JP2004032944A - Control device for synchronous motor and synchronous motor - Google Patents

Abstract

An object of the present invention is to provide a control device for a synchronous motor having high motor efficiency and low torque ripple and good controllability.
A synchronous frequency and a voltage compensation value of a plurality of arbitrary higher-order frequencies are referred to by referring to current command amplitude values SIQC, SIDC, a rotor position detection value SVD, and a rotor speed detection value SPD to be applied to an electric motor. A harmonic voltage compensation value calculator 16 is provided to calculate SVBCC and SVACC and add and combine them. The voltage compensation values SVBCC and SVACC calculated by the harmonic voltage compensation value calculator 16 are converted into voltage command values SVU, SVV and SVW. to add.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control device for a synchronous motor using a reluctance torque and a magnet torque used for a machine tool or the like, and more particularly to a technique for controlling and controlling a voltage applied to the motor.
[0002]
[Prior art]
FIG. 6 shows a control block diagram of a motor applied to feed axis control and a spindle of a general machine tool.
[0003]
6, 1 is a speed controller, 2 is a torque-current converter, 3 is a current controller, 4 is a dq axis coordinate converter, 5 is an α-β axis coordinate converter, 6 is a phase calculator, 7 is a 3/2 converter, 8 is a 2/3 converter, 9 is a power converter, 10 is a synchronous motor, 11 is a detector, 12 is a position-speed converter, 13 is a current sensor, and 14 is an adder. is there.
[0004]
Next, the command system will be described. The speed controller 1 is provided with a speed command value SVC from a higher-level controller (not shown) and a rotor speed detection value SVD from the position-speed converter 12, and the error thereof is determined by a PI controller (not shown). By performing the calculation, the torque command value STC is obtained.
[0005]
The torque command value STC is converted by the torque-current converter 2 into a d-axis current command amplitude value SIDC and a q-axis current command amplitude value SIQC.
[0006]
The d-axis current command amplitude SIDC and the q-axis current command amplitude SIQC described above are input to the current controller 3, and the d-axis current detection value SIDD output from the dq-axis coordinate converter 4 is input to the current controller 3. The q-axis current detection value SIQD is input, and the error between the command value of each axis and the detection value is converted into a d-axis voltage command value SVDC and a q-axis voltage command value SVQC via a PI controller.
[0007]
Here, the d-axis current command amplitude SIDC and the q-axis current command amplitude SIQC, the d-axis current detection value SIDD and the q-axis current detection value SIQC, the d-axis voltage command value SVDC and the q-axis voltage command value SVQC are rotor coordinates. (D-q axes), it is necessary to convert the current to the stator coordinates (α-β axes) in order to actually apply a current to the electric motor 10.
[0008]
Then, the α-β axis coordinate converter 5 converts the command into an α-axis voltage command value SVAC and a β-axis voltage command value SVBC of the stator coordinates. For this coordinate conversion, COS (SPD) and SIN (SPD) output from the phase calculator 6 are used. COS means a cosine function, SIN means a sine function, and the argument SPD uses the output of the detector 11 as the rotor position detecting means, that is, the rotor position detection value SPD.
[0009]
In addition, since the control of the electric motor 10 is based on the three-phase control, it is necessary to convert the two-phase command values α-axis voltage command value SVAC and β-axis voltage command value SVBC into three phases. By applying a U-phase voltage command value SVU, a V-phase voltage command value SVV, and a U-phase voltage command value SVW, and applying the voltage of each phase to the electric motor 10 through a power converter 9 represented by an inverter, The electric motor 10 is actually driven.
[0010]
Next, the detection system will be described. The electric motor 10 is provided with a detector 11 serving as a rotor position detecting means, and the rotor 11 detects a rotor position detection value SPD. The rotor position detection value SPD is converted into a rotor speed SVD by the position-speed converter 12, and the rotor speed SVD is output to the speed controller 1 as described above.
