Motor control device

Abstract

To stabilize motor control.SOLUTION: In a motor control device 100a, adders 44, 45 calculate a d-axis voltage command value Vd* and a q-axis voltage command value Vq* by adding a d-axis driving voltage command value Vdm and a q-axis driving voltage command value Vqm for driving a motor M at a desired rotation number to a d-axis high frequency voltage command value Vdh* and a q-axis high frequency voltage command value Vqh* for generating a high frequency current for use in estimation of a rotor position of the motor M. An axis error computer 30 calculates an axis error Δθ by using a high frequency current which is generated in response to application of the d-axis high frequency voltage command value Vdh* and the q-axis high frequency voltage command value Vqh*. A high frequency current frequency calculator 61 calculates a high frequency current frequency that corresponds to a mechanical angular velocity command value ωm*. A high frequency voltage command value generator 43 generates the d-axis high frequency voltage command value Vdh* and the q-axis high frequency voltage command value Vqh* on the basis of the high frequency current frequency.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a motor control device. [Background technology]

[0002] One technique for estimating rotor position in sensorless vector control for AC motors is to apply a high-frequency voltage that does not contribute to torque generation to the motor and estimate the rotor position using high-frequency components contained in the detected current (hereinafter sometimes referred to as "high-frequency current").This technique estimates the rotor position based on an in-phase current vector that rotates in the same direction as the high-frequency magnetic flux vector generated in response to the application of the high-frequency voltage, and a mirror-phase current vector that rotates in the opposite direction to the high-frequency magnetic flux vector (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-171799 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a motor is driven, high-frequency fluctuations occur in the current depending on the rotational speed of the motor, mainly due to the cogging torque of the motor. The frequency (hereinafter sometimes referred to as the "fluctuation frequency") of the current fluctuations (hereinafter sometimes referred to as "current fluctuations") changes depending on the rotational speed of the motor. Therefore, depending on the rotational speed of the motor, the fluctuation frequency may approach the frequency of the high-frequency current (hereinafter sometimes referred to as the "high-frequency current frequency") used to estimate the rotor position. When the fluctuation frequency approaches the high-frequency current frequency, fluctuations occur in the high-frequency current, which reduces the accuracy of rotor position estimation (hereinafter sometimes referred to as the "position estimation accuracy"). As a result, motor control becomes unstable.

[0005] Therefore, the present disclosure proposes a technique that can stabilize motor control. [Means for solving the problem]

[0006] The motor control device disclosed herein includes an adder, an axis error calculator, a high-frequency current frequency output device, and a high-frequency voltage command value generator. The adder calculates a voltage command value by adding a drive voltage command value for driving a motor at a desired rotation speed and a high-frequency voltage command value for generating a high-frequency current used to estimate a rotor position of the motor. The axis error calculator calculates the axis error using the high-frequency current generated in response to application of the high-frequency voltage command value. The high-frequency current frequency output device outputs a high-frequency current frequency corresponding to the rotation speed of the motor. The high-frequency voltage command value generator generates the high-frequency voltage command value based on the high-frequency current frequency. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to stabilize the control of the motor. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a motor control device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating a configuration example of a high-frequency voltage command value generator according to the first embodiment of the present disclosure. [Figure 3] FIG. 3 is a diagram illustrating a configuration example of an axis error calculator according to the first embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram illustrating a configuration example of an in-phase and mirror-phase current vector generator according to the first embodiment of the present disclosure. [Figure 5] FIG. 5 is a flowchart illustrating an example of a processing procedure in the motor control device according to the first embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram illustrating an example of the operation of the motor control device according to the first embodiment of the present disclosure. [Figure 7]FIG. 7 is a diagram illustrating a configuration example of a motor control device according to a second embodiment of the present disclosure. [Figure 8] FIG. 8 is a diagram illustrating a configuration example of a motor control device according to a third embodiment of the present disclosure. [Figure 9] FIG. 9 is a diagram illustrating an example of the operation of the motor control device according to the third embodiment of the present disclosure. [Figure 10] FIG. 10 is a diagram illustrating a configuration example of a motor control device according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, examples of the present disclosure will be described with reference to the drawings. In the following examples, the same components are denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0010] This disclosure will explain an example of a motor control device that performs position sensorless vector control of a permanent magnet synchronous motor (PMSM) that drives a compressor. However, the disclosed technology is widely applicable to motor control devices that estimate rotor position using magnetic saliency for motors with magnetic saliency.

[0011] [Example 1] <Motor control device configuration> Fig. 1 is a diagram illustrating an example configuration of a motor control device according to a first embodiment of the present disclosure. In Fig. 1, a motor control device 100a includes subtractors 11, 18, and 19, a speed controller 12, adders 21, 22, 44, and 45, a current command value calculator 14, a current controller 20, a dq / u, v, w converter 23, a PWM (Pulse Width Modulation) modulator 24, and an IPM (Intelligent Power Module) 25. The IPM 25 is connected to a motor M. An example of the motor M is a PMSM.

