JP5104217B2 - 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. It relates to the device.

So-called sensorless control technology that operates the motor by estimating the magnetic pole position without using the magnetic pole position detector from the viewpoint of cost reduction and space saving of the control device of the permanent magnet type synchronous motor (hereinafter also referred to as PMSM) Has been put to practical use.
This sensorless control calculates the rotor magnetic pole position and speed from information on the terminal voltage and armature current of the motor, and controls the torque and rotation speed of the motor by controlling the armature current based on these. Yes, for example, described in Non-Patent Document 1.

However, it is known that the sensorless control disclosed in Non-Patent Document 1 uses an induced voltage of an electric motor, so that it cannot be applied in principle at zero speed, and there is a problem in stability at low speed.
For this reason, for example, as disclosed in Patent Document 1, the amplitude of the armature current is made constant in the low speed region, and the rotor of the permanent magnet type synchronous motor is controlled by controlling the frequency of the armature current to the command value. A technique of operating by drawing in an armature current may be applied. Hereinafter, such an operation method is referred to as “current draw control”.
On the other hand, in Patent Document 2, as a problem to be solved, it is pointed out that there is a problem in stability because the speed control system becomes oscillating if the above-described current drawing control is left as it is.

Therefore, a technique described in Non-Patent Document 2 is known as a technique for improving the stability of the speed control system at a low speed.
In the technique described in Non-Patent Document 2, when the voltage command value in the direction orthogonal to the current command value vector (v _γ in the document) is controlled to zero, the current in the direction orthogonal to the current command value vector (i in the document) _{Since γ} ) flows and this can suppress the vibration of the rotor, the speed control system can be stabilized.

Koji Tanaka and Ichiro Miki, “Position Sensorless Control of Embedded Magnet Synchronous Motor Using Extended Inductive Voltage”, IEEJ Transactions D, Vol. 125, no. 9, p. 833-p. 838, 2005 Mitsuo Kawachi, Naoki Yamamura, Joe Tsunehiro, “Improvement of operating characteristics of low-speed position sensorless permanent magnet synchronous motor”, IEEJ Transactions D, Vol. 121, no. 1, pp. 7-13, 2001 JP 2000-287494 A (paragraphs [0012] to [0015], FIG. 1, etc.) JP 2001-190093 (paragraphs [0007] to [0008], FIG. 7 and the like)

  However, since the technique described in Non-Patent Document 2 does not actively control the current in the direction orthogonal to the current command value vector, when the motor is rotating, the current is steady due to the induced voltage of the motor. Current control error may occur and current may be excessive.

  On the other hand, according to the technique described in Patent Document 2, since the current in the direction orthogonal to the current command value vector is controlled to zero, the current can be controlled to the command value even when the motor is rotating. Is possible. However, in general, in order to perform current control with high response, the response angular frequency of the current control system is designed to be higher than the natural angular frequency of the speed control system. As a result, the current that has been flowing in Non-Patent Document 2 and that serves to suppress the vibration of the rotor is controlled to zero, and the speed control system cannot be stabilized.

  In view of such points, claim 1 of Patent Document 2 discloses a stabilization control method that corrects a frequency command value using a component in a direction parallel to a current command value vector among voltage command value vectors. Has been. However, in this method, as shown in FIG. 5 of the same document, in principle, the zero gain is obtained at zero speed, as is clear from the fact that the polarity of the gain of the regulator is reversed according to the sign of the frequency command value. Is not applicable.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a control device that can stably operate a permanent magnet type synchronous motor even at low speeds including zero speed.

In order to solve the above problems, the control device according to claim 1 is a control device for a permanent magnet type synchronous motor that does not have a magnetic pole position detector, and regards the terminal voltage and current of the permanent magnet type synchronous motor as vectors, In the control device of the permanent magnet type synchronous motor that controls the speed of the current command value vector to the speed command value, and controls the terminal voltage to control the current vector to the current command value vector.
Current adjusting means for amplifying a deviation between the current command value vector and the current vector to calculate a terminal voltage command value vector;
The gain characteristic of the current adjusting means is set so that the current at the low speed including the zero speed is low so that the current having the same angular frequency as the natural angular frequency that flows when the rotor vibrates at the natural angular frequency of the speed control system is not suppressed. Means to reduce the gain characteristics in normal times other than the time ,
And a means for controlling the terminal voltage vector to the terminal voltage command value vector.
As a result, the current can be controlled to a command value, and when the rotor vibrates, the safety can be improved by flowing a current that suppresses the vibration.

A control device according to claim 2 is a control device for a permanent magnet type synchronous motor that does not have a magnetic pole position detector, wherein the terminal voltage and current of the permanent magnet type synchronous motor are regarded as vectors, and the speed of the current command value vector is determined. In the control device of the permanent magnet type synchronous motor that controls the speed command value and controls the terminal voltage to control the current vector to the current command value vector,
Define the γ-axis and δ-axis of the orthogonal rotation coordinate system that rotates at the speed command value,
Means for setting a γ-axis current command value that is a γ-axis component of the current command value vector to a non-zero value;
Means for setting a δ-axis current command value, which is a δ-axis component of the current command value vector, to zero;
Means for decomposing the current vector into a γ-axis current that is a γ-axis component and a δ-axis current that is a δ-axis component;
Γ-axis current adjusting means for amplifying a deviation between the γ-axis current command value and the γ-axis current to calculate a γ-axis voltage command value;
Δ-axis current adjusting means for amplifying a deviation between the δ-axis current command value and the δ-axis current to calculate a δ-axis voltage command value;
The gain characteristic of the δ-axis current adjusting means is such that the current at the same angular frequency as the natural angular frequency that flows when the rotor vibrates at the natural angular frequency of the speed control system is not suppressed at a low speed including zero speed, Means for reducing the gain characteristics at normal times other than at low speed ,
Means for synthesizing a terminal voltage command value vector with the γ-axis component and δ-axis component of the terminal voltage command value vector as the γ-axis voltage command value and the δ-axis voltage command value, respectively;
And a means for controlling the terminal voltage vector to the terminal voltage command value vector.
As a result, the γ-axis current can be controlled with high response, and the δ-axis current is controlled to a command value. When the rotor vibrates, a current that suppresses vibration flows, so safety can be improved. is there.

In the control device according to claim 3, the current adjusting means in claim 1 or the δ-axis current adjusting means in claim 2 is a proportional / integral adjusting means, and the reciprocal of the integration time constant of the proportional / integral adjusting means is the It is characterized by being smaller than the natural angular frequency of the speed control system.
As a result, the current can be controlled to the command value in the steady state, and when the rotor vibrates, a current for controlling the vibration flows, so that stability can be improved.

The control device according to claim 4 is a control device for a permanent magnet type synchronous motor that does not have a magnetic pole position detector, and takes the terminal voltage and current of the permanent magnet type synchronous motor as vectors, and determines the speed of the current command value vector. In the control device of the permanent magnet type synchronous motor that controls the speed command value and controls the terminal voltage to control the current vector to the current command value vector,
Current adjusting means for amplifying a deviation between the current command value vector and the current vector to calculate a terminal voltage command value vector;
Means for reducing the gain characteristic of the current adjusting means at a low speed including zero speed, compared to the normal gain characteristic other than the low speed;
And a means for controlling the terminal voltage vector to the terminal voltage command value vector .
As a result, the speed control system can be stabilized at the start of the motor or at a low speed, and the current can be controlled with high accuracy at other normal times.

The control device according to claim 5 is a control device for a permanent magnet type synchronous motor that does not have a magnetic pole position detector, and takes the terminal voltage and current of the permanent magnet type synchronous motor as vectors, and determines the speed of the current command value vector. In the control device of the permanent magnet type synchronous motor that controls the speed command value and controls the terminal voltage to control the current vector to the current command value vector,
Define the γ-axis and δ-axis of the orthogonal rotation coordinate system that rotates at the speed command value,
Means for setting a γ-axis current command value that is a γ-axis component of the current command value vector to a non-zero value;
Means for setting a δ-axis current command value, which is a δ-axis component of the current command value vector, to zero;
Means for decomposing the current vector into a γ-axis current that is a γ-axis component and a δ-axis current that is a δ-axis component;
Γ-axis current adjusting means for amplifying a deviation between the γ-axis current command value and the γ-axis current to calculate a γ-axis voltage command value;
Δ-axis current adjusting means for amplifying a deviation between the δ-axis current command value and the δ-axis current to calculate a δ-axis voltage command value;
Means for reducing the gain characteristic of the δ-axis current adjusting means at a low speed including zero speed, compared to the normal gain characteristics other than the low speed;
Means for synthesizing a terminal voltage command value vector with the γ-axis component and δ-axis component of the terminal voltage command value vector as the γ-axis voltage command value and the δ-axis voltage command value, respectively;
And a means for controlling the terminal voltage vector to the terminal voltage command value vector .
As a result, the speed control system can be stabilized at the start of the motor or at a low speed, and the current can be controlled with high accuracy at other normal times.

When the gain characteristic of the current adjusting means in claim 4 or the δ-axis current adjusting means in claim 5 is reduced, the control apparatus according to claim 6 converts the gain characteristics of these current adjusting means to the speed control system. The current is set so as not to be suppressed at the same angular frequency as the natural angular frequency that flows when the rotor vibrates at the natural angular frequency.
Thereby, the same effect as that of the invention according to claim 1 or claim 2 can be obtained.

When the gain characteristic of the current adjusting means in claim 4 or the δ-axis current adjusting means in claim 5 is reduced, the control device according to claim 7 integrates the proportional / integral adjusting means constituting these current adjusting means. The reciprocal of the time constant is made smaller than the natural angular frequency of the speed control system.
Thereby, the same effect as that of the invention according to claim 3 can be obtained.

  According to the present invention, the permanent magnet type synchronous motor can be stably operated at a low speed including zero speed by a simple control method. In principle, the present invention is not restricted by the electric characteristics of the electric motor, and therefore can be applied to all types of permanent magnet synchronous motors regardless of the presence or absence of saliency.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention corresponding to claims 1 to 3, in which a permanent magnet type synchronous motor is operated by current drawing control.
First, a method for matching the magnitude of the current of the permanent magnet type synchronous motor with the current command value and controlling the rotation speed of the current vector to the speed command value will be described.

The permanent magnet synchronous motor can realize high-precision control by performing current control on the d-axis (rotor magnetic pole direction) of the rotor and the q-axis advanced 90 degrees from the d-axis. However, when the magnetic pole position detector is not provided, the d and q axes cannot be directly detected.
For this reason, the control calculation is performed on the γ and δ axes of the orthogonal rotation coordinate system that rotates at the angular velocity ω ₁ corresponding to the d and q axes. The definition of the γ and δ axes is shown in FIG. In FIG. 5, ω _r is the rotational angular velocity of the d and q axes, and θ _err is the angular error (position calculation error) between the d and q axes and the γ and δ axes.

Returning to FIG. 1, first, the current command value i _γ ^* is controlled to a constant value I _γ ^* other than zero, and i _δ ^* is controlled to zero.
The current coordinate converter 14 detects the phase current detection values i _u and i _w detected by the u-phase current detector 11u and the w-phase current detector 11w, respectively, based on the magnetic pole position calculation value θ ₁ and γ and δ-axis current detection values. Coordinates are converted to i _γ and i _δ .
The γ-axis voltage command value v _γ ^* is calculated by _obtaining the deviation between the γ-axis current command value i _γ ^* and the detected γ-axis current value i _γf by the subtractor 19a and amplifying the deviation by the γ-axis current regulator 20a. To do. The δ-axis voltage command value v _δ ^* is obtained by subtracting the difference between the δ-axis current command value i _δ ^* and the δ-axis current detection value i _δ by the subtractor 19b and amplifying the deviation by the δ-axis current regulator 20b. To calculate.

Here, each of the γ-axis current regulator 20a and the δ-axis current regulator 20b is composed of a proportional / integral regulator. The arithmetic expressions of γ and δ-axis voltage command values v _γ ^* and v _δ ^* by the regulators 20a and 20b are expressed by Expressions 1 and 2, respectively.
As described later, the controller 20a, the proportional gain _{K P?} Inputted to _{20b, K} Pδ and integral time constant _{T i?, T it?} Is set to _{K P2, T I2,} respectively.

The γ and δ-axis voltage command values v _γ ^* and v _δ ^* are converted by the voltage coordinate converter 15 into phase voltage command values v _u ^* , v _v ^* , and v _w ^* based on the magnetic pole position calculation value θ _1. .

The rectifier circuit 60 supplies a DC voltage obtained by rectifying the voltage of the three-phase AC power supply 50 to a power converter 70 such as an inverter. The PWM circuit 13 calculates the output voltage of the power converter 70 from the phase voltage command values v _u ^* , v _v ^* , v _w ^* and the input voltage E _dc of the power converter 70 detected by the input voltage detection circuit 12. A gate signal for controlling the phase voltage command values v _u ^* , v _v ^* , and v _w ^* is generated.
The power converter 70 controls the internal semiconductor switching element based on the gate signal, thereby controlling the terminal voltage of the permanent magnet type synchronous motor 80 to the phase voltage command values v _u ^* , v _v ^* , v _w ^* . .

On the other hand, 41 is a change amount limiter to which the speed command value ω ^* and the start speed ω _start are input, and 40 is a speed command value ω ^** output from the change amount limiter 41 or the start speed ω _start . This is a switch for switching and inputting the speed command value ω ₁ to the electrical angle calculator 26. Electrical angle calculator 26 outputs the magnetic pole position calculation value theta ₁ by integrating the speed command value omega _1.

For a predetermined period immediately after the start of operation of the electric motor 80, the switch 40 is switched as shown in FIG. 1 to set the starting speed ω _start to the speed command value ω ₁ . The starting speed ω _start is set to a very small value, and the current is controlled by drawing the rotor into the current vector within the predetermined period to adjust the magnetic pole position to the direction of the current vector. Thereby, speed control can be started from a state in which the current vector and the magnetic pole position coincide with each other, and the electric motor 80 can be started stably.

Then, switching by switching the exchangers 40, the speed command value omega _1, and controls the speed command value omega ^** that by variation limiter 41 limits the speed command value omega ^* rate of change per unit time. Note that the initial value of the variation limiter 41 is the starting speed ω _start .
Thus, a current vector having an amplitude I _γ ^* rotating at the speed ω ₁ is generated, and the rotor is drawn into this current vector to control the speed of the electric motor 80.

Next, the principle of this embodiment will be described.
FIG. 6 shows a block diagram of the δ-axis current control system in FIG. In order to simplify the explanation, it is assumed that the δ-axis voltage v _δ is equal to the δ-axis voltage command value v _δ ^* . The armature winding of the permanent magnet synchronous motor 80 can be modeled by a series circuit of an inductance L _a and the armature resistance R _a as shown, a first-order lag circuit. Note that v _dis is a disturbance voltage.
Usually, in order to increase the followability to the current command value and suppress the current error due to the disturbance voltage _vdis , the gain characteristic of the δ-axis current regulator 20b is designed as high as possible as long as the control system is stable.

On the other hand, as described with respect to Non-Patent Document 2, by controlling the δ-axis voltage v _δ to zero, a current that suppresses vibration of the rotor flows. Therefore, among the current flowing due to the disturbance voltage v _dis, since current equal angular frequency component to the natural angular frequency omega _n of the speed control system is useful for stabilization, it is better not to control.

Here, FIG. 7 is a diagram in which the frequency characteristics of the gains of the current regulators 20a and 20b are logarithmically displayed.
In the present embodiment, the current regulator 20a, 20b of the proportional gain _{K P?,} The _{K Pderuta,} as _{K P2} for "gain characteristic reduction time" in FIG. 7, and designed smaller than _{K P1} of "normal" Each of the adjusters 20a and 20b is input, and the integration time constants T _Iγ and T _Iδ are designed to be longer than the “normal time” T _I1 , like T _I2 at the time of “gain characteristic reduction”. The gain characteristics at the natural angular frequency ω _n of the speed control system are reduced by inputting the signals to the devices 20a and 20b.
As a result, a current that suppresses the vibration of the rotor flows as in Non-Patent Document 2, so that the control system can be stabilized.

In this case, the current response is slower than usual, but it is possible to control to the command values i _γ ^* and i _δ ^* . In particular, as shown in FIG. 7, when the reciprocal of the integral time constant T _I2 is designed to be lower than the natural angular frequency ω _n , the integral regulators constituting the current regulators 20a and 20b have the natural angular frequency ω _n . Since the current component is not affected, a sufficient stabilizing effect can be obtained.

Next, FIG. 2 is a block diagram showing a second embodiment of the present invention corresponding to claims 1 to 3.
The configuration of this embodiment is almost the same as that of FIG. 1, but is characterized in that the gain characteristics are different between the γ-axis current regulator 20a and the δ-axis current regulator 20b. That is, K _P1 and T _I1 are set in the γ-axis current regulator 20a to set the gain characteristics to “normal time” in FIG. 7, and K _P2 and T _I2 are set to the δ-axis current regulator 20b and the gain characteristics are set. Is “when gain characteristics are reduced” in FIG.

