Motor control device

Abstract

To stabilize motor control.SOLUTION: In a motor controller 100, adders 44 and 45 add 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 speed, and 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 used for estimating the rotor position of a motor M to generate a d-axis voltage command value Vd* and a q-axis voltage command value Vq*; an axis error calculator 30 calculates an axis error Δθ using a high frequency current generated in response to the application of the d-axis high-frequency voltage command value Vdh* and the q-axis high-frequency voltage command value Vqh*; a high-frequency voltage amplitude adjuster 72 adjusts a high-frequency voltage amplitude command value Vh* on the basis of the mirror phase current vector Ihn separated from the two-phase current; and a high-frequency voltage command value generator 43 generates a d-axis high-frequency voltage command value Vdh* and a q-axis high-frequency voltage command value Vqh* on the basis of the adjusted high frequency voltage amplitude command value.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] As one of the rotor position estimation techniques in sensorless vector control for an AC motor, there is a technique of applying a high-frequency voltage that does not contribute to torque generation to the motor and estimating the rotor position using the high-frequency component (hereinafter sometimes referred to as "high-frequency current") included in the detected current. In this technique, the rotor position is estimated based on the 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 the mirror-image 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

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, the accuracy of estimating the rotor position of the motor (hereinafter sometimes referred to as "position estimation accuracy") is greatly affected by the amplitude of the mirror-image current vector. Further, the amplitude of the mirror-image current vector varies depending on the parameters of the motor (hereinafter sometimes referred to as "motor parameters"). Since the motor parameters with current characteristics change according to the driving conditions of the motor (hereinafter sometimes referred to as "motor driving conditions") such as the load of the motor and the rotational speed of the motor, the amplitude of the mirror-image current vector may become small depending on the motor driving conditions. When the amplitude of the mirror-image current vector becomes small, the ratio of noise to the amplitude of the mirror-image current vector increases, so that the S / N ratio cannot be sufficiently ensured. As a result, the control of the motor becomes unstable due to the influence of noise.

[0005] Therefore, the present disclosure proposes a technique capable of stabilizing the control of a motor.

Means for Solving the Problem

[0006] The motor control device of the present disclosure includes an adder, an axis error calculator, a current calculator, a converter, an adjuster, and a generator. The adder calculates a voltage command value by adding a driving voltage command value for driving the motor at a desired rotational speed and a high-frequency voltage command value for generating a high-frequency current used for estimating the rotor position of the motor. The axis error calculator calculates an axis error using the high-frequency current generated in response to the application of the high-frequency voltage command value. The current calculator calculates a three-phase current including the high-frequency current. The converter converts the three-phase current into a two-phase current including the high-frequency current. The adjuster adjusts a high-frequency voltage amplitude command value based on a mirror-phase current vector separated from the two-phase current. The generator generates the high-frequency voltage command value based on the adjusted high-frequency voltage amplitude command value.

Advantages of the Invention

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

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same parts may be denoted by the same reference numerals, and redundant descriptions may be omitted.

[0010] In the present disclosure, a motor control device that performs sensorless vector control of a permanent magnet synchronous motor (PMSM) that drives a compressor will be described as an example. However, the disclosed technology is widely applicable to a motor control device that estimates the rotor position using magnetic salient poles for a motor having magnetic salient poles.

[0011] [Embodiment 1] <Configuration of Motor Control Device> FIG. 1 is a diagram showing a configuration example of the motor control device according to Embodiment 1 of the present disclosure. In FIG. 1, the motor control device 100 includes subtracters 11, 18, 19, a speed controller 12, adders 21, 22, 44, 45, a current command value calculator 14, a current controller 20, a d-q / 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 the motor M. An example of the motor M is a PMSM.

[0012] The motor control device 100 also includes a shunt resistor 26, current sensors 27a and 27b, and a three-phase current calculator 28. Note that the motor control device 100 only needs to include either the shunt resistor 26 or one of the current sensors 27a and 27b.

[0013] The motor control device 100 also includes a u, v, w / d-q 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 also includes high-frequency filters 41 and 42, a high-frequency voltage command value generator 43, and a Pn processor 46.

[0015] The motor control device 100 also includes a high-frequency voltage amplitude adjuster 72.

