JP2953044B2 - Vector controller for induction motor - Google Patents

Description

The present invention relates to a vector control device for an induction motor.

B. Summary of the Invention The present invention relates to a vector provided with a slip angular frequency calculation unit for calculating a slip angular frequency based on a component of each axis of a primary current of an orthogonal two-axis coordinate system and a secondary time constant in an induction motor. Focusing on the fact that the δ-axis component of the primary voltage on the rotating coordinate γ-δ axis with the primary current as the reference axis is not affected by the magnitude of the primary resistance, the target value of the slip angular frequency is determined based on the variation component. And by temporarily suspending the compensation calculation when the speed changes, it is possible to compensate for the ideal secondary resistance change that is not affected by the primary resistance change, thereby improving torque control accuracy and speed change. Acceleration / deceleration characteristics at the time are well maintained.

Furthermore, paying attention to the fact that the torque current becomes zero during the no-load operation and the influence of the secondary resistance change does not appear on the primary voltage fluctuation, the primary resistance, the exciting inductance and the excitation inductance are determined based on the primary voltage fluctuation during the no-load operation. By calculating the above, these compensations are also made possible.

C. Prior Art Vector control of an induction motor that controls a secondary magnetic flux and a secondary current orthogonal thereto in a non-interfering manner has been widely applied.

In this vector control, in the case of a three-phase induction motor, current and magnetic flux are treated as vectors in a d-q coordinate system of two orthogonal axes rotating at the same speed as the rotating magnetic field generated by the power supply, and the operation result is calculated for each phase of the three-phase power supply. This is a method of controlling by converting to a current command value.

The voltage equation in the dq coordinate system is expressed by the following equation (1).

However _{ω s = ω-ω r L} σ = (L 1 L 2 -M 2) is / L _2.

Here, v _1d and v _1q are d and q axis components of the primary voltage, i _1d and i _1q are d and q axis components of the primary current, respectively, and λ _2d and λ _2q are d and q of the secondary magnetic flux, respectively. Axial components, R ₁ , R ₂ are primary and secondary resistances respectively, L ₁ , L ₂ , M are primary and secondary, excitation inductances, ω, ω _r , ω _s are primary power supply angular frequencies, respectively. Rotor angular frequency, slip angular frequency, and P represent d / dt.

If the d axis is taken on the secondary magnetic flux in the dq coordinate system, λ _2q
= 0. At this time, λ _2d = Φ ₂ = constant, i _2d = 0, i _2d
= It becomes possible orthogonal control similar torque and flux and i ₂ becomes a direct current machine.

 On the other hand, the secondary magnetic flux has the following relationship.

I _2d = 0 according to the vector control condition, and λ _2d = Mi _1d from the equation (2).

Also, from λ _2q = 0 And i _1q is proportional to the torque current.

Next, equation (3) is obtained from the fourth row of equation (1), and when the condition of the slip angular frequency is determined from equation (3), ω _s is expressed by equation (4).

The above is the vector control condition when the control is performed so that the secondary magnetic flux coincides with the d-axis. Therefore, in order to perform vector control, it is necessary to set i _1d to λ _2d / M and control ω _s so that equation (4) holds.

Here, the secondary resistance R ₂ used for calculating the slip angular frequency ω _s
To change the resistance value by a temperature change such as self-heating of the ambient temperature and the rotor based on the output voltage of the motor to estimate the change in resistance value, the target value of the slip angular frequency omega _s This variation It is necessary to make a correction to compensate for the generated torque fluctuation due to the secondary resistance change. If the change in the secondary resistance is neglected, the torque control accuracy and the torque response deteriorate. As described above, if the estimation of the change in the secondary resistance is performed by using, for example, the output voltage of the inverter as it is, the change in the primary resistance is captured. Therefore, the signal used for the estimation is a signal independent of the primary resistance. It is desirable.

For this reason, a control circuit shown in FIG. 8 has already been proposed. In the figure, reference numeral 1 denotes an excitation current command unit, which changes λ _2d * / M * to a target value i _1d of i _1d until the angular frequency ω _r exceeds a certain value.
And i _1d * is reduced when ω _r exceeds a certain value.
Hereinafter, when a target value or an ideal value is indicated by *, the deviation between the speed commands ω _r * and ω _r is calculated by the speed amplifier 2 through i _1q
*, The ideal values v _1d *, v _1q * of the primary voltage on the dq axis are calculated based on i _1d *, i _1q *, and correction of the voltage fluctuation due to the change in the primary resistance and the secondary resistance is performed. i _1d * = i _1d , i _1q * = 1
When controlled to be _1q, i _1d * = 1 in the PI amplifier 3 ₁ for controlling _1d delta _1d is obtained, i _1q * = i is the PI amplifier 3 ₂ for controlling _1q Delta] v _1q is obtained. Since Δv _1d and Δv _1q include both the voltage change due to the change in the primary resistance and the secondary resistance, if the component that does not include the voltage change due to the change in the primary resistance is obtained, the compensation of the change in the secondary resistance is performed. Compensation that is not affected by the primary resistance change is possible. So the primary current I ₁
And of taking a rotational coordinate gamma-[delta] axes spaced reference axis gamma on vector, determined by the [delta] sliding the primary voltage change [Delta] V _{I delta} axis correcting arithmetic section 3 _3. This ΔV _1δ is represented by an expression not including the primary resistance R ₁ , and thus is not affected by the primary resistance R ₁ .
Since Δv _1δ is also used in the present invention, it will be described in detail in the description of the present invention.

FIG. 6 is a vector diagram showing the relationship between the dq axis and the γ-δ axis and the voltage and current, and FIG. 7 is a vector diagram showing the primary voltage fluctuation, where V ₁ and E are the primary voltages, respectively. , Secondary voltage,
Δv ₁ is the primary voltage variation, Δv _1γ and Δv _1δ are the γ-axis component and δ-axis component of the variation, respectively, and ψ is the phase ψ of tan ⁻¹ (i _1q * / i _1d *) with _respect to the dq axis. The different phases, I _0, are the excitation currents and I ₂ is the torque currents. Δv _1δ is represented by the following equation (5).

 Δv_1δ= −Δv_1d・ Sinψ + Δv_1qcosψ …… (5) where cosψ ＝ I₀/ I₁= I_1d/ i_1γ, Sinψ ＝ I_Two/ I₁= I_1q
/ i_1γ  And the slip correction operation unit 3_ThreeThen Δv_1δ2 based on
Correction of slip angular frequency corresponding to secondary resistance change Δω_s
Is calculated, and the slip angular frequency calculation unit 3_FourΩ obtained by_s*
And Δω_sIs the target value of the slip angular frequency.
The rotor angular frequency ω_rAnd the angular frequency of the primary voltage
The target value of ω = dθ / dt is set. 3 in Fig. 8_FiveIs polar coordinates
Conversion part, 3₆Is the coordinate converter, 4₁Is the PWM circuit, 4_TwoIs Invar
IM, induction motor, PP: pulse pickup unit, 4_ThreeIs
It is a speed detector.

D. Problems to be Solved by the Invention Since the primary voltage fluctuations Δv _1d and Δv _1q include both the fluctuation of the primary resistance and the fluctuation of the secondary resistance, in the circuit of FIG. ₃ at delta] v _1d, further calculates a received no delta _{I delta} influence of the primary resistance change from delta] v _1q, calculates the [delta] [omega _r further from this delta] v _{I delta.}

When the field control is performed, λ _2d and i _1d are expressed by the following equation (1).
From the line, the following equation (6) is established.

Since λ _2q = 0, equation (7) holds.

From equation (7), it can be seen that during field control, i _1d is first-orderly controlled with respect to a change in λ _2d . That is, the field command λ
_{When 2d} * is changing, λ _2d = Mi _1d does not hold.