Thereby, the γ-axis current can be controlled with high accuracy, and the current can be stably controlled even when there is a load fluctuation or a speed fluctuation.
On the other hand, since a current for suppressing the vibration of the rotor flows through the δ axis as in the first embodiment, the control system can be stabilized.

FIG. 3 is a block diagram showing a third embodiment of the present invention corresponding to claims 4-7.
According to the first embodiment, the stability of the speed control system can be improved, but since the response of the current control system is lowered, the current control error tends to increase due to the influence of the induced voltage as the speed increases.
Therefore, in the third embodiment, as shown in FIG. 3, the switching device 30 causes the proportional gain K _Pγ of the γ-axis current regulator 20a, the integral time constant T _Iγ , and the proportional gain K of the δ-axis current regulator 20b. _Pδ and integration time constant T _Iδ can be switched between values K _P1 and T _I1 at “normal time” and values K _P2 and T _I2 at “gain characteristic reduction”.

The switch 30 selects the values K _P2 and T _I2 when the gain characteristic is reduced because the rotor vibration is large and the stabilization is required for a predetermined period from the start or during low speed operation including zero speed. And In this state, it becomes substantially the same as in the first embodiment, and the response of the current control system becomes slow, but the stability of the speed control system can be improved.
In contrast, when the switch 30 selects the “normal” values K _P1 and T _I1 to increase the response of the current control system, the stabilization effect cannot be obtained. The stabilization control described in Document 2 may be applied.

Next, FIG. 4 is a block diagram showing a fourth embodiment of the present invention corresponding to claims 4-7.
In the second embodiment described above, the current control error tends to increase as the speed increases, as in the first embodiment. Therefore, in the fourth embodiment, as shown in FIG. 4, K _P1 and T _I1 of “normal time” are always set in the γ-axis current regulator 20a, and a switch 30 is provided in the δ-axis current regulator 20b. Thus, K _P1 and T _{I1 in} “normal time” and K _P2 and T _{I2 in} “gain characteristic reduction” can be switched and set.

Thus, at a low speed including zero speed, the switch 30 is switched to the value K _P2 , T _I2 side of “when gain characteristic is reduced” as shown in FIG. High-precision control of the current and stable control of the current when the load or speed fluctuates can be achieved, and the control system can be stabilized by supplying a current that suppresses the vibration of the rotor to the δ axis.
Further, by switching the switch 30 to the “normal time” values K _P1 and T _I1 except at low speeds, it is substantially the same as when switching the switch 30 in the third embodiment (FIG. 3). The effect of this can be obtained.

1 is a block diagram showing a first embodiment of the present invention. It is a block diagram which shows 2nd Embodiment of this invention. It is a block diagram which shows 3rd Embodiment of this invention. It is a block diagram which shows 4th Embodiment of this invention. It is a figure which shows the definition of (gamma) and (delta) axis. FIG. 2 is a block diagram of a δ-axis current control system in FIG. 1. It is the figure which carried out the logarithm display of the frequency characteristic of the gain of the current regulator in each embodiment of this invention.

Explanation of symbols

11u u-phase current detection circuit 11w w-phase current detection circuit 12 input voltage detection circuit 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 30 and 40 Changer 41 Change limiter 50 Three-phase AC power supply 60 Rectifier circuit 70 Power converter 80 Permanent magnet synchronous motor

Claims (7)