[0012] Furthermore, the motor control device 100a has a shunt resistor 26, current sensors 27a and 27b, and a 3φ current calculator 28. Note that the motor control device 100a only needs to have either the shunt resistor 26 or the current sensors 27a and 27b.

[0013] The motor control device 100a also has a u, v, w / dq converter 29, an axis error calculator 30, a PLL (Phase Locked Loop) controller 31, a position estimator 32, a 1 / Pn processor 33, and a decoupling controller 36.

[0014] The motor control device 100 a also includes high-frequency removal filters 41 and 42 , a high-frequency voltage command value generator 43 , a Pn processor 46 , and a high-frequency current frequency calculator 61 .

[0015] The subtractor 11 subtracts the mechanical angular velocity command value ωm input to the motor control device 100a from an external device (for example, a higher-level controller) outside the motor control device 100a. * The angular velocity error Δω is calculated by subtracting the estimated mechanical angular velocity ωm, which is the current estimated angular velocity output from the 1 / Pn processor 33, from the angular velocity error Δω.

[0016] The speed controller 12 determines the torque command value T such that the average of the angular speed error Δω approaches zero. * Generate.

[0017] The current command value calculator 14 calculates the torque command value T * is the d-axis current command value Id on the dq coordinate axes. * and the q-axis current command value Iq * and distribute it to:

[0018] The subtractor 18 subtracts the high-frequency-removed d-axis current value Idm output from the high-frequency removal filter 41 from the d-axis current command value Id * By subtracting from the d-axis current command value Id * The subtractor 19 subtracts the high-frequency-removed q-axis current value Iqm output from the high-frequency-removed filter 42 from the q-axis current command value Iq* By subtracting from the q-axis current command value Iq * and the high-frequency-removed q-axis current value Iqm, the q-axis current error Iq_diff is calculated.

[0019] The current controller 20 calculates a temporary d-axis voltage command value Vdt by performing PI (Proportional Integral) control based on the input d-axis current error Id_diff, and calculates a temporary q-axis voltage command value Vqt by performing PI control based on the input q-axis current error Iq_diff.

[0020] The decoupling controller 36 controls the electrical angular velocity command value ωe output from the Pn processor 46. * and the d-axis current command value Id output from the current command value calculator 14. * The decoupling controller 36 generates a d-axis decoupling voltage command value Vda for compensating for the virtual d-axis voltage command value Vdt based on the above. * and the q-axis current command value Iq output from the current command value calculator 14. * The q-axis decoupling voltage command value Vqa for compensating for the tentative q-axis voltage command value Vqt is generated based on the above. The d-axis decoupling voltage command value Vda and the q-axis decoupling voltage command value Vqa are decoupling compensation values for canceling interference between the d and q coordinate axes in a feedforward manner.

[0021] An adder 21 calculates a d-axis drive voltage command value Vdm by adding the d-axis non-interacting voltage command value Vda to the temporary d-axis voltage command value Vdt. An adder 22 calculates a q-axis drive voltage command value Vqm by adding the q-axis non-interacting voltage command value Vqa to the temporary q-axis voltage command value Vqt. This results in the d-axis drive voltage command value Vdm and the q-axis drive voltage command value Vqm, in which interference between the d and q coordinate axes has been cancelled out by feedforward.

[0022] The dq / u,v,w converter 23 converts the two-phase d-axis voltage command value Vd * and q-axis voltage command value Vq* Based on the electrical angle phase θe output from the position estimator 32, the three-phase U-phase output voltage command value Vu * , V-phase output voltage command value Vv * and W-phase output voltage command value Vw * The electrical angle phase θe output from the position estimator 32 indicates the current rotor position of the motor M.

[0023] The PWM modulator 24 outputs a U-phase output voltage command value Vu * , V-phase output voltage command value Vv * , W-phase output voltage command value Vw * and the PWM carrier signal, and outputs the generated six-phase PWM signals to the IPM 25.

[0024] The IPM 25 generates three-phase AC voltages, U phase, V phase, and W phase, from the DC voltage Vdc based on the six-phase PWM signal output from the PWM modulator 24, and applies each of the generated three-phase AC voltages to the U phase, V phase, and W phase of the motor M.

[0025] When the bus current is detected by the one-shunt method using shunt resistor 26, 3φ current calculator 28 calculates the U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw of motor M from the six-phase PWM switching information output from PWM modulator 24 and the detected bus current. Alternatively, when U-phase current and V-phase current are detected by current sensors 27a and 27b, 3φ current calculator 28 calculates the remaining W-phase current value Iw based on Kirchhoff's law of "Iu + Iv + Iw = 0." 3φ current calculator 28 outputs the phase current values Iu, Iv, and Iw of each phase to u, v, w / dq converter 29.

[0026] The u, v, w / dq converter 29 converts the three-phase U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw into two-phase d-axis current value Id and q-axis current value Iq based on the electrical angle phase θe output from the position estimator 32.