However, in the conventional circuit, since the field control is not considered, the theoretical development is performed with the excitation current i _1d being fixed, that is, i _1d = λ _2d / M, and the slip correction calculation is performed. For this reason, in the field control region, the set value of the slip angular frequency cannot be accurately calculated, and is not an effective method.

An object of the present invention is to compensate for the change in the secondary resistance in the equation for calculating the slip angular frequency, to perform ideal compensation that is not affected by the change in the primary resistance, and to change the speed of the electric motor, Acceleration / deceleration characteristics can be kept good without adverse effects due to the compensation, and the calculation of the target value of the slip angular frequency becomes simpler than the method already proposed, which is also effective when performing upper field control. It is to propose a simple vector control device.

Another object of the present invention is to provide a vector control device capable of compensating for changes in primary resistance and exciting inductance.

E. Means and action to solve the problem As described above, not only the secondary resistance but also the primary resistance changes with temperature, so it is ideal to perform secondary resistance compensation without being affected by the primary resistance change. is there. Here, in the present invention, the variation Δv of the δ-axis component of the primary voltage is similar to the circuit of FIG.
_In addition to using _1δ , a control system that is one step further is adopted.

That is, in the vector control shown in FIG. 8, the exciting current is set by setting the d axis of the rotating coordinate dq axis to the same axis as the secondary magnetic flux.
i _1d and the torque current i _1q were controlled to maintain orthogonality.

This time, the rotational coordinate is the γ-δ axis, and the γ axis is the primary current.
It was investigated a method of controlling set on I _1. However, since it is necessary to control the on course d-q axes in order to perform the vector control, rotates at power supply angular frequency omega ₀ and the same speed, a combination of different d-q axis and the gamma-[delta] axis of the phase New control method.

When considering on the γ-δ axis based on the primary current I ₁ , the primary voltage fluctuation due to the secondary resistance change is represented by the δ-axis fluctuation Δv _1δ
, The voltage component does not include the voltage fluctuation due to the primary resistance, so that the secondary resistance compensation with robustness can be performed.

Therefore, the ideal primary voltage v _1γ *, v on the γ-δ axis
_1δ * is obtained by calculation, and the correction of the voltage fluctuation due to the change in the primary resistance and the secondary resistance is executed by controlling so that i _1γ = I ₁ and i _1δ = 0. By _performing such control, the output of the PI amplifier that controls i _1γ = I ₁ is Δv
_1γ is obtained, and Δv _1δ is obtained at the output of the PI amplifier that controls i _1δ = 0. Since Δv _1δ does not include a voltage component due to a primary resistance change, it can be used for compensating for a secondary resistance change. In other words, if the secondary resistance change is compensated for using Δv _1δ , ideal compensation independent of the primary resistance change can be performed.

As described above, using the γ-δ axis with the primary current I ₁ as a reference value has the advantage that primary voltage fluctuation data used for compensating for the secondary resistance change can be directly obtained on the δ axis.

In the present invention, when the field command λ _2d * is changed from the above equation (7), λ _2d = Mi _1d is not satisfied.
λ _2d / M and i _1d are used separately.

Further, the speed change of the motor is detected, and when there is a speed change, the compensation of the secondary resistance change is temporarily stopped,
The compensation amount up to that point is held, and the compensation is performed again when there is no change in speed. As a result, an accurate slip frequency can be given even when the speed changes, and good acceleration / deceleration characteristics can be maintained.

 Hereinafter, the present invention will be described in detail.

FIG. 3 is a vector diagram corresponding to an asymmetric TI type equivalent circuit of an induction motor, and FIG. 4 is a vector diagram corresponding to this equivalent circuit.

If the γ-axis is now on the primary current I ₁ , i _1γ = I ₁ , i _1δ =
It becomes 0. On the γ-δ axis, an equation similar to the equation (1) shown in the section of “Prior Art” holds, so if d and q in the equation (1) are changed to γ and δ, respectively, Equations (8) and (9) hold from the fourth row.

If the term including P is removed, the condition of ω _s that always holds can be obtained. The following equation is obtained from the equation (9).

By substituting equation (10) into equation (8), the following equation is obtained, and therefore equation (11) holds.

Here, the relationship between λ _2d and λ _2γ and λ _2δ is as follows.

λ _2γ2 + λ _2δ ² = λ _2d ² (13) By substituting equations (12) and (13) into equation (11), the following equation is obtained.

As described above, with the γ axis on the primary current I ₁ , i _1γ =
By controlling so that I ₁ , i _1δ = 0 and satisfying the vector control condition on the dq axis, ω _s becomes the same expression as the expression (4) in the section of “prior art”. It was found that the same condition was obtained. However, if λ _2d ≠ Mi _1d is taken into account in consideration of the field control region, ωs is expressed as in equation (15) from the first stage of equation (14).

Ideal voltage on the γ-δ axis On the γ-δ axis, i _1γ * = I ₁ and i _1δ * = 0 are controlled.
6) Equation is obtained.

If the term with P is omitted, equation (17) is obtained.

Here, when the vector control condition is satisfied, the following expression is satisfied.

Therefore, equation (19) is obtained.

When the torque current command i _1q * changes abruptly or when the exciting current command i _1d * changes by entering the field control, the term of Pi _1γ applied to Lσ in equation (16) cannot be ignored. The ideal voltage when this P term is considered is as follows.

Secondary magnetic flux fluctuation when the secondary resistance changes The secondary magnetic flux fluctuation when the secondary resistance changes is examined.

 The following equation is obtained from the third and fourth lines of the equation (1).

(21), as it follows multiplied by L ₂ / R ₂ in (22).

_Λ2γ is obtained from equations (23) and (24). First Is given by

Is given by

From (25) + (26), _λ2γ is as follows.

Next, _λ2δ is obtained from the equations (23) and (24). First Is given by

Is given by

When λ _2δ is obtained from (29)-(28), the following is obtained.

Here, the following assumptions are made.

(A) Assuming that the current is controlled to flow according to the command value, _i1γ * = _i1γ and _i1δ * = _i1δ = 0. The currents on the dq axes are i _1d * = i _1d , i _1q * = i _1q
And

(B) When the secondary resistance change is K, R ₂ = (1 + K) R ₂ *
In equations (27) and (30) Can be expressed as follows.

(C) It is assumed that the exciting current is controlled as shown in equation (7), and therefore equation (32) is established.

(D) To perform secondary resistance compensation, It is assumed that a specific number of transient terms of L ₂ / R ₂ = L ₂ * / R ₂ . (Short time and R ₂ does not change.) Therefore, the following equation is established.

Substituting the above relational expressions into the expressions (27) and (30) and transforming them results in the following.

Here, the ideal value of the secondary magnetic flux on the γ-δ axis is expressed by the following equation.

By multiplying the denominator and the numerator of Expression (34) by _i1γ * and using Expression (36), the secondary magnetic flux variation _Δλ2γ on the γ-axis is expressed by Expression (39).

Multiply the denominator and numerator of equation (35) by _i1γ * to _obtain (37)
Using the equation, the secondary magnetic flux variation Δλ _2δ on the δ axis is (40)
It is expressed like a formula.

Primary voltage fluctuation when secondary magnetic flux fluctuates The primary voltage when the secondary magnetic flux fluctuates can be expressed as follows from equation (16).

Since the ideal value of the primary voltage is expressed by equation (19),
From Equations (19) and (41), which take into account the equation, the voltage variation Δ
v _1γ and Δv _1δ are as follows. Where Δλ _2δ ,
The expansion of Δλ _2γ uses equations (40) and (39), respectively.

Here, since v _1γ includes the component of R ₁ i _1γ *, v _1γ also includes a voltage change due to a change in the primary resistance R ₁ . Therefore, when also considering the change in the primary resistance R ₁ (42) equation is as follows. However, K ₁ is the primary resistance variation.

