JPH10191677A - Speed control apparatus for ac motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce thrust pulsation due to the end effect of a linear motor when the linear motor is used as an AC motor for drive and by which the three-phase unbalance of a motor constant and a torque pulsation due to an irregularity in an amplitude at every phase of a current detector when an ordinary rotation-type AC motor is used as the AC motor for drive. SOLUTION: A torque current reference from a speed controller 7 and a flux current reference from a flux-current-reference generator 10 are output to a stationary/rotatory coordinate converter 16 so as to be converted into a three-phase-current reference signal at a rotary coordinate system. Gain- constant setters 17a, 17c, 17b are installed as adjusting means by which the amplitude and the phase of an output current at respective phases of a three- phase current source 15 as a power converter are adjusted at the respective phase. That is to say, every current reference signal from the coordinate converter 16 is multiplied by fixed gain constants KU, KV, KW so as to be output to the respective phases of the three-phase current source 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC motor speed controller for controlling the speed of an AC motor via a power converter based on vector control.

[0002]

2. Description of the Related Art As a result of adopting vector control in variable speed control of an AC motor and greatly improving control characteristics, an AC motor has been used in various variable speed control devices, like a DC motor. The development of linear motors, which are a type of AC motors, has been greatly advanced.
2. Description of the Related Art Linear motors are used as drive motors for various devices such as elevators.

FIG. 10 is a block diagram showing a configuration of a conventional AC motor speed control device using such a linear motor. In this figure, a control device for controlling the speed of a three-phase linear motor 3 as an AC motor includes a DC power supply 1, a power converter 2, a speed detector 4, a speed reference generator 5,
Comparator 6, speed controller 7, current detectors 8a and 8b, rotating / stationary coordinate converter 9, magnetic flux current reference generator 10, comparators 11a and 11b, current controller 12, stationary / rotating coordinate converter 13, And a PWM pattern generator 14.

[0004] Next, the operation of the conventional device configured as described above will be described. DC power from a DC power supply 1 is input to a power converter 2, which converts AC power of variable amplitude and frequency into a three-phase linear motor 3 as an AC motor.
Output to A speed detector 4 for detecting the speed is attached to the linear motor 3, and a detection signal is output to the comparator 6.

On the other hand, the speed reference generator 5 is a linear motor 3
Is output to the comparator 6. The comparator 6
The deviation between the speed reference from the speed reference generator 5 and the detected speed from the speed detector 4 is output to the speed controller 7. The speed controller 7 and the flux current reference generator 10 output a torque current reference and a flux current reference in a vector control stationary coordinate system, respectively.

The current detectors 8 a and 8 b detect two-phase output currents of the power converter 2 and output detection signals to the rotating / stationary coordinate converter 9. Based on the input of the detection signal, the rotation / stationary coordinate converter 9 outputs a torque current component detection signal and a magnetic flux current component detection signal in the vector control stationary coordinate system to the comparators 11a and 11b. The comparator 11a
The deviation between the magnetic flux current reference from the magnetic flux current reference generator 10 and the magnetic flux current component detection signal from the rotating / stationary coordinate converter 9 is output to the current controller 12, and the comparator 11 b outputs the torque from the speed controller 7. The deviation between the current reference and the torque current component detection signal from the rotating / stationary coordinate converter 9 is output to the current controller 12.

The current controller 12 includes comparators 11a and 11b
And outputs a voltage command signal for controlling the output current of the power converter 2 so that each deviation becomes zero. The stationary / rotating coordinate converter 13 converts the voltage command signal into a signal in a rotating coordinate system, and outputs the signal to the PWM pattern generator 14. Then, the PWM pattern generator 14 outputs a PWM signal to the power converter 2 based on the voltage command signal.

In the above configuration, the torque current reference and the flux current reference from the speed controller 7 and the flux current reference generator 10, and the torque current component detection signal and the flux current component detection signal from the rotating / stationary coordinate converter 9 Is given as a DC quantity. Therefore, the current controller 12 only has to control the DC amount, so that the burden on the current controller 12 is smaller than in the case where the three-phase AC, which is the AC amount, is directly controlled, and the design is easy. It has become something.