[0027] The high frequency current frequency calculator 61 calculates the mechanical angular velocity command value ωm *The angular frequency of the high frequency voltage (hereinafter referred to as "high frequency angular frequency") ωh * Calculate the high frequency angular frequency ωh * is the high frequency current frequency fh * The high frequency current frequency calculator 61 calculates the mechanical angular velocity command value ωm * Based on the high frequency current frequency FH * By determining the mechanical angular velocity command value ωm * High frequency angular frequency ωh according to * The high frequency current frequency calculator 61 calculates the high frequency angular frequency ωh calculated according to the formula (1). * is output to the axis error calculator 30, the high frequency elimination filters 41 and 42, and the high frequency voltage command value generator 43.

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[0028] The high frequency elimination filter 41 removes the high frequency components of the d axis current value Id from the d axis current value Id, thereby extracting the high frequency removed d axis current value Idm, which is a drive component that contributes to torque generation, from the d axis current value Id. The high frequency elimination filter 42 removes the high frequency components of the q axis current value Iq from the q axis current value Iq, thereby extracting the high frequency removed q axis current value Iqm, which is a drive component that contributes to torque generation, from the q axis current value Iq. The high frequency elimination filters 41 and 42 are realized, for example, by a band stop filter F(s). High frequency angular frequency ωh * A bandstop filter F(s) with a bandstop center frequency of can be realized according to equation (2), where "s" is the Laplace operator, "d" is the notch depth, and "ζ" is a predetermined filter coefficient representing the notch bandwidth.

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[0029] The PLL controller 31 calculates an estimated electrical angular velocity ωe, which is the current estimated angular velocity of the motor M, based on the axis error Δθ.

[0030] The position estimator 32 estimates the electrical angle phase θe based on the electrical angle estimated angular velocity ωe.

[0031] The 1 / Pn processor 33 calculates the estimated mechanical angle angular velocity ωm by dividing the estimated electrical angle angular velocity ωe by the number Pn of pole pairs of the motor M.

[0032] The Pn processor 46 calculates the mechanical angular velocity command value ωm * is multiplied by the number of pole pairs Pn of the motor M to obtain the electrical angular velocity command value ωe * Calculate.

[0033] The high-frequency voltage command value generator 43 generates a high-frequency angular frequency ωh * and a high-frequency voltage amplitude command value Vh input to the motor control device 100a from outside the motor control device 100a (for example, from a higher-level controller). * Based on this, the d-axis high frequency voltage command value Vdh * and q-axis high frequency voltage command value Vqh * Hereinafter, the d-axis high-frequency voltage command value and the q-axis high-frequency voltage command value may be collectively referred to as the "high-frequency voltage vector." The high-frequency voltage vector Vdh * ,Vqh * is generated to generate the high frequency current used for estimating the rotor position, and does not contribute to torque generation for estimating the rotor position. In other words, the high frequency current used for estimating the rotor position is generated by the high frequency voltage vector Vdh * ,Vqh * It occurs in response to the application of

[0034] The adder 44 calculates the d-axis drive voltage command value Vdm and the d-axis high-frequency voltage command value Vdh, which contribute to torque generation for estimating the rotor position. * By adding these, the d-axis voltage command value Vd * The adder 45 calculates the q-axis drive voltage command value Vqm and the q-axis high frequency voltage command value Vqh, which contribute to torque generation for estimating the rotor position. * By adding these, the q-axis voltage command value Vq *Hereinafter, the d-axis drive voltage command value Vdm and the q-axis drive voltage command value Vqm may be collectively referred to as the "drive voltage command values."

[0035] The axis error calculator 30 calculates the d-axis current value Id, the q-axis current value Iq, and the high-frequency angular frequency ωh * The d-axis current value Id and the q-axis current value Iq contain high-frequency current components. In other words, the axis error calculator 30 calculates the axis error Δθ (the difference between the actual rotation axis and the estimated rotation axis) based on the high-frequency voltage vector Vdh * ,Vqh * Using the high frequency current vector generated in response to the application of the current, an axis error Δθ, which is the deviation between the dq coordinate axes and the estimated dq coordinate axes, is calculated.

[0036] <Configuration of high-frequency voltage command value generator> 2 is a diagram illustrating a configuration example of a high-frequency voltage command value generator according to the first embodiment of the present disclosure. In FIG. 2, the high-frequency voltage command value generator 43 includes a phase generator 43a, a cosine / sine signal generator 43b, and a multiplier 43c.

[0037] The phase generator 43a generates a high frequency angular frequency ωh in the range of "0≦θh≦2π". * By integrating, the high frequency phase θh, which is the phase of the high frequency voltage vector, is generated.

[0038] The cosine-sine signal generator 43b generates the cosine-sine value u(θh) of the high-frequency phase θh according to equation (3).

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[0039] The multiplier 43c multiplies the cosine and sine values u(θh) by the high-frequency voltage amplitude command value Vh * Based on this, the d-axis high frequency voltage command value Vdh is calculated according to equation (4). * and q-axis high frequency voltage command value Vqh * Generate.