[0016] The subtractor 11 calculates an angular velocity error Δω by subtracting the mechanical angular estimated velocity ωm, which is the current estimated angular velocity output from the 1 / Pn processor 33, from the mechanical angular velocity command value ωm input from outside the motor control device 100 (for example, a higher-level controller) to the motor control device 100. * from the mechanical angular estimated velocity ωm, which is the current estimated angular velocity output from the 1 / Pn processor 33.

[0017] The speed controller 12 generates a torque command value T such that the average of the angular velocity error Δω approaches 0. * to generate.

[0018] The current command value calculator 14 distributes the torque command value T * to a d-axis current command value Id * and a q-axis current command value Iq * on the d-q coordinate axes.

[0019] The subtractor 18 subtracts the high-frequency removed d-axis current value Idm output from the high-frequency filter 41 from the d-axis current command value Id * to obtain the d-axis current command value Id *Calculate the d-axis current error Id_diff, which is the error between the high-frequency-removed d-axis current value Idm and the d-axis current command value. The subtractor 19 subtracts the high-frequency-removed q-axis current value Iqm output from the high-frequency removal filter 42 from the q-axis current command value Iq * to calculate the q-axis current error Iq_diff, which is the error between the q-axis current command value Iq * and the high-frequency-removed q-axis current value Iqm.

[0020] 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. Also, the current controller 20 calculates a temporary q-axis voltage command value Vqt by performing PI control based on the input q-axis current error Iq_diff.

[0021] The decoupling controller 36 generates a d-axis decoupling voltage command value Vda for compensating the temporary d-axis voltage command value Vdt based on 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. * Also, the decoupling controller 36 generates a q-axis decoupling voltage command value Vqa for compensating the temporary q-axis voltage command value Vqt based on the electrical angular velocity command value ωe output from the Pn processor 46 * and the q-axis current command value Iq output from the current command value calculator 14. * The d-axis decoupling voltage command value Vda and the q-axis decoupling voltage command value Vqa are decoupling compensation values for canceling the interference between the d-q coordinate axes by feedforward.

[0022] The adder 21 calculates a d-axis drive voltage command value Vdm by adding the d-axis decoupling voltage command value Vda to the temporary d-axis voltage command value Vdt. The adder 22 calculates a q-axis drive voltage command value Vqm by adding the q-axis decoupling voltage command value Vqa to the temporary q-axis voltage command value Vqt. Thereby, the d-axis drive voltage command value Vdm and the q-axis drive voltage command value Vqm with the interference between the d-q coordinate axes canceled by feedforward are obtained.

[0023] The d-q / u,v,w converter 23 converts the two-phase d-axis voltage command value Vd * and the q-axis voltage command value Vq * output from the adders 44 and 45 into 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 * based on the electrical angular phase θe output from the position estimator 32. The electrical angular phase θe output from the position estimator 32 indicates the current rotor position of the motor M.

[0024] The PWM modulator 24 generates six-phase PWM signals based on the U-phase output voltage command value Vu * , V-phase output voltage command value Vv * , W-phase output voltage command value Vw * and a PWM carrier signal, and outputs the generated six-phase PWM signals to the IPM 25.

[0025] Based on the six-phase PWM signals output from the PWM modulator 24, the IPM 25 generates three-phase AC voltages of the U-phase, V-phase, and W-phase from the DC voltage Vdc, and applies the generated three-phase AC voltages to the U-phase, V-phase, and W-phase of the motor M.

[0026] When the bus current is detected by the one-shunt method using the shunt resistor 26, the three-phase current calculator 28 calculates the U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw of the motor M from the six-phase PWM switching information output from the PWM modulator 24 and the detected bus current. Alternatively, when the U-phase current and V-phase current are detected by the current sensors 27a and 27b, the three-phase current calculator 28 calculates the remaining W-phase current value Iw based on Kirchhoff's law of "Iu + Iv + Iw = 0". The three-phase current calculator 28 outputs the phase current values Iu, Iv, and Iw of each phase to the u,v,w / d-q converter 29.

[0027] The u, v, w / d-q converter 29 converts the three-phase U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw into the 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.

[0028] The high-frequency removal filter 41 extracts the high-frequency removal d-axis current value Idm, which is a driving component contributing to torque generation, from the d-axis current value Id by removing the high-frequency component of the d-axis current value Id. Also, the high-frequency removal filter 42 extracts the high-frequency removal q-axis current value Iqm, which is a driving component contributing to torque generation, from the q-axis current value Iq by removing the high-frequency component of the q-axis current value Iq. The high-frequency removal filters 41 and 42 are realized, for example, by a band-stop filter F(s). The high-frequency angular frequency ωh * The band-stop filter F(s) with the high-frequency angular frequency ωh as the center frequency of the band-stop can be realized according to Equation (1). The high-frequency angular frequency ωh * is input from the outside of the motor control device 100 (for example, a higher-level controller) to the motor control device 100. In Equation (1), "s" is the Laplace operator, "d" is the notch depth, and "ζ" is a predetermined filter coefficient representing the notch bandwidth.

Equation

[0029] The PLL controller 31 calculates the electrical angle estimated 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 mechanical angle estimated angular velocity ωm by dividing the electrical angle estimated angular velocity ωe by the number of pole pairs Pn of the motor M.

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

[0033] The high-frequency voltage command value generator 43 uses the high-frequency angular frequency ωh * and the high-frequency voltage amplitude command value Vh input from the high-frequency voltage amplitude adjuster 72 * to generate the d-axis high-frequency voltage command value Vdh * and the q-axis high-frequency voltage command value Vqh * are generated. 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 the torque generation for estimating the rotor position. That is, the high-frequency current used for estimating the rotor position is generated in response to the application of the high-frequency voltage vectors Vdh * , Vqh * .

[0034] The adder 44 calculates the d-axis voltage command value Vd * by adding the d-axis driving voltage command value Vdm that contributes to the torque generation for estimating the rotor position and the d-axis high-frequency voltage command value Vdh * . The adder 45 calculates the q-axis voltage command value Vq * by adding the q-axis driving voltage command value Vqm that contributes to the torque generation for estimating the rotor position and the q-axis high-frequency voltage command value Vqh * .

[0035] 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 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 include high-frequency current. That is, the axis error calculator 30 is based on the high-frequency voltage vectors Vdh * , Vqh *Using the high-frequency current vector generated in response to the application of [[ID=]], the axis error Δθ, which is the deviation between the d-q coordinate axes and the estimated coordinate axes of the d-q coordinate axes, is calculated. Further, the axis error calculator 30 detects the mirror image current vector Ihn included in the d-axis current value Id and the q-axis current value Iq, and outputs the detected mirror image current vector Ihn to the high-frequency voltage amplitude adjuster 72.

[0036] The high-frequency voltage amplitude adjuster 72 adjusts the high-frequency voltage amplitude command value Vh * based on the mirror image current vector Ihn, and outputs the adjusted high-frequency voltage amplitude command value Vh * to the high-frequency voltage command value generator 43. Thereby, the amplitude of the high-frequency voltage for generating the high-frequency current used for estimating the rotor position of the motor M is adjusted.

[0037] <Configuration of High-Frequency Voltage Command Value Generator> FIG. 2 is a diagram showing a configuration example of the high-frequency voltage command value generator according to Embodiment 1 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.

[0038] The phase generator 43a generates a high-frequency phase θh, which is the phase of the high-frequency voltage vector, by integrating the high-frequency angular frequency ωh * in the range of “0 ≦ θh ≦ 2π”.

[0039] The cosine-sine signal generator 43b generates cosine and sine values u(θh) of the high-frequency phase θh according to Equation (2).

Equation

[0040] The multiplier 43c generates a d-axis high-frequency voltage command value Vdh * and a q-axis high-frequency voltage command value Vqh * according to Equation (3) based on the cosine and sine values u(θh) and the high-frequency voltage amplitude command value Vh * .

Equation

[0041] <Configuration of Axis Error Calculator> FIG. 3 is a diagram showing a configuration example of the axis error calculator according to Embodiment 1 of the present disclosure. In FIG. 3, the axis error calculator 30 includes a cosine-sine current vector generator 301 and a sine estimator 302. The axis error calculator 30 utilizes the magnetic salient polarity of the motor M and calculates the axis error Δθ based on the high-frequency angular frequency ωh * , the d-axis current value Id, and the q-axis current value Iq. FIG. 4 is a diagram showing a configuration example of the cosine-sine current vector generator according to Embodiment 1 of the present disclosure. In FIG. 4, the cosine-sine current vector generator 301 includes an inverter b11 and D-factor filters b12, b13.

[0042] In FIG. 4, the inverter b11 inverts the sign of the high-frequency angular frequency ωh * and outputs the inverted high-frequency angular frequency -ωh * to the D-factor filter b12.

[0043] The D-factor filters b12, b13 are filters that separate and extract the cosine component and the sine component. The D-factor in the D-factor filters b12, b13 is defined by Equation (4) using the identity matrix I, the alternating matrix J, and the Laplace operator s.

Equation

[0044] Based on the inverted high-frequency angular frequency -ωh * , the D-factor filter b12 detects the cosine current vector Ihp included in the d-axis current value Id and the q-axis current value Iq. The cosine current vector Ihp rotates in the same direction as the high-frequency magnetic flux vector generated in response to the application of the high-frequency voltage vectors Vdh * , Vqh * . The D-factor filter b12 outputs the cosine current vector Ihp to the sine estimator 302.

[0045] Based on the high-frequency angular frequency ωh *Based on this, the mirror image current vector Ihn included in the d-axis current value Id and the q-axis current value Iq is detected. The mirror image current vector Ihn rotates in the opposite direction to the high-frequency magnetic flux vector generated in response to the application of the high-frequency voltage vectors Vdh * , Vqh * . The D-factor filter b13 outputs the mirror image current vector Ihn to the mirror image estimator 302 and the high-frequency voltage amplitude adjuster 72.

[0046] Here, the D-factor filters b12 and b13 perform a function equivalent to that of a filter with a frequency characteristic F(s + jωh * ) for each scalar signal that is a component of the 2×1 vector. Therefore, by designing F(s) to have a low-pass characteristic and applying it to the D-factor filters b12 and b13, the D-factor filters b12 and b13 will function as band-pass filters centered at ωh * . Furthermore, the D-factor filters b12 and b13 have the characteristic of polarity separation. That is, due to the band-pass characteristics of polarity separation in the D-factor filters b12 and b13, the d-axis current value Id and the q-axis current value Iq can be separated into the in-phase current vector Ihp and the mirror image current vector Ihn.

[0047] The mirror image estimator 302 calculates the axis error Δθ according to equations (5) and (6) based on the in-phase current vector Ihp and the mirror image current vector Ihn. That is, the mirror image estimator 302 calculates the arctangent of the composite vector obtained by vector addition of the in-phase current vector Ihp and the mirror image current vector Ihn with the norms equalized as the axis error Δθ. [Number] [Number]

[0048] [Configuration of the High-Frequency Voltage Amplitude Adjuster] FIG. 5 is a diagram showing a configuration example of the high-frequency voltage amplitude adjuster according to Embodiment 1 of the present disclosure. The high-frequency voltage amplitude adjuster 72a shown in FIG. 5 corresponds to the high-frequency voltage amplitude adjuster 72 shown in FIG. 1. In FIG. 5, the high-frequency voltage amplitude adjuster 72a includes a peak hold calculator 72a1, a subtractor 72a2, and a voltage amplitude calculator 72a3.

[0049] <Processing procedure in the high-frequency voltage amplitude adjuster> FIG. 6 is a flowchart showing an example of a processing procedure in the high-frequency voltage amplitude adjuster according to Embodiment 1 of the present disclosure.

[0050] The mirror image current vector Ihn can be decomposed on the d-q coordinate axes into a d-axis mirror image current vector Idn that is the d-axis mirror image current vector and a q-axis mirror image current vector Iqn that is the q-axis mirror image current vector. Further, since the mirror image current vector Ihn draws a perfect circle on the d-q coordinate axes, the d-axis mirror image current vector Idn and the q-axis mirror image current vector Iqn swing with the same amplitude, and the peak value of the d-axis mirror image current vector Idn and the peak value of the q-axis mirror image current vector Iqn correspond to the peak value of the mirror image current vector Ihn.

[0051] Therefore, as shown in FIG. 6, in step S50, the peak hold calculator 72a1 sets the counter n to the initial value "1".

[0052] Next, in step S100, the peak hold calculator 72a1 determines whether the phase θdh of the d-axis mirror image current vector Idn obtained from the mirror image current vector Ihn is less than 2πn. While the phase θdh is less than 2πn (step S100: Yes), the process proceeds to step S105, and when the phase θdh reaches 2πn (step S100: No), the process proceeds to step S115.

[0053] In step S105, the peak hold calculator 72a1 determines whether the temporarily stored d-axis mirror image current vector peak value Idn_peak_temp (initialized to 0) in the peak hold calculator 72a1 is less than the amplitude value of the d-axis mirror image current vector Idn. When the temporarily stored d-axis mirror image current vector peak value Idn_peak_temp is less than the amplitude value of the d-axis mirror image current vector Idn (step S105: Yes), the process proceeds to step S110. When the temporarily stored d-axis mirror image current vector peak value Idn_peak_temp is greater than or equal to the amplitude value of the d-axis mirror image current vector Idn (step S105: No), the process returns to step S100.

[0054] In step S110, the peak hold calculator 72a1 updates the temporarily stored d-axis mirror image current vector peak value Idn_peak_temp with the amplitude value of the d-axis mirror image current vector Idn. After the process of step S110, the process returns to step S100.

[0055] On the other hand, in step S115, the peak hold calculator 72a1 updates the d-axis mirror image current vector peak value Idn_peak with the temporarily stored d-axis mirror image current vector peak value Idn_peak_temp.

[0056] Next, in step S120, the peak hold calculator 72a1 initializes the temporarily stored d-axis mirror image current vector peak value Idn_peak_temp to "0".

[0057] Next, in step S125, the peak hold calculator 72a1 increments n.

[0058] Next, in step S130, the subtractor 72a2 subtracts the d-axis mirror image current vector amplitude command value |Idn| * from the d-axis mirror image current vector peak value Idn_peak to calculate the deviation |Idn|err of the d-axis mirror image current vector peak value Idn_peak with respect to the d-axis mirror image current vector amplitude command value |Idn| * The d-axis mirror image current vector amplitude command value |Idn| *It is set to the minimum value at which it is known that an S / N ratio sufficient to stably drive the motor M can be ensured, and is input from the outside of the motor control device 100 (for example, a higher-level controller) to the high-frequency voltage amplitude adjuster 72a.

[0059] Next, in step S135, the voltage amplitude calculator 72a3 multiplies a predetermined gain value g by the deviation |Idn|err, and subtracts g×|Idn|err from the high-frequency voltage amplitude command value Vh calculated in the previous cycle. * The high-frequency voltage amplitude command value Vh * is updated to calculate the high-frequency voltage amplitude command value Vh * in this cycle. As a result, the deviation |Idn|err approaches 0. After the process of step S135, the process returns to step S100.

[0060] As described above, in the high-frequency voltage amplitude adjuster 72a, every period of 2π, the d-axis mirror image current vector peak value Idn_peak is updated, and the high-frequency voltage amplitude command value Vh is adjusted so that the d-axis mirror image current vector peak value Idn_peak becomes the d-axis mirror image current vector amplitude command value |Idn|. * *

[0061] Also, since the amplitude |Ihn| of the mirror image current vector Ihn is represented by Equation (7), the amplitude |Ihn| is adjusted according to the adjustment of the high-frequency voltage amplitude command value Vh. In Equation (7), "Ld" is the d-axis inductance of the motor M, and "Lq" is the q-axis inductance of the motor M. *

Equation

[0062] Note that in FIG. 6, the update period of the d-axis mirror image current vector peak value Idn_peak and the high-frequency voltage amplitude command value Vh * is set to 2π. However, the update period of the d-axis mirror image current vector peak value Idn_peak and the high-frequency voltage amplitude command value Vh *The update period may be a predetermined period Tm other than 2π. The period Tm may be, for example, 4π.

[0063] <Operation of Peak Hold Calculator> FIG. 7 is a diagram showing an operation example of the peak hold calculator according to the first embodiment of the present disclosure. In FIG. 7, as an example, the case where the update period Tm of the d-axis mirror image current vector peak value Idn_peak and the high-frequency voltage amplitude command value Vh * is set to 2π is shown.

[0064] As shown in FIG. 7, within one predetermined period Tm (step S100: Yes), when the amplitude value of the d-axis mirror image current vector Idn becomes larger than the temporary d-axis mirror image current vector peak value Idn_peak_temp (step S105: Yes), the temporary d-axis mirror image current vector peak value Idn_peak_temp is sequentially updated by the amplitude value of the d-axis mirror image current vector Idn (step S110). That is, within one predetermined period Tm, in the section where the amplitude value of the d-axis mirror image current vector Idn increases, the temporary d-axis mirror image current vector peak value Idn_peak_temp is updated so as to trace the maximum value of the amplitude of the d-axis mirror image current vector Idn.

[0065] Then, at the end of one predetermined period Tm (step S100: No), the d-axis mirror image current vector peak value Idn_peak is updated by the temporary d-axis mirror image current vector peak value Idn_peak_temp (step S115).

[0066] The peak hold calculator 72a1 repeats the above operation at the period Tm.

[0067] Here, the amplitude |Ihn| of the mirror-image current vector Ihn generally becomes smaller than the amplitude |Ihp| of the in-phase current vector Ihp. Also, as can be seen from Equation (7), the amplitude |Ihn| varies according to the motor parameters Ld and Lq. Since the motor parameters Ld and Lq have current characteristics, the motor parameters Ld and Lq change depending on the motor drive conditions. Therefore, depending on the motor drive conditions, the amplitude |Ihn| may become small, and the signal-to-noise ratio may not be sufficiently ensured.

[0068] On the other hand, by uniformly increasing the high-frequency voltage amplitude command value Vh * it becomes possible to maintain the amplitude |Ihn| at a level where the signal-to-noise ratio can be sufficiently ensured under any motor drive conditions.

[0069] However, if the high-frequency voltage amplitude command value Vh * becomes excessively large, it will cause an increase in the noise of the motor M and a deterioration in the efficiency of the motor M.

[0070] Therefore, in the first embodiment, as described above, the high-frequency voltage amplitude command value Vh * is adjusted based on the d-axis mirror-image current vector Idn. By doing so, it is possible to prevent an increase in the noise of the motor M and a deterioration in the efficiency of the motor M, while sufficiently ensuring the signal-to-noise ratio of the mirror-image current vector Ihn, thereby achieving stabilization of the control of the motor M.

[0071] The first embodiment has been described above.

[0072] [Second Embodiment] In the second embodiment, the difference from the first embodiment is that the high-frequency voltage amplitude command value Vh * is adjusted based on the q-axis mirror-image current vector Iqn. The differences from the first embodiment will be described below.

[0073] [Configuration of High-Frequency Voltage Amplitude Regulator] FIG. 8 is a diagram showing a configuration example of the high-frequency voltage amplitude adjuster according to Embodiment 2 of the present disclosure. The high-frequency voltage amplitude adjuster 72b shown in FIG. 8 corresponds to the high-frequency voltage amplitude adjuster 72 shown in FIG. 1. In FIG. 8, the high-frequency voltage amplitude adjuster 72b includes a peak hold calculator 72b1, a subtractor 72b2, and a voltage amplitude calculator 72b3.

[0074] <Processing Procedure in High-Frequency Voltage Amplitude Adjuster> FIG. 9 is a flowchart showing an example of a processing procedure in the high-frequency voltage amplitude adjuster according to Embodiment 2 of the present disclosure.

[0075] As shown in FIG. 9, in step S70, the peak hold calculator 72b1 sets the counter n to the initial value "1".

[0076] Next, in step S200, the peak hold calculator 72b1 determines whether the phase θqh of the q-axis mirror image current vector Iqn obtained from the mirror image current vector Ihn is less than 2πn. While the phase θqh is less than 2πn (step S200: Yes), the process proceeds to step S205, and when the phase θqh reaches 2πn (step S200: No), the process proceeds to step S215.

[0077] In step S205, the peak hold calculator 72b1 determines whether the temporary q-axis mirror image current vector peak value Iqn_peak_temp stored in advance in the peak hold calculator 72b1 with an initial value of 0 is less than the amplitude value of the q-axis mirror image current vector Iqn. When the temporary q-axis mirror image current vector peak value Iqn_peak_temp is less than the amplitude value of the q-axis mirror image current vector Iqn (step S205: Yes), the process proceeds to step S210, and when the temporary q-axis mirror image current vector peak value Iqn_peak_temp is greater than or equal to the amplitude value of the q-axis mirror image current vector Iqn (step S205: No), the process returns to step S200.