As described above, since Δv _1γ includes the fluctuation of the primary resistance R ₁ , it is not suitable for use in compensating for a change in the secondary resistance R ₂ . On the other hand, since Δv _1δ does not include the component of R ₁ , it is considered to be a voltage fluctuation equation due to a secondary resistance change. Therefore,
If the secondary resistance compensation is performed by detecting the variation Δv _1δ of the primary voltage v _{1δ on} the δ axis, the following advantages are obtained because the influence of the primary resistance R ₁ is not included.

(I) can be carried out secondary resistance compensation without being affected by the temperature change of the position resistor R _1.

(Ii) the influence of the voltage drop R ₁ is greater in the low-speed range, since the primary voltage v _{I delta} of δ-axis contains no voltage drop R _1, also secondary resistance compensation at low speed accurately It is possible to do.

(Iii) by performing secondary resistance compensation than _Δv 1δ, Δv 1γ
Only the voltage component due to R ₁ variation occurs in. This allows estimation of R _1. R ₁ is considered to containing such V _CE partial voltage drop main circuit elements of the resistance component dead time of the primary resistance cable.

 Calculation of Secondary Resistance Change K By modifying equation (43), the following equation (45) is obtained.

Therefore, if the primary voltage variation Δv _1δ on the δ-axis can be detected, the secondary resistance variation K can be obtained from equation (45).

Method of Identifying Primary Resistance and Exciting Inductance During No-Load Operation In the present invention, in addition to compensating for a change in secondary resistance, the primary resistance and exciting inductance can be identified as described below.

When the exciting inductance changes, the shunt ratio between the exciting current and the torque current changes, and the primary voltage also changes. Primary voltage in order to vary similarly be secondary resistance changes, it is impossible to distinguish changes in the excitation inductance M and the secondary resistance R _2. However, during the no-load operation, the torque current i _1q = 0, so that the primary voltage fluctuation does not appear to be affected by the secondary resistance change. Therefore, the excitation inductance can be compensated using the primary voltage fluctuation during the no-load operation.

The vector diagram at the time of no-load operation can be represented as shown in FIG. 5 by the TI equivalent circuit. At the time of no-load operation, since the torque current i _1q = 0, the dq axis coincides with the γ-δ axis.
Therefore, consider the dq axis. The primary voltage at the time of no-load operation can be expressed as follows from equation (16). Where i _1q
= 0 and the P term is ignored.

Here, the following assumptions are made.

(A) Assuming that the current is controlled to flow according to the command value, _i1d * = _i1d .

(B) the amount of change in the magnetizing inductance put the A _M.

(C) placing the A ₁ a change in the primary resistance.

(D) Add * to the set value of the motor constant.

(E) The change is ignored because the leakage inductance _Lσ is small.

Now, the ideal voltage at the time of no-load operation can be expressed as follows from the equation (46).

When the primary voltage is expressed using the primary resistance change A ₁ and the excitation inductance change A _M , the following is obtained.

From equations (47) and (48), the primary voltage fluctuations Δv _1d and Δv _1q during no-load operation are as follows.

(49) exciting inductance variation A _M and the primary resistance change in A ₁ from equation becomes:.

In a steady state where the excitation command does not change, λ _2d * = M * i _1d
* And since the A _M is as follows.

From the above, it was found that the primary resistance and the exciting inductance can be identified by detecting the primary voltage fluctuation during the no-load operation. The summary is as follows.

(A) Primary resistance change A from d-axis primary voltage fluctuation Δv _1d
I know ₁ .

(B) primary voltage change Delta] v _1q than exciting inductance variation A _M of the q-axis is seen.

Means of the Invention If the target value R ₂ * of the secondary resistance matches the actual secondary resistance, ω _s is obtained based on the equation (15), and this may be set as ω _s *. The secondary resistance changes with temperature. Therefore, in the present invention, K is calculated using Δv _1δ, and
Correct ω _s * by modifying R ₂ *. To obtain ω _s *, the following equation (52) obtained from equation (15) is used.

On the other hand, the primary resistance also changes depending on the temperature, but Δv _1δ does not include the value of the primary resistance as can be seen from the equation (43), so that the secondary resistance is not affected by the primary resistance change in compensating the secondary resistance. In this respect, the circuit is common to the circuit shown in FIG. 8, but the current control in the dq coordinate system is performed in the circuit in FIG. 8, whereas the current control in the γ-δ coordinate system is performed in the present invention. The primary voltage is controlled on the basis of the control, whereby Δv _1γ and ΔV _1δ are obtained in the current control amplifier output,
The secondary resistance is compensated for using this Δv _1δ .

Here, when the speed of the motor suddenly changes, an error occurs in the slip frequency, primary frequency, etc. due to a delay in speed detection,
This deviates from the ideal vector control condition. Δv _1δ also changes in order to correct it, and it cannot be used for secondary resistance fluctuation compensation. Therefore, if the secondary resistance fluctuation compensation is executed when the motor speed changes, an incorrect slip frequency will be given, and the characteristics at the time of acceleration / deceleration will deteriorate. Therefore, based on the speed detection signal of the motor, provided a speed change detection unit that detects the presence or absence of a speed change,
When the speed change detecting unit detects that there is a speed change,
The value of the secondary resistance change K before the occurrence of the speed change is held, and the calculation of the K is stopped. When the speed change detection unit detects no speed change, the calculation of the K is restarted.

Specifically, a first coordinate conversion unit for calculating a target value i _1γ * (= I ₁ ) of the γ-axis component of the primary current and the phase ψ based on i _1d * and i _1q *, and λ _2d * the ratio lambda _2d / M between the excitation inductance M, gamma of the primary voltage based on the command value omega ₀ of the result and power supply angular frequency of the first coordinate conversion unit, a target value of δ -axis component _v 1γ *, v 1δ * And a second coordinate conversion unit that converts the primary current detection value of the induction motor into each of the axis components i _1γ and i _1δ of the γ-δ coordinates, and i _1γ * and the δ-axis component of the primary current. Based on the target value i _1δ * and i _1γ , i _1δ from the second coordinate conversion unit, the variation Δv _1γ of the current primary voltage γ-axis component from v _1γ * and the current primary voltage v in the δ-axis component
Means for calculating a variation Δv _1δ from _1δ *, i _1d *, i _1q *, i _1γ *, λ _2d *, primary power supply angular frequency ω
₀ , a secondary resistance change calculator for calculating a change with respect to the set value of the secondary resistance based on the set values M * and Δv _1δ of the excitation inductance, and determining whether there is a speed change based on a speed detection signal of the motor. A speed change detection unit for detecting the change in the speed, a sum of v _1γ * and Δv _1γ is set as a target value v _1γ of the γ-axis component of the primary voltage, and an addition of v _1δ * and Δv _1δ is set as δ of the primary voltage. The target value v _1δ of the axis component is used, the power supply voltage is controlled based on the target values v _1γ and v _1δ , and the set value of the secondary time constant and the secondary resistance change calculation unit are calculated by the slip angular frequency calculation unit. The secondary time constant at that time is obtained based on the calculation result obtained in
Calculation is performed using i _1q * and λ _2d * / M *, and when the speed change detection unit detects that there is a speed change, the calculation result of the secondary resistance change calculation unit before the speed change occurs is held. At the same time, the calculation of the calculation unit is stopped, and when the speed change detection unit detects no speed change, the calculation of the calculation unit is restarted.

Also, in the present invention, instead of using the secondary resistance change calculator, a deviation between a change Δv _1δ from v _1δ * in the δ-axis component of the current primary voltage and a target value zero of this Δv _1δ is input, the slip angular frequency control amplifier for outputting a variation [Delta] [omega _s from the target value omega _{s *} slip angular frequency (voltage change control amplifier) provided, [Delta] [omega _s of from the slip angular frequency control amplifier (voltage change control amplifier) And ω _s obtained by the slip angle frequency calculation unit
The same operation and effect can be obtained by using the value added with * as the target value of the slip angular frequency.