A control device for a permanent magnet type synchronous motor having no magnetic pole position detector, taking the terminal voltage and current of the permanent magnet type synchronous motor as a vector, controlling the speed of the current command value vector to a speed command value, and In a control device for a permanent magnet synchronous motor that controls a terminal voltage to control a current vector to the current command value vector,
Current adjusting means for amplifying a deviation between the current command value vector and the current vector to calculate a terminal voltage command value vector;
The gain characteristic of the current adjusting means is set so that the current at the low speed including the zero speed is low so that the current having the same angular frequency as the natural angular frequency that flows when the rotor vibrates at the natural angular frequency of the speed control system is not suppressed. Means to reduce the gain characteristics in normal times other than the time ,
Means for controlling a terminal voltage vector to the terminal voltage command value vector;
A control device for a permanent magnet type synchronous motor. A control device for a permanent magnet type synchronous motor having no magnetic pole position detector, taking the terminal voltage and current of the permanent magnet type synchronous motor as a vector, controlling the speed of the current command value vector to a speed command value, and In a control device for a permanent magnet synchronous motor that controls a terminal voltage to control a current vector to the current command value vector,
Define the γ-axis and δ-axis of the orthogonal rotation coordinate system that rotates at the speed command value,
Means for setting a γ-axis current command value that is a γ-axis component of the current command value vector to a non-zero value;
Means for setting a δ-axis current command value, which is a δ-axis component of the current command value vector, to zero;
Means for decomposing the current vector into a γ-axis current that is a γ-axis component and a δ-axis current that is a δ-axis component;
Γ-axis current adjusting means for amplifying a deviation between the γ-axis current command value and the γ-axis current to calculate a γ-axis voltage command value;
Δ-axis current adjusting means for amplifying a deviation between the δ-axis current command value and the δ-axis current to calculate a δ-axis voltage command value;
The gain characteristic of the δ-axis current adjusting means is such that the current at the same angular frequency as the natural angular frequency that flows when the rotor vibrates at the natural angular frequency of the speed control system is not suppressed at a low speed including zero speed, Means for reducing the gain characteristics at normal times other than at low speed ,
Means for synthesizing a terminal voltage command value vector with the γ-axis component and δ-axis component of the terminal voltage command value vector as the γ-axis voltage command value and the δ-axis voltage command value, respectively;
Means for controlling a terminal voltage vector to the terminal voltage command value vector;
A control device for a permanent magnet type synchronous motor.   The current adjusting means in claim 1 or the δ-axis current adjusting means in claim 2 is a proportional / integral adjusting means, and the reciprocal of the integral time constant of the proportional / integral adjusting means is greater than the natural angular frequency of the speed control system. A control device for a permanent magnet type synchronous motor characterized by being small. A control device for a permanent magnet type synchronous motor having no magnetic pole position detector, taking the terminal voltage and current of the permanent magnet type synchronous motor as a vector, controlling the speed of the current command value vector to a speed command value, and In a control device for a permanent magnet synchronous motor that controls a terminal voltage to control a current vector to the current command value vector,
Current adjusting means for amplifying a deviation between the current command value vector and the current vector to calculate a terminal voltage command value vector;
Means for reducing the gain characteristic of the current adjusting means at a low speed including zero speed, compared to the normal gain characteristic other than the low speed ;
Means for controlling a terminal voltage vector to the terminal voltage command value vector;
A control device for a permanent magnet type synchronous motor. A control device for a permanent magnet type synchronous motor having no magnetic pole position detector, taking the terminal voltage and current of the permanent magnet type synchronous motor as a vector, controlling the speed of the current command value vector to a speed command value, and In a control device for a permanent magnet synchronous motor that controls a terminal voltage to control a current vector to the current command value vector,
Define the γ-axis and δ-axis of the orthogonal rotation coordinate system that rotates at the speed command value,
Means for setting a γ-axis current command value that is a γ-axis component of the current command value vector to a non-zero value;
Means for setting a δ-axis current command value, which is a δ-axis component of the current command value vector, to zero;
Means for decomposing the current vector into a γ-axis current that is a γ-axis component and a δ-axis current that is a δ-axis component;
Γ-axis current adjusting means for amplifying a deviation between the γ-axis current command value and the γ-axis current to calculate a γ-axis voltage command value;
Δ-axis current adjusting means for amplifying a deviation between the δ-axis current command value and the δ-axis current to calculate a δ-axis voltage command value;
Means for reducing the gain characteristic of the δ-axis current adjusting means at a low speed including zero speed, compared to the normal gain characteristics other than the low speed ;
Means for synthesizing a terminal voltage command value vector with the γ-axis component and δ-axis component of the terminal voltage command value vector as the γ-axis voltage command value and the δ-axis voltage command value, respectively;
Means for controlling a terminal voltage vector to the terminal voltage command value vector;
A control device for a permanent magnet type synchronous motor. In the case of reducing the gain characteristic of the current adjusting means in claim 4 or the δ-axis current adjusting means in claim 5,
The gain characteristics of these current adjusting means are set so that current having the same angular frequency that flows when the rotor vibrates at the natural angular frequency of the speed control system is not suppressed. Control device for magnet-type synchronous motor. In the case of reducing the gain characteristic of the current adjusting means in claim 4 or the δ-axis current adjusting means in claim 5,
A control apparatus for a permanent magnet type synchronous motor, wherein the reciprocal of the integral time constant of the proportional / integral adjusting means constituting these current adjusting means is made smaller than the natural angular frequency of the speed control system.

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