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[0040] <Configuration of axis error calculator> 3 is a diagram illustrating an example of the configuration of an axis error calculator according to the first embodiment of the present disclosure. In FIG. 3, the axis error calculator 30 includes an in-phase mirror phase current vector generator 301 and a mirror phase estimator 302. The axis error calculator 30 utilizes the magnetic saliency of the motor M to calculate the high frequency angular frequency ωh * The axis error Δθ is calculated based on the d-axis current value Id and the q-axis current value Iq. Fig. 4 is a diagram showing an example of the configuration of an in-phase mirror phase current vector generator according to the first embodiment of the present disclosure. In Fig. 4, the in-phase mirror phase current vector generator 301 includes a sign inverter b11 and D-module filters b12 and b13.

[0041] In FIG. 4, the sign inverter b11 operates at a high frequency angular frequency ωh * The sign of is inverted, and the high frequency angular frequency after sign inversion is -ωh * is output to the D-factor filter b12.

[0042] The D-module filters b12 and b13 are filters that separate and extract positive and negative sequence components, and the D-modules in the D-module filters b12 and b13 are defined by equation (5) using a unit matrix I, a skew matrix J, and a Laplace operator s.

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[0043] The D-module filter b12 has a high frequency angular frequency of -ωh after sign inversion. * The in-phase current vector Ihp contained in the d-axis current value Id and the q-axis current value Iq is detected based on the above equation. The in-phase current vector Ihp is * ,Vqh * The magnetic flux vector generated in response to the application of the magnetic field rotates in the same direction as the high frequency magnetic flux vector.

[0044] The D-factor filter b13 has a high frequency *The mirror phase current vector Ihn contained in the d-axis current value Id and the q-axis current value Iq is detected based on the above equation. The mirror phase current vector Ihn is calculated by dividing the high frequency voltage vector Vdh * ,Vqh * The magnetic flux vector rotates in the opposite direction to the high frequency magnetic flux vector generated in response to the application of the magnetic field.

[0045] Here, the D-module filters b12 and b13 have the frequency characteristic F(s+jωh * ) filter. Therefore, by designing F(s) to have low-pass characteristics and applying it to the D-module filters b12 and b13, the D-module filters b12 and b13 function as follows: * Furthermore, the D filters b12 and b13 have polarity separation characteristics. That is, the polarity separation bandpass characteristics of the D filters b12 and b13 allow the d-axis current value Id and the q-axis current value Iq to be separated into an in-phase current vector Ihp and a mirror-phase current vector Ihn.

[0046] The mirror phase estimator 302 calculates the axis error Δθ based on the in-phase current vector Ihp and the mirror phase current vector Ihn according to equations (6) and (7). That is, the mirror phase estimator 302 calculates, as the axis error Δθ, the arctangent of a resultant vector obtained by vector addition of the in-phase current vector Ihp and the mirror phase current vector Ihn, whose norms have been unified.

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[0047] <Processing procedure in the motor control device> FIG. 5 is a flowchart illustrating an example of a processing procedure in the motor control device according to the first embodiment of the present disclosure.

[0048] The order of the fluctuation frequency at which current fluctuations due to cogging torque occur is determined by the number of poles of the rotor of motor M (hereinafter sometimes referred to as the "rotor pole number") and the number of slots of motor M (hereinafter sometimes referred to as the "motor slot number"). For example, if motor M is a motor with P poles and S slots, current fluctuations will occur at a frequency that is the least common multiple of P and S. Furthermore, current fluctuations will occur at frequencies that are half, twice, three times, ..., n times the least common multiple of P and S. For example, if motor M is a motor with 6 poles and 9 slots, current fluctuations will occur at the 18th order frequency, which is the least common multiple of 6 and 9, as well as the 9th order frequency, which is half the least common multiple of 6 and 9, and 18 x n orders of frequencies, such as 36th order, 54th order, ...

[0049] On the other hand, the in-phase mirror phase current vector generator 301 functions as a bandpass filter, and the wider the pass frequency range, the faster the response speed of the in-phase mirror phase current vector generator 301 as a bandpass filter. For this reason, it is preferable to design the filter constants in the in-phase mirror phase current vector generator 301 to a degree that can sufficiently remove the current of the driving component.

[0050] Here, the axis error is calculated for each cycle of the carrier signal, so the high frequency current frequency fh * If the high frequency fh is close to the carrier frequency, the number of samplings per cycle of the high frequency current will be small, and the accuracy of position estimation will decrease. * is preferably a sufficiently low frequency (for example, 1 / 20) with respect to the carrier frequency. As described above, the high-frequency current frequency fh * It is preferable that the frequency fh is sufficiently higher than the frequency band of the drive voltage command value (for example, 25 times higher). * is preferably set to a frequency that is sufficiently lower than the carrier frequency of motor control device 100a and sufficiently higher than the frequency band of the drive voltage command value.

