JP3066697B2 - Vector control method and device for induction motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an induction motor vector.
The present invention relates to a control method and device . Specifically, the speed is estimated based on the primary current detection value of the induction motor and the speed command value without using the speed detector and the voltage detector for detecting the speed of the induction motor, and the speed is estimated using the estimated speed. And so-called sensorless speed control.

[0002]

2. Description of the Related Art A so-called sensorless speed control in which an induction motor is controlled by a vector without using a speed detector or the like, that is, a sensorless speed control is disclosed in Japanese Patent Application Laid-Open Nos. 60-18782 or 61-52176. More widely known.

For example, in the former publication, the speed is controlled as follows. First, an estimated speed ωr ′ of the induction motor obtained as described later is converted into a speed command value ωr.
A command value i of a torque component current (hereinafter, referred to as a q-axis component current) by proportional integral control or the like so as to match r *.
Calculate q *.

On the other hand, a detection value iq of a q-axis component current and a detection value id of an excitation component current (hereinafter, referred to as a d-axis component current) are calculated from the detection value of the primary current of the induction motor.

Then, a command value Vq * of a q-axis voltage corresponding to the q-axis component current is calculated by proportional integration control or the like so that the detected value iq of the q-axis component current matches the command value iq *. Similarly, a command value Vd * of the d-axis voltage corresponding to the d-axis component current is calculated by proportional integration control or the like so that the detected value id of the d-axis component current matches the set command value id *.

[0006] An estimated speed ωr 'of the induction motor is obtained by calculation based on the command value Vq * of the q-axis voltage component obtained above. Further, the slip frequency ωs is obtained based on a value (r ₂ ′ · iq *) obtained by multiplying the command value of the q-axis component current by the secondary resistance (primary conversion value) of the induction motor. The slip frequency ωs and the estimated speed value ωr ′ thus obtained are added to create a primary frequency command value ω ₁ *. The primary frequency command value ω ₁ * is corrected by adding a slip correction by the d-axis voltage command value Vd *.

The PWM inverter is controlled by the d-axis voltage and q-axis voltage command values Vd * and Vq * and the primary frequency command value ω ₁ * thus obtained, and the speed control by vector control is performed. .

[0008]

The equivalent circuit of the induction motor can be represented as shown in FIG. FIG.
, V ₁ is the primary voltage, i ₁ is the primary current, and io is d
An axis component current (hereinafter, represented by id), i ₂ ′ is a secondary current converted into a primary side (q-axis component current, hereinafter, represented by iq), E ′.
Is an induced voltage (hereinafter, represented by e ′), r ₁ is a primary resistance, r
_{2 'primary} conversion value of the secondary resistance, l ₁ is the primary leakage inductance, l _2' is primary converted value of the secondary leakage inductance, M 'is excitation inductance, s represents the slip.

FIG. 3A shows an example of a current vector diagram.
And the corresponding voltage vector is shown in FIG.

[0010] In the above-mentioned conventional technique, d viewed from the primary side
The axis voltage Vd and the q-axis voltage Vq are expressed by the following equations (1), respectively.
This is represented by (2).

Vd = r ₁ · id−ω ₁ (l ₁ + l ₂ ′) iq (1) Vq = r ₁ · iq + ω ₁ (l ₁ + l ₂ ′) id + e ₁ ′ (2) , Q-axis component current command means for generating a command value for the d- and q-axis component voltages based on the deviation between the set value of the q-axis component current and the detected value.

In the above equation, when the primary current changes to i ₁ ′ due to an increase in load, the q-axis component current iq changes, and the above equations become the following equations (1 ′) and (2 ′), respectively. Become. The vector relationship is as shown in FIGS. 3 (A) and 3 (B).

Vd ′ = r ₁ · id−ω ₁ (l ₁ + l ₂ ′) iq ′ (1 ′) Vq ′ = r ₁ · iq ′ + ω ₁ (l ₁ + l ₂ ′) id + e ₁ ′ (2 ′) The right side of the above equation (1) is the impedance drop in the induction motor, and corresponds to the case where the internal induced voltage of the d-axis component is “0”. In the right side of the equation (2), the first and second terms are the impedance drop, and the third term is the internal induced voltage of the q-axis component.

As described above, in the conventional technique, compensation for the impedance drop is taken into consideration, but no consideration is given to a sudden change in current caused by a sudden change in load or sudden acceleration / deceleration.

