compensation voltage amplitude Ku and the V-phase compensation voltage are set to the order N. the U-phase compensation voltage amplitude Ku and the V-phase compensation voltage with reference to the compensation voltage amplitude information and amplitude Kv and the W-phase compensation voltage amplitude Kw is stored on the associated serial憶部, corresponding to the order N Obtain the amplitude Kv and the W-phase compensation voltage amplitude Kw.
The phase θe of the basic current is acquired from a position detection unit that detects the phase of the motor.
The U-phase initial phase θu, the V-phase initial phase θv, and the W-phase initial phase θw use the order N, and the U-phase initial phase θu, the V-phase initial phase θv, and the W are used in the order N. The U phase initial phase θu, the V phase initial phase θv, and the W phase initial phase θw corresponding to the order N are referred to with reference to the initial phase information stored in the storage unit in association with the phase initial phase θw. asked Me the door,
The first adder included in the control circuit is
Add the d-axis compensation voltage value Vd_sw to the d-axis voltage command value,
The second adder included in the control circuit is
The q-axis compensation voltage value Vq_sw is added to the q-axis voltage command value.
A motor control device characterized by the fact that. The inverter circuit that drives the motor and
A control circuit that controls the inverter circuit and
It is a motor control device equipped with
The harmonic compensation unit of the control circuit
Using the fundamental frequency of the fundamental current flowing through the motor and the switching frequencies of each of the three phases when pulse width modulation is performed on the inverter circuit, the order of torque ripple caused by the pulse width modulation with respect to the fundamental frequency is switched. Calculated for each frequency
Using the following equations, the U-phase compensation voltage value Vu_sw , the V- phase compensation voltage value Vv_sw, and the W- phase compensation voltage value Vw_sw, which are the opposite components of the torque ripple caused by the pulse width modulation of each of the three phases, are obtained.
Vu_sw = Ku x sin (Nu x θe + θu)
Vv_sw = Kv × sin (Nv × θe + θv)
Vw_sw = Kw × sin (Nw × θe + θw)
Nu = Fsw_u / Finv
Nv = Fsw_v / Finv
Nw = Fsw_w / Finv
The degree Nu calculates the U-phase switching frequency Fsw_u by dividing by the fundamental frequency Finv,
The degree Nv calculates the V-phase switching frequency Fsw_v by dividing by the fundamental frequency Finv,
The degree Nw calculates the W-phase switching frequency Fsw_w by dividing by the fundamental frequency Finv,
The U-phase compensation voltage amplitude Ku refers to the U-phase compensation voltage amplitude information stored in the storage unit in which the U-phase compensation voltage amplitude Ku is associated with the order Nu by using the order Nu, and the order is the order. Obtaining the U-phase compensation voltage amplitude Ku corresponding to Nu,
For the V-phase compensation voltage amplitude Kv, the V-phase compensation voltage amplitude Kv is associated with the order Nv and the V-phase compensation voltage amplitude information stored in the storage unit is referred to. The V-phase compensation voltage amplitude Kv corresponding to the order Nv was obtained.
The W-phase compensation voltage amplitude Kw refers to the W-phase compensation voltage amplitude information stored in the storage unit in which the W-phase compensation voltage amplitude Kw is associated with the order Nw by using the order Nw. The W-phase compensation voltage amplitude Kw corresponding to the order Nw is obtained.
The phase θe of the basic current is acquired from a position detection unit that detects the phase of the motor.
The U-phase initial phase θu refers to the U-phase initial phase information stored in the storage unit in which the U-phase initial phase θu is associated with the order Nu by using the order Nu, and the order Nu is set to the U-phase initial phase θu. Find the corresponding U-phase initial phase θu and
The V-phase initial phase θv uses the order Nv to refer to the V-phase initial phase information stored in the storage unit in which the V-phase initial phase θv is associated with the order Nv and becomes the order Nv. Find the corresponding V-phase initial phase θv and
The W phase initial phase θw refers to the W phase initial phase information stored in the storage unit in which the W phase initial phase θw is associated with the order Nw by using the order Nw, and the order Nw is set to the W phase initial phase θw. obtains the corresponding said W-phase initial phase .theta.w,
The first adder included in the control circuit is
The U-phase compensation voltage value Vu_sw is added to the U-phase voltage command value, and
The second adder included in the control circuit is
Add the V-phase compensation voltage value Vv_sw to the V-phase voltage command value,
The third adder included in the control circuit is
The W-phase compensation voltage value Vw_sw is added to the W-phase voltage command value.