[0051] However, the high frequency current frequency fh * If is set to a fixed value, the high frequency angular frequency ωh * are also fixed values, and the passing frequency range of the in-phase and mirror phase current vector generator 301 is fixed. Therefore, depending on the rotation speed of the motor M, the passing frequency range of the in-phase and mirror phase current vector generator 301 may include fluctuation frequencies caused by cogging torque. In this case, in the in-phase and mirror phase current vector generator 301, the high frequency voltage vector Vdh * ,Vqh * As a result, depending on the rotation speed of the motor M, the accuracy of position estimation may deteriorate.

[0052] First, in step S100, the high-frequency current frequency calculator 61 calculates the least common multiple of the number of rotor poles P and the number of motor slots S and the mechanical angular velocity command value ωm * The result of multiplication by is divided by 2π to calculate the cogging frequency fcog, which represents the fluctuation frequency.

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[0053] Next, in step S105, the high-frequency current frequency calculator 61 determines whether the sum of the cogging frequency fcog and the first margin fmg1 (hereinafter referred to as the "margin added frequency") is equal to or greater than a predetermined reference frequency fh1, according to equation (9). *The reference frequency fh1 is predetermined to be a frequency that is sufficiently lower than the carrier frequency of the motor control device 100a and sufficiently higher than the frequency band of the drive voltage command value. For example, when the carrier frequency is 4 kHz and the drive voltage frequency is 8 Hz, the reference frequency fh1 can be set to 200 Hz. If the margin addition frequency is equal to or greater than the reference frequency fh1 (step S105: Yes), the process proceeds to step S110. If the margin addition frequency is less than the reference frequency fh1 (step S105: No), the process proceeds to step S115.

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[0054] In step S110, the high frequency current frequency calculator 61 calculates the margin addition frequency as the high frequency current frequency fh * Set as.

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[0055] On the other hand, in step S115, the high-frequency current frequency calculator 61 determines whether the value obtained by subtracting the second margin fmg2 from twice the cogging frequency fcog (hereinafter sometimes referred to as the "margin subtraction frequency") is less than the reference frequency fh1 in accordance with equation (11). If the margin subtraction frequency is less than the reference frequency fh1 (step S115: Yes), the process proceeds to step S120. If the margin subtraction frequency is equal to or greater than the reference frequency fh1 (step S115: No), the process proceeds to step S125.

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[0056] The first margin fmg1 is a margin determined in advance based on the width of the frequency range passed by the in-phase and mirror-phase current vector generator 301, the magnitude of the high-frequency current, and the magnitude of fluctuations in the cogging frequency fcog, and is, for example, 60 Hz. The second margin fmg2 is a margin determined in advance based on the width of the frequency range passed by the in-phase and mirror-phase current vector generator 301, the magnitude of the high-frequency current, and the magnitude of fluctuations in the frequency twice the cogging frequency fcog, and is, for example, 30 Hz.

[0057] In step S120, the high frequency current frequency calculator 61 calculates the margin subtraction frequency as the high frequency current frequency fh * Set as.

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[0058] On the other hand, in step S125, the high-frequency current frequency calculator 61 calculates the reference frequency fh1 in accordance with the equation (13) as the high-frequency current frequency fh * Set as.

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[0059] After the processes of steps S110, S120, and S125, the process proceeds to step S130.

[0060] In step S130, the high-frequency current frequency calculator 61 calculates the high-frequency current frequency fh * From high frequency angular frequency ωh * Calculate the high frequency angular frequency ωh * is output to the axis error calculator 30, the high frequency elimination filters 41 and 42, and the high frequency voltage command value generator 43.

[0061] As described above, the mechanical angular velocity command value ωm * The cogging frequency FCOG varies depending on the high frequency current frequency FH *By changing the frequency, it is possible to prevent the fluctuation frequency caused by the cogging torque from being included in the passing frequency range of the in-phase and mirror-phase current vector generator 301.

[0062] <Motor control device operation> FIG. 6 is a diagram illustrating an example of the operation of the motor control device according to the first embodiment of the present disclosure.

[0063] As a result of the high frequency current frequency calculator 61 operating in accordance with the flowchart shown in FIG. 5, the mechanical angular velocity command value ωm * and high frequency current frequency fh * As can be seen from FIG. 6, in the motor control device 100a, the mechanical angular velocity command value ωm * Depending on the high frequency current frequency FH * changes.