That is, when the current changes transiently, as is apparent from the above equations (1 ') and (2'), the command value of each axis component voltage changes, and the speed estimated based on these changes. Since the estimated value, the slip correction value, and the like change transiently and the command value of each axis component voltage changes due to the interference between the d and q axis components, the response of the speed following control decreases. was there.

It is an object of the present invention to provide a vector control method and apparatus for an induction motor having a response of speed following control even when a current is suddenly changed due to a sudden change of a load, sudden acceleration or deceleration, or the like.

[0017]

In order to achieve the above object, a vector control method and apparatus for an induction motor according to the present invention are provided.
Compares the speed command value and the speed estimated value, their polarization
Generating a q-axis component current command value for reducing the difference;
And the detected value of the q-axis component current of the induction motor
Of the induced voltage inside the q-axis component of the induction motor and the current of the q-axis component
Q-axis component that is the sum of the inductance drop due to the change
While obtaining the basic command value of the divided voltage, the q-axis component current
The inductor associated with a change in the q-axis component current based on the command value;
And the inductance drop is calculated as described above.
Subtract from the basic command value to obtain the estimated value of the q-axis component internal induced voltage.
Generated based on the estimated value of the q-axis component internal induced voltage.
The speed estimation value is obtained and used for comparison with the speed command value.
At the same time, the speed estimation value is calculated based on the command value of the q-axis component current.
The primary frequency command value by adding the slip speed
Generated based on the deviation between the command value of the d-axis component current and the detected value.
Generating an estimated value of the d-axis component internal induced voltage,
Based on the command value of the component current and the command value of the q-axis component current.
Including the resistance drop of the d-axis component voltage of the induction motor.
The impedance drop is determined, and the impedance drop
Of the d-axis component voltage
A command value is generated, and the command value of the q-axis current component and the d-axis current component are generated.
Q-axis component voltage of the induction motor based on the command value of the component current
The impedance drop including the resistance drop of
Add the impedance drop to the basic command value and
A pressure command value is generated, and the primary frequency command value and the d-axis
Based on the command value of the component voltage and the command value of the q-axis component voltage.
And controlling the induction motor.

In this case, it is preferable to change the polarity of the slip correction value according to the rotation direction of the induction motor.
Thus, the responsiveness of the speed following control can be achieved regardless of the forward rotation / reverse rotation.

[0019]

According to the present invention, according to the present invention, the above-mentioned object is attained by the following operations.

[0020] Originally, in the state where vector control is performed completely, the secondary magnetic flux axis phi ₂ of the d-axis and an induction motor which is the reference axis in the controller to match. However, when the current suddenly changes due to a sudden change in the load or sudden acceleration / deceleration, FIG.
As shown in (B), the secondary magnetic flux axis φ ₂ has a phase shift (lead or delay angle δ) from the d axis. This gives d,
Primary current corresponding to command values id *, iq * of q-axis component current
i ₁ corresponds to im, it inside the actual induction motor. Further, the phase shifts in accordance with the shift of the secondary magnetic flux axis φ ₂ , causing a d-axis component ed, and the internal induced voltage e ₁ becomes q
The vector sum of the axis component eq and the d-axis component ed is obtained.

[0021] Therefore, d-axis component Vd of the primary voltages _{V 1}
Is the sum of the d-axis component ed impedance drop of the internal induced voltage and _{(-r 1 · id + ω 1} (l 1 + l 2 ') iq). The q-axis component Vq is equal to the q-axis component eq of the internal induced voltage and the impedance drop (r ₁ · iq + ω ₁ (l ₁
+ L ₂ ') id).

Therefore, according to the present invention, the estimated values ed 'and e of the d- and q-axis components of the internal induced voltage which are not affected by a sudden change in current.
q ′ was determined separately from the impedance drop affected by the sudden change in current. Then, an estimated speed value is obtained based on eq ′, and a slip correction value for controlling ed ′ to be zero, that is, controlling the deviation angle δ of the secondary magnetic flux to “0” is obtained. . As a result, the speed estimation value and the slip correction value can be calculated without being interfered by a sudden change in current, so that the responsiveness of the speed following control can be maintained high even for a sudden change in load or a sudden change in acceleration or deceleration. .

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.