The voltage command value supplied to the PWM pattern generator 14 via the stationary / rotary coordinate converter 13 is three-phase symmetric, and the current output from the power converter 2 is also three-phase symmetric sine. It becomes a wave.

[0010]

In the case of a normal rotary AC motor, if the current output from the power converter 2 is a three-phase symmetric sine wave, torque pulsation does not occur. However, when the AC motor is a linear motor,
Even if the current output from the power converter 2 is a three-phase symmetric sine wave, the thrust pulsates at twice the power supply frequency due to the so-called "end effect" of the linear motor ( Examples of data on the end effect include, for example, a report of the Institute of Electrical Engineers of Japan, March, 1970, Vol.
3) There is "About the end effect of the induction type linear motor". ). Therefore, when a linear motor is used as the AC motor for driving the elevator control device, the pulsation deteriorates the riding comfort. In addition,
The “power supply” of the “power supply frequency” is a power supply as viewed from the AC motor side, and the “power supply frequency” indicates an output frequency of the power converter 2.

Further, even when torque pulsation does not actually occur, if the amplitudes of the output signals of the current detectors 8a and 8b fluctuate, a frequency component twice the power supply frequency is included in the torque current component. Since the current controller 12 operates to superimpose and remove this fluctuation, the output current of the power converter 2 becomes three-phase asymmetric and torque pulsation occurs.

Further, even when a normal rotary type AC motor is used, the same phenomenon as described above occurs when the circuit constant of the motor is three-phase asymmetric.

The present invention has been made in view of the above circumstances, and when a linear motor is used as a driving AC motor, the thrust pulsation due to the end effect of the linear motor is reduced. To provide an AC motor control device capable of reducing torque pulsation caused by three-phase imbalance of motor constants and variation in amplitude of each phase of a current detector when a rotary AC motor is used. It is an object.

[0014]

According to a first aspect of the present invention, there is provided a motor control system comprising: a controller for detecting a stationary state based on a deviation between a speed reference for an N-phase AC motor and a detected speed of the AC motor; A speed controller that outputs a torque current reference signal in a coordinate system, a flux current reference generator that generates a flux current reference signal in a direction orthogonal to the torque current reference in the stationary coordinate system, the speed controller and a magnetic flux The torque current reference signal and the magnetic flux current reference signal from the current reference generator are
Stationary / rotary coordinate converter for converting into N current reference signals in a rotating coordinate system, and electric power for supplying an alternating current of variable amplitude and variable frequency to the N-phase AC motor based on the N current reference signals A converter for controlling the speed of the AC motor based on vector control, wherein the adjusting means adjusts the amplitude and phase of the output current of each phase of the power converter for each phase. ,
It is characterized by the following.

According to a second aspect of the present invention, in the first aspect of the present invention, the N phase is three phases.

According to a third aspect of the present invention, in the second aspect of the present invention, the adjusting means is a gain constant setting unit for multiplying each current reference signal from the stationary / rotary coordinate converter by a predetermined gain constant. , Characterized in that.

According to a fourth aspect of the present invention, in the third aspect of the invention, three current detectors for detecting the output current of each phase of the power converter, and a current reference from the three gain constant setting devices. Current control for calculating a voltage command signal for controlling an output current of the power converter based on a difference between a signal and a current detection signal from the three current detectors and outputting the signal to the power converter And a container.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the current detector and the gain constant setting device for any one of the phases are omitted, and the output of the current controller is A subtractor for subtracting the deviations of the two phases calculated by the current controller is provided, and the current controller and the subtractor output the voltage command signals of the three phases to the power converter. It is characterized by.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, there is provided a rotating / stationary coordinate converter for detecting current provided on the output side of the current detector and an output side of the gain constant setting device. A current reference rotary / stationary coordinate converter provided, and a second stationary / stationary converter provided on the output side of the current controller.
A rotating coordinate converter, wherein the current controller determines the voltage based on a deviation between a signal from the detected current rotating / stationary coordinate converter and a signal from the current reference rotating / stationary coordinate converter. A command signal is calculated, and this is calculated by the second stationary /
The electric power is output to the power converter via a rotary coordinate converter.