In this case when said speed change detection section detects the presence of the speed change were stopped the operation of the voltage variation control amplifier holds the output [Delta] [omega _s of the voltage change control amplifier before speed change occurs, the speed change detection When the unit detects no change in speed, the operation of the voltage fluctuation control amplifier is restarted. Alternatively, when the speed change detection unit detects that there is a speed change, the secondary resistance change K is calculated based on the output Δω _s of the voltage fluctuation control amplifier and the slip angular frequency ω _s before the speed change occurs, Using the secondary resistance change K, the secondary resistance target value R ₂ * of the slip angular frequency calculation unit is changed, and then the calculation of the voltage fluctuation control amplifier is stopped, and the speed change detection unit detects no speed change. Then, the operation of the voltage fluctuation control amplifier is restarted.

Further, in the present invention, a change in the primary resistance set value is calculated based on Δv _1γ , the primary resistance set value R ₁ * and i _1d * during the no-load operation, and Δv _1δ , M *, secondary self inductance It is also possible to provide an identification circuit unit for calculating a change from the set value of the excitation inductance based on L ₂ *, ω ₀ and λ _2d *.

F. Embodiment FIG. 1A is a circuit diagram showing an embodiment of the present invention.
The same reference numerals as those in FIG. 8 indicate the same parts. 1 ₁ is a secondary magnetic flux instruction amplifier that outputs λ _2d * / M * according to the angular frequency ωr of from speed detector 4 _3, until it exceeds have ωr value outputs λ _2do * / M * , Ωr exceeds a certain value and enters the field control region, λ _2d * / M * decreases according to ωr. 1 ₂ is the formula (7), that is, λ _2d * / M * (1 + L ₂ * / R ₂ *
An operation unit that executes the operation of (S).

5 ₁ is a first coordinate conversion _{unit, i 1d *, i 1q *} i in gamma-[delta] coordinates relative axis primary current I ₁ based on
_Has the function of calculating _1γ * and the phase difference _と between the d-axis and the γ-axis. Execute the operation of 5 ₂ is an ideal voltage calculation unit for calculating a target value of the primary voltage, the first coordinate conversion unit 5 ₁ than output the sinψ, I _1, λ _2d than cosψ and secondary magnetic flux command amplifier 1 ₁ * / M * and power supply angular frequency ω ₀ (19)
The calculation of the expression is performed to calculate _v1γ *, _v1δ *.

Reference numeral 6 denotes a second coordinate conversion unit which detects primary current detection values i _u , i
_w is converted into each axis component i _1γ , i _1δ of the γ-δ coordinate. These i _1γ and i _1δ are the target values i _1γ * and i _1δ * (=
0), and the deviation is input to PI amplifiers 7 and 8, which are current control amplifiers, respectively. Δ from PI amplifiers 7 and 8 respectively
v _1γ and ΔV _1δ are output, and as described above, Δv _1γ
Is added to v _1γ *, and Δv _1δ is added to v _1δ *. Reference numeral 9 denotes a polar coordinate converter, which outputs the magnitude | V ₁ | of the primary voltage vector V ₁ and the phase angle φ with the γ-axis (see FIG. 3). The phase angle phi, is summed with θ described later and ψ (= ω ₀ t), these sum values and | primary to and is inputted to the PWM circuit 4 _1, corresponding U, V, and W-phase | V ₁ It is converted into a voltage command value, thereby the voltage of the inverter 4 ₂ is controlled.

Reference _numeral 10 denotes a secondary resistance change calculating unit, and λ _2d * / M *, i
_1d *, i _1q *, ω ₀ , i _1γ * and Δv _1δ
5) This is a part for calculating the secondary resistance change K by executing the calculation of the equation. Reference numeral 11 denotes a slip angular frequency calculation unit, and K, λ _2d
* / M * and i _1q * are taken in, and the function of obtaining ω _s by executing equation (52) is provided. By the way, first by computer
When the operation of each part of the circuit of FIG. 7A is performed, ω _s is calculated as follows. That is, a series of calculations including the calculation of K and the calculation of the slip angle frequency are instantaneously performed by the clock signal, and the secondary resistance value obtained by the (n-1) th calculation in the slip angle frequency calculation unit 11 is calculated by the nth calculation. The set value in. Husband K and R ₂ obtained in the n-th operation s K _n, R _2n
When a preset value R ₂ * is assigned to the initial value R ₂₀ of R _2n , the first to n-th calculations are as follows.

Thus to represent the omega _s calculated by the n-th operation as ω _sn, ω _sn becomes next expression _{(53), ω sn = (1 + K} n) · ω s (ne) ...... (53) (n-1) keep in store the obtained ω _{s (n-1)} at times th computation, omega _sn by using K _n obtained by equation (53)
Is required.

In this case, the initial value ω _s1 is ω _s1 = (1 + K ₁ ) · R ₂ * · 1 / L ₂ * · i _1q * / (λ _2d * /
M *).

The thus obtained ω _s and the detected rotor angular frequency ω _{r of the} electric motor IM are added, and the added value ω ₀ is set as the target value of the power supply angular frequency.

Numeral 12 denotes an identification circuit unit, which takes in Δv _1γ and i _1d * during no-load operation and executes the upper equation of equation (50) to calculate a change A ₁ in the primary resistance. At the same time, Δv _1δ , ω _0, and λ _2d * / M * are taken in, and the lower part of the equation (50) is executed to calculate the change A _M in the excitation inductance, thereby obtaining the excitation inductance M ² / L
_It has the function of identifying ₂ . That is, the changes A ₁ and A _M
Based on, for example, a first view of an ideal voltage calculation unit 5 ₂ (A)
R ₁ *, to change the M *. Here, the comparator 13 determines whether or not the operation is the no-load operation and the drive timing of the identification circuit unit 12. Comparator 13, a set value, for example, the value of the 5% if the rated torque current is 100% as compared to i _1q * values, i _1q * is lower than the set value, determines that the no-load operation In this case, the identification circuit 12 is driven, and in this case, the influence of the secondary resistance change does not appear.

21 is a speed change detection unit that detects the presence or absence of change in speed of the motor based on the detection signal of the speed detector 4 _3. When the speed change detecting unit 21 detects that there is a speed change, the speed change detecting unit 21 holds the calculation result of the secondary resistance change amount calculating unit 10 before the speed change occurs, stops the calculation of the calculating unit 10, and stops the speed change. Is detected, the operation of the operation unit 10 is restarted. As a result, the acceleration / deceleration characteristics when the motor speed changes can be kept good.

In the above, in order to perform the calculation by the calculation unit 5 ₂ v In computing the _{1 gamma} * Considering P term (20) of, i
_{1 gamma} * R such term from R ₁ * to _{1 * (1 + Lσ / R} 1 * P)
By replacing it with the first order, a more accurate ideal voltage can be given and the current response can be improved.

Next, an embodiment in which the embodiment of FIG. 1A is improved will be described.

From the equation (16), if the change in the secondary magnetic flux is ignored, the following (16)
a) The equation is obtained. Here, λ _2γ and λ _2δ represent λ _2d using the equation (18).

As can be seen from this equation, when the primary current changes _abruptly , v _1γ and v _1δ change by a value corresponding to the temporal change rate. That is, the change in v _1δ includes the temporal change rate of the primary current in addition to the change in the secondary resistance,
The change in v _1γ includes the time change rate of the primary current in addition to the change in the primary resistance and the exciting inductance. Therefore, in the embodiment of FIG. 1 (A), when the primary current suddenly changes, the change is regarded as a change in the secondary resistance, and also as a change in the primary resistance and a change in the excitation inductance. Becomes lower.