FIG. 1 shows an entire configuration diagram of an induction motor vector control apparatus to which the speed control method of the present invention is applied.

As shown in FIG. 1, the PWM inverter 1 is driven in accordance with the gate signal of the inverter switch element provided from the PWM pulse generating means 10, and converts the DC power supplied from the DC power supply 4 to a desired frequency and voltage. The AC is converted to a primary voltage and a current which are supplied to the induction motor 2.

The primary current of the induction motor 2 is detected by a current detector 3. The detected primary current is converted by the three-phase / two-phase conversion means 11 into known two-phase currents iα and iβ. The converted iα and iβ are input to current detecting means 12 for detecting current components of two orthogonal axes (d and q axes), and the detected value i of the d-axis component current is calculated by the following equations (3) and (4).
The detection values iq of the d-axis and q-axis component currents are obtained.

[0027] _{id = iα · cos (ω 1} * · t + θ *) + iβ · sin (ω 1 * · t + θ *) (3) iq = -iα · sin (ω 1 * · t + θ *) + iβ · cos (ω 1 * · T + θ *) (4) Here, ω ₁ * is a primary frequency command value described later, and θ *
Is an angle command value obtained by the phase calculation means 9 by the following equation (5).

Θ * = tan ⁻¹ (Vd * / Vq *) (5) The d-axis component induced voltage calculation means 6 inputs the detected value iq of the d-axis component current and the set value id *, and calculates the deviation between them. An estimated value ed 'of the d-axis component induced voltage of the induction motor is calculated and output based on the calculated value.

The speed control means (ASR) 5 inputs the speed command value ωr * and the speed estimated value ωr 'output from the speed estimating means 17 which will be described later, and reduces the q-axis component current so as to reduce their deviation. A command value iq * is generated and output.

The q-axis component voltage calculating means 7 relates to a characteristic portion, inputs a command value iq * of the q-axis component current and a detection value iq thereof, and based on a deviation therebetween, determines the q-axis voltage of the induction motor. The basic command value of the component voltage is calculated and output. This basic command value is an estimated value eq ′ of the internal induced voltage of the q-axis component.
And the inductance drop due to the change in the q-axis component current
(p (l ₁ + l ₂ ') iq *).

The q-axis current change correction means 16 and the subtraction means 3
Numeral 3 relates to a characteristic portion, and the q-axis current variation correction means 16 uses the q-axis component current command value iq * to determine the inductance drop (p (l ₁
+ L ₂ ') iq *). The subtraction means 33 calculates the q-axis component
Q-axis current change correction means 16 from the output of voltage calculation means 7
Is subtracted to obtain an estimated value eq ′ of the q-axis component induced voltage.

The speed estimating means 17 calculates an estimated speed ωr 'of the induction motor based on the estimated value eq' of the q-axis component induced voltage output from the subtracting means 33. The slip converter 14 determines a slip speed ωs * based on the command value iq * of the q-axis component current. The adding means 34 adds the slip speed ωs * to the estimated speed value ωr ′ to obtain a primary frequency command value ω ₁ * of the induction motor.

The slip correcting means 15 also relates to the characteristic portion, and d
Input the estimated value ed 'of the axis component induced voltage, and enter "0"
Is subjected to a proportional integration process to generate a slip correction value dωs, which is added to the primary frequency command value ω ₁ * by the adding means 35 to perform slip correction.

Here, in order to avoid interference of a sudden change in current, which is one of the characteristic portions, the impedance drop is obtained by separating and finding the impedance drop, and the impedance drop compensation is performed.
The q-axis impedance non-interference correction unit 13 will be described.

The first calculating means 20 is a coefficient multiplying means, by multiplying the primary resistance r ₁ to the set value of the d-axis component current id *, the ohmic drop of the d-axis component voltage of the induction motor corresponding to the id * Ask for minutes. The second calculating means is a coefficient multiplying means 21
, Multiplying the command value iq * of the q-axis current by the inductance (l ₁ + l ₂ ′), and multiplying this by the corrected primary frequency command value ωs * to correspond to the q-axis component current The impedance drop of the d-axis component voltage of the induction motor is calculated. These first and second calculation means 20, 2
The outputs of 1 and 24 are input to the adding means 31. The adding means 31 adds the estimated value ed 'of the d-axis component induced voltage in consideration of the polarity, and inputs the added value to the amplitude calculating means 8 and the phase calculating means 9 as a d-axis component voltage command value Vd *. You.