According to a seventh aspect of the present invention, there is provided a speed controller for outputting a torque current reference signal in a stationary coordinate system based on a deviation between a speed reference for an N-phase AC motor and a detected speed of the AC motor. A magnetic flux current reference generator for generating a magnetic flux current reference signal in a direction orthogonal to the torque current reference in the stationary coordinate system, and the N current reference signal based on the N current reference signals;
A power converter for supplying an alternating current having a variable amplitude and a variable frequency to the AC motor of the phase, and an AC motor speed control device that performs speed control on the AC motor based on vector control. Two current detectors for detecting the two-phase output currents; two gain constant setting devices for multiplying each detection signal from each of the current detectors by a predetermined gain constant; A rotation / stationary coordinate converter that inputs each detection signal and outputs a torque current component detection signal and a magnetic flux current component detection signal in a stationary coordinate system, a deviation between the torque current reference signal and the torque current component detection signal, and A current controller that outputs a voltage command signal for controlling an output current of the power converter based on a deviation between the magnetic flux current reference signal and the magnetic flux current component detection signal; A static / rotary coordinate converter that converts a voltage command signal in a stationary coordinate system output from the current controller into a voltage command signal for each phase in a rotary coordinate system and outputs the voltage command signal to the power converter. It is characterized by having.

The invention according to claim 8 is the invention according to claim 7, wherein an acceleration detector for detecting acceleration of the AC motor and the power converter based on a detection signal input from the acceleration detector. A power double frequency vibration amplitude detector for detecting the amplitude of a double frequency component of the power frequency of the power supply, and a pulsation of the AC motor based on a detection signal from the power double frequency vibration amplitude detector. A compensation amount calculation circuit for calculating a compensation amount, wherein the two gain constant setting units each set a gain constant corresponding to the compensation amount calculated by the compensation amount calculation circuit from each of the current detectors. It is characterized by multiplying the detection signal.

According to a ninth aspect of the present invention, in the invention of the eighth aspect, the power double frequency vibration amplitude detector detects the speed of the AC motor instead of the detection signal from the acceleration detector. The amplitude of the double frequency component is detected based on an input of a speed detection signal from a detector.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the power supply double frequency vibration amplitude detector is omitted, and the compensation amount calculation circuit directly outputs a speed detection signal from the speed detector. The compensation amount is input to calculate the compensation amount.

According to an eleventh aspect of the present invention, in the invention of the tenth aspect, the compensation amount calculating circuit replaces the input of the speed detection signal from the speed detector with a voltage from the stationary / rotary coordinate converter. The compensation amount is calculated based on the input of the command signal.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. However, the same components as those in FIG. 10 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a block diagram showing the configuration of the first embodiment. In this figure, a three-phase alternating current having a variable amplitude and a variable frequency is supplied to a linear motor 3 from a three-phase current source 15. This three-phase current source 15
For example, it is constituted by a current type three-phase inverter, three current type single-phase inverters, or the like.

The torque current reference from the speed controller 7 and the magnetic flux current reference from the magnetic flux current reference generator 10 are output to the stationary / rotary coordinate converter 16, and these reference signals in the stationary coordinate system are converted into the rotational coordinate system. Is converted to a three-phase current reference signal. The gain constant setting units 17a, 17c and 17b are provided as adjusting means for adjusting the amplitude and phase of the output current of each phase of the three-phase current source 15 as a power converter for each phase. Each current reference signal from the rotary coordinate converter 16 is multiplied by a fixed gain constant KU, KV, KW, and this is output to each phase of the three-phase current source 15.

The values of these gain constants KU, KV, and KW have been determined by trial and error as values that can most effectively reduce pulsation in a test operation performed in advance.