[0064] Alternatively, the high-frequency current frequency calculator 61 may calculate a margin-addition frequency by adding a first margin fmg1 to a first multiplication result obtained by multiplying the cogging frequency fcog by a first predetermined value α, and may calculate a margin-subtraction frequency by subtracting a second margin fmg2 from a second multiplication result obtained by multiplying the cogging frequency fcog by a second predetermined value β. The first predetermined value α is a positive integer greater than 0, and the second predetermined value β is a value obtained by adding 1 to the first predetermined value α. In FIGS. 5 and 6, the first predetermined value α is set to 1 as an example. In other words, the high-frequency current frequency calculator 61 calculates a frequency in a frequency range equal to or greater than the frequency obtained by adding the first margin fmg1 to the first multiplication result obtained by multiplying the cogging frequency fcog by the first predetermined value α and equal to or less than the frequency obtained by subtracting the second margin fmg2 from the second multiplication result obtained by multiplying the cogging frequency fcog by the second predetermined value β as the high-frequency current frequency fh. * By doing so, the high frequency current frequency fh * Whatever value is set to, the high frequency current frequency fh * can be moved away from the fluctuation frequency.

[0065] As described above, the mechanical angular velocity command value ωm corresponding to the rotational speed of the motor M * Depending on the high frequency current frequency FH * By changing the frequency, the high-frequency current frequency can be set to a frequency sufficiently lower than the carrier frequency of the motor control device 100a and sufficiently higher than the frequency band of the drive voltage command value, and thus can be kept away from the fluctuation frequency, thereby preventing the high-frequency current from being affected by current fluctuations. This allows the rotor position to be estimated with high accuracy, thereby stabilizing the control of the motor M.

[0066] The first embodiment has been described above.

[0067] [Example 2] In the second embodiment, the high-frequency voltage amplitude command value Vh is set so that the amplitude of the mirror phase current vector Ihn is constant. * The difference from the first embodiment is that the following points are different from the first embodiment.

[0068] <Motor control device configuration> 7 is a diagram illustrating an example of the configuration of a motor control device according to a second embodiment of the present disclosure. In FIG. 7, a motor control device 100b includes a high-frequency voltage amplitude calculator 62. The high-frequency voltage amplitude calculator 62 receives the high-frequency angular frequency ωh from the high-frequency current frequency calculator 61. * is input, and a mirror phase current vector amplitude command value |Ihn| is input from outside the motor control device 100b (for example, from a higher-level controller). * is entered.

[0069] Here, as in the first embodiment, the mechanical angular velocity command value ωm * Depending on the high frequency current frequency FH * When the frequency fh is changed, the amplitude of the high frequency current that does not contribute to torque generation changes. * The amplitude of the mirror phase current vector Ihn contained in the high frequency current varies depending on the high frequency voltage amplitude command value Vh * The larger the amplitude of the mirror phase current vector Ihn, the higher the accuracy of position estimation. *To ensure accuracy in position estimation regardless of the magnitude of the high-frequency current frequency fh * Regardless of the magnitude of * However, it is possible to increase the high frequency voltage amplitude command value Vh * If the value is increased, there will be disadvantages such as noise being generated in the motor M and the efficiency of the motor M being reduced.

[0070] Therefore, the high frequency voltage amplitude calculator 62 calculates the mirror phase current vector amplitude command value |Ihn| according to the equation (14). * and high frequency angular frequency ωh * Based on this, the high frequency voltage amplitude command value Vh * In equation (14), "Ld" is the d-axis inductance of motor M, and "Lq" is the q-axis inductance of motor M. Here, the mirror phase current vector amplitude command value |Ihn| * is determined in advance to be the minimum value that ensures the accuracy of the position estimation. The high frequency voltage amplitude calculator 62 calculates the high frequency voltage amplitude command value Vh * to the high frequency voltage command value generator 43.

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[0071] According to equation (14), the high-frequency voltage amplitude command value Vh * By calculating the above, the amplitude of the mirror phase current vector Ihn becomes constant as the minimum value that guarantees the position estimation accuracy. As a result, the high frequency voltage amplitude command value Vh * can be reduced to a minimum value.

[0072] The second embodiment has been described above.

[0073] [Example 3] In the third embodiment, the high-frequency angular frequency ωh is calculated based on the estimated mechanical angle angular velocity ωm_iir after the fluctuation component of the estimated mechanical angle angular velocity ωm is removed. *The difference from the first embodiment is that the following points are different from the first embodiment.

[0074] <Motor control device configuration> 8 is a diagram illustrating an example of the configuration of a motor control device according to a third embodiment of the present disclosure. In FIG. 8, a motor control device 100c includes an IIR filter 51 and a high-frequency current frequency calculator 65.

[0075] The IIR filter 51 removes fluctuation components from the mechanical angle estimated angular velocity ωm output from the 1 / Pn processor 33 and outputs the mechanical angle estimated angular velocity ωm_iir after the fluctuation components have been removed to the high frequency current frequency calculator 65.

[0076] In step S100 of FIG. 5, the high-frequency current frequency calculator 65 calculates the cogging frequency fcog by dividing the product of the least common multiple of the rotor pole number P and the motor slot number S and the mechanical angle estimated angular velocity ωm_iir by 2π according to equation (15).

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[0077] <Motor control device operation> FIG. 9 is a diagram illustrating an example of the operation of the motor control device according to the third embodiment of the present disclosure.