The third calculating means 23 is a coefficient multiplying means, and adds a primary / secondary resistance r ₁₂ (=
r ₁ + r ₂ ′) to determine a resistance drop of the q-axis component voltage of the induction motor corresponding to the q-axis current command value. The fourth operation means includes a coefficient multiplication means 22 and a multiplication means 25,
Inductance (l ₁ +
l ₂ ′) and the corrected primary frequency command value ω ₁ * to obtain the impedance drop of the q-axis component voltage of the induction motor corresponding to the d-axis component current. The sum of these is added by the adding means 32 to the command value Vq * of the q-axis component voltage.
To correct for this.

The command value Vq of the corrected q-axis component voltage
* Is input to the amplitude calculator 8 and the phase calculator 9.
The amplitude calculating means 8 includes a command value Vd * of the d- and q-axis component voltages,
Based on Vq *, the primary voltage command value V ₁ * = √ (Vd * ²
+ Vq * ² ) and outputs it to the PWM pulse generating means 10. Similarly, based on the command values Vd * and Vq * of the d- and q-axis component voltages, the phase calculation means 9 calculates the angle command value θ * by executing the calculation of the equation (5), and obtains the PWM pulse generation means 1
0 is output to the current detection means 12.

The PWM pulse generating means 10 generates a PWM pulse based on the input primary voltage command value V ₁ *, angle command value θ *, and corrected primary frequency command value ω ₁ *,
Thus, by controlling the driving of the PWM inverter, the speed of the induction motor is controlled in accordance with the speed command value.

Next, the operation according to the features of the embodiment of FIG. 1 will be described.

D and q axis component voltages Vd and Vq of the induction motor
Can be expressed by the following equations (6) to (9) as is known. In these equations, p is the operator (d / dt), L ₂ = l ₂ '+ M'
It is.

Vd = r ₁ · id + p (l ₁ + l ₂ ') id-ω ₁ (l ₁ + l ₂ ') iq + p · M '· φ ₂ d / L ₂ -ω ₁ · M'・ Φ ₂ q / L ₂ (6) = r ₁ ・ id-ω ₁ (l ₁ + l ₂ ') iq-ed + p (l ₁ + l ₂ ') id + p ・ M ' ・ φ ₂ d / _{L 2 (7) Vq = r} 1 · iq + p (l 1 + l 2 ') iq + ω 1 (l 1 + l 2') id + ω 1 · M '· φ 2 d / L 2 + p · _{M '· φ 2 q / L} 2 (8) = (r 1 + r 2) · iq + ω 1 (l 1 + l 2') id + eq + p (l 1 + l 2 ') iq + p · M ′ · φ ₂ q / L ₂ (9) Here, eq = ω ₁ · M ′ · φ ₂ d / L ₂ .

In the above embodiment, since the d-axis component current id, which is the exciting current, is controlled to be constant, the d-axis component φ ₂ d of the secondary magnetic flux is also kept constant. The slip correction means 15 controls the q-axis component φ ₂ q of the secondary magnetic flux to be maintained at “0”. Therefore, the third and fourth terms on the right side of equation (7) can be regarded as “0”, and similarly, the fifth term on the right side of equation (9) can be regarded as “0”. 10) and (11).

Vd ≒ r ₁ · id-ω ₁ (l ₁ + l ₂ ') iq-ed + p (l ₁ + l ₂ ') id ₂ (10) Vq ≒ (r ₁ + r ₂ ) · iq + ω ₁ (l ₁ + l ₂ ') id + eq + p (l ₁ + l ₂ ') iq (11) Focusing on this, in the present embodiment, the d and q axis voltage command values Vd
*, Vq * are determined by the following equations (12) and (13), and the terms are appropriately separated and calculated in consideration of the influence of the current.