A motor control device characterized by the fact that. The inverter circuit that drives the motor and
A control circuit that controls the inverter circuit and
It is a motor control device equipped with
The harmonic compensation unit of the control circuit
Using the fundamental frequency of the fundamental current flowing through the motor and the switching frequencies of each of the three phases when pulse width modulation is performed on the inverter circuit, the order of torque ripple caused by the pulse width modulation with respect to the fundamental frequency is switched. Calculated for each frequency
Using the following equations, the U-phase compensation voltage value Vu_sw , the V- phase compensation voltage value Vv_sw, and the W- phase compensation voltage value Vw_sw, which are the opposite components of the torque ripple caused by the pulse width modulation of each of the three phases, are obtained.
Vu_sw = Ku x sin (Nu x θe + θu)
Vv_sw = Kv × sin (Nvv × θe + θv)
Vw_sw = Kw × sin (Nww × θe + θw)
Nu = Fsw_u / Finv_u
Nvv = Fsw_v / Finv_v
Nww = Fsw_ w / Finv_w
The degree Nuu is the U-phase switching frequency Fsw_u, calculated by dividing by the fundamental frequency Finv_u obtained using the U-phase current value,
The degree Nvv is the V-phase switching frequency Fsw_v, calculated by dividing by the fundamental frequency Finv_v obtained using the V-phase current value,
The degree Nww is the W-phase switching frequency Fsw_w, calculated by dividing by the fundamental frequency Finv_w obtained using the W-phase current values,
The U-phase compensation voltage amplitude Ku refers to the U-phase compensation voltage amplitude information stored in the storage unit in which the U-phase compensation voltage amplitude Ku is associated with the order Nu using the order Nu, and the order is the order. Obtaining the U-phase compensation voltage amplitude Ku corresponding to Nu,
For the V-phase compensation voltage amplitude Kv, the V-phase compensation voltage amplitude Kv is associated with the order Nvv by using the order Nvv, and the V-phase compensation voltage amplitude information stored in the storage unit is referred to. The V-phase compensation voltage amplitude Kv corresponding to the order Nvv was obtained.
The W-phase compensation voltage amplitude Kw refers to the W-phase compensation voltage amplitude information stored in the storage unit in which the W-phase compensation voltage amplitude Kw is associated with the order Nww by using the order Nww. The W-phase compensation voltage amplitude Kw corresponding to the order Nww is obtained.
The phase θe of the basic current is acquired from a position detection unit that detects the phase of the motor.
The U-phase initial phase θu refers to the U-phase initial phase information stored in the storage unit in which the U-phase initial phase θu is associated with the order Nuu by using the order Nuu, and the order Nuu is set to the U-phase initial phase θu. Find the corresponding U-phase initial phase θu and
The V-phase initial phase θv uses the order Nvv to refer to the V-phase initial phase information stored in the storage unit in which the V-phase initial phase θv is associated with the order Nvv and becomes the order Nvv. Find the corresponding V-phase initial phase θv and
The W phase initial phase θw refers to the W phase initial phase information stored in the storage unit in which the W phase initial phase θw is associated with the order Nww by using the order Nww, and the order Nww is set to the W phase initial phase θw. obtains the corresponding said W-phase initial phase .theta.w,
The first adder included in the control circuit is
The U-phase compensation voltage value Vu_sw is added to the U-phase voltage command value, and
The second adder included in the control circuit is
Add the V-phase compensation voltage value Vv_sw to the V-phase voltage command value,
The third adder included in the control circuit is
The W-phase compensation voltage value Vw_sw is added to the W-phase voltage command value.
A motor control device characterized by the fact that. The motor control device according to claim 2 or 3 .
The U-phase switching frequency Fsw_u is obtained by using the U-phase voltage command value.
The V-phase switching frequency Fsw_v is obtained by using the V-phase voltage command value.
The W-phase switching frequency Fsw_w is obtained by using the W-phase voltage command value.
A motor control device characterized by the fact that. The motor control device according to claim 2 or 3 .
The U-phase switching frequency Fsw_u is obtained by using the U-phase current value.
The V-phase switching frequency Fsw_v is obtained by using the V-phase current value.
The W-phase switching frequency Fsw_w is obtained by using the W-phase current value.
A motor control device characterized by the fact that.

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