Motor control device

Abstract

To suppress destabilization of motor control without reducing a control response of an output voltage amplitude in a voltage saturation region.SOLUTION: In a motor control device 100a, a voltage command value generator 14 generates a voltage command value of a motor on the basis of a speed error between a speed command value and a speed of a motor M, and a control switching determination section 15 determines whether or not a control region of the motor M is in a voltage saturation region. A non-interference correction value calculator 14b7A calculates a correction value for non-interfering an interference caused by an induction voltage of the motor M and if it is determined by the control switching determination section 15 that the control region is in the voltage saturation region, the voltage command value generator 14 generates a voltage amplitude of an output voltage applied to the motor M and a voltage phase of the output voltage applied to the motor M and calculates a voltage command value which is corrected by the correction value.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] There is a technique for varying the motor control method between a region where the output voltage of the motor control device does not saturate (hereinafter sometimes referred to as the “normal region”) and a region including the vicinity of the limit value of the output voltage of the motor control device where the output voltage of the motor control device saturates (hereinafter sometimes referred to as the “voltage saturation region”). For example, in the normal region, MTPA (Maximum Torqe Per Ampere) control is performed in which the output torque of the motor with respect to the current is maximized, while in the voltage saturation region, a technique for controlling the amplitude (hereinafter sometimes referred to as the “output voltage amplitude”) and phase of the output voltage of the motor is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a motor control device, when the motor control method is switched, vibrations and noises may occur in the motor due to the discontinuity of the motor control before and after the switch. The vibrations and noises generated in the motor when the motor control method is switched are sometimes referred to as “switching shocks”. When the region where the voltage command value is held at the output limit value in the voltage saturation region is defined as the field weakening region, in order to reduce the switching shock, for example, in the region between the normal control region and the field weakening region, motor control is known in which the output voltage amplitude is adjusted so that the current vector moves on the MTPA control curve (Patent Document 2).

[0005] In contrast, when the current vector moves on the MTPA control curve, in the voltage saturation region where the output voltage amplitude is adjusted, for example, when the winding resistance or inductance of the motor is small, the inventors of the present application have discovered that the current vector may oscillate on the MTPA control curve. In order to avoid this phenomenon, it is conceivable to reduce the control response of the output voltage amplitude in the voltage saturation region.

[0006] However, when the induced voltage of the motor changes with the change in the rotational speed of the motor, the responsiveness of the output voltage amplitude adjustment is impaired due to the interference of the induced voltage of the motor with the output voltage amplitude adjustment (hereinafter sometimes referred to as "induced voltage interference"), so that the efficiency of the motor control deteriorates due to the deviation of the current vector from the MTPA control curve.

[0007] Therefore, the present disclosure proposes a technique capable of suppressing the destabilization of motor control without reducing the control response of the output voltage amplitude in the voltage saturation region.

Means for Solving the Problems

[0008] The motor control device of the present disclosure includes a voltage command value generator, a control switching determination unit, and a non-interference correction value calculator. The voltage command value generator generates a voltage command value for the motor based on a speed error between a speed command value and the speed of the motor. The control switching determination unit determines whether the control region of the motor is in the voltage saturation region. The non-interference correction value calculator calculates a correction value for non-interfering the interference caused by the induced voltage of the motor. Then, when it is determined by the control switching determination unit that the control region is in the voltage saturation region, the voltage command value generator generates the voltage amplitude of the output voltage applied to the motor and the voltage phase of the output voltage applied to the motor, and calculates a voltage command value corrected by the correction value.

Effects of the Invention

[0009] According to the present disclosure, it is possible to suppress the destabilization of motor control without reducing the control response of the output voltage amplitude in the voltage saturation region.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 7

Figure 8

Figure 9

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Figure 11

Figure 12

Figure 13

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same components are denoted by the same reference numerals.

[0012] [Embodiment 1] <Configuration of Motor Control Device> FIG. 1 is a diagram showing a configuration example of a motor control device according to Embodiment 1 of the present disclosure. In FIG. 1, a motor control device 100a includes a subtractor 11, a speed controller 12, a voltage command value generator 14, a control switching determination unit 15, 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 a motor M. An example of the motor M is a permanent magnet synchronous motor (PMSM (Permanent Magnet Synchronous Motor)).

[0013] Further, the motor control device 100a includes a shunt resistor 26, either one of current sensors 27a and 27b, and a 3φ current calculator 28.

[0014] Further, the motor control device 100a 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, and a 1 / Pn processor 33.

[0015] The voltage command value generator 14 includes a normal control region voltage command value generator 14a-1, a voltage saturation region voltage command value generator 14b-1, a switch SW1, and a switch SW2. The switch SW1 has contacts 14c-1, 14c-2, and 14c-3. The switch SW2 has contacts 14c-4, 14c-5, and 14c-6.

[0016] The subtractor 11 receives a mechanical angular velocity command value ωm input from outside the motor control device 100a (for example, a higher-level controller) to the motor control device 100a *From the mechanical angle estimated angular velocity ωm, which is the current estimated angular velocity output from the 1 / Pn processor 33, an angular velocity error Δωm is calculated by subtraction, and the calculated angular velocity error Δωm is output to the speed controller 12.

[0017] The speed controller 12 generates a torque command value T such that the angular velocity error Δωm approaches zero, according to, for example, the formula (1) by PI (Proportional Integral) control. * and outputs the generated torque command value T * to the voltage command value generator 14. In formula (1), kp is the proportional gain of the PI control, and ki is the integral gain of the PI control.

Equation

[0018] The voltage command value generator 14 generates a d-axis voltage command value Vd * and a q-axis voltage command value Vq * based on the torque command value T output from the speed controller 12 in each of the normal control region and the voltage saturation region, * and outputs the generated d-axis voltage command value Vd * and the q-axis voltage command value Vq. * The voltage saturation region is a region where the output voltage amplitude Va saturates and field weakening control is performed in the high rotation region of the motor M. The normal control region is a region other than the voltage saturation region, where the output voltage is variable and the motor M is controlled. In the normal control region, maximum torque / current control and the like are performed.

[0019] When the control signal CONTROL_TYPE:A (normal control) is output from the control switching determination unit 15, the voltage command value generator 14 connects the contact 14c-1 and the contact 14c-3 of the switch SW1, and connects the contact 14c-4 and the contact 14c-6 of the switch SW2, and the d-axis voltage command value Vd * and the q-axis voltage command value Vq *It outputs to the d-q / u, v, w converter 23. On the other hand, when the control signal CONTROL_TYPE: B (voltage saturation control) is output from the control switching determination unit 15, the voltage command value generator 14 connects the contact 14c-2 and the contact 14c-3 of the switch SW1, and connects the contact 14c-5 and the contact 14c-6 of the switch SW2, and the d-axis voltage command value Vd * and the q-axis voltage command value Vq * are output to the d-q / u, v, w converter 23.

[0020] The control switching determination unit 15 determines whether the current control region of the motor M is in the normal control region or the voltage saturation region based on the output voltage limit value Vdq_limit, the d-axis voltage command value Vd * and the q-axis voltage command value Vq * When the control switching determination unit 15 determines that the current control region of the motor M is the normal control region, it outputs the control signal CONTROL_TYPE: A (normal control) to the voltage command value generator 14. When it determines that the current control region of the motor M is the voltage saturation region, it outputs the control signal CONTROL_TYPE: B (voltage saturation control) to the voltage command value generator 14. The output voltage limit value Vdq_limit is the DC voltage Vdc supplied from the outside of the IPM25 (for example, a power converter not shown) to the IPM25, which is converted into a voltage value in the dq rotating coordinate axis system that is the control system.

[0021] 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 voltage command value generator 14 into the three-phase U-phase output voltage command value Vu * , the V-phase output voltage command value Vv * and the W-phase output voltage command value Vw * based on the electrical angular phase (dq-axis phase) θe, which is the current rotor position output from the position estimator 32. Then, the d-q / u, v, w converter 23 outputs the U-phase output voltage command value Vu * , the V-phase output voltage command value Vv * and the W-phase output voltage command value Vw* Output it to the PWM modulator 24.

[0022] The PWM modulator 24 generates a six-phase PWM signal based on the U-phase output voltage command value Vu * the V-phase output voltage command value Vv * the W-phase output voltage command value Vw * and a PWM carrier signal, and outputs the generated six-phase PWM signal to the IPM 25.

[0023] Based on the six-phase PWM signal output from the PWM modulator 24, the IPM 25 converts the DC voltage Vdc supplied from outside the IPM 25 to generate an AC voltage to be applied to each of the U-phase, V-phase, and W-phase of the motor M, and applies each AC voltage to the U-phase, V-phase, and W-phase of the motor 10.

[0024] 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 calculated phase current values Iu, Iv, and Iw of each phase to the u, v, w / d-q converter 29. In this way, the shunt resistor 26 and the three-phase current calculator 28 correspond to a current detector that detects the U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw. Also, the U-phase current value Iu, V-phase current value Iv, and W-phase current value Iw correspond to the motor current flowing through the motor M.

[0025] 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 output from the 3φ current calculator 28 into two-phase d-axis current Id and q-axis current Iq based on the electrical angle phase θe indicating the current rotor position output from the position estimator 32. Then, the u, v, w / d-q converter 29 outputs the d-axis current Id and the q-axis current Iq to the voltage command value generator 14 and the axis error calculator 30.

[0026] The axis error calculator 30 uses the d-axis voltage command value Vd * and the q-axis voltage command value Vq * output from the voltage command value generator 14 and the d-axis current Id and q-axis current Iq output from the u, v, w / d-q converter 29 to calculate the axis error Δθ (the difference between the estimated rotation axis and the actual rotation axis). Then, the axis error calculator 30 outputs the calculated axis error Δθ to the PLL controller 31.

[0027] The PLL controller 31 calculates the electrical angle estimated angular velocity ωe, which is the current estimated angular velocity, based on the axis error Δθ output from the axis error calculator 30, and outputs the calculated electrical angle estimated angular velocity ωe to the position estimator 32 and the 1 / Pn processor 33.

[0028] The position estimator 32 estimates the electrical angle phase θe based on the electrical angle estimated angular velocity ωe output from the PLL controller 31, and outputs the estimated electrical angle phase θe to the d-q / u, v, w converter 23 and the u, v, w / d-q converter 29.

[0029] The 1 / Pn processor 33 calculates the mechanical angle estimated angular velocity ωm by dividing the electrical angle estimated angular velocity ωe output from the PLL controller 31 by the number of pole pairs Pn of the motor M, and outputs the calculated mechanical angle estimated angular velocity ωm to the subtractor 11.

[0030] <Configuration of the control switching determination unit> FIG. 2 is a diagram showing a configuration example of the control switching determination unit according to Embodiment 1 of the present disclosure. In FIG. 2, the control switching determination unit 15 includes a voltage amplitude calculator 15a and a control switching determiner 15b, and determines whether the current control region of the motor is the normal control region or the voltage saturation region as follows.

[0031] The voltage amplitude calculator 15a calculates the output voltage amplitude Va according to Equation (2) based on the d-axis voltage command value Vd * and the q-axis voltage command value Vq * output from the voltage command value generator 14. [Number]

[0032] The control switching determiner 15b compares the output voltage amplitude Va (or the peak value of the output voltage amplitude Va when the output voltage fluctuates) calculated by the voltage amplitude calculator 15a with the output voltage limit value Vdq_limit.

[0033] When the output voltage amplitude Va is less than the output voltage limit value Vdq_limit, the control switching determiner 15b determines that the current control region of the motor M is the normal control region, and outputs the control signal CONTROL_TYPE:A to the voltage command value generator 14.

[0034] On the other hand, when the output voltage amplitude Va is greater than or equal to the output voltage limit value Vdq_limit, the control switching determiner 15b determines that the current control region of the motor M is the voltage saturation region, and outputs the control signal CONTROL_TYPE:B to the voltage command value generator 14.