In this embodiment, the stationary / rotary coordinate converter 1
The gain constant KU is added to the current reference signal of each phase output from
, KV, and KW, the current supplied from the three-phase current source 15 to the linear motor 3 becomes asymmetrical in three phases, and a thrust pulsation is intentionally generated in the linear motor 3. However, the thrust pulsations intentionally generated are in opposite phase to the thrust pulsations generated by the end effect of the linear motor 3, and therefore, these thrust pulsations cancel each other. Therefore, as a result, thrust pulsation due to the end effect of the linear motor 3 is reduced.

FIG. 2 is a block diagram showing the configuration of the second embodiment. In this figure, the output current of each phase of the power converter 2 is detected by current detectors 8a, 8c, 8b,
The current detection signal is output to comparators 11a, 11c, 11b.

On the other hand, the torque current reference from the speed controller 7 and the magnetic flux current reference from the magnetic flux current reference generator 10 are converted into a three-phase current reference signal by the stationary / rotary coordinate converter 16. The gain constant setting units 17a, 17c and 17b multiply the respective current reference signals output from the stationary / rotary coordinate converter 16 by gain constants KU, KV and KW, and multiply them by the comparator 1
Output to 1a, 11c and 11b. Comparators 11a, 11
c and 11b are gain constant setting devices 17a, 17c and 17
b and the current detectors 8a, 8c, 8b
And outputs a deviation from the current detection signal to the current controller 12. The current controller 12 outputs a voltage command signal for controlling the output current of the power converter 2 to the PWM pattern generator 14 so that these deviations become zero.

In this embodiment, similarly to the first embodiment, the current supplied to the linear motor 3 is intentionally made three-phase asymmetric by setting the gain constants KU, KV, KW optimally. Therefore, thrust pulsation due to the end effect of the linear motor can be reduced.

FIG. 3 is a block diagram showing the configuration of the third embodiment. When power is supplied to the linear motor 3 by a three-phase three-wire system, the sum of the output current and the output voltage of the power converter 2 becomes zero. Will also be known. In the present embodiment, the configuration is simplified utilizing this fact.

That is, the current detector 8c in FIG.
In this configuration, the gain constant setting unit 17c and the comparator 11c are omitted, and a subtractor 19 is provided on the output side of the current controller 12.

In this embodiment, the stationary / rotary coordinate converter 16 outputs a current reference signal for two phases of U phase and W phase based on the input of the torque current reference and the magnetic flux current reference,
Further, the current detectors 8a and 8b output current detection signals for two phases of U-phase and W-phase. The comparators 11a and 11b output the deviation between the current reference signal and the current detection signal to the PWM pattern generator 14. Then, a subtractor 19 provided on the output side of the current controller 12 calculates the remaining V-phase deviation from the U-phase and W-phase deviations, and outputs this to the PWM pattern generator 14.

FIG. 4 is a block diagram showing the configuration of the fourth embodiment. 4 is different from FIG. 3 in that a current reference rotating / stationary coordinate converter 18 is provided on the output side of the gain constant setting units 17a and 17b, and the current detectors 8a and
8b is output to the comparators 11a and 11b via the detected current rotating / stationary coordinate converter 24, and a second stationary / rotating coordinate converter 25 is provided on the output side of the current controller 12. It is a point provided.

In this embodiment, the torque current reference generated by the speed controller 7 and the magnetic flux current base generated by the magnetic flux current reference generator 10 are coordinate-transformed by the stationary / rotary coordinate converter 16, and gain constant setting units 17a, After multiplying the gain constants KU and KW by 17b, coordinate conversion is further performed by the current reference rotating / stationary coordinate converter 18. The current detection signals from the current detectors 8a and 8b are also subjected to coordinate conversion by the detected current rotation / stationary coordinate converter 24. The comparators 11a and 11b output to the current controller 12 the deviation between the magnetic flux current reference and the magnetic flux current component detection signal converted into the stationary coordinate system and the deviation between the torque current reference and the torque current component detection signal. I do. The current controller 12 generates a voltage command signal for the power converter 2 on the basis of these deviations, returns the voltage command signal to the rotating coordinate system again by the second stationary / rotary coordinate converter 25, and then transmits the voltage command signal to the PWM pattern generator 14. Output.