[0078] The high-frequency current frequency calculator 65 operates according to the flowchart shown in FIG. 5, and as a result, the estimated mechanical angle angular velocity ωm_iir and the high-frequency current frequency fh * As can be seen from FIG. 9, in the motor control device 100c, the high-frequency current frequency fh is adjusted according to the estimated mechanical angle angular velocity ωm_iir so as to avoid current fluctuations that occur according to the rotation speed of the motor M. * changes.

[0079] As described above, the mechanical angular velocity command value ωm *Even if the estimated mechanical angle angular velocity ωm_iir is used instead of the above, the high-frequency current frequency can be kept away from the fluctuation frequency, similar to the first embodiment, and therefore the high-frequency current can be prevented from being affected by the current fluctuation.

[0080] The third embodiment has been described above.

[0081] [Example 4] In the fourth embodiment, the high-frequency voltage amplitude command value Vh is set so that the amplitude of the mirror phase current vector Ihn is constant. * The difference from the third embodiment is that the following difference from the third embodiment is calculated.

[0082] <Motor control device configuration> 10 is a diagram illustrating an example of the configuration of a motor control device according to a fourth embodiment of the present disclosure. In FIG. 10, a motor control device 100d includes a high-frequency voltage amplitude calculator 62. The high-frequency voltage amplitude calculator 62 receives a high-frequency angular frequency ωh from a high-frequency current frequency calculator 65. * is input, and a mirror phase current vector amplitude command value |Ihn| is input from outside the motor control device 100d (for example, from a higher-level controller). * is entered.

[0083] The high frequency voltage amplitude calculator 62 calculates the mirror phase current vector amplitude command value |Ihn| according to the equation (14). * and high frequency angular frequency ωh * Based on this, the high frequency voltage amplitude command value Vh * is calculated, and the calculated high frequency voltage amplitude command value Vh * to the high frequency voltage command value generator 43.

[0084] As described above, the mechanical angular velocity command value ωm * Even if the estimated mechanical angle angular velocity ωm_iir is used instead of the high-frequency voltage amplitude command value Vh, the position estimation accuracy can be guaranteed regardless of the rotation speed of the motor M, as in the second embodiment. * can be reduced to a minimum value.

[0085] The fourth embodiment has been described above.

[0086] As described above, the motor control device (motor control devices 100a, 100b, 100c, 100d of the embodiments) of the present disclosure includes an adder (adder 44, 45 of the embodiments), an axis error calculator (axis error calculator 30 of the embodiments), a high-frequency current frequency output device (high-frequency current frequency calculators 61, 65 of the embodiments), and a high-frequency voltage command value generator (high-frequency voltage command value generator 43 of the embodiments). The adder outputs drive voltage command values (d-axis drive voltage command value Vdm, q-axis drive voltage command value Vqm of the embodiments) for driving a motor (motor M of the embodiments) at a desired rotation speed, and a high-frequency voltage command value (d-axis high-frequency voltage command value Vdh of the embodiments) for generating a high-frequency current used to estimate the rotor position of the motor. * ,q-axis high frequency voltage command value Vqh * ) to obtain the voltage command value (d-axis voltage command value Vd * ,q-axis voltage command value Vq * The axis error calculator calculates the axis error using the high frequency current generated in response to the application of the high frequency voltage command value. The high frequency current frequency output unit calculates the rotation speed of the motor (the mechanical angular velocity command value ωm * , the estimated mechanical angle angular velocity ωm_iir) according to the high frequency current frequency (the high frequency current frequency fh * The high-frequency voltage command value generator generates a high-frequency voltage command value based on the high-frequency current frequency.

[0087] For example, the high-frequency current frequency output device calculates the cogging frequency (cogging frequency fcog in the embodiment), which is a frequency caused by the cogging torque of the motor and represents the frequency of the fluctuations in the high-frequency current, by dividing the product of the least common multiple of the number of poles of the motor rotor and the number of slots of the motor and the rotation speed by 2π, and then calculates the high-frequency current frequency based on the cogging frequency.

[0088] Furthermore, for example, the high-frequency current frequency output device sets the high-frequency current frequency to a frequency range equal to or greater than a first frequency (margin-added frequency in the embodiment) obtained by adding a first margin (first margin fmg1 in the embodiment) to a first multiplication result obtained by multiplying the cogging frequency by a first predetermined value (first predetermined value α in the embodiment) and equal to or less than a second frequency (margin-subtracted frequency in the embodiment) obtained by subtracting a second margin (second margin fmg2 in the embodiment) from a second multiplication result obtained by multiplying the cogging frequency by a second predetermined value (second predetermined value β in the embodiment). The first predetermined value is a positive integer greater than 0, and the second predetermined value is a value obtained by adding 1 to the first predetermined value.

[0089] For example, the first predetermined value is 1.