Therefore, in the embodiment of FIG. 1B, L _σ Pi _1γ and L _σ Pi
_The primary voltage fluctuation including the term of 1δ (this is Δv _1γ , Δ
v _1δ ), and the primary voltage fluctuations not included (this is Δ
_v 1γI, calculates both the and _Δv 1δI), the former value Delta] v _{1 gamma,} and controls the primary voltage using a Delta] v _{I delta,} the latter value _Δv 1γI, compensation of the secondary resistance change using Delta] v _1DerutaI And identification of primary resistance and the like.

Specifically, as shown in FIG. 1B, the PI amplifier 7 corresponds to L _σ Pi _1γ (i _1γ * −i _1γ ).
× a proportional element ₇₁ for calculating the _{L σ / T s (I 1γ} * -
and a integral element 7 ₂ integrating the i _{1γ), Δv} the sum of the integral term output from the proportional element 7 proportional term output integral element 7 ₂ than ₁ outputs as Delta] v _{1 gamma,} the integral term output
It is configured to output as _1γI . For the PI amplifier 8, it is equivalent to L _σ Pi _1δ (i _1δ * −i
_1δ) × L _{σ /} T _s the calculating proportional element 8 _{1 (i} 1γ * -
i _{1 gamma)} and a integral element ₈₂ for integrating the sum of the integral term output from the proportional term output integral element ₈₂ than the proportional element 8 ₁ outputs as Delta] v _{I delta,} than integral element 8 ₂ It is configured to output the integral term output as Δv _1δI . Here, T _s indicates the operation cycle, and (i _1γ * −i _1γ )
/ T _s and (i _1δ * −i _1δ ) / T _s are calculated by using differential elements.

According to such a configuration, even when the primary current changes suddenly, the influence does not appear on Δv _1γI and Δv _1δI ,
Accurate secondary resistance compensation, primary voltage identification, and the like can be performed.

FIG. 2 is a circuit diagram showing another embodiment of the present invention. Instead of using the secondary resistance change calculating section 10, a PI amplifier 14 which is a voltage fluctuation control amplifier is used.
_1δ and Δv _1δ variation Δω _s from the target value ω _{s *} in the current slip angular frequency by entering the deviation between the target value zero
Is obtained as an output signal. Then, the slip angular frequency calculator 15 assumes that R ₂ does not fluctuate from the ideal value. Ω _s * is calculated based on ω _s *, and the sum of ω _s * and Δω _s is set as the target value of the slip angular frequency. According to such an embodiment, the target value of the slip angular frequency is automatically corrected according to the secondary resistance change. 16 is a comparator 13
Alternatively, the PI amplifier 14 is controlled by the output signal of the speed change detection unit 21.
This is a switch section for invalidating the output of.

In the configuration of FIG. 2, when the speed of the electric motor changes and the speed change detecting unit 21 detects that the speed has changed, first, the PI amplifier
Suspend the calculation of 14 and keep the previous value. When the change in the speed of the motor stops, the stop of the operation of the PI amplifier 14 is released and each operation is executed again.

Or, the secondary resistance variation based on the compensation amount Δωs slip and slip frequency omega _s of the front motor speed change occurs is calculated from the following expression (54), the secondary resistance set value of the slip angular frequency calculation unit 15 R ₂ Change *.

1 + Kn = ω _s / ω _s * (54) where , And the is _{ω s = ω s * + Δω} s, K n is a secondary resistance variation. Here, from equation (54), ω _s is ω _s = (1
+ Kn) a × ω _s *, and substituting the omega _s * in the _{equation, ω s = (1 + Kn} ) × ω s * = (1 + Kn) × (R 2n-1 * / L 2 *) · {i 1q * / (Λ _2d * / M
*)｝ = (1 + Kn) × [｛(1 + K ₁ ) (1 + K ₂ ) ... (1 + K _n-1 ) · R ₂ *｝ / L ₂ *] ｛{i _1q * / (λ _2d * / M *)} Becomes

The secondary resistance set value R ₂ * is changed as follows.

R _2n * = (1 + K _n ) · R _2n-1 * (55) where R _2n-1 * = (1 + K ₁ ) (1 + K ₂ ) ... (1 + K
_n-1) · R ₂ is *, K ₁ ~K _n is secondary resistance variation at each time, R ₂ * is the initial secondary resistance set value.

In the embodiment shown in FIG. 2, the PI amplifiers 7 and 8 shown in FIG.
Inputs the _1γI the identification circuit 12, Delta] v _{I delta} * and by entering the deviation between Delta] v _1DerutaI the PI amplifier 14 can accurately perform that the secondary resistance variation compensation such as previously described.

G. Effects of the Invention According to the present invention, the circuit coordinates γ with the primary current I ₁ as the reference axis
The δ-axis component v _1δ of the primary voltage on the −δ axis does not include the voltage drop of the primary resistance R ₁ , and therefore, even with respect to the primary voltage fluctuation due to the secondary resistance change, the influence of the primary resistance on the fluctuation component Δv _1δ Note that Δv _1δ is obtained by, for example, a current control amplifier, and the secondary resistance change when the target value of the slip angular frequency is obtained is compensated by using the obtained value. Compensation can be provided. Moreover, the ideal primary voltage values v _1γ *, v _1δ *
_Is calculated separately without _treating the excitation command λ _2d * / M * and the excitation current i _1d * as equal, so that the vector control is effective even for the field control. Further, since voltage control is performed by obtaining Δv _1γ and Δv _1δ , voltage correction for primary resistance and secondary resistance changes can be performed, and high torque control accuracy can be obtained and torque response can be improved. .

In comparison with the circuit of FIG. 8, the voltage control is performed only on the dq coordinates in the circuit of FIG. 8, and Δv _1d , Δv _1d
Since v _1q includes the variation for both changes in primary resistance and secondary resistance, data affected by only the secondary resistance change from Δv _1d and Δv _1q and data affected by both changes However, in the present invention, it is possible to directly control by Δv _1γ and Δv _1δ without performing such separation.

Since only the influence of the primary resistance change remains in the Delta] v _{1 gamma} be performed secondary resistance compensation by Delta] v _{I delta,} the Delta] v
It is also possible to estimate the primary resistance R ₁ based on _{1 gamma.}

Furthermore, in the present invention, the primary voltage during no-load operation is analyzed,
Paying attention to the analysis result, a change with respect to the set value of the primary resistance is calculated based on Δv _1γ (= Δv _1d ), and Δv _1δ
Because we calculate the variation of the exciting inductance M ² / L ₂ based on, allowed the compensation of the primary resistance and excitation inductor scan.

Also, the configuration of the current control amplifier is L _σ Pi _1γ , L _σ Pi _1δ
To obtain a voltage deviation corresponding to
If a voltage variation generated by a secondary resistance change is obtained as an integral term output, L _σ Pi _1γ , L
The term _σ Pi _1δ does not appear in the integral term output. Thereby, the current response is improved and the integral term output Δv
_1GanmaI, primary resistance using Delta] v _1DerutaI, secondary resistance, it becomes possible to accurately compensate the exciting inductance.

Further, when the motor speed is changing, the secondary resistance variation compensation calculation is stopped, and the data of the secondary resistance change up to that time is held, so that the acceleration / deceleration characteristics can be kept good.

When there is no change in the motor speed, the calculation of the secondary resistance fluctuation compensation is restarted, so that stable secondary resistance compensation is possible.

[Brief description of the drawings]

FIG. 1A is a block circuit diagram showing an embodiment of the present invention,
FIG. 1 (B) is a block circuit diagram showing another embodiment of the present invention, FIG. 2 is a block diagram showing still another embodiment of the present invention, FIG. 3 is an equivalent circuit diagram of an induction motor, FIG. 7 are vector diagrams of current, voltage and the like, respectively, and FIG. 8 is a block circuit diagram showing a comparative example of the vector control device. 1 ₁ ... Secondary magnetic flux command amplifier, 1 ₂ ... Calculation unit, 2... Speed amplifier, 5 ₁ ... First coordinate conversion unit, 5 ₂ ... Ideal voltage calculation unit, 6. Conversion unit, 7,8: PI amplifier as current control amplifier, 10: Secondary resistance change calculation unit, 11,15
...... Slip angular frequency calculation unit, 12 ... Identification circuit unit, 14 ...
Voltage fluctuation control amplifier, 21 Speed change detector.