The current controller 12 shown in FIG. 4 is different from the current controller 12 shown in FIGS. 1 to 3 in that it is not based on a deviation on a rotating coordinate system (AC value) but on a deviation on a stationary coordinate system (DC value). Since the calculation is performed by the calculation, the control operation can be performed with a small load, and the control characteristics can be improved. Although the number of coordinate converters is increased by adopting a configuration in which the input of the current controller 12 is a DC amount, there is no particular problem because the coordinate converter can be configured on software.

FIG. 5 is a block diagram showing the configuration of the fifth embodiment. In the embodiments described above, the gain constant setting device is provided on the output side of the speed controller 7 and the output side of the magnetic flux current reference generator 10 and thereafter. In the present embodiment, the gain constant is set on the output side of the current detector. The configuration is provided with a setting device.

That is, gain constant setting units 20a and 20b are provided on the output side of the current detectors 8a and 8b, and after multiplying the current detection signals by the gain constants KU and KW, the detected current is converted into a rotational / stationary coordinate converter for detected current. The data is converted into a stationary coordinate system by 24 and output to the comparators 11a and 11b. Current controller 1
2 controls the torque current component detection signal and the magnetic flux current component detection signal gain-compensated by the gain constant setting devices 20a and 20b so that the torque current reference and the magnetic flux current reference match, so that the gain constants KU and KW are set. By appropriately setting, the current supplied to the linear motor 3 can be intentionally made three-phase asymmetric, and thrust pulsation due to the end effect of the linear motor 3 can be reduced.

FIG. 6 is a block diagram showing the configuration of the sixth embodiment. In the above embodiments, the case where the gain constant is a fixed value has been described, but in the present embodiment, the gain constant is configured to be variable. That is, gain constant setting devices 20a and 20b capable of setting variable gain constants are provided on the output side of the current detectors 8a and 8b, the acceleration detector 21 is attached to the linear motor 3, and the power source is doubled. The configuration is such that a frequency vibration amplitude detector 22 and a compensation amount calculation circuit 23 are provided.

The current detection signals from the current detectors 8a and 8b are multiplied by the gain constants KU and KW by the gain constant setting units 20a and 20b, and sent to the detected current rotation / stationary coordinate converter 24. At this time, the acceleration detector 21 detects the acceleration of the linear motor 3 and outputs a detection signal to the power double frequency vibration amplitude detector 22. The power double frequency vibration amplitude detector 22 obtains the amplitude of a frequency component twice as high as the power frequency from the acceleration detection signal, and outputs the amplitude to the compensation amount calculation circuit 23. The compensation amount calculation circuit 23 calculates a compensation gain for preventing thrust pulsation due to the end effect of the linear motor 3 based on the output of the power double frequency vibration amplitude detector 22. The gain constant setting units 20a and 20b determine the gain constants KU and KW corresponding to the compensation gains calculated by the compensation amount calculation circuit 23 in this manner by the current detectors 8a and 20b.
8b is multiplied by the current detection signal.

In this embodiment, the gain constant is not a fixed value as in the previous embodiments, but a variable value corresponding to the state of the linear motor 3, so that thrust pulsation can be reduced more effectively. Can be. In the present embodiment, the main object is to provide a power double frequency vibration amplitude detector 22 to reduce the thrust pulsation peculiar to the linear motor. The phenomenon that pulsation occurs due to the generation of a frequency component twice the power supply frequency can occur not only in a linear motor but also in a normal rotary AC motor, but since this phenomenon appears most prominently in a linear motor,
The configuration of the present embodiment is more effectively applied when the AC motor is a linear motor.

FIG. 7 is a block diagram showing the configuration of the seventh embodiment. FIG. 7 differs from FIG. 6 in that the acceleration detector 21 in FIG. 6 is omitted and the speed detection signal from the speed detector 4 is input to the power double frequency vibration amplitude detector 22. . Since the frequency component twice as high as the power supply frequency can be obtained not only from the acceleration detection signal but also from the speed detection signal, the configuration can be simplified by omitting the acceleration detector 21 as in the present embodiment.

FIG. 8 is a block diagram showing the configuration of the eighth embodiment. In this embodiment, the power double frequency vibration amplitude detector 22 is further omitted from the configuration of FIG.
In the present embodiment, the compensation amount calculation circuit 23 directly inputs the speed detection signal from the speed detector 4 to calculate the compensation gain. This is because the phenomenon of thrust pulsation due to the end effect of the linear motor is determined by a function of the motor speed. It is based on what is expressed. Therefore, the present embodiment is also particularly effective when the AC motor is a linear motor.

FIG. 9 is a block diagram showing the configuration of the ninth embodiment. In the configuration of FIG. 8, the compensation amount calculation circuit 23 calculates the compensation gain based on the input of the speed detection signal from the speed detector 4. A voltage command signal from the converter 25 is input, and a compensation gain is calculated based on the voltage command signal. The thrust pulsation due to the end effect of the linear motor occurs due to a frequency component that is twice the power supply frequency, and the power supply frequency is nothing but the output frequency of the power converter 2 as described above.
As a result, the compensation amount calculation circuit 23 can calculate the compensation gain based on the voltage command signal for controlling the output of the power converter 2. This embodiment is also particularly effective when the AC motor is a linear motor.

As described above, the technique of the present invention is particularly effective when the AC motor is a linear motor, but is also effective for a rotary AC motor. In addition, the configuration of each of the above embodiments is basically assumed to be applied to an elevator control device employing a linear motor, but is not limited to an elevator control device.
It can be applied to various driving devices using a linear motor. Furthermore, in each of the above embodiments, the case of a three-phase linear motor has been described as an example, but the present invention is applicable to an N-phase (N is an integer of 2 or more) AC motor. However, in the case of two phases, it is preferable that the two-phase current is an orthogonal two-phase alternating current.

[0048]

As described above, according to the present invention, when a linear motor is used as a driving AC motor, thrust pulsation due to the end effect of the linear motor is reduced, and a normal driving AC motor is used. When a rotary AC motor is used, it is possible to reduce torque pulsation due to three-phase imbalance of the motor constant and variation in the amplitude of each phase of the current detector.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a sixth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a seventh embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of an eighth embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a ninth embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a conventional device.

[Explanation of symbols]

 Reference Signs List 1 DC power supply 2 Power converter 3 Linear motor 4 Speed detector 5 Speed reference generator 6 Comparator 7 Speed controller 8a, 8b, 8c Current detector 9 Rotation / stationary coordinate converter 10 Magnetic flux current reference generator 11a, 11b Comparator 12 Current controller 13 Stationary / rotary coordinate converter 14 PWM pattern generator 15 Three-phase current source 16 Stationary / rotary coordinate converter 17a, 17b, 17c Gain constant setting unit 18 Current reference rotary / stationary coordinate converter 19 Subtractors 20a, 20b Gain constant setting unit 21 Acceleration detector 22 Power double frequency vibration amplitude detector 23 Compensation amount operation circuit 24 Rotation / stationary coordinate converter for detected current 25 Second stationary / rotary coordinate converter

Claims (11)