[0011]
The current detection is performed by the current sensor 13 to detect two phases (for example, the U-phase current detection value SIUD and the V-phase current detection value SIVDD), and the adder 14 detects the remaining phases (W-phase current detection value SIWD). And outputs the three-phase current detection values to the 3/2 conversion unit 7.
[0012]
The 3/2 conversion section 7 outputs the α-axis current detection value SIAD and β-axis current detection value SIBD of the stator coordinates subjected to the two-phase conversion to the dq axis coordinate converter 4.
[0013]
The dq-axis coordinate converter 4 converts COS (SPD) and SIN (SPD) output from the phase calculator 6 into a d-axis current detection value SIDD and a q-axis current detection value SIQD of rotor coordinates. I do.
[0014]
[Problems to be solved by the invention]
Generally, permanent magnet motors that adopt a structure in which permanent magnets are attached to the surface of a rotor are designed so that the shape of the induced voltage due to the permanent magnet magnetic flux becomes sinusoidal by devising the shape of the permanent magnet. ing.
[0015]
This is because the current (or voltage) waveform for driving the electric motor 10 is based on a sinusoidal waveform, and it is well known that this makes it possible to obtain an efficient and low torque ripple characteristic.
[0016]
However, a reluctance type electric motor (RM) and a permanent magnet built-in type electric motor (IPM) using reluctance torque and permanent magnet type torque have a structure in which the rotor surface is covered with a soft magnetic material. Since the magnetic flux concentrates on the place where the permeance is large, the induced voltage (or the excitation voltage in the case of RM) waveform does not become a sine wave shape. Change.
[0017]
It has been experimentally understood that this waveform becomes a waveform containing a plurality of harmonics with respect to the fundamental wave (synchronous frequency).
[0018]
This is due to the change in permeance between the stators due to the rotor shape and, in the case of a permanent magnet insertion motor (IPM), the magnetic flux distribution on the rotor surface due to the permanent magnets (N / S) in the direction of rotation. This is due to the property that it is easy to concentrate on the switching part. The induced voltage (excitation voltage in the case of RM) containing this harmonic appears as a harmonic current component in the control current waveform, leading to an increase in iron loss.
[0019]
Since such iron loss increases as the frequency increases, a higher-frequency harmonic current causes a reduction in efficiency when the motor is driven.
[0020]
In addition, since the waveform ratio of the drive current becomes worse due to the harmonic current, which causes torque ripple of the motor, a small harmonic current component means that the efficiency of the motor is high and the torque ripple is low. I do. Therefore, controllability is improved.
[0021]
The present invention has been made in view of the above circumstances, and has as its object to provide a control device for a synchronous motor having good motor efficiency and low torque ripple and good controllability.
[0022]
[Means for Solving the Problems]
In order to achieve the object, a synchronous motor control device of the present invention is a synchronous motor for controlling a motor having a rotor that is made of a soft magnetic material or a hard magnetic material and has a change in inductance when viewed from a stator winding in a rotational direction. In the motor control device, with reference to the current command amplitude value applied to the motor, the rotor position detection value obtained from the rotor position detection means, and the rotor speed detection value obtained from the rotor speed detection means, A harmonic voltage compensation value calculator for calculating, synthesizing and synthesizing voltage compensation values of the synchronization frequency and a plurality of arbitrary higher-order frequencies is provided, and the voltage compensation value calculated by the harmonic voltage compensation value calculator is a voltage command value. , Is added.
[0023]
The voltage compensation value calculated by the harmonic voltage compensation value calculation unit is calculated and synthesized for a frequency equal to or lower than a threshold frequency at which a synchronization frequency and a plurality of arbitrary higher-order frequencies are arbitrarily set. I do.
[0024]
Furthermore, it is calculated for each of the α-β axes that are the stator coordinates, and compensated for the α-axis voltage command value and the β-axis voltage command value as the α-axis harmonic voltage compensation value and the β-axis harmonic voltage compensation value, respectively. It is characterized by.