Claims (8)

(57) [Claims] 1. A d-axis component of a primary current of an induction motor, wherein dq coordinates are rotation coordinates that rotate in synchronization with a power supply angular frequency of the induction motor and have a secondary magnetic flux as a reference axis. Induction motor having means for calculating the target values i _1d * and i _1q * of the q-axis component, and a slip angular frequency calculator for calculating the slip angular frequency based on an arithmetic expression including a set value of the secondary time constant Means for calculating i _1d * includes means for outputting a target value λ _2d * of the d-axis component of the secondary magnetic flux in accordance with the rotor angular frequency of the induction motor, and means for differentiating this λ _2d * Means for calculating i _1d * on the basis of the term, the phase ψ being different from the dq axis by tan ⁻¹ (i _1q * / i _1d *), and the coordinates having the primary current I ₁ as a reference axis. When the the gamma-[delta] coordinate, i _1d *, i _1q * target value of gamma-axis component of the primary current based on i 1γ * (= I ₁₎ A first coordinate conversion unit for calculating the fine the phase [psi, the ratio lambda _2d of lambda _2d * and the excitation inductance M * / M, the command value omega ₀ of the result and power supply angular frequency of the first coordinate conversion unit,
Secondary inductance L _2, the primary resistance R _1, based on the leakage inductance _{L σ, R 1 i 1γ *} + (M 2 / L 2) · ω 0 · (λ
_2d * / M) sinψ is calculated to calculate the target value v _1γ * of the γ-axis component of the primary voltage, and L _σ ω ₀ i _1γ ++
Means for performing a calculation of (M ² / L ₂ ) · ω ₀ · (λ _2d * / M) cosψ to calculate a target value v _1δ * of the δ-axis component of the primary voltage, and a detection value of a primary current of the induction motor _Into the respective axis components i _1γ , i _1δ of the γ-δ coordinate, the target value i _{1δ of} i _1γ * and the δ-axis component of the primary current, and the second coordinate converter. Based on i _1γ and i _1δ , the variation Δv _1γ from v _1γ * in the γ-axis component of the current primary voltage and v _1δ in the δ-axis component of the current primary voltage
Means for calculating a variation Δv _1δ from *, i _1d *, i _1q *, i _1γ *, λ _2d *, primary power supply angular frequency ω ₀ , excitation inductance set value M * and Δv _1δ. a secondary resistance variation calculator for calculating a change amount for the set value of the rotor resistance, based on the speed detection signal of the motor, provided the speed change detection unit that detects the presence or absence of change in velocity, v _{1 gamma} * and Δ The added value of _1γ is set as a target value v _1γ of the γ-axis component of the primary voltage, and the added value of v _1δ * and Δ _1δ is set as the target value v _1δ of the δ-axis component of the primary voltage.
_1γ , v _{1 δ} and the power supply voltage is controlled based on the set value of the secondary time constant and the calculation result obtained by the secondary resistance change calculator based on the slip angular frequency calculation unit at that time. _{Calculate the} secondary time constant and calculate this secondary time constant, i _1q *
And λ _2d * / M *, and when the speed change detection unit detects that there is a speed change,
The calculation result of the secondary resistance change calculation unit before the speed change occurs is held and the calculation of the calculation unit is stopped. When the speed change detection unit detects no speed change, the calculation of the calculation unit is restarted. A vector control device for an induction motor, wherein the vector control device comprises: 2. A d-axis coordinate of a primary current of an induction motor, wherein d-q coordinates are rotational coordinates rotating in synchronization with a power supply angular frequency of the induction motor and coordinates having a secondary magnetic flux as a reference axis. Induction motor having means for calculating the target values i _1d * and i _1q * of the q-axis component, and a slip angular frequency calculator for calculating the slip angular frequency based on an arithmetic expression including a set value of the secondary time constant Means for calculating i _1d * includes means for outputting a target value λ _2d * of the d-axis component of the secondary magnetic flux in accordance with the rotor angular frequency of the induction motor, and means for differentiating this λ _2d * Means for calculating i _1d * on the basis of the term, the phase ψ being different from the dq axis by tan ⁻¹ (i _1q * / i _1d *), and the coordinates having the primary current I ₁ as a reference axis. When the the gamma-[delta] coordinate, i _1d *, i _1q * target value of gamma-axis component of the primary current based on i 1γ * (= I ₁₎ A first coordinate conversion unit for calculating the fine the phase [psi, the ratio lambda _2d of lambda _2d * and the excitation inductance M * / M, the command value omega ₀ of the result and power supply angular frequency of the first coordinate conversion unit,
Secondary inductance L _2, the primary resistance R _1, based on the leakage inductance _{L σ, R 1 i 1γ *} + (M 2 / L 2) · ω 0 · (λ
_2d * / M) sinψ is calculated to calculate the target value v _1γ * of the γ-axis component of the primary voltage, and L _σ ω ₀ i _1γ ++
Means for performing a calculation of (M ² / L ₂ ) · ω ₀ · (λ _2d * / M) cosψ to calculate a target value v _1δ * of the δ-axis component of the primary voltage, and a detection value of a primary current of the induction motor From the second coordinate conversion unit, which converts i into the respective axis components i _1γ , i _1δ of the γ-δ coordinate, i _1γ * and the target value i _1δ * of the δ-axis component of the primary current. Based on i _1γ and i _{1δ of}
Variation Δv _1γ from v _1γ * in the γ-axis component of the current primary voltage and v in the δ-axis component of the current primary voltage
Means for calculating a variation Delta] v _{I delta} from _{I delta} *, inputs the deviation between the target value zero Delta] v _{I delta} of variation Delta] v _{I delta} Toko from v _{I delta} * in δ-axis component of the current of the primary voltage, slip A voltage variation control amplifier that outputs a variation Δω _s from the angular frequency target value ω _s *; and a speed change detection unit that detects the presence or absence of a speed change based on a speed detection signal of the motor. The sum of Δω _s from the variation control amplifier and ω _s * obtained by the slip angular frequency calculation unit is set as the target value of the slip angular frequency, and the added value of v _1γ * and Δv _1γ is the γ-axis component of the primary voltage. with the target value v _{1 gamma,} also v and _{I delta} * and delta _{I delta} and the target value v _{I delta} of δ-axis component of the sum value primary voltage, controls the power supply voltage on the basis of these target values v _{1 gamma,} the v _{I delta} of, The speed change detecting unit detects that there is a speed change. When,
The output Δω _s of the voltage fluctuation control amplifier before the speed change occurs is held, and the operation of the voltage fluctuation control amplifier is stopped. When the speed change detection unit detects no speed change, the voltage fluctuation control amplifier A vector control device for an induction motor, wherein the operation is restarted. 3. A d-axis component of a primary current of an induction motor, wherein dq coordinates are rotation coordinates that rotate in synchronization with a power supply angular frequency of the induction motor and have a secondary magnetic flux as a reference axis. Induction motor having means for calculating the target values i _1d * and i _1q * of the q-axis component, and a slip angular frequency calculator for calculating the slip angular frequency based on an arithmetic expression including a set value of the secondary time constant Means for calculating i _1d * includes means for outputting a target value λ _2d * of the d-axis component of the secondary magnetic flux in accordance with the rotor angular frequency of the induction motor, and means for differentiating this λ _2d * Means for calculating i _1d * on the basis of the term, the phase ψ being different from the dq axis by tan ⁻¹ (i _1q * / i _1d *), and the coordinates having the primary current I ₁ as a reference axis. When the the gamma-[delta] coordinate, i _1d *, i _1q * target value of gamma-axis component of the primary current based on i 1γ * (= I ₁₎ A first coordinate conversion unit for calculating the fine the phase [psi, the ratio lambda _2d of lambda _2d * and the excitation inductance M * / M, the command value omega ₀ of the result and power supply angular frequency of the first coordinate conversion unit,