[0035] [Configuration of Voltage Saturation Region Voltage Command Value Generator] FIG. 3 is a diagram showing a configuration example of the voltage saturation region voltage command value generator of Embodiment 1 of the present disclosure. The voltage saturation region voltage command value generator 14b-1a shown in FIG. 3 corresponds to the voltage saturation region voltage command value generator 14b-1 shown in FIG. 1. In FIG. 3, the voltage saturation region voltage command value generator 14b-1a includes a voltage amplitude regulator 14b1, an induced voltage command value calculator 14b2, a current command value calculator 14b3, a temporary voltage command value calculator 14b4, a voltage phase regulator 14b5A, a voltage command value calculator 14b6, a non-interference correction value calculator 14b7A, and an adder 14b8.

[0036] The voltage amplitude regulator 14b1 generates a PI voltage command value Va_pi adjusted such that the current vector moves on the MTPA control curve based on the d-axis current Id and q-axis current Iq output from the u, v, w / d-q converter 29, and outputs the generated PI voltage command value Va_pi to the adder 14b8. Details of the processing in the voltage amplitude regulator 14b1 will be described later.

[0037] The decoupling correction value calculator 14b7A calculates a voltage amplitude decoupling correction value Va_ff for decoupling the induced voltage interference based on the electrical angle estimated angular velocity ωe output from the PLL controller 31, the d-axis current Id and q-axis current Iq output from the u, v, w / d-q converter 29, and outputs the calculated voltage amplitude decoupling correction value Va_ff to the adder 14b8. Details of the processing in the decoupling correction value calculator 14b7A will be described later.

[0038] The adder 14b8 calculates the voltage amplitude command value Va by adding the PI voltage command value Va_pi output from the voltage amplitude regulator 14b1 and the voltage amplitude decoupling correction value Va_ff output from the decoupling correction value calculator 14b7A, and outputs the calculated voltage amplitude command value Va * to the induced voltage command value calculator 14b2 and the voltage command value calculator 14b6. *

[0039] The induced voltage command value calculator 14b2 calculates the induced voltage command value Vo based on the voltage amplitude command value Va according to the motor model equations shown in Equations (3.1) and (3.2) based on the current d-axis current Id, current q-axis current Iq, and current electrical angle estimated angular velocity ωe. Note that Equations (3.1) and (3.2) may be motor model equations that do not include the transient terms (p·Ld·Id, p·Lq·Iq) when there is no variation in the motor current. Details of the calculation of the induced voltage command value Vo * are shown below. * *

[0040] The voltage equations of the PMSM (d-axis voltage Vd, q-axis voltage Vq), the theoretical formula of the output voltage amplitude Va, and the theoretical formula of the induced voltage Vo of the motor M are shown in Eqs. (3.1) to (5). In Eqs. (3.1) to (5), R is the winding resistance of the motor M, Ψa is the electrical sub-link flux of the motor M, Ld is the d-axis inductance of the motor M, and Lq is the q-axis inductance of the motor M.

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[0041] Also, from Eqs. (3.1) to (5), the equation relating the voltage amplitude command value Va * and the induced voltage command value Vo * is as shown in Eq. (6). Therefore, the induced voltage command value calculator 14b2 calculates the induced voltage command value Vo * according to Eq. (6), and outputs the calculated induced voltage command value Vo * to the current command value calculator 14b3. Similar to Eqs. (3.1) and (3.2), Eq. (6) can also be a motor model equation without transient terms (p·Ld·Id, p·Lq·Iq) when there is no fluctuation in the motor current.

Number

[0042] The current command value calculator 14b3, as shown in FIG. 4, calculates the q-axis current command value Iq * and the d-axis current command value Id * based on the intersection of the constant torque curve, which is the locus of the current when the torque command value T * is constant, and the constant induced voltage ellipse, which is the locus of the current when the induced voltage command value Vo * and the estimated electrical angular velocity ωe are constant. FIG. 4 is a diagram for explaining an operation example of the motor control device according to Embodiment 1 of the present disclosure. The current command value calculator 14b3 outputs the calculated q-axis current command value Iq* and the d-axis current command value Id * is output to the virtual voltage command value calculator 14b4.

[0043] The intersection point of the constant torque curve and the constant induced voltage ellipse can be calculated using, for example, the motor torque equation shown in Equation (7) and the induced voltage equation shown in Equation (8).

Equation

Equation

[0044] By eliminating the d-axis current Id from Equation (7) and Equation (8), a quartic equation with respect to the q-axis current Iq can be obtained as shown in Equation (9). However, in Equation (9), ΔL = Ld - Lq.

Equation

[0045] As the solution of the quartic equation shown in Equation (9), for the quartic equation shown in Equation (9), for example, by using the Newton method or the like, the q-axis current command value Iq * at the intersection point where the constant torque curve, which is the locus of the current for which the torque command value T * is constant, and the constant induced voltage ellipse, which is the locus of the current for which the induced voltage Vo and the estimated electrical angular velocity ωe are constant, intersect can be derived (see Figure 4).

[0046] The current command value calculator 14b3 calculates the d-axis current command value Id * based on the q-axis current command value Iq * after calculating the q-axis current command value Iq, according to Equation (10) obtained by transforming the induced voltage equation shown in Equation (8) into the d-axis current equation. * is calculated.

Equation

[0047] Here, in Equation (10), whether to take the positive or negative sign for the √ is determined by calculating the torque (hereinafter sometimes referred to as "torque T_M on the M - point boundary") at the intersection of the straight line parallel to the Iq - axis and passing through the M point (-Ψa / Ld, 0) (hereinafter sometimes referred to as the "M - point boundary line") and the constant - induced - voltage ellipse, and comparing the torque T_M on the M - point boundary with the torque command value T * and can be determined by comparison.

[0048] The following shows the calculation procedure of the d - axis current command value Id * and the q - axis current command value Iq. * FIG. 5 and FIG. 6 are diagrams for explaining the operation example of the current command value calculator according to the first embodiment of the present disclosure.

[0049] The current command value calculator 14b3 first calculates the d - axis current Id_M on the M point according to Equation (11).

Equation

[0050] Next, the current command value calculator 14b3 calculates the q - axis current Iq_M at the intersection of the M - point boundary line and the constant - induced - voltage ellipse. Since the q - axis current Iq_M can be calculated by substituting the d - axis current Id_M on the M point into Equation (8), it is calculated according to Equation (12).

Equation

[0051] Therefore, the current command value calculator 14b3 calculates the torque T_M on the M - point boundary according to Equation (13).

Equation

[0052] And the current command value calculator 14b3 calculates the torque command value T *Based on the magnitude relationship with the torque \(T_M\) at the M - point boundary, according to Equation (14.1) and Equation (14.2), the d - axis current command value \(I_d\) * is determined. In Equation (14.1), the d - axis current command value \(I_d\) * when "torque command value \(T\) * \(\leq\) torque \(T_M\) at the M - point boundary" is shown (see Figure 5), and in Equation (14.2), the d - axis current command value \(I_d\) * when "torque command value \(T\) * \(> \) torque \(T_M\) at the M - point boundary" is shown (see Figure 6).

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[0053] The current command value calculator 14b3 outputs the calculated d - axis current command value \(I_d\) * and the q - axis current command value \(I_q\) * to the virtual voltage command value calculator 14b4.

[0054] The virtual voltage command value calculator 14b4 calculates the feed - forward virtual d - axis voltage command value \(V_{d\_m}\) and virtual q - axis voltage command value \(V_{q\_m}\) according to the motor model equations shown in Equation (15.1) and Equation (15.2) based on the electrical angle estimated angular velocity \(\omega_e\), the d - axis current command value \(I_d\) * and the q - axis current command value \(I_q\) * . Note that Equation (15.1) and Equation (15.2) may be motor model equations without transient terms (\(p\cdot L_d\cdot I_d\), \(p\cdot L_q\cdot I_q\)) when there is no fluctuation in the motor current, similar to Equation (3.1) and Equation (3.2). The virtual voltage command value calculator 14b4 outputs the calculated virtual d - axis voltage command value \(V_{d\_m}\) and virtual q - axis voltage command value \(V_{q\_m}\) to the voltage phase regulator 14b5A.

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[0055] The voltage phase regulator 14b5A adjusts the voltage phase command value \(\delta\) * according to Equation (16) based on the virtual d - axis voltage command value \(V_{d\_m}\) and the virtual q - axis voltage command value \(V_{q\_m}\), and the adjusted voltage phase command value \(\delta\) *Output it to the voltage command value calculator 14b6. Thus, in the voltage saturation region, the voltage phase command value δ * is adjusted by feedforward according to the torque command value T * to speed up the torque response in the voltage saturation region. Therefore, for example, when performing vibration control of the motor M in the voltage saturation region, it is possible to improve the vibration control efficiency and suppress the sudden speed change operation of the motor M due to external disturbances.

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[0056] The voltage command value calculator 14b6, based on the adjusted voltage phase command value δ * and the voltage amplitude command value Va * performs coordinate transformation from polar coordinates to rectangular coordinates according to equations (17.1) and (17.2) to calculate the d-axis voltage command value Vd * and the q-axis voltage command value Vq *

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[0057] <Generation of the voltage amplitude command value Va * > Next, the generation of the voltage amplitude command value Va * by the voltage amplitude regulator 14b1, the decoupling correction value calculator 14b7A, and the adder 14b8 will be described.

[0058] The voltage amplitude regulator 14b1 calculates the d-axis current Id_mtpa * on the MTPA control curve based on the current q-axis current Iq according to equation (18) so that the current vector moves on the MTPA control curve, and calculates the d-axis current Id_mtpa * ​A PI voltage command value Va_pi is calculated such that the error from the current d-axis current Id becomes small. The voltage amplitude regulator 14b1 outputs the calculated PI voltage command value Va_pi to the adder 14b8. In equations (18) and (19), Ψa is the armature cross-magnetizing flux of the motor M, Ld is the d-axis inductance of the motor M, Lq is the q-axis inductance of the motor M, kp is the proportional gain in PI control, and ki is the integral gain in PI control.

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[0059] On the other hand, the decoupling correction value calculator 14b7A calculates a d-axis decoupling correction value Vd_ff and a q-axis decoupling correction value Vq_ff for decoupling the induced voltage interference according to equations (20) and (21), respectively. Then, the decoupling correction value calculator 14b7A calculates the synthetic induced voltage vector amplitude from the d-axis decoupling correction value Vd_ff and the q-axis decoupling correction value Vq_ff according to equation (22), and outputs the calculated synthetic induced voltage vector amplitude to the adder 14b8 as the voltage amplitude decoupling correction value Va_ff.

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[0060] The adder 14b8 adds the voltage amplitude decoupling correction value Va_ff output from the decoupling correction value calculator 14b7A to the PI voltage command value Va_pi output from the voltage amplitude regulator 14b1 according to equation (23), thereby generating a voltage amplitude command value Va in which the induced voltage interference is decoupled. * is generated.

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[0061] <Configuration of Normal Control Region Voltage Command Value Generator> FIG. 7 is a diagram showing a configuration example of a normal control region voltage command value generator according to Embodiment 1 of the present disclosure. In FIG. 7, the normal control region voltage command value generator 14a-1 includes a current command value calculator 14a1, subtractors 18, 19, a voltage command value calculator 20, adders 21, 22, and a decoupling correction value calculator 36.

[0062] The current command value calculator 14a1 calculates the q-axis current command value Iq * and the d-axis current command value Id * based on the intersection of the constant torque curve, which is the locus of the current when the torque command value T * is constant, and the MTPA control curve.

[0063] Here, the intersection of the constant torque curve and the MTPA control curve can be calculated, for example, using the motor torque equation shown in Equation (7) and the equation (18) showing the relationship between the d-axis current Id and the q-axis current Iq in the MTPA control curve. In the right side of Equation (7), the first term represents the magnet torque, the second term represents the reluctance torque, the magnet torque includes only the q-axis current Iq, and the reluctance torque includes both the q-axis current Iq and the d-axis current Id. Therefore, by appropriately controlling the q-axis current Iq and the d-axis current Id, an appropriate torque can be generated in the motor M.