[0025]
In the synchronous motor of the present invention, the torque command value output from the speed controller is converted into a current command amplitude value by a torque-current converter, and the current command amplitude value is converted into a voltage command value. In the applied synchronous motor, the harmonic voltage is obtained by acquiring the current command amplitude value and referring to a rotor position detection value based on the rotation position of the rotor and a rotor speed detection value based on the rotation speed of the rotor. The compensation value is calculated by the harmonic voltage compensation value calculation unit, and the harmonic voltage compensation value output from the harmonic voltage compensation value calculation unit is added in the process of converting the current command amplitude value to the voltage command value. The present invention is characterized in that a voltage after compensation is applied after setting a voltage command value after compensation.
[0026]
Further, in the synchronous motor of the present invention, the torque command value output from the speed controller is converted into a two-phase d-axis current command amplitude value and a q-axis current command amplitude value by a torque-current converter, and the d-axis current After converting the command amplitude value and the q-axis current command amplitude value into an α-axis voltage command value and a β-axis voltage command value, the phase conversion unit converts the α-axis voltage command value and the β-axis voltage command value into a three-phase voltage. In the synchronous motor to which the voltage of each phase is applied via the power converter after being converted into the command value, the d-axis current command amplitude value and the q-axis current command amplitude value are obtained and the rotational position of the rotor is changed. The α-axis harmonic voltage compensation value and the β-axis harmonic voltage compensation value are calculated by the harmonic voltage compensation value calculating unit with reference to the detected rotor position value based on the rotor position and the detected rotor speed value based on the rotation speed of the rotor. Α-axis harmonic voltage calculated and output from the harmonic voltage compensation value calculation unit The compensation value and the β-axis harmonic voltage compensation value are added to the α-axis voltage command value and the β-axis voltage command value, and the compensated α-axis voltage command value and the compensated β-axis voltage command value are converted into three phases by a phase converter. After the conversion into the voltage command value, and applying the compensated voltage of each phase via the power converter.
[0027]
Further, in the synchronous motor according to the present invention, the harmonic voltage compensation value calculation unit includes a d-axis magnetic flux calculator that outputs a d-axis magnetic flux value obtained from the d-axis current command amplitude value, and the q-axis current command amplitude value. A q-axis magnetic flux calculator that outputs a q-axis magnetic flux value obtained from the above, a unit converter that generates an angular frequency from the detected rotor speed value, and an angle calculator for each of the d-axis magnetic flux value and the q-axis magnetic flux value. A multiplier for multiplying a frequency to output a d-axis basic voltage compensation amplitude value and a q-axis basic voltage compensation amplitude value; and a high-order angular frequency obtained from the rotor position detection value using the angular frequency as a fundamental wave. After comparing with the preset threshold angular frequency, the α-axis harmonic voltage is calculated from the d-axis basic voltage compensation amplitude value and the q-axis basic voltage compensation amplitude value using the higher-order angular frequency after the comparison. High value for calculating the compensation value and the β-axis harmonic voltage compensation value. And an order voltage compensation value synthesizer.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a control device for a synchronous motor according to the present invention will be described with reference to FIGS.
[0029]
FIG. 1 is a control block diagram of a motor applied to a feed shaft control and a spindle of a machine tool as a control device of a synchronous motor according to the present invention.
[0030]
In FIG. 1, 1 is a speed controller, 2 is a torque-current converter, 3 is a current controller, 4 is a dq axis coordinate converter, 5 is an α-β axis coordinate converter, 6 is a phase calculator, 7 is a 3/2 converter, 8 is a 2/3 converter, 9 is a power converter, 10 is a synchronous motor, 11 is a detector, 12 is a position-speed converter, 13 is a current sensor, 14 is an adder, An adder 15 is provided between the α-β axis coordinate converter 5 and the 2/3 converter adder 8, and 16 is a harmonic voltage compensation value calculator.