[Claims] A speed controller for outputting a torque current reference signal in a stationary coordinate system based on a deviation between a speed reference for the N-phase AC motor and a detected speed of the AC motor; A magnetic flux current reference generator that generates a magnetic flux current reference signal in a direction orthogonal to the torque current reference, and a torque current reference signal and a magnetic flux current reference signal from the speed controller and the magnetic flux current reference generator in a rotating coordinate system. N
A stationary / rotary coordinate converter for converting the current reference signals into a plurality of current reference signals; and a power converter for supplying a variable amplitude / variable frequency AC current to the N-phase AC motor based on the N current reference signals. An AC motor speed control device that performs speed control on the AC motor based on vector control, wherein an adjusting unit that adjusts the amplitude and phase of the output current of each phase of the power converter for each phase is provided. Characteristic AC motor speed control device. 2. The AC motor control device according to claim 1, wherein the N phase is three phases. 3. The AC motor control device according to claim 2, wherein said adjusting means is a gain constant setting device for multiplying each current reference signal from said stationary / rotary coordinate converter by a predetermined gain constant. Characteristic AC motor speed control device. 4. The AC motor control device according to claim 3, wherein: three current detectors for detecting output current of each phase of the power converter; a current reference signal from the three gain constant setting devices; A current controller that calculates a voltage command signal for controlling the output current of the power converter based on a deviation from the current detection signals from the three current detectors and outputs the signal to the power converter; An AC motor speed control device comprising: 5. The AC motor control device according to claim 4, wherein the current detector and the gain constant setting device for any one of the phases are omitted, and the current controller is provided on the output side of the current controller. Is provided with a subtractor for subtracting the deviations of the two phases calculated by the current controller and the subtractor.
An AC motor speed control device, wherein the voltage command signal for each phase is output to the power converter. 6. The AC motor control device according to claim 5, wherein the detection current rotation / reception provided on the output side of the current detector.
A stationary coordinate converter, a current reference rotating / stationary coordinate converter provided on the output side of the gain constant setting device, and a second stationary / rotating coordinate converter provided on the output side of the current controller. The current controller calculates the voltage command signal based on a deviation between a signal from the detected current rotating / stationary coordinate converter and a signal from the current reference rotating / stationary coordinate converter. And outputting the same to the power converter via the second stationary / rotary coordinate converter. 7. A speed controller for outputting a torque current reference signal in a stationary coordinate system based on a deviation between a speed reference for the N-phase AC motor and a detected speed of the AC motor; A magnetic flux current reference generator for generating a magnetic flux current reference signal in a direction orthogonal to the torque current reference; and power for supplying an alternating current of variable amplitude and variable frequency to the N-phase AC motor based on the N current reference signals. A speed converter for controlling the speed of the AC motor based on vector control, wherein an output current of any two phases of the power converter is detected.
Two current detectors, two gain constant setting devices for multiplying each detection signal from each of the current detectors by a predetermined gain constant, and inputting each detection signal from the two gain constant setting devices to a stationary coordinate system A rotation / stationary coordinate converter for outputting a torque current component detection signal and a magnetic flux current component detection signal, a deviation between the torque current reference signal and the torque current component detection signal, and a detection of the magnetic flux current reference signal and the magnetic flux current component A current controller that outputs a voltage command signal for controlling an output current of the power converter based on a deviation from the signal, a voltage command signal in a stationary coordinate system that is output from the current controller and a rotation coordinate. And a stationary / rotary coordinate converter for converting a voltage command signal for each phase in the system and outputting the voltage command signal to the power converter. 8. The AC motor speed control device according to claim 7, wherein an acceleration detector for detecting acceleration of the AC motor, and a power supply for the power converter based on a detection signal input from the acceleration detector. A power double frequency vibration amplitude detector for detecting the amplitude of a double frequency component of the frequency; and a compensation amount for preventing pulsation of the AC motor based on a detection signal from the power double frequency vibration amplitude detector. And a compensation amount calculation circuit for calculating the compensation amount. The two gain constant setting units set a gain constant corresponding to the compensation amount calculated by the compensation amount calculation circuit in each detection signal from each of the current detectors. An AC motor speed control device, characterized by multiplying by: 9. The AC motor control device according to claim 8, wherein the power double frequency vibration amplitude detector detects a speed of the AC motor instead of a detection signal from the acceleration detector. Based on the input of the speed detection signal of
An AC motor speed control device for detecting the amplitude of the double frequency component. 10. The AC motor control device according to claim 9, wherein the power double frequency vibration amplitude detector is omitted, and the compensation amount calculation circuit directly inputs a speed detection signal from the speed detector. An AC motor speed control device for calculating the compensation amount. 11. The AC motor control device according to claim 10, wherein the compensation amount calculation circuit is configured to receive a voltage command signal from the stationary / rotary coordinate converter instead of inputting a speed detection signal from the speed detector. An AC motor speed control device for calculating the compensation amount based on an input.