[0064] By eliminating the d-axis current Id from Equation (8) and Equation (18), an equation (24), which is a quartic equation with respect to the q-axis current Iq, can be obtained.

Equation

[0065] As the solution of the quartic equation shown in Equation (24), for the quartic equation shown in Equation (24), for example, by using the Newton method or the like, the q-axis current command value Iq * at the intersection of the constant torque curve of the torque command value T *It is possible to derive a solution corresponding to []. Further, the current command value calculator 14a1 uses the q-axis current command value Iq derived using Equation (24). * Based on [], the d-axis current command value Id is calculated according to Equation (25). * is calculated.

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[0066] The subtractor 18 subtracts the d-axis current Id output from the u,v,w / d-q converter 29 from the d-axis current command value Id output from the current command value calculator 14a1, thereby calculating the d-axis current error Id_diff, which is the error between the d-axis current command value Id and the d-axis current Id. The subtractor 19 subtracts the q-axis current Iq output from the u,v,w / d-q converter 29 from the q-axis current command value Iq output from the current command value calculator 14a1, thereby calculating the q-axis current error Iq_diff, which is the error between the q-axis current command value Iq and the q-axis current Iq. * from, subtracting the d-axis current Id output from the u,v,w / d-q converter 29, to calculate the d-axis current error Id_diff, which is the error between the d-axis current command value Id and the d-axis current Id. The subtractor 19 subtracts the q-axis current Iq output from the u,v,w / d-q converter 29 from the q-axis current command value Iq output from the current command value calculator 14a1, thereby calculating the q-axis current error Iq_diff, which is the error between the q-axis current command value Iq and the q-axis current Iq. * and the d-axis current Id. The voltage command value calculator 20 calculates the pre-non-interference d-axis voltage command value Vdt by performing PI control on the d-axis current error Id_diff according to Equation (26.1). Further, the voltage command value calculator 20 calculates the pre-non-interference q-axis voltage command value Vqt by performing PI control on the q-axis current error Iq_diff according to Equation (26.2). Note that kp_d in Equation (26.1) and kp_q in Equation (26.2) are proportional gains, and ki_d in Equation (26.1) and ki_q in Equation (26.2) are integral gains. * from, subtracting the q-axis current Iq output from the u,v,w / d-q converter 29, to calculate the q-axis current error Iq_diff, which is the error between the q-axis current command value Iq and the q-axis current Iq. * and the q-axis current Iq is calculated.

[0067] The voltage command value calculator 20 calculates the pre-non-interference d-axis voltage command value Vdt by performing PI control on the d-axis current error Id_diff according to Equation (26.1). Further, the voltage command value calculator 20 calculates the pre-non-interference q-axis voltage command value Vqt by performing PI control on the q-axis current error Iq_diff according to Equation (26.2). Note that kp_d in Equation (26.1) and kp_q in Equation (26.2) are proportional gains, and ki_d in Equation (26.1) and ki_q in Equation (26.2) are integral gains.

Number

[0068] The non-interference correction value calculator 36 generates a d-axis non-interference correction value Vda for correcting the d-axis voltage command value Vdt before non-interference according to Equation (27) based on the estimated electrical angular velocity ωe output from the PLL controller 31 and the d-axis current Id and q-axis current Iq output from the u, v, w / d-q converter 29. Also, the non-interference correction value calculator 36 generates a q-axis non-interference correction value Vqa for correcting the q-axis voltage command value Vqt before non-interference according to Equation (28) based on the estimated electrical angular velocity ωe output from the PLL controller 31 and the d-axis current Id and q-axis current Iq output from the u, v, w / d-q converter 29. The d-axis non-interference correction value Vda and the q-axis non-interference correction value Vqa are correction values for canceling the interference term between the d and q axes by feedforward. Here, in order to achieve stable control, it is desirable that the non-interference correction value be a rectified value. Therefore, when generating the non-interference correction value, for the speed, the electrical angular velocity command value ωe input from outside the motor control device 100a (for example, a higher-level controller) * may be used, and for the d-axis current Id and the q-axis current Iq, the d-axis current Id and the q-axis current Iq from which the noise components have been removed by an IIR filter (Infinite Impulse Response Filter) may be used. Note that the IIR filter is an example of a noise removal filter. [Number] [Number]

[0069] The adder 21 calculates the d-axis voltage command value Vd by adding the d-axis non-interference correction value Vda to the d-axis voltage command value Vdt before non-interference according to Equation (29). * The adder 22 calculates the q-axis voltage command value Vq by adding the q-axis non-interference correction value Vqa to the q-axis voltage command value Vqt before non-interference according to Equation (30). * As a result, the d-axis voltage command value Vd * and the q-axis voltage command value Vq in which the interference between the d and q axes is canceled by feedforward* is calculated. [Number] [Number]

[0070] The above describes Example 1 of the present disclosure.

[0071] [Example 2] [Configuration of Voltage Saturation Region Voltage Command Value Generator] FIG. 8 is a diagram showing a configuration example of a voltage saturation region voltage command value generator according to Example 2 of the present disclosure. The voltage saturation region voltage command value generator 14b-1b shown in FIG. 8 corresponds to the voltage saturation region voltage command value generator 14b-1 shown in FIG. 1. In FIG. 8, the voltage saturation region voltage command value generator 14b-1b includes a voltage amplitude adjuster 14b1, an induced voltage command value calculator 14b2, a current command value calculator 14b3, a temporary voltage command value calculator 14b4, a voltage phase adjuster 14b5A, a voltage command value calculator 14b6, a non-interference correction value calculator 14b7B, an adder 14b8, an LPF (Low Pass Filter) processor 14b9, and a Pn processor 14b10. Hereinafter, differences from the voltage saturation region voltage command value generator 14b-1a of Example 1 will be described.

[0072] The LPF processor 14b9 performs LPF processing on the d-axis current Id and q-axis current Iq output from the u,v,w / d-q converter 29 to remove high-frequency noise from the d-axis current Id and q-axis current Iq, and outputs the d-axis current Id_LPF after high-frequency noise removal and the q-axis current Iq_LPF after high-frequency noise removal to the non-interference correction value calculator 14b7B.

[0073] The Pn processor 14b10 multiplies the mechanical angular velocity command value ωm * input from outside the motor control device 100a (for example, an upper controller) to the motor control device 100a by the number of pole pairs Pn of the motor M to obtain the electrical angular velocity command value ωe *Calculate it, and output the calculated electrical angular velocity command value ωe * to the decoupling correction value calculator 14b7B.

[0074] The decoupling correction value calculator 14b7B calculates a voltage amplitude decoupling correction value Va_ff for decoupling the induced voltage interference according to Equations (31), (32), and (33), and outputs the calculated voltage amplitude decoupling correction value Va_ff to the adder 14b8. [Equation] [Equation] [Equation]

[0075] The above is the description of Example 2 of the present disclosure.

[0076] [Example 3] [Configuration of the Voltage Saturation Region Voltage Command Value Generator] FIG. 9 is a diagram showing a configuration example of the voltage saturation region voltage command value generator according to Example 3 of the present disclosure. The voltage saturation region voltage command value generator 14b-1c shown in FIG. 9 corresponds to the voltage saturation region voltage command value generator 14b-1 shown in FIG. 1. In FIG. 9, the voltage saturation region voltage command value generator 14b-1c includes a voltage amplitude regulator 14b1, an induced voltage command value calculator 14b2, a current command value calculator 14b3, a temporary voltage command value calculator 14b4, a voltage phase regulator 14b5A, a voltage command value calculator 14b6, a decoupling correction value calculator 14b7B, an adder 14b8, an LPF (Low Pass Filter) processor 14b9, a Pn processor 14b10, and a voltage limit processor 14b11. Hereinafter, differences from the voltage saturation region voltage command value generator 14b-1a of Example 1 and the voltage saturation region voltage command value generator 14b-1b of Example 2 will be described.

[0077] The adder 14b8 calculates the voltage amplitude command value Va' by adding the PI voltage command value Va_pi output from the voltage amplitude regulator 14b1 and the voltage amplitude non-interference correction value Va_ff output from the non-interference correction value calculator 14b7B, and outputs the calculated voltage amplitude command value Va' to the voltage limit processor 14b11.

[0078] The output voltage limit value Vdq_limit is input to the voltage limit processor 14b11. The voltage limit processor 14b11 limits the voltage amplitude command value Va' input from the adder 14b8 according to equations (34.1) and (34.2). That is, when the voltage amplitude command value Va' reaches the output voltage limit value Vdq_limit, the voltage limit processor 14b11 limits the voltage amplitude command value Va * to the output voltage limit value Vdq_limit.

Number

[0079] Note that the voltage limit processor 14b11 limits the integrator output Va_i (not shown) of the voltage amplitude regulator 14b1 where PI control is performed to the voltage limit value Va_i_limit represented by equation (35.1) according to equation (35.2).

Number

[0080] The above is the description of Example 3 of the present disclosure.

[0081] [Example 4] FIG. 10 is a diagram showing a configuration example of a motor control device according to Example 4 of the present disclosure. In FIG. 10, the motor control device 100b includes a subtractor 11, a voltage command value generator 14, a control switching determination unit 15, a d-q / u,v,w converter 23, a PWM modulator 24, and an IPM 25. The IPM 25 is connected to the motor M.

[0082] In addition, the motor control device 100b includes a shunt resistor 26, current sensors 27a and 27b, and a three-phase current calculator 28. Note that the motor control device 100b only needs to have either the shunt resistor 26 or one of the current sensors 27a and 27b.

[0083] In addition, the motor control device 100b includes a u,v,w / d-q converter 29, an axis error calculator 30, a PLL controller 31, a position estimator 32, and a 1 / Pn processor 33.

[0084] The voltage command value generator 14 includes a normal control region voltage command value generator 14a-2, a voltage saturation region voltage command value generator 14b-2, a switch SW1, and a switch SW2. The switch SW1 has contacts 14c-1, 14c-2, and 14c-3. The switch SW2 has contacts 14c-4, 14c-5, and 14c-6.

[0085] Hereinafter, the differences from the motor control device 100a of the first embodiment will be described.

[0086] In the motor control device 100b shown in FIG. 10, the subtractor 11 outputs the calculated angular velocity error Δωm to the normal control region voltage command value generator 14a-2 and the voltage saturation region voltage command value generator 14b-2.

[0087] <Configuration of Voltage Saturation Region Voltage Command Value Generator> FIG. 11 is a diagram showing a configuration example of the voltage saturation region voltage command value generator according to the fourth embodiment of the present disclosure. The voltage saturation region voltage command value generator 14b-2a shown in FIG. 11 corresponds to the voltage saturation region voltage command value generator 14b-2 shown in FIG. 10. In FIG. 11, the voltage saturation region voltage command value generator 14b-2a includes a voltage amplitude regulator 14b1, a voltage phase regulator 14b5B, a voltage command value calculator 14b6, a non-interference correction value calculator 14b7A, an adder 14b8, a voltage saturation speed controller 14b12, and a subtractor 14b13.

[0088] The voltage saturation speed controller 14b12 generates a d-axis current command value Id such that the angular velocity error Δωm approaches zero, according to, for example, Equation (36) by PI control. * The generated d-axis current command value Id * is output to the subtracter 14b13. In Equation (36), kp is the negative proportional gain of PI control, and ki is the negative integral gain of PI control.

Equation

[0089] The subtracter 14b13 calculates a d-axis current error ΔId by subtracting the d-axis current Id output from the u, v, w / d-q converter 29 from the d-axis current command value Id output from the voltage saturation speed controller 14b12, and outputs the calculated d-axis current error ΔId to the voltage phase regulator 14b5B. *

[0090] The voltage phase regulator 14b5B adjusts a voltage phase command value δ according to, for example, Equation (37) by PI control so that the d-axis current error ΔId approaches zero. * The adjusted voltage phase command value δ * is output to the voltage command value calculator 14b6. In Equation (37), kp is the negative proportional gain of PI control, and ki is the negative integral gain of PI control.

Equation

[0091] <Configuration of Normal Control Region Voltage Command Value Generator> FIG. 12 is a diagram showing a configuration example of a normal control region voltage command value generator according to Embodiment 4 of the present disclosure. In FIG. 12, the normal control region voltage command value generator 14a-2 includes adders 21, 22, subtracters 18, 19, a voltage command value calculator 20, a decoupling correction value calculator 36, a normal control speed controller 37, and a d-axis current command value calculator 38.

[0092] Normally, the control speed controller 37 generates a q-axis current command value Iq such that the angular velocity error Δωm approaches zero according to, for example, Equation (38) using PI control. * The generated q-axis current command value Iq * is output to the d-axis current command value calculator 38 and the subtractor 19. In Equation (38), kp is the proportional gain of PI control, and ki is the integral gain of PI control.

Equation

[0093] Based on the q-axis current command value Iq * the d-axis current command value calculator 38 calculates the d-axis current command value Id * according to Equation (25), and outputs the calculated d-axis current command value Id * to the subtractor 19.

[0094] The above is the description of Example 4 of the present disclosure.

[0095] [Example 5] <Configuration of Voltage Saturation Region Voltage Command Value Generator> FIG. 13 is a diagram showing a configuration example of the voltage saturation region voltage command value generator according to Example 5 of the present disclosure. The voltage saturation region voltage command value generator 14b-2b shown in FIG. 13 corresponds to the voltage saturation region voltage command value generator 14b-2 shown in FIG. 10. In FIG. 13, the voltage saturation region voltage command value generator 14b-2b includes a voltage amplitude regulator 14b1, a voltage phase regulator 14b5C, a voltage command value calculator 14b6, a non-interference correction value calculator 14b7C, adders 14b8 and 14b14, a voltage saturation speed controller 14b12, and a subtractor 14b13. Hereinafter, the differences from the voltage saturation region voltage command value generator 14b-2a of Example 4 will be described.

[0096] The voltage phase regulator 14b5B adjusts the voltage phase command value δ_pi so that the d-axis current error ΔId approaches zero according to, for example, Equation (39) by PI control, and outputs the adjusted voltage phase command value δ_pi to the adder 14b14. In Equation (39), kp is the negative proportional gain of PI control, and ki is the negative integral gain of PI control.

Number

[0097] The decoupling correction value calculator 14b7C calculates a d-axis decoupling correction value Vd_ff and a q-axis decoupling correction value Vq_ff for decoupling the induced voltage interference according to Equations (20) and (21), respectively. Then, the decoupling correction value calculator 14b7C calculates the synthetic induced voltage vector amplitude from the d-axis decoupling correction value Vd_ff and the q-axis decoupling correction value Vq_ff according to Equation (22), and outputs the calculated synthetic induced voltage vector amplitude to the adder 14b8 as the voltage amplitude decoupling correction value Va_ff.

[0098] Also, the decoupling correction value calculator 14b7C calculates a voltage phase decoupling correction value δ_ff for decoupling the induced voltage interference according to Equation (40) based on the d-axis decoupling correction value Vd_ff and the q-axis decoupling correction value Vq_ff, and outputs the calculated voltage phase decoupling correction value δ_ff to the adder 14b14.

Number

[0099] The adder 14b14 adds the voltage phase decoupling correction value δ_ff output from the decoupling correction value calculator 14b7C to the voltage phase command value δ_pi output from the voltage phase regulator 14b5B according to Equation (41), thereby calculating the voltage phase command value δ * in which the induced voltage interference is decoupled, and outputs the calculated voltage phase command value δ * to the voltage command value calculator 14b6.

Number

[0100] Note that the decoupling correction value calculator 14b7C in Embodiment 5, similar to the decoupling correction value calculator 14b7B in Embodiment 2, is based on the electrical angular velocity command value ωe * , the d-axis current after high-frequency noise is removed, i.e., Id_LPF, and the q-axis current after high-frequency noise is removed, i.e., Iq_LPF, to calculate the voltage amplitude decoupling correction value Va_ff. Also, the voltage saturation region voltage command value generator 14b-2b in Embodiment 5 may have a voltage limit processor 14b11, similar to the voltage saturation region voltage command value generator 14b-1c in Embodiment 3.

[0101] The above is the description of Embodiment 5.

[0102] As described above, the motor control device (the motor control devices 100a and 100b in the embodiments) of the present disclosure includes a voltage command value generator (the voltage command value generator 14 in the embodiments), a control switching determination unit (the control switching determination unit 15 in the embodiments), and a decoupling correction value calculator (the decoupling correction value calculators 14b7A, 14b7B, and 14b7C in the embodiments). The voltage command value generator generates a voltage command value for the motor based on the speed error between the speed command value and the speed of the motor (the motor M in the embodiments). The control switching determination unit determines whether the control region of the motor is in the voltage saturation region. The decoupling correction value calculator calculates a correction value for decoupling the interference caused by the induced voltage of the motor. When the control switching determination unit determines that the control region is in the voltage saturation region, the voltage command value generator generates the voltage amplitude and voltage phase of the output voltage applied to the motor, and calculates the voltage command value corrected by the correction value.

[0103] For example, the motor control devices (motor control devices 100a and 100b of the embodiments) of the present disclosure include a current detector (shunt resistors 26 and 3φ current calculator 28 of the embodiments) that detects a motor current, and a converter (u, v, w / d-q converter 29 of the embodiments) that converts the motor current detected by the current detector into a d-axis current and a q-axis current. When it is determined by the control switching determination unit that the control region is in the voltage saturation region, the voltage command value generator adjusts the voltage amplitude of the output voltage of the motor based on the d-axis current and the q-axis current so that the motor current moves on the MTPA control curve, and adds a correction value to the adjusted voltage amplitude to calculate a voltage command value.

[0104] By doing so, it is possible to eliminate the interference caused by the induced voltage of the motor in the voltage saturation region, and thus it is possible to suppress the destabilization of motor control without degrading the control response of the output voltage amplitude.

[0105] Further, the motor control device (motor control device 100a of the embodiment) of the present disclosure includes a subtractor (subtractor 11 of the embodiment) that calculates a speed error between a speed command value and the current speed of the motor, and a torque command value generator (speed controller 12 of the embodiment) that generates a torque command value according to the speed error. The voltage command value generator generates a voltage command value based on the torque command value.

[0106] By doing so, in a motor control device having a voltage command value generator that generates a voltage command value from a torque command value, it is possible to share the torque command value generator between the normal control region and the voltage saturation region.

[0107] Further, the motor control devices (motor control devices 100a and 100b of the embodiments) of the present disclosure include a noise remover (LPF processor 14b9 of the embodiment) that removes noise included in the motor current flowing through the motor. The non-interference correction value calculator calculates a correction value based on the motor current after the noise has been removed.

[0108] By doing so, it is possible to prevent the destabilization of motor control caused by noise being superimposed on the correction value.

[0109] Further, the motor control device of the present disclosure (the motor control devices 100a and 100b of the embodiments) includes an adder (adder 14b8 of the embodiment) that adds a correction value to the voltage amplitude and outputs the voltage amplitude with the correction value added as an addition result, and a limiter (voltage limit processor 14b11 of the embodiment) that limits the addition result by the voltage amplitude of the maximum voltage. The voltage command value generator calculates a voltage command value based on the addition result.

[0110] By doing so, it is possible to smoothly transition from MTPA control to field-weakening control by adjusting the voltage phase, and it is possible to avoid control destabilization caused by the integrator used for adjusting the output voltage amplitude winding up during field-weakening control.

[0111] Further, the motor control device of the present disclosure (the motor control device 100b of the embodiment) includes a first subtractor (subtractor 11 of the embodiment), a d-axis current command value calculator (voltage saturation speed controller 14b12 of the embodiment), a second subtractor (subtractor 14b13 of the embodiment), and a voltage phase generator (voltage phase regulator 14b5B of the embodiment). The first subtractor calculates a speed error between the speed command value and the current speed of the motor. The d-axis current command value calculator calculates a d-axis current command value according to the speed error. The second subtractor calculates a d-axis current error between the d-axis current command value and the current d-axis current of the motor. The voltage phase generator generates a voltage phase according to the d-axis current error. Then, the voltage command value generator calculates a voltage command value based on the voltage phase.

[0112] By doing so, even in a method of generating a voltage phase according to a d-axis current error, interference by the induced voltage of the motor in the voltage saturation region can be made non-interfering, so that destabilization of motor control can be suppressed without degrading the control response of the output voltage amplitude.

[0113] Further, the non-interference correction value calculator (non-interference correction value calculator 14b7C of the embodiment) calculates a first correction value for correcting the voltage amplitude and a second correction value for correcting the voltage phase.

[0114] By doing so, it becomes possible to correct both the voltage amplitude and the voltage phase for which PI control is performed together, so that it is possible to further achieve both prevention of a decrease in the control response of the output voltage amplitude and suppression of destabilization of the motor control.

Explanation of symbols

[0115] 100a, 100b Motor control device 14 Voltage command value generator 15 Control switching determination unit 14b7A, 14b7B, 14b7C Decoupling correction value calculator 11, 14b13 Subtractor 12 Speed controller 14b9 LPF processor 26 Shunt resistor 28 3φ current calculator 29 u, v, w / d - q converter 14b8 Adder 14b11 Voltage limit processor 14b12 Voltage saturation speed controller 14b15 Voltage phase regulator

Claims

1. A voltage command value generator that generates a voltage command value for the motor based on a speed error between a speed command value and the speed of the motor; A control switching determination unit that determines whether or not the control region of the motor is in a voltage saturation region; A non-interference correction value calculator that calculates a correction value for canceling interference caused by the induced voltage of the motor; comprising: When the control switching determination unit determines that the control region is in the voltage saturation region, the voltage command value generator generates a voltage amplitude of an output voltage applied to the motor and a voltage phase of the output voltage applied to the motor, and calculates a voltage command value corrected by the correction value. A motor control device.

2. Further comprising a noise remover that removes noise included in the motor current flowing through the motor, The non-interference correction value calculator calculates the correction value based on the motor current after the noise has been removed. The motor control device according to claim 1.

3. A current detector that detects the motor current; A converter that converts the motor current detected by the current detector into a d-axis current and a q-axis current; further comprising: When the control switching determination unit determines that the control region is in the voltage saturation region, the voltage command value generator adjusts the voltage amplitude of the output voltage of the motor based on the d-axis current and the q-axis current so that the motor current moves on the MTPA control curve, and adds the correction value to the adjusted voltage amplitude to calculate the voltage command value. The motor control device according to claim 2.

4. An adder that adds the correction value to the voltage amplitude and outputs the added voltage amplitude with the correction value as an addition result; A limiter that limits the addition result by a limit value of the voltage amplitude; further comprising: The voltage command value generator calculates the voltage command value based on the addition result. The motor control device according to claim 3.

5. A subtractor that calculates a speed error between the speed command value and the speed of the motor; A torque command value generator that generates a torque command value corresponding to the speed error; further comprising: The voltage command value generator generates the voltage command value based on the torque command value. The motor control device according to claim 1.

6. A first subtractor that calculates a speed error between the speed command value and the speed of the motor; A d-axis current command value calculator that calculates a d-axis current command value according to the speed error; A second subtractor that calculates a d-axis current error between the d-axis current command value and the d-axis current of the motor; A voltage phase generator that generates the voltage phase according to the d-axis current error; Further comprising: The voltage command value generator calculates the voltage command value based on the voltage phase. The motor control device according to claim 3.

7. The decoupling correction value calculator calculates a first correction value for correcting the voltage amplitude and a second correction value for correcting the voltage phase. The motor control device according to claim 5.

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