JPH0870598A - Sensorless vector control apparatus for induction motor speed - Google Patents

Abstract

PURPOSE: To improve the accuracy of speed estimation by comparing a reference value of secondary exciting axis magnetic flux, corresponding to a value of motor speed, with an estimated value of secondary exciting axis magnetic flux, and correcting an estimated value of motor actual speed using the resultant error as actual speed correction value. CONSTITUTION: An identical dimension magnetic flux observer arithmetic operation unit 4 and a coordinate transformer 12, estimate secondary magnetic fluxes λ22d , λ2q . An estimated value of torque axis magnetic flux λ2q # is subjected to proportional integration at a speed estimation arithmetic operation unit 15 to estimate an actual value of motor speed ωr'#. A function generating unit 13 outputs a value of exciting axis magnetic flux corresponding to the actual speed of the motor as secondary exciting axis magnetic flux reference value λ2d *. It is compared with exciting axis magnetic flux estimated value λ2d # through a collating circuit 16. An error obtained as a result of the collation is subjected to proportional integration at a speed correction arithmetic operation unit 14 to obtain a speed correction value ωrc. A collating circuit 18 corrects the estimated value of the motor's actual speed ωr'# to match the estimated value of the motor's actual speed ωr# with actual speed ωr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction motor vector control, and more particularly to an induction motor speed sensorless vector control device for estimating an actual speed value (ω _r ) of the induction motor by using an observer. .

[0002]

2. Description of the Related Art A vector control system has become popular as a high-performance speed control system for induction motors, and a speed sensorless vector control device for controlling the vector control system is known.

FIG. 2 shows the same-dimensional magnetic flux observer computing unit 4
1 shows a conventional speed sensorless vector control device for an induction motor that estimates an actual speed value (ω _r ) of the induction motor by using a speed adaptive secondary magnetic flux observer composed of a speed adaptive calculation unit 6.

First, the estimation of the actual speed value (ω _r , rotational angular frequency) of the induction motor 1 will be described with reference to FIG.

The voltage equation of the induction motor 1 is given by the following equation (1) when it is represented by d-q axes for observing various quantities from the synchronous rotation coordinates rotating at the power supply angular frequency (ω ₀ ).

[0006]

## EQU1 ## However, on the synchronous rotation coordinates (d-q axes), v _1d , v _1q ... Excitation axis voltage of primary voltage v ₁ , torque axis voltage (V) i _1d , i _1q .. Synchronous rotation coordinates (d- (q-axis), primary current i
Excitation axis current of ₁ and torque axis current (A) λ _2d , λ _2q・ ・ ・ Excitation axis magnetic flux of secondary magnetic flux λ ₂ and torque axis magnetic flux (Wb) ω ₀・ ・ ・ on the synchronous rotation coordinates (d-q axes). Power source angular frequency (rad / sec) ω _r ‥‥‥‥ Motor actual speed (rotational angular frequency) (rad / sec) ω _s ‥‥‥‥ Slip angular frequency (rad / sec) R ₁ , R ₂ ‥‥ Primary , Secondary resistance (Ω) L ₁ , L ₂ …… Primary and secondary inductance (H) M ‥‥‥‥ Mutual (excitation) inductance (H) Lσ ‥‥‥ Equivalent leakage inductance (H) (Lσ = ( L
₁ L ₂ −M ² ) / L ₂ ) s ·········· Time fine molecule (d / dt) and the power source angular frequency (ω ₀ ), motor speed (ω _r ), slip angular frequency (ω _s *) The relationship and the calculation of the slip angular frequency (ω _s *) are expressed by the following equation (2). ω ₀ = ω _r + ω _s *, ω _s * = i ₁ q * / (i ₁ d * · τ ₂ ) ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ (2) However, τ ₂ ‥‥‥‥‥‥‥‥‥ Time constant (τ ₂ = L ₂ / R ₂ ) Subscript (*) ‥‥‥‥ Indicates a command value or set value.
Now, i _1d * = constant ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ (3), and in equation (1) above, equations (2) and (3) are used. Under the condition of, the primary voltage command value v ₁ * (v _1d *, v _1q *) on the synchronous rotation coordinates (d-q axes) is expressed by the following equation (4) which is a constitutive equation of the current control calculation unit 3.

[0007]

When given by [Equation 2], the primary current i ₁ on the synchronous rotation coordinates (d-q axes) is the current according to the command value i ₁ * (i _1d *, i _1q *), and the synchronous rotation coordinates (d -q axis) secondary magnetic flux λ ₂
(Λ _2d , λ _2q ) is kept at λ _2d = M · i _1d (constant), λ _2q = 0 ‥‥‥‥‥‥‥‥‥‥‥‥ (5).

As a result, the torque (T) of the induction motor 1
Is T = M / L ₂ · (λ _2d · i _1q −λ _2q · i _1d ) = M ² / L ₂ · (i _1d · i _1q ) ... (6), and the synchronous rotation coordinate (d-q axis ) Secondary magnetic flux λ ₂ (λ
_2d , λ _2q ) and the secondary current i ₂ (i _2d , i _2q ) are independent of each other, and vector control of decoupling control is established.

By the way, as is apparent from the equation (2), when the speed sensor is not used, the slip angular frequency ω _s *
Even if is set, since the motor speed ω _r is unknown,
Although the power source angular frequency ω ₀ cannot be determined, the secondary magnetic flux λ ₂ (λ _2d , λ _2q ) on the synchronous rotation coordinates (d-q axes) that rotates at the power source angular frequency ω ₀ is (5) above. By controlling the power source angular frequency ω ₀ so as to satisfy the expression, similarly, vector control of decoupling control can be realized. That is, by using the speed adaptive secondary magnetic flux observer including the same-dimensional magnetic flux observer calculation unit 4 and the speed adaptive calculation unit 6, the synchronous rotation coordinate (d-
The secondary magnetic flux λ ₂ (λ _2d , λ _2q ) on the q-axis) is estimated, and the actual motor speed value ω _r is estimated based on the estimated secondary magnetic flux λ ₂ # (λ _2d #, λ _2q #) ( By doing ω _r #), the above (2)
To realize vector control of decoupling control by obtaining the power source angular frequency ω ₀ from the formula (ω ₀ = ω _r # + ω _s *) and controlling the current control calculation unit 3 with the power source angular frequency ω _0. You can

In the conventional induction motor speed sensorless vector controller shown in FIG. 2, the primary current (1) of the induction motor 1 is detected in order to detect the actual speed value (ω _r ) of the induction motor 1 without using the speed sensor. Phase current) iu, iv, iw is detected, and the primary current detection value i ₁ (i _1a , i _1b ) on the stator coordinates (ab axis) obtained by phase number conversion by the three-phase to two-phase number converter 11 And a stator coordinate (a- to the power conversion unit (hereinafter, simply referred to as “power conversion unit”) 2 including the primary current detection value i ₁ (i _1a , i _1b ) and a power converter such as a PWM control inverter. b
Motor primary voltage command values on the _{axis) v 1 * (v 1a *} , v 1b *),
And the motor actual speed estimated value ω _r # as an input, the same-dimensional magnetic flux observer calculation unit 4 causes the secondary magnetic flux λ ₂ (λ _2a , λ _2b ) of the motor on the stator coordinates (ab axis) and the primary motor current i.
₁ (i _1a , i _1b ) is calculated and estimated, and the speed adaptive calculation unit 6 estimates the primary current i ₁ # (i _1a #, i _1b #) and the detected primary current i ₁ (i _1a , i _1b). ) Is compared with the primary current estimation error signal (i ₁ −i ₁ #) to calculate and estimate the actual motor speed (ω _r #) according to the adaptive adjustment law expressed by the following equation (7). The detected value (ω _r ) is used.

Ω ^r # = K _p (e _ia λ _2b # −e _ib λ _2a #) + K i ∫ (e _ia λ _2b # −e _ib λ _2a #) dt (7) However, e _ia = I _1a −i _1a #: estimation error e _ib = i _1b −i _1b #: estimation error K _p : velocity estimation unit proportional gain K _i : velocity estimation unit integration gain Note that the same dimension magnetic flux observer computing unit 4 and velocity adaptation are used. By the velocity adaptive secondary magnetic flux observer consisting of the computing unit 6
Regarding the speed sensorless vector control method of the induction motor 1 for estimating the actual speed value (ω _r ) of the induction motor,
Published in "The Institute of Electrical Engineers of Japan, D, Vol. 111, No. 11, 1991" (Kubota, Ozaki, Matsuse, Nakano: "Velocity sensorless direct vector control of induction motor using adaptive secondary magnetic flux observer") .

A conventional speed sensorless vector controller for estimating the actual speed value (ω _r ) of the induction motor using the speed adaptive secondary magnetic flux observer will be described below.

FIG. 2 (speed sensorless vector control device)
The operation of the induction motor 1 will now be explained. Now, the excitation axis current command value (i _1d *) and torque axis current command value (i _1q ) of the primary current command value i ₁ * on the synchronous rotation coordinates (d-q axes) of the induction motor 1 are described. *),
And the primary current detection value i ₁ on the synchronous rotation coordinates (d-q axes)
When the excitation axis current (i _1d ) and the torque axis current command value (i _1q ) are given to the current control calculation section 3 in the current control section (ACR), the synchronous rotation coordinates (dq axes) of the induction motor 1 are calculated. The primary voltage command value v ₁ * (v _1d *, v _1q *) is the primary current command value i ₁ * (i _1d *, i _1q *) and the primary current detection value i ₁ (i _1d ,
i _1q ) is equal (i _{1 d} * = i _1d , i _1q * = i _1q ), which is a conditional expression that enables _decoupling control (4) above.
It is calculated by an expression.

The primary voltage command value v ₁ * (v _1d *, v _1q *) on the synchronous rotation coordinates (d-q axes) is converted by the coordinate converter 8 into the primary voltage on the stator coordinates (a-b axes). Command value v ₁ * (v _1a *, v
_The coordinates are converted into _1b *) and supplied to the power conversion unit 2. As a result, the power conversion unit 2 causes the primary voltage command value v ₁ *.
It is controlled according to (v _1a *, v _1b *) and controls the three-phase primary input voltages Vu, Vv, Vw of the induction motor 1. as a result,
The induction motor 1 is torque-controlled according to a desired torque command value (the torque shaft current command value i _1q *).

Coordinates for converting between synchronous rotation coordinates (dq axes) rotating at the power supply angular frequency ω ₀ and stator coordinates (ab axes) fixed to the stator of the induction motor 1. The unit vector (Sin θ ₀ , Cos used in the converters 7 and 8)
θ ₀ ) basic phase angle θ ₀ (θ ₀ = ω ₀ t)
Is calculated by the slip calculator 5 as shown in the above equation (2),
Primary current command value i ₁ * (i on synchronous rotation coordinates (d-q axes)
_1d *, i _1q *) and the secondary time constant τ ₂ (= L _{2 of the} induction motor 1
/ R ₂ ) slip angular frequency command value (ω _s
*) And the power source angular frequency (ω ₀ ) obtained from the motor actual speed estimation value (ω _r #) estimated by the speed adaptive secondary magnetic flux observer (4, 6) by the basic phase angle calculating integrator 9. It can be obtained by integrating.

[0016]

As described above, in the conventional speed sensorless vector control device, in the calculation process of estimating the actual speed value (ω _r ) of the induction motor 1, the same-dimensional magnetic flux observer calculation unit 4 estimates the actual speed value (ω _r ). Stator coordinates (ab
The secondary magnetic flux on the axis) λ ₂ # (λ _2a #, λ _2b #) and the primary current estimate i ₁ # (i _1a #, i _1b #) Although the calculation and estimation are performed by the integral operation, the speed estimation error occurs due to the following causes, and the actual speed estimated value (ω _r #) and the actual speed value (ω _r ) do not match. 1 causes a serious problem that the torque according to the torque command value cannot be obtained.

"Cause of speed estimation error" 1. Mismatch between the primary voltage command value v ₁ * and the primary voltage actual value The input of the same-dimensional magnetic flux observer computing unit 4 includes the primary voltage actual value and the primary current detection value of the induction motor 1, and the primary voltage actual value is the primary value. The detected voltage value is the primary voltage command value v
₁ * (v _1a *, v _1b *) is substituted, and it is assumed that the primary voltage detection value and the primary voltage command value v ₁ * match.

However, in reality, even if the primary voltage command value v ₁ * is input to the power conversion unit 2, the power converter that constitutes the power conversion unit 2 (for example, a PWM-controlled voltage-type inverter).
Of the primary voltage detection value due to the decrease in the output voltage of the power converter due to the installation of the arm short-circuit prevention period (dead time) and the decrease in the output voltage of the power converter due to the forward voltage drop of the power switch element forming the arm of the power converter. Will fall.
Although the reduction of the output voltage of the power converter is compensated, the present situation is that the compensation error remains due to the error of the compensation circuit.

2. Primary current detection error The input of the same-dimensional magnetic flux observer computing unit 4 has the actual primary voltage value and the primary current detection value of the induction motor 1, and the primary current is detected accurately with the fundamental wave component of the current including the PWM control ripple. Even so, the error still remains.

Further, in the conventional speed sensorless vector control device, in the calculation process for estimating the actual speed value (ω _r ) of the induction motor 1, the calculation and estimation are performed by the proportional-plus-integral operation shown in the above equation (7). However, in such speed estimation calculation, the proportional gain K _p that determines the response of the speed estimation,
Also, it becomes very difficult to set the integral gain K ₁ and it is difficult to determine an appropriate proportional and integral gain, which may cause a problem in control responsiveness.

The present invention has been made in view of the above points, and improves the speed estimation accuracy of the induction motor actual speed value (ω _r ) to obtain the torque according to the torque command value, and at the same time, the induction motor actual speed value (ω _The purpose is to obtain a velocity sensor vector controller that can obtain the stability of the estimation of _r ) and an appropriate response.

[0022]

[Means and Actions for Solving the Problems] In the process of estimating the actual speed estimated value of the induction motor, the same-dimensional magnetic flux observer arithmetic unit arithmetically estimates the secondary magnetic flux of the electric motor and estimates the torque axis magnetic flux of the estimated secondary magnetic flux. The value is controlled so that the vector control of the decoupling control is established, and the function generator having a table for calculating the excitation axis magnetic flux of the secondary magnetic flux according to the motor actual speed value (ω _r ) in advance is provided. Actual speed value
The excitation axis magnetic flux of the secondary magnetic flux corresponding to (ω _r ) is output as the secondary excitation axis magnetic flux reference value, and the secondary excitation axis magnetic flux reference value and the excitation axis magnetic flux estimated value of the secondary magnetic flux estimated value are compared. Then, the estimated speed value (ω _r '#) of the induction motor actual speed value (ω _r ) is calculated and estimated based on the secondary magnetic flux estimated value by using the speed correction value (ω _rc ) obtained by proportionally integrating the error. ), So that the actual speed estimate (ω _r #) matches the actual speed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a speed sensorless vector control device of the present invention, in which 1 to 11 have the same functions as those of the same reference numerals in FIG. 2 (conventional speed sensorless vector control device). The constituent elements are shown, and 12 is the secondary magnetic flux estimated value λ ₂ # (λ ₂ a #, λ ₂ b) on the stator coordinates (a-b axis) calculated and estimated by the same-dimensional magnetic flux observer arithmetic unit 4.
#) Is the estimated secondary magnetic flux on the synchronous rotation coordinates (d-q axes) λ ₂ #
A coordinate converter for converting into (λ _2d #, λ _2q #), 13 is a motor constant of the induction motor 1 (primary and secondary resistances R ₁ and R ₂ , primary and secondary inductances L ₁ and L ₂ , mutual inductance M, etc.). from according to the speed value (omega _r) previously doubly-axis magnetic flux (lambda
_2d ) has a table for calculating the magnitude (amplitude) and has a secondary excitation axis magnetic flux reference value (λ) corresponding to the actual motor speed value (ω _r ).
_2d *) function generator, 14 is the secondary excitation axis magnetic flux estimated value (λ _2d #) and the secondary magnetic flux excitation axis reference value ((λ _2d *)
In a matching circuit 16 and proportionally integrates the comparison error to calculate a correction value (ω _rc ) of the estimated actual speed value (ω _r #), and 15 is a secondary torque shaft magnetic flux estimation value ( λ _2q #) and zero (0, see the above formula 5) are compared in the matching circuit 17, and the comparison error is proportional-integrally calculated to obtain the electric estimated actual speed value (ω _r '#), 18 Is the estimated motor actual speed value (ω _r '#) corrected by the correction value (ω _rc ).
_It shows a matching circuit for obtaining _r #).