[0078] In step S210, the peak hold calculator 72b1 updates the temporary q-axis mirror image current vector peak value Iqn_peak_temp based on the amplitude value of the q-axis mirror image current vector Iqn. After the process of step S210, the process returns to step S200.

[0079] On the other hand, in step S215, the peak hold calculator 72b1 updates the q-axis mirror image current vector peak value Iqn_peak based on the temporary q-axis mirror image current vector peak value Iqn_peak_temp.

[0080] Next, in step S220, the peak hold calculator 72b1 initializes the temporary q-axis mirror image current vector peak value Iqn_peak_temp to "0".

[0081] Next, in step S225, the peak hold calculator 72b1 increments n.

[0082] Next, in step S230, the subtractor 72b2 subtracts the q-axis mirror image current vector amplitude command value |Iqn| * from the q-axis mirror image current vector peak value Iqn_peak to calculate the deviation |Iqn|err of the q-axis mirror image current vector peak value Iqn_peak with respect to the q-axis mirror image current vector amplitude command value |Iqn| * The q-axis mirror image current vector amplitude command value |Iqn| * is determined to be the minimum value at which a sufficient signal-to-noise ratio can be ensured for stable driving of the motor M, and is input from the outside of the motor control device 100 (for example, a higher-level controller) to the high-frequency voltage amplitude adjuster 72b.

[0083] Next, in step S235, the voltage amplitude calculator 72b3 multiplies a predetermined gain value g by the deviation |Iqn|err, and subtracts g×|Iqn|err from the high-frequency voltage amplitude command value Vh * calculated in the previous cycle, and updates the high-frequency voltage amplitude command value Vh * with the resulting value to obtain the high-frequency voltage amplitude command value Vh *Calculate this. As a result, the deviation |Iqn|err approaches 0. After the process of step S235, the process returns to step S200.

[0084] As described above, in the high-frequency voltage amplitude adjuster 72b, every period of 2π, the peak value Iqn_peak of the q-axis mirror image current vector is updated, and the peak value Iqn_peak of the q-axis mirror image current vector becomes the q-axis mirror image current vector amplitude command value |Iqn| * so that the high-frequency voltage amplitude command value Vh * is adjusted.

[0085] Also, since the amplitude |Ihn| of the mirror image current vector Ihn is represented by Equation (7), the amplitude |Ihn| is adjusted according to the adjustment of the high-frequency voltage amplitude command value Vh * of.

Equation

[0086] In addition, in FIG. 9, the update period of the peak value Iqn_peak of the q-axis mirror image current vector and the high-frequency voltage amplitude command value Vh * is set to 2π. However, the update periods of the peak value Iqn_peak of the q-axis mirror image current vector and the high-frequency voltage amplitude command value Vh * may be a predetermined period Tm other than 2π. The period Tm may be, for example, 4π.

[0087] <Operation of the peak hold calculator> FIG. 10 is a diagram showing an operation example of the peak hold calculator according to Embodiment 2 of the present disclosure. FIG. 10 shows, as an example, the case where the update period Tm of the peak value Iqn_peak of the q-axis mirror image current vector and the high-frequency voltage amplitude command value Vh * is 2π.

[0088] As shown in FIG. 10, within one predetermined period Tm (step S200: Yes), when the amplitude value of the q-axis virtual current vector Iqn becomes larger than the peak value Iqn_peak_temp of the q-axis virtual current vector (step S205: Yes), the peak value Iqn_peak_temp of the q-axis virtual current vector is sequentially updated by the amplitude value of the q-axis virtual current vector Iqn (step S210). That is, within one predetermined period Tm, in the section where the amplitude value of the q-axis virtual current vector Iqn increases, the peak value Iqn_peak_temp of the q-axis virtual current vector is updated so as to trace the maximum value of the amplitude of the q-axis virtual current vector Iqn.

[0089] And at the end of one predetermined period Tm (step S200: No), the peak value Iqn_peak of the q-axis virtual current vector is updated by the peak value Iqn_peak_temp of the q-axis virtual current vector (step S215).