Secondary inductor scan L _2, the primary resistance R _1, based on the leakage inductance _{L σ, R 1 i 1γ *} + (M 2 / L 2) · ω 0 · (λ 2d
* / M) sinψ is calculated to calculate the target value v _1γ * of the γ-axis component of the primary voltage, and L _σ ω ₀ i _1γ ++
Means for performing a calculation of (M ² / L ₂ ) · ω ₀ · (λ _2d * / M) cosψ to calculate a target value v _1δ * of the δ-axis component of the primary voltage, and a detection value of a primary current of the induction motor From the second coordinate conversion unit, which converts i into the respective axis components i _1γ , i _1δ of the γ-δ coordinate, i _1γ * and the target value i _1δ * of the δ-axis component of the primary current. Based on i _1γ and i _{1δ of}
Variation Δv _1γ from v _1γ * in the γ-axis component of the current primary voltage and v in the δ-axis component of the current primary voltage
Means for calculating a variation Delta] v _{I delta} from _{I delta} *, inputs the deviation between the target value zero Delta] v _{I delta} of variation Delta] v _{I delta} Toko from v _{I delta} * in δ-axis component of the current of the primary voltage, slip A voltage variation control amplifier that outputs a variation Δω _s from the angular frequency target value ω _s *; and a speed change detection unit that detects the presence or absence of a speed change based on a speed detection signal of the motor. The sum of Δω _s from the variation control amplifier and ω _s * obtained by the slip angular frequency calculation unit is set as the target value of the slip angular frequency, and the added value of v _1γ * and Δv _1γ is the γ-axis component of the primary voltage. with the target value v _{1 gamma,} also v and _{I delta} * and delta _{I delta} and the target value v _{I delta} of δ-axis component of the sum value primary voltage, controls the power supply voltage on the basis of these target values v _{1 gamma,} the v _{I delta} of, The speed change detecting unit detects that there is a speed change. When,
Based on the output [Delta] [omega _s and slip angular frequency omega _s of the voltage change control amplifier before speed change _{occurs, 1 + Kn = ω s /} ω s *
(Where Kn is the secondary resistance change at an arbitrary time) to calculate the secondary resistance change K, and calculate the secondary resistance change K
And R _2n * = (1 + Kn) · R _2n-1 * (where R _2n *
Calculates the secondary resistance target value at an arbitrary point in time), changes the setting of the secondary resistance target value R ₂ * of the slip angular frequency calculation unit, and then stops the calculation of the voltage fluctuation control amplifier. Restarting the operation of the voltage fluctuation control amplifier when detecting that there is no speed change. 4. A method for calculating a change in a primary resistance set value based on Δv _1γ , a primary resistance set value R ₁ * and i _1d * during a no-load operation, and calculating Δv _1δ , M *, a secondary self-inductance. Based on L ₂ *, ω ₀ and λ _2d *, a change with respect to the set value of the exciting inductance is calculated, and the calculated value is used as a target value v _1γ of the γ- and δ-axis components of the primary voltage.
The vector control device for an induction motor according to claim 1, further comprising an identification circuit unit used for an operation performed by the means for calculating *, v _1δ *. . 5. A d-axis component of a primary current of an induction motor, wherein dq coordinates are rotation coordinates which rotate in synchronization with a power supply angular frequency of the induction motor and have a secondary magnetic flux as a reference axis. Induction motor including means for calculating target values i _1d * and i _1q * of the q-axis component, and a slip angular frequency calculator for calculating a slip angular frequency based on an arithmetic expression including a set value of a secondary time constant Means for calculating i _1d * includes means for outputting a target value λ _2d * of the d-axis component of the secondary magnetic flux in accordance with the rotor angular frequency of the induction motor, and means for differentiating this λ _2d * Means for calculating i _1d * on the basis of the term, the phase ψ being different from the dq axis by tan ⁻¹ (i _1q * / i _1d *), and the coordinates having the primary current I ₁ as a reference axis. When the the gamma-[delta] coordinate, i _1d *, i _1q * target value of gamma-axis component of the primary current based on i 1γ * (= I ₁ And wherein a first coordinate conversion unit for calculating the phase [psi, lambda _2d * and the exciting inductance ratio between M λ _2d * / M, the command value omega ₀ of the result and power supply angular frequency of the first coordinate conversion unit,
Secondary inductance L _2, the primary resistance R _1, based on the leakage inductance _{L σ, R 1 i 1γ *} + (M 2 / L 2) · ω 0 · (λ
_2d * / M) sinψ is calculated to calculate the target value v _1γ * of the γ-axis component of the primary voltage, and L _σ ω ₀ i _1γ ++
Means for performing a calculation of (M ² / L ₂ ) · ω ₀ · (λ _2d * / M) cosψ to calculate a target value v _1δ * of the δ-axis component of the primary voltage, and a detection value of a primary current of the induction motor _Into the respective axis components i _1γ , i _1δ of the γ-δ coordinate, a target value i _1δ * of the δ-axis component of the primary current, and i _1δ from the second coordinate converter. A proportional element that obtains a product of the current deviation of the current deviation over time and the leakage inductance L _σ as a proportional term output, and an integral element that outputs a value obtained by integrating the current deviation as an integral term output, The sum of the proportional term output and the integral term output is represented by v _1δ in the δ-axis component of the current primary voltage.
* Outputs a voltage change Delta] v _{I delta} from, based on the integral term output a current control amplifier to output as Delta] v _1DerutaI, the i _{1 gamma} * and the second i _{1 gamma} than the coordinate conversion unit, the current of the primary Means for calculating a variation Δ _1γ from v _1γ * in the γ-axis component of the voltage; i _1d *, i _1q *, i _1γ *, λ _2d *, the primary power supply angular frequency ω ₀ , and the excitation inductance set value M * And Δv _1δI
And a speed change detection unit for detecting the presence or absence of a speed change based on a speed detection signal of the electric motor, and v _1γ The sum of * and Δv _1γ is the target value v _1γ of the γ-axis component of the primary voltage, and the sum of v _1δ * and Δ _1δ is the target value v _1δ of the δ-axis component of the primary voltage, and these target values The power supply voltage is controlled on the basis of v _1γ and v _1δ, and the slip angular frequency calculation unit performs the control based on the set value of the secondary time constant and the calculation result obtained by the secondary resistance change calculation unit at that time. _Is obtained, and this secondary time constant, i _1q *
And λ _2d * / M *, and when the speed change detection unit detects that there is a speed change,
The calculation result of the secondary resistance change calculation unit before the speed change occurs is held and the calculation of the calculation unit is stopped. When the speed change detection unit detects no speed change, the calculation of the calculation unit is restarted. A vector control device for an induction motor, wherein the vector control device comprises: 6. A d-axis component of a primary current of an induction motor, assuming that dq coordinates are rotation coordinates that rotate in synchronization with a power supply angular frequency of the induction motor and that use secondary magnetic flux as a reference axis. Induction motor having means for calculating the target values i _1d * and i _1q * of the q-axis component, and a slip angular frequency calculator for calculating the slip angular frequency based on an arithmetic expression including a set value of the secondary time constant Means for calculating i _1d * includes means for outputting a target value λ _2d * of the d-axis component of the secondary magnetic flux in accordance with the rotor angular frequency of the induction motor, and means for differentiating this λ _2d * Means for calculating i _1d * on the basis of the term, the phase ψ being different from the dq axis by tan ⁻¹ (i _1q * / i _1d *), and the coordinates having the primary current I ₁ as a reference axis. When the the gamma-[delta] coordinate, i _1d *, i _1q * target value of gamma-axis component of the primary current based on i 1γ * (= I ₁₎ A first coordinate conversion unit for calculating the fine the phase [psi, the ratio lambda _2d of lambda _2d * and the excitation inductance M * / M, the command value omega ₀ of the result and power supply angular frequency of the first coordinate conversion unit,