[0090] For example, when the first frequency is equal to or higher than a predetermined reference frequency (reference frequency fh1 in the embodiment) determined based on the carrier frequency of the motor control device and the frequency band of the drive voltage command value, the high-frequency current frequency output device sets the first frequency as the high-frequency current frequency.For example, when the first frequency is lower than the reference frequency and the second frequency is lower than the reference frequency, the high-frequency current frequency output device sets the second frequency as the high-frequency current frequency.For example, when the first frequency is lower than the reference frequency and the second frequency is equal to or higher than the reference frequency, the high-frequency current frequency output device sets the reference frequency as the high-frequency current frequency.

[0091] Moreover, the motor control device (motor control devices 100b and 100d of the embodiment) of the present disclosure further includes a high-frequency voltage amplitude calculator (high-frequency voltage amplitude calculator 62 of the embodiment). The high-frequency voltage amplitude calculator calculates a mirror-phase current vector amplitude command value (mirror-phase current vector amplitude command value |Ihn| * ) and the high-frequency current frequency, the high-frequency voltage amplitude command value (high-frequency voltage amplitude command value Vh * The high-frequency voltage command value generator generates a high-frequency voltage command value based on the high-frequency current frequency and the high-frequency voltage amplitude command value. [Explanation of symbols]

[0092] 100a, 100b, 100c, 100d Motor control device 44,45 adder 30 Axis error calculator 61,65 High frequency current frequency calculator 43 High frequency voltage command generator 62 High frequency voltage amplitude calculator

Claims

1. an adder that calculates a voltage command value by adding a drive voltage command value for driving the motor at a desired rotation speed and a high-frequency voltage command value for generating a high-frequency current used to estimate a rotor position of the motor; an axis error calculator that calculates an axis error using the high-frequency current generated in response to application of the high-frequency voltage command value; a high frequency current frequency output device that outputs a high frequency current frequency corresponding to the rotation speed of the motor; a high-frequency voltage command value generator that generates the high-frequency voltage command value based on the high-frequency current frequency; Equipped with the high frequency current frequency output device calculates a cogging frequency that is caused by the cogging torque of the motor and represents a frequency of fluctuations in the high frequency current by dividing the product of the least common multiple of the number of poles of the rotor of the motor and the number of slots of the motor by 2π and the rotation speed, and calculates the high frequency current frequency based on the cogging frequency; the high frequency current frequency output device sets, as the high frequency current frequency, a frequency in a frequency range equal to or higher than a first frequency obtained by adding a first margin to a first multiplication result obtained by multiplying the cogging frequency by a first predetermined value and equal to or lower than a second frequency obtained by subtracting a second margin from a second multiplication result obtained by multiplying the cogging frequency by a second predetermined value; A motor control device, wherein the first predetermined value is a positive integer greater than 0, and the second predetermined value is a value obtained by adding 1 to the first predetermined value.

2. the first predetermined value is 1; The motor control device according to claim 1 .

3. The high frequency current frequency output device is when the first frequency is equal to or higher than a predetermined reference frequency determined based on a carrier frequency of the motor control device and a frequency band of the drive voltage command value, the first frequency is set as the high-frequency current frequency; When the first frequency is lower than the reference frequency and the second frequency is lower than the reference frequency, the second frequency is set as the high-frequency current frequency; When the first frequency is lower than the reference frequency and the second frequency is equal to or higher than the reference frequency, the reference frequency is set as the high-frequency current frequency. The motor control device according to claim 1 .

4. an adder that calculates a voltage command value by adding a drive voltage command value for driving the motor at a desired rotation speed and a high-frequency voltage command value for generating a high-frequency current used to estimate a rotor position of the motor; an axis error calculator that calculates an axis error using the high-frequency current generated in response to application of the high-frequency voltage command value; a high frequency current frequency output device that outputs a high frequency current frequency corresponding to the rotation speed of the motor; a high-frequency voltage command value generator that generates the high-frequency voltage command value based on the high-frequency current frequency; a high-frequency voltage amplitude calculator that calculates a high-frequency voltage amplitude command value based on a mirror-phase current vector amplitude command value and the high-frequency current frequency; Equipped with The high-frequency voltage command value generator generates the high-frequency voltage command value based on the high-frequency current frequency and the high-frequency voltage amplitude command value.

5. the high-frequency current frequency output device calculates a cogging frequency resulting from the cogging torque of the motor, which represents a frequency of fluctuations in the high-frequency current, by dividing the product of the least common multiple of the number of poles of the rotor of the motor and the number of slots of the motor by 2π and the rotation speed, and then calculates the high-frequency current frequency based on the cogging frequency; The motor control device according to claim 4.

6. the high frequency current frequency output device sets, as the high frequency current frequency, a frequency in a frequency range equal to or higher than a first frequency obtained by adding a first margin to a first multiplication result obtained by multiplying the cogging frequency by a first predetermined value and equal to or lower than a second frequency obtained by subtracting a second margin from a second multiplication result obtained by multiplying the cogging frequency by a second predetermined value; the first predetermined value is a positive integer greater than 0, and the second predetermined value is the first predetermined value plus 1; The motor control device according to claim 5 .

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