[0090] The peak hold calculator 72b1 repeats the above operations at the period Tm.

[0091] As described above, by adjusting the high-frequency voltage amplitude command value Vh based on the q-axis virtual current vector Iqn, similar to the first embodiment, it is possible to sufficiently secure the S / N ratio of the virtual current vector Ihn while preventing an increase in noise of the motor M and a deterioration in the efficiency of the motor M, etc., so that the control of the motor M can be stabilized. * As described above, the second embodiment has been described.

[0092] The second embodiment has been described above.

[0093] As described above, the motor control device (motor control device 100 of the embodiment) of the present disclosure includes an adder (adders 44 and 45 of the embodiment), an axis error calculator (axis error calculator 30 of the embodiment), a current calculator (3φ current calculator 28 of the embodiment), a converter (u, v, w / d-q converter 29 of the embodiment), an adjuster (high-frequency voltage amplitude adjusters 72, 72a, and 72b of the embodiment), and a generator (high-frequency voltage command value generator 43 of the embodiment). The adder adds a driving voltage command value (d-axis driving voltage command value Vdm and q-axis driving voltage command value Vqm of the embodiment) for driving the motor (motor M of the embodiment) at a desired rotational speed and a high-frequency voltage command value (d-axis high-frequency voltage command value Vdh * , q-axis high-frequency voltage command value Vqh * ) for generating a high-frequency current used for estimating the rotor position of the motor to calculate a voltage command value (d-axis voltage command value Vd * , q-axis voltage command value Vq * ). The axis error calculator calculates an axis error using the high-frequency current generated in response to the application of the high-frequency voltage command value. The current calculator calculates a three-phase current (U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw of the embodiment) including the high-frequency current. The converter converts the three-phase current into a two-phase current (d-axis current value Id and q-axis current value Iq of the embodiment) including the high-frequency current. The adjuster adjusts a high-frequency voltage amplitude command value (high-frequency voltage amplitude command value Vh of the embodiment * ) based on the mirror image current vector (d-axis mirror image current vector Idn and q-axis mirror image current vector Iqn of the embodiment) separated from the two-phase current. The generator generates a high-frequency voltage command value based on the adjusted high-frequency voltage amplitude command value.

[0094] For example, the adjuster adjusts the high-frequency voltage amplitude command value based on the amplitude peak values (d-axis mirror image current vector peak value Idn_peak and q-axis mirror image current vector peak value Iqn_peak of the embodiment) of the mirror image current vector.

[0095] Also, for example, the adjuster adjusts the high-frequency voltage amplitude command value based on the amplitude command values (d-axis mirror image current vector amplitude command value |Idn| * , q-axis mirror image current vector amplitude command value |Iqn| *Based on the deviation of the amplitude peak value with respect to (the deviation |Idn|err and the deviation |Iqn|err in the embodiment) and the high-frequency voltage amplitude command value in the previous cycle of the mirror image current vector, calculate the high-frequency voltage amplitude command value in the current cycle of the mirror image current vector.

Explanation of symbols

[0096] 100 Motor control device 72, 72a, 72b High-frequency voltage amplitude adjuster 43 High-frequency voltage command value generator

Claims

【Claim 1】 An adder that calculates a voltage command value by adding a drive voltage command value for driving a motor at a desired rotational speed and a high-frequency voltage command value for generating a high-frequency current used for estimating the rotor position of the motor; An axial error calculator that calculates an axial error using the high-frequency current generated in response to the application of the high-frequency voltage command value; A current calculator that calculates a three-phase current including the high-frequency current; A converter that converts the three-phase current into a two-phase current including the high-frequency current; A regulator that adjusts a high-frequency voltage amplitude command value based on a mirror-image current vector separated from the two-phase current; A generator that generates the high-frequency voltage command value based on the adjusted high-frequency voltage amplitude command value; Comprising: The regulator adjusts the high-frequency voltage amplitude command value based on the amplitude peak value of the mirror-image current vector; The regulator calculates the high-frequency voltage amplitude command value in the current cycle of the mirror-image current vector based on the deviation of the amplitude peak value from the amplitude command value of the mirror-image current vector and the high-frequency voltage amplitude command value in the previous cycle of the mirror-image current vector. A motor control device.

Images