JP5282443B2 - Control device for permanent magnet type synchronous motor - Google Patents

Description

  The present invention relates to a control device for a permanent magnet type synchronous motor that does not have a magnetic pole position detector, and more particularly, to reliably determine the magnetic pole position of a motor using the saliency and magnetic saturation characteristics of a rotor of a permanent magnet type synchronous motor. The present invention relates to a control device that can be operated on.

In order to reduce the cost of a control device for a permanent magnet type synchronous motor (hereinafter also referred to as PMSM), a so-called sensorless control technique that operates without using a magnetic pole position detector has been put into practical use.
By the way, PMSM is roughly classified into a surface magnet structure permanent magnet synchronous motor (hereinafter also referred to as SPMSM) and an embedded magnet structure permanent magnet synchronous motor (hereinafter also referred to as IPMSM) depending on the structure of the rotor. Among these, in IPMSM, a technique for calculating the magnetic pole position using the saliency of the rotor and the magnetic saturation characteristics has been put into practical use.

For example, Patent Document 1 and Non-Patent Document 1 disclose a technique for calculating the magnetic pole position using the saliency of a rotor (the property that inductance differs between a d-axis and a q-axis, which will be described later). According to these documents, when there is an angular error between the d-axis that is the magnetic pole direction of the rotor and the d-axis estimated on the control device side (denoted as dc axis in both documents), the estimated d-axis The magnetic pole position is calculated using the mutual inductance generated depending on the angle error between the angle q and the estimated q axis orthogonal to this (indicated by the qc axis in both documents).
Specifically, a high-frequency alternating voltage that is a vector parallel to the estimated d-axis is applied to the motor, and the magnetic pole position is calculated so that the high-frequency current flowing in the estimated q-axis direction becomes zero at this time. Thus, sensorless control of the electric motor at low speeds including zero speed is enabled.

However, the magnetic pole position calculated using the saliency of the rotor may have an error of 180 [deg] because the N pole and S pole of the rotor cannot be discriminated in principle.
Therefore, it is conceivable to discriminate between the N pole and the S pole of the rotor by utilizing the difference in the inductance value due to the magnetic saturation characteristics of the electric motor core between the N pole direction and the S pole direction. For example, in Non-Patent Document 1 described above, the current response when a pulse voltage is applied in the positive direction of the estimated d-axis and the negative direction of the estimated d-axis is compared to determine the N-pole direction and the S-pole direction. It is determined and the magnetic pole position is corrected.
Further, in claim 4 of Patent Document 2, while performing the magnetic pole position calculation using the saliency shown in Patent Document 1 and Non-Patent Document 1, the estimated d-axis plus direction and the estimated d-axis minus A direct current is passed in the direction, and the N pole direction and the S pole direction are discriminated from the high frequency current at this time to correct the magnetic pole position.
By operating the motor using the magnetic pole position calculated as described above, the motor can be started stably.

  On the other hand, in order to discriminate between the N pole and the S pole of the rotor using the magnetic saturation characteristics of the motor iron core, it is necessary to be able to detect the difference between the two from the current information. However, in the case of an electric motor having a small difference in magnetic saturation characteristics between the N-pole direction and the S-pole direction, the current information for discriminating between the N-pole and the S-pole is small, so that the current detection circuit is limited by the accuracy The magnetic pole position may not be accurately calculated. If the magnetic pole position cannot be calculated accurately, the torque of the electric motor cannot be accurately controlled, and operation may become impossible, or the control system may become unstable in some cases.

A technique for solving the above problem is disclosed in Patent Document 3.
In Example 1 of Patent Document 3, when the calculation of the magnetic pole position is completed, the estimated q-axis (δ-axis in this document) current is controlled to be constant, and the speed after a predetermined time has not exceeded a predetermined value. , It is determined that the discrimination between the N pole and the S pole has failed. When a determination failure is detected in this way, the initial value of the estimated d-axis (γ-axis in the same document) is corrected by a predetermined value, and the magnetic pole position calculation is performed again.
However, in this prior art, it is necessary to accelerate the electric motor in order to detect a failure in discrimination between the N pole and the S pole, which may cause the motor to reverse during starting and may increase the starting time.

  In Patent Document 4, when the magnetic pole position is calculated from the high-frequency current that flows when a rotating high-frequency voltage is applied to the synchronous machine using the saliency and the magnetic saturation characteristic, the magnetic saturation characteristic is reliably detected. In the first aspect, the amplitude of the high-frequency voltage to be applied is set so that the difference in the amplitude of the high-frequency current in the N-pole direction and the S-pole direction is equal to or greater than a predetermined threshold value. It has been shown to adjust. Further, claim 8 shows that the magnetic pole position calculation using the magnetic saturation characteristic is executed only when the difference in amplitude of the high-frequency current exceeds a predetermined threshold value.

Japanese Patent No. 331472 (paragraphs [0014] to [0044], FIG. 1, FIG. 5, FIG. 6 etc.) JP 2002-171798 A (claim 4, paragraphs [0033] to [0036], FIG. 4 etc.) JP 2007-68255 A (paragraphs [0026] to [0029], FIG. 1 etc.) JP 2007-124835 A (Claim 1, Claim 8, Paragraphs [0010] to [0036], FIG. 1, FIG. 2, etc.) Takashi Aihara, Akio Toba, Takao Yanase, Akihide Mashimo, and Kenji Endo, “Sensorless Torque Control of Salient-Pole Synchronous Motor at Zero-Speed Operation”, IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 14, NO.1, JANUARY 1999

  In Patent Document 4, when there is a restriction on the maximum output voltage and maximum output current of a power converter that supplies power to the motor, or because the magnetic flux density of the motor is low, it is impossible to perform magnetic pole position calculation using magnetic saturation characteristics. However, there is a problem that the starting method is not disclosed, and the operable motors are limited.

  Accordingly, a problem to be solved by the present invention is that a permanent magnet synchronous motor that can reliably start a motor by reliably calculating a magnetic pole position even when magnetic pole position calculation using magnetic saturation characteristics is impossible. It is to provide a control device.

In order to solve the above-described problem, the invention according to claim 1 is directed to a control device for a permanent magnet synchronous motor that does not have a magnetic pole position detector.
First magnetic pole position calculating means for calculating the first magnetic pole position using the saliency of the rotor;
Second magnetic pole position calculating means for calculating the second magnetic pole position from the first magnetic pole position using the magnetic saturation characteristics of the electric motor;
Means for determining whether or not the second magnetic pole position calculation is possible;
When it is determined that the second magnetic pole position calculation is possible, the first starting means is selected as the motor starting means, and when it is determined that the second magnetic pole position calculation is impossible, the motor starting means is selected. Selecting means for selecting the second starting means,
The first starting means has means for starting the electric motor using the second magnetic pole position calculation value,
The second starting means captures the current of the motor as a vector, controls the amplitude of the current vector to a non-zero constant value for a predetermined period, and magnetic pole alignment means for drawing the rotor into the current vector, and this magnetic pole alignment And a means for starting the motor using the position of the current vector after the means is executed.
Thereby, even when it is difficult to calculate the magnetic pole position using the magnetic saturation characteristic, the electric motor can be started reliably.

The invention according to claim 2 is a control device for a permanent magnet type synchronous motor having no magnetic pole position detector.
First magnetic pole position calculating means for calculating the first magnetic pole position using the saliency of the rotor;
Second magnetic pole position calculating means for calculating the second magnetic pole position from the first magnetic pole position using the magnetic saturation characteristics of the electric motor;
Means for determining whether or not the second magnetic pole position calculation is possible;
When it is determined that the second magnetic pole position calculation is possible, the first starting means is selected as the motor starting means, and when it is determined that the second magnetic pole position calculation is impossible, the motor starting means is selected. Selecting means for selecting the second starting means,
The first starting means has means for starting the electric motor using the second magnetic pole position calculation value,
The second starting means captures the terminal voltage of the motor as a vector, controls the amplitude of the terminal voltage vector to a constant value that is not zero for a predetermined period, and magnetic pole positioning means for drawing the rotor into the terminal voltage vector, And a means for starting the motor using the position of the terminal voltage vector after executing the magnetic pole alignment means.
According to the present invention, the configuration of the second starting means in claim 1 can be simplified.

The invention according to claim 3 is a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
First magnetic pole position calculating means for calculating the first magnetic pole position using the saliency of the rotor;
Second magnetic pole position calculating means for calculating the second magnetic pole position from the first magnetic pole position using the magnetic saturation characteristics of the electric motor;
Means for determining whether or not the second magnetic pole position calculation is possible;
When it is determined that the second magnetic pole position calculation is possible, the first starting means is selected as the motor starting means, and when it is determined that the second magnetic pole position calculation is impossible, the motor starting means is selected. Selecting means for selecting the second starting means,
The first starting means has means for starting the electric motor using the second magnetic pole position calculation value,
The second starting means has means for obtaining the orthogonal direction of the first magnetic pole position calculation value as the third magnetic pole position calculation value, and means for starting the electric motor using the third magnetic pole position calculation value. It is.
According to the present invention, the characteristics of the second starting means in the invention of claim 1 can be improved and the time required for magnetic pole alignment can be shortened.

The invention according to claim 4 is the control device according to any one of claims 1 to 3,
The second magnetic pole position calculating means is
A plus d-axis passage means for passing a direct current in the N-pole direction of the rotor permanent magnet obtained from the first magnetic pole position calculation value;
Minus d-axis passage means for passing a direct current in the S-pole direction of the rotor permanent magnet obtained from the first magnetic pole position calculation value;
Means for applying a high frequency voltage alternating in a direction parallel to the first magnetic pole position calculation value;
Means for detecting a γ-axis high-frequency current, which is a high-frequency current flowing in a direction parallel to the first magnetic pole position calculation value by the high-frequency voltage;
A positive d-axis high-frequency current that is the γ-axis high-frequency current when a direct current is passed in the N-pole direction of the rotor permanent magnet, and a direct-current current is passed in the S-pole direction of the rotor permanent magnet. Means for determining a second magnetic pole position calculation value by correcting the first magnetic pole position calculation value in accordance with the magnitude relationship with the minus d-axis high frequency current that is the γ-axis high-frequency current;
Means for determining whether or not the second magnetic pole position calculation is possible,
When the deviation between the plus d-axis high-frequency current and the minus d-axis high-frequency current is larger than a predetermined value, it is determined that the second magnetic pole position calculation is possible.

The invention according to claim 5 is the control device according to any one of claims 1 to 3,
The second magnetic pole position calculating means is
The rotor permanent magnet obtained from the plus d-axis pulse current, which is the current when the pulse voltage is applied in the N-pole direction of the rotor permanent magnet obtained from the first magnetic pole position calculated value, and the first magnetic pole position calculated value Means for calculating the second magnetic pole position calculation value by correcting the first magnetic pole position calculation value in accordance with the magnitude relationship with the minus d-axis pulse current, which is a current when a pulse voltage is applied in the S-pole direction. With
Means for determining whether or not the second magnetic pole position calculation is possible,
When the deviation between the plus d-axis pulse current and the minus d-axis pulse current is larger than a predetermined value, it is determined that the second magnetic pole position calculation is possible.
According to the present invention, the second magnetic pole position calculation means in the invention of claim 1 can be simplified.

  According to the present invention, in the control device including the magnetic pole position calculation means using the saliency and magnetic saturation characteristics of the rotor, even when the magnetic pole position calculation using the magnetic saturation characteristics is impossible, the magnetic saturation characteristics The magnetic pole position can be calculated without using the motor, and the electric motor can be started reliably and stably.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, PMSM can realize highly accurate torque control by performing current control according to the d-axis of the rotor (the magnetic pole direction of the rotor) and the q-axis advanced 90 degrees from the d-axis. However, since the d and q axes cannot be directly detected without the magnetic pole position detector, γ and δ of the orthogonal rotation coordinate system that rotates at the angular velocity ω ₁ (= speed calculation value) corresponding to the d and q axes. The control calculation is performed by estimating the axis to the control device side. Here, the angle of the γ and δ axes (= magnetic pole position calculation value) is defined as θ ₁ .
The definition of the γ and δ axes is shown in FIG. In FIG. 7, ω _r is the rotational angular velocity of the d and q axes, and θ _err is an angular error (position calculation error) between the d and q axes and the γ and δ axes. For convenience, the γ-axis direction is a direction parallel to the estimated magnetic pole position, and the δ-axis direction is a direction orthogonal to the estimated magnetic pole position.

FIG. 6 is a control block diagram for realizing the first magnetic pole position calculation using the saliency of the rotor in the embodiment of the present invention. Hereinafter, a method for applying a high-frequency alternating voltage to the motor for calculating the magnetic pole position in this control block diagram will be described.
First, the main circuit for driving the permanent magnet type synchronous motor 80 having no magnetic pole position detector will be described. 50 is a three-phase AC power source, and the rectifier circuit 60 rectifies the three-phase AC voltage of the power source 50 to generate a DC voltage. Convert to This DC voltage is supplied to a power converter 70 composed of a PWM inverter, and is converted into a predetermined three-phase AC voltage for driving the electric motor 80.

Next, the configuration and operation of the control device are as follows.
The current coordinate converter 14 converts the phase current detection values i _u and i _w detected by the u-phase current detector 11 u and the w-phase current detector 11 w on the output side of the power converter 70 into the magnetic pole position calculation value θ ₁ . Based on this, coordinate conversion is performed to the detected current values i _γ and i _δ on the γ and δ axes.
The notch filter 23 removes the high-frequency current that flows due to the high-frequency alternating voltage superimposed for the magnetic pole position calculation from the γ and δ-axis current detection values i _γ and i _δ , and the γ and δ-axis fundamental wave currents i _γf and i _δf. Is detected.

A deviation between the γ-axis current command value i _γ ^* and the γ-axis fundamental wave current i _γf is calculated by the subtractor 19a, and the deviation is amplified by the γ-axis current regulator 20a, thereby _{obtaining the} γ-axis fundamental wave voltage command value v _γf. ^* Is calculated. On the other hand, the deviation between the δ-axis current command value i _δ ^* and the δ-axis fundamental wave current i _δf is calculated by the subtractor 19b, and this deviation is amplified by the δ-axis current regulator 20b, thereby obtaining the δ-axis fundamental wave voltage command value. v _δf ^* is calculated. Here, the γ and δ-axis current command values i _γ ^* and i _δ ^* are both set to zero.

Frequency voltage calculator 21, the amplitude is equal to the high-frequency voltage amplitude command value V _{y H} ^*, cycle calculates the T _h at a rectangular wave frequency alternating voltage command values v _{y H} ^*.
An adder 22 obtains a γ-axis voltage command value v _γ ^* by superimposing the high-frequency alternating voltage command value v _γh ^* on the γ-axis fundamental wave voltage command value v _γf ^* output from the γ-axis current regulator 20a. On the other hand, the δ-axis voltage command value v _δ ^* is controlled to the fundamental wave voltage command value v _δf ^* output from the δ-axis current regulator 20b.
The γ and δ-axis voltage command values v _γ ^* and v _δ ^* are input to the voltage coordinate converter 15 and the three-phase voltage command values v _u ^* , v _v ^* , and v _w based on the magnetic pole position calculation value θ _1. Converted to ^* .

The DC input voltage E _dc of the power converter 70 detected by the voltage detector 12 and the phase voltage command values v _u ^* , v _v ^* , v _w ^* are input to the PWM circuit 13, and the semiconductor switching of the power converter 70 is performed. A gate signal for turning on and off the element is generated. The power converter 70 performs on / off control of the semiconductor switching element based on the gate signal, whereby the terminal voltage of the permanent magnet type synchronous motor 80 is controlled to the phase voltage command values v _u ^* , v _v ^* , v _w ^*. The

Next, the principle of the first magnetic pole position calculation in this embodiment will be described. This principle is the same as that described in Patent Document 1 and Non-Patent Document 1 described above.
When the PMSM is stopped, the state equation of the high-frequency component when a rectangular high-frequency alternating voltage is applied in a direction parallel to the γ-axis is expressed by Equation 1 when the armature resistance can be ignored.

The amplitudes of the γ and δ-axis high-frequency currents flowing at this time are as shown in Equation 2 from the integration of a half cycle of the high-frequency alternating voltage v _γh in the state equation of Equation 1.

From Equation 2, it is clear that when the high-frequency alternating voltage v _γh is applied in the direction parallel to the γ-axis, the δ-axis high-frequency current amplitude I _{δh at} this time changes at a period twice the angular error θ _err . FIG. 8 shows the relationship between the angle error θ _err and the γ and δ-axis high-frequency current amplitudes I _γh and I _δh .
Based on the above results, a PLL circuit having the δ-axis high-frequency current amplitude I _δh as an input is configured, and the δ-axis high-frequency current amplitude I _δh is controlled to be zero so that the angle error θ _err is zero or 180 degrees. The calculated value θ ₁ can be converged to a true value.

Next, the first magnetic pole position calculation operation according to the control block diagram of FIG. 6 will be described.
The bandpass filter 24 calculates γ and δ-axis high-frequency current amplitudes I _γh and I _δh having the same frequency as the high-frequency alternating voltage v _γh from the γ and δ-axis current detection values i _γ and i _δ . The speed calculator 25 performs a proportional integration calculation based on the δ-axis high-frequency current amplitude I _δh to obtain a speed calculation value ω ₁ . The electrical angle calculator 26 integrates the speed calculation value ω ₁ to obtain the magnetic pole position calculation value θ ₁ .
A PLL circuit that converges the δ-axis high-frequency current amplitude I _δh to zero is configured by these calculations, so that the magnetic pole position θ ₁ can be calculated.
Note that the magnetic pole position θ1 obtained using the saliency of the rotor as described above is referred to as a _first magnetic pole position for convenience.

Next, in addition to the first magnetic pole position calculation according to the control block diagram of FIG. 6, a first embodiment for performing the second magnetic pole position calculation using the magnetic saturation characteristic of the electric motor core will be described.
FIG. 1 is a control block diagram showing the first embodiment, which corresponds to the first and fourth aspects of the invention.
As already described, the magnetic pole position calculation value obtained using the saliency of the rotor may have an error of 180 [deg]. Therefore, in the first embodiment, the first magnetic pole position calculation value obtained by using the saliency is obtained from the control block diagram of FIG. 6, and the magnetic saturation characteristic is used by the technique described in Patent Document 2 described above. Thus, the second magnetic pole position calculation value is obtained by correcting the error. Then, it is determined whether or not the second magnetic pole position calculation is possible. If it is possible, the motor 80 is operated using the second magnetic pole position calculation value, and the second magnetic pole position calculation is impossible. In some cases, I tried to drive without using it.

In the control block diagram of FIG. 1, portions common to FIG. 6 are denoted by the same reference numerals and description thereof is omitted, and the following description is centered on points different from FIG. 6.
In FIG. 1, the current command value generator 31 sets the γ-axis current command value i _γ ^* to a positive constant value (+ I _dNS ^* ) and subsequently to a negative constant value (−I _dNS ^* ). The γ-axis current i _γ is controlled to be positive or negative based on the first magnetic pole position calculation value θ ₁ .

As shown in FIG. 9, when a current is passed in the positive d-axis direction that is the N-pole direction of the rotor permanent magnet, the magnetic flux generated by the current of the rotor permanent magnet and the magnetic flux generated by the current are combined. The flux linkage increases. As a result, the d-axis inductance decreases due to the magnetic saturation of the electric motor core accompanying the increase in magnetic flux.
On the other hand, when a current is passed in the negative d-axis direction, which is the S-pole direction of the rotor permanent magnet, the flux of the rotor permanent magnet and the magnetic flux generated by the current cancel each other, so the linkage flux of the motor decreases. . As a result, the d-axis inductance increases.
From these facts, the true d-axis can be detected by comparing the γ-axis inductance when the γ-axis current i _γ is positively controlled by the current command value generator 31 and when it is negatively controlled. . The γ-axis inductance can be detected from the magnitude of the high-frequency current that flows when a high-frequency alternating voltage is applied to the motor or the magnitude of the current that is applied when a pulse voltage is applied.

The principle described above, NS discriminator 32 in FIG. 1, gamma gamma-axis high frequency current when controlling the negative and when the positively controlled axis current _{i γ I} γh _{(respectively} a positive d-axis high frequency current _{I γhP,} minus d-axis high-frequency current I _γhM ) is compared, and a correction value θ _NS of the first magnetic pole position calculation value θ ₁ is calculated by Equation 3 from the magnitude relationship.

The adder 33 in FIG. 1 adds the first magnetic pole position calculation value θ ₁ and the correction value θ _NS to calculate the second magnetic pole position calculation value θ ₁₀ and holds it as the output of the sample hold circuit 34a. .
The speed initial value ω ₁₀ that is the output of the sample hold circuit 34b holds the speed calculation value ω ₁ .
The starting method selector 35 _compares the deviation of the γ-axis high-frequency currents I _γhP and I _γhM with a predetermined value, selects the first or second starting method based on the result, and uses this result as a starting method selection signal. Is stored in the sample hold circuit 34c.
Further, the output of the sample-and-hold circuit 34d for storing the first magnetic pole position calculation value theta ₁ pointing to the saliency of the rotor and theta _101.

When the deviation _{between the} γ-axis high-frequency currents I _γhP and I _γhP is larger than a predetermined value, it is determined that the second magnetic pole position calculation value θ ₁₀ can be calculated accurately. In this case, an operation method for operating the motor 80 with the second magnetic pole position calculated value θ ₁₀ and the speed calculated value ω ₁ as initial values is selected as the first starting method by the starting method selection signal. The first starting method is arbitrary. For example, the driving method is based on the sensorless control technique described in Non-Patent Document 1.

On the other hand, when it is determined that the deviation of the γ-axis high-frequency currents I _γhP and I _γhP is smaller than a predetermined value and the second magnetic pole position calculation value θ ₁₀ cannot be calculated accurately, the second magnetic pole position is determined by the starting method selection signal. without using the position calculated value theta ₁₀ selects an operating method of operating a motor 80 as a second start-up method. The second starting method is also arbitrary, and for example, a technique described in Japanese Patent Laid-Open No. 2001-190093 is used.
Specifically, by controlling the amplitude of the current to a non-zero constant value, the rotor is drawn into the current vector and the magnetic pole position is matched with the current vector (hereinafter, the process of matching the magnetic pole position with the current vector is referred to as “magnetic pole”. Called "alignment"). Next, by controlling the speed of the current vector to the speed command value, the rotor is drawn into the current vector and the motor is operated (hereinafter, this control method is referred to as “current draw control”).

FIG. 2 is a control block diagram for realizing the second starting method using the current drawing control technique described in the above-mentioned Japanese Patent Application Laid-Open No. 2001-190093.
2, by setting the gamma-axis current value i _gamma ^* to a non-zero constant value I _gamma ^*, controlling the amplitude of gamma-axis current i _gamma in I _gamma ^*. On the other hand, the δ-axis current command value i _δ ^* is set to zero, and the δ-axis current i _δ is controlled to zero.
In order to perform magnetic pole alignment, the speed initial value ω ₁₀ that is the output of the sample hold circuit 34b in FIG. 1 is set as the speed command value ω ₁ by switching the switch 40 for a predetermined time from the start of operation. The electrical angle calculator 26 calculates the electrical angle θ ₁ by integrating the speed command value ω ₁ with the initial value of the electrical angle set to zero. By these processes, the speed of the current vector is controlled to be approximately equal to the rotor speed, and the magnetic pole alignment can be performed quickly even when the rotor is rotating.

When the magnetic pole positioning is completed after a predetermined time has elapsed, the speed command value ω ₁ is controlled to the speed command value ω ^** by the switch 40. The speed command value ω ^** is calculated by limiting the rate of change per unit time of the speed command value ω ^* by a change rate limiter (HLR in the figure) 41. Note that the initial value of the change rate limiter 41 is a speed calculation value ω ₁₀ .
By these processes, the speed of the current vector increases from ω ₁₀ to ω ^* at a predetermined change rate, and the rotor is drawn into the current vector and accelerated, so the speed of the motor 80 is controlled to the speed command value ω ^* . can do.

  The start method selection process by the start method selector 35 in FIG. 1 may be performed every time at the start. However, a trial run is performed before the actual operation of the apparatus, the start method selected at this time is stored, and the actual start method is stored. During operation, the stored starting method may be selected.

Next, a second embodiment of the present invention will be described. The second embodiment is a simplified version of the second starting method in the first embodiment described above, and corresponds to the invention according to claim 2.
FIG. 3 is a control block diagram for realizing the second starting method in the second embodiment, and the following description will focus on parts different from FIG.

In FIG. 3, by inputting the speed command value ω ₁ to the f / v converter 42, the amplitude of the γ-axis voltage command value v _γ ^* is made to be a non-zero value over a certain period while being substantially proportional to the speed command value ω _1. And the δ-axis voltage command value v _δ ^* is controlled to zero.
This can control the speed of the terminal voltage vector to the speed command value omega _1, since the motor rotor 80 is drawn into the current vector generated by the terminal voltage vector, it similarly to the first embodiment to start the motor 80 Can do.

  Next, a third embodiment of the present invention will be described. The third embodiment corresponds to the invention according to claim 3, and the characteristics of the second starting method in the first embodiment described above are described in the prior application (Japanese Patent Application No. 2007-279795) by the present applicant. It is improved by using the developed technology.

FIG. 4 is a control block diagram for realizing the second starting method in the third embodiment. The only difference from FIG. 2 is the initialization method for the electrical angle calculator 26.
First, in FIG. 1, the magnetic pole position calculation value θ ₁ obtained by the first magnetic pole position calculation using the saliency of the rotor is stored in the sample-and-hold circuit 34d, and its output is set to θ ₁₀₁ .

Next, in the control block diagram shown in FIG. 4, the third magnetic pole position calculation obtained by setting the above-mentioned θ ₁₀₁ as the magnetic pole position initial value and adding 90 [deg] to the magnetic pole position initial value θ ₁₀₁ by the adder 36. The value θ ₁₀₃ is set as the initial value of the electrical angle θ ₁ that is the output of the electrical angle calculator 26. Here, since the δ-axis current command value i _δ ^* is controlled to zero, the current vector of the electric motor 80 is controlled in a direction orthogonal to the magnetic pole position θ _r .
According to the present embodiment, since the angle error θ _err between the electrical angle θ ₁ and the magnetic pole position θ _r can be made 90 [deg] or less, the time required for magnetic pole alignment can be shortened.

Next, a fourth embodiment of the present invention will be described. The fourth embodiment corresponds to the invention according to claim 5, and the second magnetic pole position calculation method in the first embodiment described above is simplified by applying the technique described in Non-Patent Document 1. Is.
FIG. 5 is a control block diagram for obtaining the second magnetic pole position calculation value θ ₁₀ in the fourth embodiment, and the same portions as those in FIG. 1 are denoted by the same reference numerals.

In FIG. 5, a pulse generator 37 generates a positive pulse voltage and a negative pulse voltage, and sets them to a γ-axis voltage command value v _γ ^* . On the other hand, the δ-axis voltage command value v _δ ^* is set to zero. Also, the speed calculation value ω ₁ input to the electrical angle calculator 26 is set to zero.
The NS discriminator 32 is a γ-axis current i _γ (a positive d-axis pulse current I _γP and a negative d-axis pulse current I _γM , respectively) when a positive pulse voltage and a negative pulse voltage are applied to the γ axis. The correction value θ _NS of the first magnetic pole position calculation value θ ₁ is calculated by Equation (4).

The starting method selector 35 selects a starting method from the deviation of the γ-axis currents I _γP and I _γM when a positive pulse voltage and a negative pulse voltage are applied to the γ-axis, and this result is used as a starting method selection signal. Is stored in the sample hold circuit 34c.
When the deviation _between the γ-axis currents I _γP and I _γM is larger than a predetermined value, it is determined that the second magnetic pole position calculation value θ ₁₀ can be calculated accurately. In this case, an operation method for operating the electric motor 80 with the second magnetic pole position calculation value θ ₁₀ and the speed calculation value ω ₁ as initial values is selected as the first starting method.
On the other hand, when it is determined that the deviation of the γ-axis currents I _γP and I _γM is smaller than a predetermined value and the second magnetic pole position calculation value θ ₁₀ cannot be calculated accurately, the second magnetic pole position calculation value θ ₁₀ is A driving method that is not used is selected as the second starting method.
Here, the method shown in the first embodiment, the second embodiment, or the third embodiment described above can be applied to the second starting method.

It is a control block diagram which shows 1st Example of this invention. It is a control block diagram for implement | achieving the 2nd starting method in 1st Example of this invention. It is a control block diagram which shows 2nd Example of this invention. It is a control block diagram which shows 3rd Example of this invention. It is a control block diagram which shows 4th Example of this invention. In the embodiment of the present invention, it is a control block diagram for realizing the first magnetic pole position calculation. It is a vector diagram showing the definition of γ and δ axes. It is a figure which shows the relationship between an angle error and a (gamma) and (delta) axis | shaft high frequency current amplitude when a high frequency alternating voltage is applied in the direction parallel to a (gamma) axis. It is a figure which shows the relationship between d-axis current, a linkage flux, and d-axis inductance.

Explanation of symbols

11u u-phase current detector 11w w-phase current detector 12 voltage detector 13 PWM circuit 14 current coordinate converter 15 voltage coordinate converters 19a and 19b subtractor 20a γ-axis current regulator 20b δ-axis current regulator 21 high-frequency voltage calculation 22 Adder 23 Notch filter 24 Band pass filter 25 Speed calculator 26 Electrical angle calculator 31 Current command value generator 32 NS discriminator 33 Adders 34a-34d Sample hold circuit 35 Start method selector 36 Adder 37 Pulse voltage Generator 40 Changer 41 Change rate limiter 42 f / v converter 50 Three-phase AC power supply 60 Rectifier circuit 70 Power converter 80 Permanent magnet synchronous motor (PMSM)

Claims (5)

In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
First magnetic pole position calculating means for calculating the first magnetic pole position using the saliency of the rotor;
Second magnetic pole position calculating means for calculating the second magnetic pole position from the first magnetic pole position using the magnetic saturation characteristics of the electric motor;
Means for determining whether or not the second magnetic pole position calculation is possible;
When it is determined that the second magnetic pole position calculation is possible, the first starting means is selected as the motor starting means, and when it is determined that the second magnetic pole position calculation is impossible, the motor starting means is selected. Selecting means for selecting the second starting means,
The first starting means has means for starting the electric motor using the second magnetic pole position calculation value,
The second starting means captures the current of the motor as a vector, controls the amplitude of the current vector to a non-zero constant value for a predetermined period, and magnetic pole alignment means for drawing the rotor into the current vector, and this magnetic pole alignment And a means for starting the motor using the position of the current vector after the means is executed, and a control device for a permanent magnet type synchronous motor.
In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
First magnetic pole position calculating means for calculating the first magnetic pole position using the saliency of the rotor;
Second magnetic pole position calculating means for calculating the second magnetic pole position from the first magnetic pole position using the magnetic saturation characteristics of the electric motor;
Means for determining whether or not the second magnetic pole position calculation is possible;
When it is determined that the second magnetic pole position calculation is possible, the first starting means is selected as the motor starting means, and when it is determined that the second magnetic pole position calculation is impossible, the motor starting means is selected. Selecting means for selecting the second starting means,
The first starting means has means for starting the electric motor using the second magnetic pole position calculation value,
The second starting means captures the terminal voltage of the motor as a vector, controls the amplitude of the terminal voltage vector to a constant value that is not zero for a predetermined period, and magnetic pole positioning means for drawing the rotor into the terminal voltage vector, And a means for starting the electric motor using the position of the terminal voltage vector after the magnetic pole alignment means is executed.
In a control device for a permanent magnet type synchronous motor having no magnetic pole position detector,
First magnetic pole position calculating means for calculating the first magnetic pole position using the saliency of the rotor;
Second magnetic pole position calculating means for calculating the second magnetic pole position from the first magnetic pole position using the magnetic saturation characteristics of the electric motor;
Means for determining whether or not the second magnetic pole position calculation is possible;
When it is determined that the second magnetic pole position calculation is possible, the first starting means is selected as the motor starting means, and when it is determined that the second magnetic pole position calculation is impossible, the motor starting means is selected. Selecting means for selecting the second starting means,
The first starting means has means for starting the electric motor using the second magnetic pole position calculation value,
The second starting means has means for obtaining the orthogonal direction of the first magnetic pole position calculated value as the third magnetic pole position calculated value, and means for starting the electric motor using the third magnetic pole position calculated value. A control device for a permanent magnet type synchronous motor. In the control device according to any one of claims 1 to 3,
The second magnetic pole position calculating means is
A plus d-axis passage means for passing a direct current in the N-pole direction of the rotor permanent magnet obtained from the first magnetic pole position calculation value;
Minus d-axis passage means for passing a direct current in the S-pole direction of the rotor permanent magnet obtained from the first magnetic pole position calculation value;
Means for applying a high frequency voltage alternating in a direction parallel to the first magnetic pole position calculation value;
Means for detecting a γ-axis high-frequency current, which is a high-frequency current flowing in a direction parallel to the first magnetic pole position calculation value by the high-frequency voltage;
A positive d-axis high-frequency current that is the γ-axis high-frequency current when a direct current is passed in the N-pole direction of the rotor permanent magnet, and a direct-current current is passed in the S-pole direction of the rotor permanent magnet. Means for determining a second magnetic pole position calculation value by correcting the first magnetic pole position calculation value in accordance with the magnitude relationship with the minus d-axis high frequency current that is the γ-axis high-frequency current;
Means for determining whether or not the second magnetic pole position calculation is possible,
A control device for a permanent magnet type synchronous motor, wherein it is determined that the second magnetic pole position calculation is possible when a deviation between the plus d-axis high-frequency current and the minus d-axis high-frequency current is larger than a predetermined value. . In the control device according to any one of claims 1 to 3,
The second magnetic pole position calculating means is
The rotor permanent magnet obtained from the plus d-axis pulse current, which is the current when the pulse voltage is applied in the N-pole direction of the rotor permanent magnet obtained from the first magnetic pole position calculated value, and the first magnetic pole position calculated value Means for calculating the second magnetic pole position calculation value by correcting the first magnetic pole position calculation value in accordance with the magnitude relationship with the minus d-axis pulse current, which is a current when a pulse voltage is applied in the S-pole direction. With
Means for determining whether or not the second magnetic pole position calculation is possible,
A control device for a permanent magnet type synchronous motor, characterized in that, when a deviation between the plus d-axis pulse current and the minus d-axis pulse current is larger than a predetermined value, it is determined that the second magnetic pole position calculation is possible. .

Images