Secondary inductance L _2, the primary resistance R _1, based on the leakage inductance _{L σ, R 1 i 1γ *} + (M 2 / L 2) · ω 0 · (λ
_2d * / M) sinψ is calculated to calculate the target value v _1γ * of the γ-axis component of the primary voltage, and L _σ ω ₀ i _1γ ++
Means for performing a calculation of (M ² / L ₂ ) · ω ₀ · (λ _2d * / M) cosψ to calculate a target value v _1δ * of the δ-axis component of the primary voltage, and a detection value of a primary current of the induction motor _Into the respective axis components i _1γ , i _1δ of the γ-δ coordinate, a target value i _1δ * of the δ-axis component of the primary current, and i _1δ from the second coordinate converter. A proportional element that obtains a product of the current deviation of the current deviation over time and the leakage inductance L _σ as a proportional term output, and an integral element that outputs a value obtained by integrating the current deviation as an integral term output, The sum of the proportional term output and the integral term output is represented by v _1δ in the δ-axis component of the current primary voltage.
* Outputs a voltage change Delta] v _{I delta} from, based on the integral term output a current control amplifier to output as Delta] v _1DerutaI, the i _{1 gamma} * and the second i _{1 gamma} than the coordinate conversion unit, the current of the primary Means for calculating a variation Δv _1γ from v _1γ * in the γ-axis component of the voltage; inputting a deviation between the integral term output _Δ1δI of the current control amplifier and a target value of _Δ1δI of zero; A voltage variation control amplifier that outputs a variation Δω _s from a standard value ω _s *; and a speed change detection unit that detects the presence or absence of a speed change based on a speed detection signal of the motor. The sum of Δω _s from the amplifier and ω _s * obtained by the slip angular frequency calculation unit is set as the target value of the slip angular frequency, and the added value of v _1γ * and Δv _1γ is set as the target value of the γ-axis component of the primary voltage. v and _1γ, also The sum of the _{I delta} * and delta _{I delta} as the target value v _{I delta} of δ-axis component of the primary voltage, these target values v _{1 gamma,} and controls the power supply voltage on the basis of v _{I delta,} wherein the speed change detection section there rate change When is detected,
The output Δω _s of the voltage fluctuation control amplifier before the speed change occurs is held, and the operation of the voltage fluctuation control amplifier is stopped. When the speed change detection unit detects no speed change, the voltage fluctuation control amplifier A vector control device for an induction motor, wherein the operation is restarted. 7. A d-axis component of a primary current of an induction motor, wherein dq coordinates are rotation coordinates that rotate in synchronization with a power supply angular frequency of the induction motor and have a secondary magnetic flux as a reference axis. Induction motor having means for calculating the target values i _1d * and i _1q * of the q-axis component, and a slip angular frequency calculator for calculating the slip angular frequency based on an arithmetic expression including a set value of the secondary time constant Means for calculating i _1d * includes means for outputting a target value λ _2d * of the d-axis component of the secondary magnetic flux in accordance with the rotor angular frequency of the induction motor, and means for differentiating this λ _2d * Means for calculating i _1d * on the basis of the term, the phase ψ being different from the dq axis by tan ⁻¹ (i _1q * / i _1d *), and the coordinates having the primary current I ₁ as a reference axis. When the the gamma-[delta] coordinate, i _1d *, i _1q * target value of gamma-axis component of the primary current based on i 1γ * (= I ₁₎ A first coordinate conversion unit for calculating the fine the phase [psi, the ratio lambda _2d of lambda _2d * and the excitation inductance M * / M, the command value omega ₀ of the result and power supply angular frequency of the first coordinate conversion unit,
Secondary inductance L _2, the primary resistance R _1, based on the leakage inductance _{L σ, R 1 i 1γ *} + (M 2 / L 2) · ω 0 · (λ
_2d * / M) sinψ is calculated to calculate the target value v _1γ * of the γ-axis component of the primary voltage, and L _σ ω ₀ i _1γ ++
Means for performing a calculation of (M ² / L ₂ ) · ω ₀ · (λ _2d * / M) cosψ to calculate a target value v _1δ * of the δ-axis component of the primary voltage, and a detection value of a primary current of the induction motor _Into the respective axis components i _1γ , i _1δ of the γ-δ coordinate, a target value i _1δ * of the δ-axis component of the primary current, and i _1δ from the second coordinate converter. A proportional element that obtains a product of the current deviation of the current deviation over time and the leakage inductance L _σ as a proportional term output, and an integral element that outputs a value obtained by integrating the current deviation as an integral term output, The sum of the proportional term output and the integral term output is represented by v _1δ in the δ-axis component of the current primary voltage.
* Outputs a voltage change Delta] v _{I delta} from, based on the integral term output a current control amplifier to output as Delta] v _1DerutaI, the i _{1 gamma} * and the second i _{1 gamma} than the coordinate conversion unit, the current of the primary Means for calculating a variation Δv _1γ from v _1γ * in the γ-axis component of the voltage; an integral term output Δv _1δI of the current control amplifier;
Inputs the deviation between the target value zero _1DerutaI, the voltage change control amplifier for outputting a variation luck [Delta] [omega _s from the target value omega _{s *} slip angular frequency, on the basis of the speed detection signal of the motor, the speed variation a speed change detection section that detects the presence or absence provided, the target value of the slip angular frequency added value of omega _{s *} and obtained in [Delta] [omega _s and slip angular frequency calculation unit than the voltage change control amplifier, v _{1 gamma} * and the sum of the Delta] v _{1 gamma} to the target value v _{1 gamma} of γ-axis component of the primary voltage and v _{I delta} * and Δ the sum of the _{I delta} as the target value v _{I delta} of δ-axis component of the primary voltage, these target values v Controlling the power supply voltage based on _1γ , v _{1δ, and} when the speed change detecting unit detects that there is a speed change,
Based on the output [Delta] [omega _s and slip angular frequency omega _s of the voltage change control amplifier before speed change _{occurs, 1 + Kn = ω s /} ω s *
(Where Kn is the secondary resistance change at an arbitrary time) to calculate the secondary resistance change K, and calculate the secondary resistance change K
And R _2n * = (1 + Kn) · R _2n-1 * (where R _2n *
Calculates the secondary resistance target value at an arbitrary point in time), changes the setting of the secondary resistance target value R ₂ * of the slip angular frequency calculation unit, and then stops the calculation of the voltage fluctuation control amplifier. Restarting the operation of the voltage fluctuation control amplifier when detecting that there is no speed change. 8. A means for calculating Δv _1γ calculates a temporal change rate of a current deviation between i _1γ * and i _1γ from the second coordinate conversion unit, and calculates a product of the rate and a leakage inductance L _σ. And a integral element that outputs a value obtained by integrating the current deviation as an integral term output, and calculates the sum of the proportional term output and the integral term output as the γ-axis of the current primary voltage. A current control amplifier that outputs as a voltage variation Δv _1γ from v _1γ * in the component and outputs the integral term output as Δv _1γI , Δv _1γI during no-load operation, a primary resistance set value R ₁ * and
Based on i _1d *, the change with respect to the set value of the primary resistance is calculated, and on the basis of Δv _1δI , M *, the secondary self inductance L ₂ *, ω ₀ and λ _2d *, the change with respect to the set value of the excitation inductance. Is calculated, and the calculated value is used as the target value v _1γ *, v of the γ and δ axis components of the primary voltage.
The vector control device for an induction motor according to claim 5, further comprising an identification circuit unit used for an operation performed by the means for calculating _1δ *.