[0031]
The harmonic voltage compensation value calculation unit 16 stores a d-axis current command amplitude value (current command amplitude value) SIDC and a q-axis current command amplitude value (current command amplitude value) SIQC of the rotor coordinates (dq axis). Is entered. The harmonic voltage compensation value calculation unit 16 receives the rotor position detection value SPD and the rotor speed detection value SVD based on the rotor position detection value SPD.
[0032]
The harmonic voltage compensation value calculator 16 outputs the α-axis harmonic voltage compensation value SVACC and the β-axis harmonic voltage compensation value SVBCC, and outputs the α-β axis coordinate converter 5 via the adder 15. Is added to the α-axis voltage command value SVAC and β-axis voltage command value SVBC. As a result, the compensated α-axis voltage command value SVADC and the compensated β-axis voltage command value SVBDC are input to the 2/3 converter 8.
[0033]
Although the details will be described later, the α-axis harmonic voltage compensation value SVACC and the β-axis harmonic voltage compensation value SVBCC are a square-axis fundamental wave (= synchronous frequency) and a plurality of arbitrary harmonic components (arbitrary higher-order frequencies). Is a voltage compensation value obtained by combining
[0034]
FIG. 2 is an explanatory diagram of the electric motor 10 to which the present invention is applied.
[0035]
In FIG. 2, 21 is a stator, 22 is a stator winding, 23 is a slot, 24 is a shaft, 25 is a permanent magnet, and 26 is a rotor.
[0036]
The stator 21 is a soft magnetic material typified by a silicon steel plate and has a slot 23 in which a stator winding 22 is housed. A rotor 26 made of the same material as the stator 21 is housed inside the stator 21, and the rotor 26 is fixed to a shaft 24 and has a structure that rotates about the shaft 24.
[0037]
An air gap is provided in the rotor 26 and the permanent magnet 25 is fixed inside. The permanent magnets 25 in FIG. 2 have the magnetization directions alternately indicated by arrows Mf opposite to each other. When no current flows through the stator windings 22 of the stator 21, the permanent magnets 25 are indicated by magnetic loops ML. A flow of magnetic flux is created.
[0038]
FIG. 3 is a graph showing an induced voltage generated when the electric motor 10 shown in FIG. 2 is rotated.
[0039]
FIG. 3A shows an example of the phase voltage. It is assumed that a waveform 31 indicated by a solid line is a U-phase voltage and a waveform 32 indicated by a broken line is a V-phase voltage. As can be seen from FIG. 3A, when each phase voltage has three phases, each phase is shifted by 2π / 3 radian. When the upper side of the vertical axis in FIG. 3A is positive (0) and the lower side is negative, the zero-cross portion of the induced voltage is just the switching portion of the polarity (N / S pole) of the permanent magnet. .
[0040]
FIG. 3B is a graph showing a voltage waveform between the U and V phases when the winding of the motor is Y-connected: a U-phase induced voltage and a V-phase induced voltage shown in FIG. Becomes a synthesized waveform. Here, since a harmonic is superimposed on the synchronization frequency (= fundamental wave component), the waveform does not have a sinusoidal waveform. (In the figure, the third or fifth harmonic components are prominent.)
[0041]
Although FIG. 3 shows a schematic waveform for convenience of description, in actuality, both of FIGS. 3A and 3B often include higher-order harmonics. However, this causes iron loss and increases the calorific value, causing a problem that the motor efficiency is reduced. In addition, the induced voltage affects the control current waveform, causing a reduction in waveform ratio, resulting in torque ripple, noise when driving, or when applied to the feed shaft of a machine tool, causing problems because it appears as streaks on the machined surface. There is.
[0042]
FIG. 4 is a block diagram showing an example of the harmonic voltage compensation value calculator 16 shown in FIG.