Vd * = r ₁ · id * −ω ₁ * (l ₁ + l ₂ ′) iq * -ed ′ (12) Vq * = (r ₁ + r ₂ ′) · iq * + ω ₁ * (l ₁ + l ₂ ′) id * + eq ′ + p (l ₁ + l ₂ ′) iq * (13) That is, the first and second terms in the equation (12) are the non-interference correction means 1
The third term is d-axis component induced voltage estimating means 6
Is calculated by The estimated value ed 'obtained by this
Controls the primary frequency command value ω ₁ * to be “0” by the slip correction means 15. Further, the first and second terms of the equation (13) are calculated by the non-interference correcting means 13, and the sum of the third and fourth terms is calculated by the q-axis component voltage calculating means 7,
Further, the estimated value eq ′ of the q-axis component induced voltage is obtained by subtracting the fourth term obtained by the iq variation correcting means 16 from the sum of the third and fourth terms by the subtracting means 33, and based on this, the speed estimated value is obtained. ωr ′ is required. That is, (M ′ · φ ₂ d / L ₂ ) is given to the speed estimation value calculating means 17 as a coefficient, and is obtained by ωr ′ = eq ′ / (M ′ · φ ₂ d / L ₂ ).

From the above, according to the embodiment of FIG. 1, the estimated values of ed ', eq', and ωr 'are obtained without being affected by the change of the torque current iq. As a result, the speed control controlled on the basis of the estimated values of ed ', eq', and ωr 'has an effect that the follow-up control can be performed with a high response even to a sudden load change or a sudden acceleration / deceleration.

In the above embodiment, the case where the induction motor rotates in a fixed direction has been described as an example. However, when the induction motor is used in forward / reverse rotation, the slip correcting means 1 shown in FIG.
The polarity of the estimated value ed 'of the d-axis component induced voltage input to 5 may be switched according to the rotation direction as shown in FIG.

That is, as shown in FIG. 5, the polarity of the primary frequency command value ω * is determined by the polarity determining means 50, and +1 or -1 is multiplied by the multiplying means 51 according to the determined polarity (+1, -1). What is necessary is just to multiply the estimated value ed 'of the d-axis component induced voltage. Note that the slip correcting means 15 of FIG.
The deviation between the input estimated value ed ′ and the set value “ed ′ = 0” is obtained, the deviation is processed by the proportional integration means 53, and the deviation is output as the slip correction value dωs.

Here, the polarity of the d-axis component induced voltage ed will be described. ed is regardless of the direction of rotation of the induction motor, if · d-axis lags behind phi ₂ axes: ed <0 · d If the shaft is advanced than phi ₂ axes: ed> 0 there is a relationship, the estimated value The same applies to ed '.

On the other hand, as can be seen from equations (6) and (10),
, Ed = ω₁* · M'φ₂q / L₂  Ω₁The polarity changes depending on the polarity of *. There
Then, as shown in FIG.₁Estimated value e according to the polarity of *
By switching the polarity of d 'to correct slip
In other words, it can be applied to a reversible rotating induction motor.

[0050]

According to the present invention, the estimated values ed 'and eq' of the d- and q-axis components of the internal induced voltage are obtained separately from the impedance drop affected by the sudden change in current, and the speed is calculated based on the obtained eq '. An estimated value is obtained, and a slip correction value is obtained so as to make ed 'zero. e
Since d 'and eq' are not affected by a sudden change in current, the response of the speed following control can be kept high even for a sudden change in load due to a sudden change in load or sudden acceleration / deceleration.

Further, the polarity of the estimated value ed ′ of the d-axis induced voltage is switched according to the polarity of the primary frequency command value ω ₁ *,
By applying slip correction, it can be applied to reversible induction motors.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an induction motor vector control device according to an embodiment to which a speed control method of the present invention is applied.

FIG. 2 is an example diagram of an equivalent circuit of the induction motor.

3A and 3B are diagrams for explaining a vector relationship in vector control, wherein FIG. 3A is a current vector diagram, and FIG. 3B is a voltage vector diagram.

4A and 4B are diagrams illustrating a change in a vector when a secondary magnetic flux axis is shifted from a d-axis due to a sudden change in load, in which FIG. 4A is a current vector and FIG. 4B is a voltage vector diagram.