The operation of the illustrated speed sensorless vector control device will be described below.

Now, the synchronous rotation coordinate (d-
primary current command value on the q-axis) i ₁ * of the exciting axis current command value (i
_1d *), torque axis current command value (i _1q *), and exciting axis current (i) of primary current detection value i ₁ on the synchronous rotation coordinates (d-q axes).
_1d ) and torque axis current command value (i _1q ) in the current controller (AC
R), the primary voltage command value v ₁ * on the synchronous rotation coordinates (dq axes) of the induction motor 1 is given to the current control calculation unit 3.
(V _1d *, v _1q *) is the primary current command value i ₁ * (i _1d *, i
_1q *) and primary current detection value i ₁ (i _1d , i _1q ) are equal (i
_1d * = i _1d , i _1q * = i _1q ) is calculated by the above equation (4), which is a conditional expression that enables _decoupling control.

The primary voltage command value v ₁ * (v _1d *, v _1q *) on the synchronous rotation coordinates (d-q axes) is converted by the coordinate converter 8 into the primary voltage on the stator coordinates (a-b axes). Command value v ₁ * (v _1a *, v
_The coordinates are converted into _1b *) and supplied to the power conversion unit 2. As a result, the power conversion unit 2 causes the primary voltage command value v ₁ *.
It is controlled according to (v _1a *, v _1b *) and controls the three-phase primary input voltages Vu, Vv, Vw of the induction motor 1. as a result,
The induction motor 1 is torque-controlled according to a desired torque command value (the torque shaft current command value i _1q *).

The actual speed value (ω _r ) of the induction motor 1 is the primary current detection value i ₁ (i _1a , i _1b ), the primary voltage command value v on the stator coordinates (ab axis) of the induction motor 1. ₁ * (v _1a *, v _1b *)
And the actual speed estimated value (ω _r #) are input, and the stator coordinate (a
-b-axis) same-dimensional flux observer calculation with primary current estimated value i ₁ # (i _1a #, i _1b #) and secondary magnetic flux estimated value λ ₂ # (λ _2a #, λ _2b #) as estimated output The secondary magnetic flux estimated value λ ₂ # of the part 4
Using (λ _2a #, λ _2b #), the operation is estimated as follows.

Estimated secondary magnetic flux value λ on the stator coordinates (ab axis) estimated by the same-dimensional magnetic flux observer computing unit 4.
₂ # torque axis flux estimation value (λ _2b #) is coordinate-transformed by coordinate converter 12 and secondary flux estimation value on synchronous rotation coordinates (d-q axes) λ ₂ # torque axis flux estimation value (λ _2q #) And is compared with zero (0, see the above formula 5) in the matching circuit 17.

By the way, as is apparent from the equation (2), when the speed sensor is not used, the actual motor speed value ω _r is unknown even if the slip angular frequency command value ω _s * is set. Although it is not possible to determine the power supply angular frequency omega _0, synchronous rotating coordinate which rotates in the power supply angular frequency ω ₀ (d-q
By controlling the power source angular frequency ω ₀ so that the secondary magnetic flux λ ₂ (λ _2d , λ _2q ) on the (axis) satisfies the above equation (5), the current control calculation unit 3 is controlled to Vector control of interference control can be realized.

That is, in the velocity sensorless vector control device of FIG. 1, the same-dimensional magnetic flux observer computing unit 4 and the coordinate converter 12 make it possible to obtain the synchronous rotation coordinates (dq axes) satisfying the above equation (5). Secondary magnetic flux λ ₂ (λ _2d , λ _2q )
Of the secondary magnetic flux estimated value λ ₂ # and the estimated torque axis magnetic flux value (λ _2q #) of the secondary magnetic flux estimated value λ ₂ # is proportional-integrated by the speed estimation calculation unit 15 to estimate the actual motor speed value (ω _r ) (ω _r # )
The power source angular frequency ω ₀ is obtained from the above equation (2) (ω ₀ = ω _r # + ω _s *), and the current control calculation unit 3 is calculated based on the power source angular frequency ω _0.
The vector control of non-interference control can be realized by controlling the.

However, the motor speed estimated value (ω _r #) calculated and estimated as described above has an estimation error due to the cause explained above, and is different from the motor actual speed value (ω _r ). There is a discrepancy.

Therefore, from the constants of the induction motor 1 (primary and secondary resistances R ₁ and R ₂ , primary and secondary inductances L ₁ and L ₂ , mutual inductance M, etc.), the actual motor speed (ω _r , horizontal axis)
The function generator 13 having a table in which the excitation axis magnetic flux value (λ _2d , vertical axis) of the secondary magnetic flux λ ₂ is calculated in advance, and the function generator 13 is prepared according to the actual motor speed (command speed ω _r *, horizontal axis). Secondary magnetic flux λ
The excitation axis magnetic flux value of ₂ (λ _2d , vertical axis) is output as the secondary excitation axis magnetic flux reference value (λ _2d *), and the excitation axis magnetic flux estimated value (λ _2d ) of the secondary magnetic flux estimated value (λ ₂ #) is output. #) In the matching circuit 16 and the comparison error is proportional-integrally calculated in the speed correction calculating unit 14 to obtain the speed correction value (ω _rc ), which is calculated in the speed estimation calculating unit 15 in the matching circuit 18. an electric motor estimated actual speed value (ω _r '#) make modifications to, as a result, the motor actual speed estimated value (ω _r
#) Can be matched with the actual velocity (ω _r ).

If the above-mentioned speed correction calculation is corrected before the secondary magnetic flux λ ₂ is established at the time of starting the induction motor 1, the secondary magnetic flux estimated value (λ _2d #) and the secondary magnetic flux will be obtained. Since the comparison error with the magnetic flux reference value (λ _2d *) becomes large and the correct speed correction value (ω _rc ) cannot be obtained and overcorrection is performed, the control becomes unstable. _It is appropriate to start execution after the lapse of the delay time from the start of the motor by a timer (not shown) that sets the time until the establishment of ₂ as the delay time.

The estimated value of the actual motor speed (ω
_r #) is corrected by the actual motor speed estimation value (ω) estimated by the speed adaptive secondary magnetic flux observer (4, 6) in the conventional speed sensorless vector controller shown in FIG.
It goes without saying that the same can be applied to _r #).

[0035]

As described above, according to the present invention, the following effects can be obtained.

1. The secondary excitation shaft magnetic flux reference value corresponding to the motor speed value (ω _r ) is compared with the secondary excitation shaft magnetic flux estimation value, and the error is used as the actual speed correction value (ω _rc ) to estimate the actual motor speed value (ω _{Since r} #) is corrected, speed estimation ability is improved and speed estimation accuracy is improved.

2. The motor secondary excitation shaft magnetic flux reference value in the function generator can be easily calculated because it is only necessary to prepare the secondary magnetic flux according to the actual motor speed value (ω _r ), and thus the constant motor output control Even in the field weakening control in the range, it can be an effective correction means of the estimated motor actual speed value (ω _r #).

3. The effective correction calculation of the estimated actual motor speed (ω _r #) at the start of the motor may be difficult to obtain because the state until the secondary magnetic flux of the motor is established is difficult to obtain. According to the present invention, this problem can be solved by executing the correction calculation after a preset delay time from the start of the electric motor. Further, by setting this delay time as the time until the secondary magnetic flux of the electric motor is established in advance, an appropriate delay time can be obtained.

[Brief description of drawings]

FIG. 1 is an embodiment of a speed sensorless vector control device of the present invention.

FIG. 2 shows an example of a conventional speed sensorless vector control device.

[Description of symbols] 1: Induction motor 2: Power conversion unit 3: Current control calculation unit 4: Same-dimensional magnetic flux observer calculation unit 5: Slip calculation unit 6: Speed adaptation calculation unit 7: Coordinate converter 9: Basic phase angle calculation For integrator 10: Matching circuit 12: Coordinate converter 13: Function generator 14: Speed correction calculator 15: Speed estimation calculator 16,17,18: Matching circuit

Claims (2)

[Claims] 1. A primary excitation axis current command value (i _1d *) and a primary torque axis current command value (i
_1q *), primary excitation axis current detection value (i _1d ), primary torque axis current detection value (i _1q ), and power supply angular frequency (ω ₀ ) are input to perform current decoupling control of the induction motor and synchronous rotation A current control calculation unit that outputs a primary excitation axis voltage command value (v _1d *) and a primary torque axis voltage command value (v _1q *) on the coordinates, and a primary on the synchronous rotation coordinates that is the output of the current control calculation unit. Excitation axis voltage command value (v _{1 d} *) and primary torque axis voltage command value (v
Two-phase primary voltage command value on the stator coordinates after coordinate conversion of ( _1q *)
a power converter for controlling a three-phase primary input voltage (Vu, Vv, Vw) of the induction motor according to (v _1a *, v _1b *) and speed control of the induction motor; and a stator coordinate of the induction motor. Upper two-phase primary current detection value
(i _1a , i _1b ), the two-phase primary voltage command value (v _1a *, v _1b *), and the actual speed estimated value (ω _r #) of the induction motor are input respectively, and the two values on the stator coordinate are input. A same-dimensional magnetic flux observer calculation unit that estimates and outputs a phase-secondary magnetic flux value (λ _2a #, λ _2b #) and a two-phase primary current detection value (i _1a #, i _1b #), and the same-dimensional magnetic flux observer calculation A speed estimation calculation unit that calculates and outputs an estimated motor actual speed value (ω _r '#) based on the estimated output of the section, and the actual motor speed value (ω _r ) from the constant of the induction motor in advance.
The function generator that outputs the secondary excitation axis magnetic flux reference value (λ _2d *) that has calculated the secondary excitation axis magnetic flux value (λ _2d ) on the synchronous rotation coordinate according to, and the synchronization that is the output of the function generator. Comparison error between the secondary excitation axis magnetic flux reference value (λ _2d *) on the rotational coordinate and the secondary excitation axis magnetic flux estimated value (λ _2d #) on the synchronous rotational coordinate that is the estimated output of the same-dimensional magnetic flux observer computing unit. A speed correction value calculation unit that outputs a speed correction value (ω _rc ) by performing a proportional integration operation on the value, and an estimated motor actual speed value that is the output of the speed estimation calculation unit.
(ω _r '#) and the speed correction value (ω _rc ) that is the output of the speed correction value calculation unit are the actual speed estimated value (ω _r #) of the butt induction motor
A speed sensorless vector control device for an induction motor, comprising: 2. The correction calculation operation of the speed correction value calculation unit is operated by a timer having a delay time set in advance from the time when the induction motor is started until the electric motor secondary magnetic flux is established. Item 1. A vector controller for speed control of an induction motor according to Item 1.