[0043]
In FIG. 4, 41 is a d-axis magnetic flux calculator, 42 is a q-axis magnetic flux calculator, 43 is a multiplier, 44 is a multiplier, 45 is a unit converter, 46 is an order generator, 47 is an order determining unit, and 48 is The high-order phase generator 49 is a high-order voltage compensation value synthesizer.
[0044]
The d-axis current command amplitude value SIDC of the rotor coordinates is input to the d-axis magnetic flux calculator 41. The d-axis magnetic flux calculator 41 estimates an inductance value in consideration of the magnitude of the current of the d-axis current command amplitude value SIDC, The rotor d-axis magnetic flux is estimated based on the estimated magnetic flux in consideration of the magnetic flux of the permanent magnet, and is output as the d-axis magnetic flux value SPHID.
[0045]
Similarly, the q-axis current command amplitude SIQC of the rotor coordinates is input to the q-axis magnetic flux calculator 42, and the q-axis magnetic flux calculator 42 estimates the inductance value in consideration of the magnitude of the q-axis current command amplitude SIQC. The rotor q-axis magnetic flux is estimated on the basis of the above, and is output as a q-axis magnetic flux value SPHIQ.
[0046]
The rotor speed detection value SVD is unit-converted by the unit converter 45 and output as the angular frequency SOMEGA. The d-axis magnetic flux value SPHID and the q-axis magnetic flux value SPHIQ are respectively multiplied by the angular frequency SOMEGA by the multipliers 43 and 44, so that the d-axis basic voltage compensation amplitude value SVED and the q-axis basic voltage compensation amplitude value SVEQ of the rotor coordinates are obtained. It is output to the high-order voltage compensation value combiner 49.
[0047]
Further, the rotor position detection value SPD is output to the order generator 46. In the order generator 46, an order DEG for the fundamental wave and an amplitude AMP for the order are set in advance, and the order can be set to any order from 1 to n (n is an integer).
[0048]
The order of the harmonics of the induced voltage may be all calculated from 1 to n (n is an integer), but from experience, it is only necessary to select the top few orders. This is because the harmonics do not include all the orders and the operation is simplified. However, this alone can provide the expected effect.
[0049]
The order DEG for the fundamental wave output from the order generator 46 and the amplitude AMP for the order are output to the order determination unit 47.
[0050]
The angular frequency SOMEGA calculated by the unit converter 45 is input to the order determining unit 47, and the angular frequency SOMEGA is used as a fundamental wave, and the angular frequency of the fundamental wave output from the order generator 46 is used. By setting SOMEGA * order DEG, a higher-order angular frequency (SOMEGA) n is calculated. Here, the subscript n means the order (the same applies hereinafter). At this time, the higher-order angular frequency (SOMEGA) n is not one, but 1 to n (n: n) selected by the order generator 46. Integers).
[0051]
Here, the higher-order angular frequency (SOMEGA) n is compared with a threshold angular frequency (threshold frequency) SOMEGAC set in advance in the order determining unit 47, and the higher-order angular frequency (SOMEGA) n is compared. Is less than or equal to the threshold angular frequency SOMEGAC, the n-th order and amplitude [DEG, AMP] n are output to the higher-order phase generator 48. If n is equal to or greater than the threshold angular frequency SOMEGAC, It is not output to the higher-order phase generator 48.
[0052]
The reason for setting the threshold value in this way is that the transfer function of the electric motor 10 (or the control device) does not respond to a high frequency. This is useful to save processing time for unnecessary compensation.
[0053]
Therefore, the threshold angular frequency SOMEGAC depends on the transfer function of the electric motor 10 (or the control device), and can be arbitrarily set by the electric motor 10 (or the control device) to be used.
[0054]
In this way, [DEG, AMP] n, which is the n-th order and amplitude filtered by the order determining unit 47, is AMPn * COS (DEGn * SPD) and AMPn * SIN (DEGn * SPD) in the high-order phase generating unit 48. ) Is calculated and output to the high-order voltage compensation value synthesizer 49. Note that SIN in the above equation is a sine function, and COS is a cosine function.
[0055]
The high-order voltage compensation value synthesizer 49 converts the d-axis basic voltage compensation amplitude value SVED and the q-axis basic voltage compensation amplitude value SVEQ of the rotor coordinates into AMPn * COS (DEGn * SPD) output from the high-order phase generator 48, And AMPn * SIN (DEGn * SPD) to calculate the α-axis harmonic voltage compensation value SVACC and the β-axis harmonic voltage compensation value SVBCC of the stator coordinates.
[0056]
Therefore, taking the α-axis harmonic voltage compensation value SVACC as an example,
SVACC = Σ [SVED * AMPn * COS (DEGn * SPD)] (1)
It has become.
[0057]
Similarly, the β-axis harmonic voltage compensation value SVBCC is
SVBCC = Σ [SVEQ * AMPn * SIN (DEGn * SPD)] (2)
It becomes.
[0058]
Here, in the high-order voltage compensation value synthesizer 49, the dq-axis rotor coordinates are converted to α-β-axis stator coordinates, and the nth-order amplitude AMPn means a ratio to the fundamental wave amplitude. Can be understood from Expressions (1) and (2).
[0059]
FIG. 5 is a graph showing an example of the effect of the present invention, showing a current command waveform and a response waveform per phase.
[0060]
With respect to the current command waveform 50, a waveform 52 is a detected current value when a current is applied to the motor by the synchronous motor control device shown in the conventional example, and a waveform 51 is a detected current value when the present invention is applied.
[0061]
A harmonic is superimposed on the fundamental wave in the waveform 52, and the harmonic component causes iron loss, resulting in an increase in the amount of heat generated, thereby reducing the motor efficiency. When applied to a driving noise or a feed shaft of a machine tool due to ripples, it becomes a problem because it appears as streaks on a processing surface.
[0062]
It can be seen that in the waveform 51, the harmonic component is reduced, the phase lag is smaller than the current command value 50, and the controllability is improved.
[0063]
Note that the present invention is not limited to the above-described embodiment, and the following modifications can be made without departing from the gist of the present invention.
[0064]
In the harmonic voltage compensation value calculation unit 16, the calculation is performed for both the dq axes of the rotor coordinates (or the α-β axes of the stator coordinates). However, even if only one of the d axis and the q axis is calculated. good.
[0065]
The order generator 46, the order determiner 47, and the higher-order phase generator 48 for each of the dq axes of the rotor coordinates (or the α-β axes of the stator coordinates) in the harmonic voltage compensation value calculator 16. And the order does not necessarily have to be the same for each axis.
[0066]
The harmonic voltage compensation values SVBCC and SVACC may be independently converted to three phases to compensate for the three-phase voltage command values SVU, SVV and SVW.
[0067]
Although the description has been given of the rotating machine, the invention may be applied to a linear motor.
[0068]
Although the winding method of the electric motor 10 has been described with respect to the Y connection, the winding method may be applied to the Δ connection.
[0069]
【The invention's effect】
As described above, according to the control device for a synchronous motor of the present invention, a motor having a rotor made of a soft magnetic material or a hard magnetic material and having a change in inductance when viewed from a stator winding in a rotational direction is controlled. In the control device for the synchronous motor, a current command amplitude value applied to the motor, a rotor position detection value obtained from the rotor position detection unit, and a rotor speed detection value obtained from the rotor speed detection unit are referred to. A harmonic voltage compensation value calculation unit for calculating and adding and synthesizing the voltage compensation values of the synchronization frequency and a plurality of arbitrary higher-order frequencies. The voltage compensation value calculated by the harmonic voltage compensation value calculation unit is a voltage command value. And a voltage compensation value calculated by the harmonic voltage compensation value calculation section is calculated for a frequency equal to or lower than a threshold frequency at which a synchronization frequency and a plurality of arbitrary higher-order frequencies are arbitrarily set. - by being synthesized, the motor efficiency and moreover can be a control device of a good synchronous motor with low controllability of torque ripple.
[0070]
The voltage compensation values calculated by the harmonic voltage compensation value calculation unit are calculated for each of the α-β axes, which are the stator coordinates, as an α-axis harmonic voltage compensation value and a β-axis harmonic voltage compensation value, respectively. By compensating for the α-axis voltage command value and the β-axis voltage command value, harmonic components of the current applied to the motor are reduced, and iron loss is reduced, so that not only is the motor efficiency improved, but also the torque ripple is reduced. Therefore, the controllability of the electric motor can be greatly improved.
[Brief description of the drawings]
FIG. 1 shows an embodiment of a control device for a synchronous motor of the present invention, and is a block diagram of the control device.
FIG. 2 is an explanatory diagram of a motor to which the control device for a synchronous motor of the present invention is applied.
3A and 3B show an induced voltage waveform of a motor to which the synchronous motor control device of the present invention is applied, wherein FIG. 3A is a graph showing phase voltages, and FIG. 3B is a graph showing U when the winding of the motor is Y-connected; FIG. 9 is a graph of a voltage waveform between lines: between V phases.
FIG. 4 is a block diagram of a control device for a synchronous motor of the present invention, showing a harmonic voltage compensation value calculation unit.
FIG. 5 is a graph showing the effect of the control device for a synchronous motor of the present invention.
FIG. 6 is a block diagram showing a conventional control device for a synchronous motor.
[Explanation of symbols]
Reference Signs List 1 speed controller, 2 torque-current converter, 3 current controller, 4 d-q axis coordinate converter, 5 α-β axis coordinate converter, 6 phase calculator, 7 3/2 converter, 8 2 / 3 conversion unit, 9 power converter, 10 synchronous motor, 11 detector, 12 position-speed conversion unit, 13 current sensor, 14 adder, 15 adder, 16 harmonic voltage compensation value calculation unit, 21 stator, 41 d-axis magnetic flux calculator, 42 q-axis magnetic flux calculator, 43 multiplier, 44 multiplier, 45 unit converter, 46 order generator, 47 order determiner, 48 higher order phase generator, 49 higher order voltage compensation value synthesis Sensor, STC torque command value, SIQC q-axis current command amplitude value, SIDC d-axis current command amplitude value, SIQC q-axis current detection value, SIDD d-axis current detection value, SVQC q-axis voltage command value, SVDC d-axis voltage command value , SVBC β axis voltage command value, SVA α axis voltage command value, SVBCC β axis harmonic voltage compensation value, SVACC α axis harmonic voltage compensation value, β axis voltage command value after SVBDC compensation, α axis voltage command value after SVADC compensation, SVU U phase voltage command value, SVV V-phase voltage command value, SVW W-phase voltage command value, SIUD U-phase current detection value, SIIV V-phase current detection value, SIWD W-phase current detection value, SIAD α-axis current detection value, SIBD β-axis current detection value, SIDD d Shaft current detection value, SIQD q-axis current detection value, SPD rotor position detection value, SVD rotor speed detection value, DEG order, AMP amplitude (ratio), SOMEGA angular frequency, SPHID d-axis magnetic flux value, SPHIQ q-axis magnetic flux value , SVED d-axis basic voltage compensation amplitude value, SVEQ q-axis basic voltage compensation amplitude value.

Claims (6)

In a synchronous motor control device for controlling a motor having a rotor that is made of a soft magnetic material or a hard magnetic material and has a change in inductance when viewed from a stator winding in a rotational direction,
A current command amplitude value applied to the motor;
A rotor position detection value obtained from the rotor position detection means,
A rotor speed detection value obtained from the rotor speed detection means,
See
A harmonic voltage compensation value calculation unit for calculating, adding and synthesizing the voltage compensation values of the synchronization frequency and a plurality of arbitrary higher-order frequencies,
A control device for a synchronous motor, comprising: means for adding a voltage compensation value calculated by the harmonic voltage compensation value calculation unit to a voltage command value. The voltage compensation value calculated by the harmonic voltage compensation value calculation unit is calculated and synthesized for a frequency equal to or lower than a threshold frequency at which a synchronization frequency and a plurality of arbitrary higher-order frequencies are arbitrarily set. Item 2. The control device for a synchronous motor according to item 1. The voltage compensation value calculated by the harmonic voltage compensation value calculation unit calculates an α-axis harmonic voltage compensation value and a β-axis harmonic voltage compensation value for each axis component of the α-β axes that are stator coordinates, The control device for a synchronous motor according to claim 1, wherein the calculated value is compensated for an α-axis voltage command value and a β-axis voltage command value. In a synchronous motor in which a torque command value output from a speed controller is converted to a current command amplitude value by a torque-current converter, and the voltage is applied after converting the current command amplitude value to a voltage command value,
The harmonic voltage compensation value is obtained by obtaining the current command amplitude value and referring to the rotor position detection value based on the rotor rotation position and the rotor speed detection value based on the rotor rotation speed. The calculated voltage command value was calculated by the value calculation unit and added in the process of converting the harmonic voltage compensation value output from the harmonic voltage compensation value calculation unit from the current command amplitude value to the voltage command value. A synchronous motor to which the compensated voltage is applied. The torque command value output from the speed controller is converted into a two-phase d-axis current command amplitude value and a q-axis current command amplitude value by a torque-current converter, and the d-axis current command amplitude value and the q-axis current command amplitude are converted. After converting the values into an α-axis voltage command value and a β-axis voltage command value, the α-axis voltage command value and the β-axis voltage command value are converted into three-phase voltage command values by a phase converter, and then power conversion is performed. In the synchronous motor to which the voltage of each phase is applied via a heater,
Acquire the d-axis current command amplitude value and the q-axis current command amplitude value, and refer to a rotor position detection value based on the rotation position of the rotor and a rotor speed detection value based on the rotation speed of the rotor. The α-axis harmonic voltage compensation value and the β-axis harmonic voltage compensation value are calculated by a harmonic voltage compensation value calculation unit, and the α-axis harmonic voltage compensation value and β-axis output from the harmonic voltage compensation value calculation unit are calculated. The harmonic voltage compensation value is added to the α-axis voltage command value and the β-axis voltage command value, and the compensated α-axis voltage command value and the compensated β-axis voltage command value are converted into a three-phase voltage command value by a phase converter. Wherein the compensated voltages of the respective phases are applied via a power converter after the conversion into a synchronous motor. The harmonic voltage compensation value calculation unit outputs a d-axis magnetic flux value obtained from the d-axis current command amplitude value, and outputs a q-axis magnetic flux value obtained from the q-axis current command amplitude value. A q-axis magnetic flux calculator, a unit converter for generating an angular frequency from the rotor speed detection value, and a d-axis basic voltage compensation by multiplying each of the d-axis magnetic flux value and the q-axis magnetic flux value by the angular frequency. A multiplier for outputting an amplitude value and a q-axis basic voltage compensation amplitude value; and a threshold angular frequency set in advance to a higher-order angular frequency obtained from the rotor position detection value using the angular frequency as a fundamental wave. After the comparison, the α-axis harmonic voltage compensation value and the β-axis harmonic voltage are calculated from the d-axis fundamental voltage compensation amplitude value and the q-axis fundamental voltage compensation amplitude value using the higher-order angular frequency after the comparison. And a high-order voltage compensation value synthesizer for calculating the compensation value. The synchronous motor according to claim 5, wherein:

Images