FIG. 5 is a diagram showing another embodiment of the slip correcting means 15 when the induction motor is used in forward / reverse rotation.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 PWM inverter 2 induction motor 6 d-axis component internal induced voltage estimating means 7 q-axis component voltage calculating means 8 amplitude calculating means 9 phase calculating means 10 PWM pulse generating means 11 three-phase / two-phase converting means 12 current detecting means 13 non-interference Correction means 14 slip conversion means 15 slip correction means 16 iq variation correction means 17 speed estimation means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 21/00 H02P 5/408-5/412 H02P 7/628-7/632

Claims (4)

(57) [Claims] A speed command value is compared with an estimated speed value.
Generates q-axis component current command values to reduce those deviations
And the detected value of the command value and the detected value of the q-axis component current of the induction motor.
Based on the deviation, the induced voltage inside the q-axis component of the induction motor and q
Is it the sum of the inductance drop due to the change of the axis component current?
While obtaining the basic command value of the q-axis component voltage
As the q-axis component current changes based on the command value of the
Calculate the inductance drop
The descent is subtracted from the basic command value to generate the q-axis internal induced power.
Pressure estimate, and the q-axis component internal induced voltage estimate
Calculating the speed estimation value based on the speed command value and
The speed estimation value is used for comparison and the q-axis component current
Add the slip speed obtained based on the command value of
Generates a wave number command value, and calculates the d-axis component current based on the deviation between the command value and the detected value.
Generating an estimated value of the component internal induced voltage,
And the q-axis component current command value.
Impedance including resistance drop of d-axis component voltage of motor
Of the d-axis component.
Command value for the d-axis component voltage by adding
Generate the command value of the q-axis current component and the command value of the d-axis component current
Includes the resistance drop of the q-axis component voltage of the induction motor based on
The impedance drop, and calculate the impedance drop
Adds to the basic command value to generate a command value for q-axis component voltage
The primary frequency command value and the d-axis component voltage command value
The induction motor is controlled based on the command value of the q-axis component voltage.
Vector control method of induction motor. 2. The method according to claim 1, wherein the d-axis component is internally induced.
The slip correction value obtained by integrating the estimated value of the electromotive voltage
Wherein the primary frequency command value is further corrected.
Vector control method for induction motor. 3. The method according to claim 1, wherein the detected value is a primary current of the induction motor.
To find the detected values of d-axis component current and q-axis component current respectively
Current detection means, the speed command value and the speed estimation value, and
Speed control means for generating a command value of the q-axis component current to be reduced
A command value of the q-axis component current and the q-axis component of the induction motor.
Based on the deviation from the detected current value, the q-axis
Inductor due to change of internal induced voltage and q-axis component current
The basic command value of the q-axis component voltage consisting of the sum with the
A q-axis component voltage calculating means for calculating the q-axis component current based on the q-axis component current command value;
Q-axis current change to find the inductance drop due to
Compound correction means, and subtracting the inductance drop from the basic command value
Subtraction means for generating an estimated value of a q-axis component internal induced voltage
And the speed estimation based on the estimated value of the q-axis component internal induced voltage.
Speed estimating means for obtaining a constant value and outputting it to the speed controlling means
And the speed estimation value based on the command value of the q-axis component current.
Generate the primary frequency command value by adding the determined slip speed
Adding means, and the q-axis of the induction motor based on the command value of the q-axis current component.
In addition to calculating the resistance drop of the component voltage, the d-axis component current
An induction motor based on a command value and the primary frequency command value
Q-axis to find the impedance drop of the q-axis component voltage of
Impedance non-interference correction means, the resistance drop of the q-axis component voltage and the impedance drop
The lower sum is added to the basic command value to determine the q-axis component voltage.
An adding means for generating a command value, and a d-axis based on a deviation between the command value of the d-axis component current and the detected value.
Induction of d-axis component to generate estimated value of component internal induced voltage
Voltage calculation means, and the d-axis of the induction motor based on the command value of the d-axis current component.
In addition to calculating the resistance drop of the component voltage,
Of the d-axis component voltage of the induction motor based on the flow command value.
D-axis impedance non-interference compensation to find the impedance drop
Positive means, resistance drop and impedance drop of the d-axis component voltage
Is added to the estimated value of the d-axis component internal induced voltage to obtain d
An adding means for generating a command value of the axis component voltage, wherein the command value of the primary frequency, the command value of the q-axis voltage,
The PWM inverter is controlled based on the divided voltage command value.
Baie induction motor comprising a PWM pulse generating unit that
Vector control device. 4. The method according to claim 3, wherein the d-axis component is internally induced.
The slip correction value obtained by integrating the estimated value of the electromotive voltage
Further comprising an adding means for correcting the primary frequency command value.
A vector control device for an induction motor, characterized in that: