JP4346574B2 - Servo motor control device - Google Patents

Description

  The present invention relates to a control device that drives a servo motor, and more particularly to a servo motor control device that effectively uses reluctance torque generated in the motor.

  A block diagram of a conventional servo motor control system is shown in FIG. The servo motor control system 100 is a system that controls the actual rotational speed ω that is the motor speed of the motor 115 and the speed command value ω * by the three-phase AC voltages U, V, and W according to the speed command value ω *. It is. Servo motor control system 100 includes subtracters 101, 104, 106, 108, 110, PI controllers 102, 105, 109, current command calculation unit 103, non-interference controller 107, dq / 3φ converter 117, and power converter. 111, a counter 112, a 3φ / dq converter 113, a current detector 114, a servo motor 115, and a speed detector 116.

Hereinafter, the operation of the servo motor control system 100 will be described.
The subtractor 101 outputs a deviation between the speed command value ω * and the actual rotational speed ω from the speed detector 116 that detects the speed of the servo motor 115, and the PI controller 102 inputs the deviation and performs PI. The calculation is performed and the torque command value τ * is output. The current command calculation unit 103 receives the torque command value τ *, the actual rotational speed ω, and the torque-sharing current feedback Iq from the 3φ / dq converter 113, performs current command calculation, and outputs the torque-sharing current command value Iq *. And the excitation current command value Id * is output.

  The dq / 3φ converter 117 inputs the q-axis voltage command value Vq *, the d-axis voltage command value Vd *, and the angle θ from the counter, performs dq / 3φ conversion, and performs a three-phase AC voltage command value Vu *. , Vv *, Vw * are output. Here, the q-axis voltage command value Vq * is a deviation between the signal sent through the subtractor 104 and the PI controller 105 and the feedforward compensation voltage Vqy from the non-interference controller 107. The d-axis voltage command value Vd * is a deviation between the signal that has passed through the subtractor 108 and the PI controller 109 and the feedforward compensation voltage Vdy from the non-interference controller 107. Further, the angle θ is an output signal from the counter 112 to which the actual rotational speed ω is input.

  The power converter 111 receives the three-phase AC voltage command values Vu *, Vv *, Vw *, performs power conversion, amplifies, and supplies the servomotor 115 with the three-phase AC voltages U, V, W. The current detector 114 detects the three-phase AC current values iu and iv in the three-phase AC voltages U, V, and W supplied to the servo motor 115. The 3φ / dq converter 113 receives the three-phase alternating current values iu and iv, performs 3φ / dq conversion, outputs the excitation current feedback Id to the subtractor 108, and outputs the torque current feedback Iq to the subtractor 104 and the current. Output to the command calculation unit 103.

  In this conventional servo motor control system, the current command calculation unit 103 calculates the excitation current command value Id * so that the current phase angle of the servo motor 115 is constant, and the excitation current command value Id *, electric element Torque component current command value Iq * is calculated using the interlaced magnetic flux, the q-axis inductance, the d-axis inductance, and the actual rotational speed ω (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-92984 (paragraphs [0009] to [0013], FIGS. 1 to 4 and FIG. 6)

  However, conventionally, in order to obtain a predetermined torque, it is necessary to preset the current phase angle as a parameter having a known value. For this reason, it was necessary to perform a load test for confirming the characteristics of the servo motor and measure the current phase angle.

  Conventionally, the maximum torque phase control is realized by calculating the torque component current command value Iq * based on the torque component current feedback Iq. For this reason, there is a possibility that a measurement error, a detection delay, etc. may occur when calculating the torque current command value Iq *.

  Conventionally, the calculation of the torque component current command value Iq * has been performed in consideration of only the magnet torque as the rated torque. Generally, the rated torque is composed of elements of magnet torque and reluctance torque. For this reason, in order to realize the linearization of the torque, it is necessary to effectively use the reluctance torque.

  Further, conventionally, the excitation current command value Id * has not been calculated based on the actual voltage obtained by converting and feeding back the voltage supplied to the servomotor, so that the terminal voltage suppression control of the servomotor could not be realized. For this reason, depending on the state of the servo motor control device, the three-phase AC voltages U, V, and W may exceed the motor rated voltage.

Therefore, in order to solve the above problems, the object of the present invention is to
(1) There is no need to measure the current phase angle in advance,
(2) No measurement error or detection delay occurs when calculating the torque current command value Iq *,
(3) Realizing torque control that effectively utilizes reluctance torque,
(4) Servo motor terminal voltage suppression control can be realized.
The object is to provide a servo motor control device.

In order to achieve the above object, a servo motor control device according to the present invention inputs a torque command value and an actual rotational speed that is the rotational speed of the servo motor, and calculates an excitation current command value and a torque component current command value. In a servo motor control device that includes a calculation unit and controls the servo motor based on the excitation current command value and the torque-divided current command value, the current command calculation unit inputs an actual voltage obtained by converting the voltage supplied to the servo motor. A first calculation means for calculating a first command value based on the actual voltage and a preset rated voltage, and an excitation current command value and a torque component current command value calculated by the current command calculation unit. And the second current based on the excitation current command value, the torque component current command value, and the preset d-axis reactance, q-axis reactance, the rated voltage, and the induced voltage. Second calculation means for calculating a value, excitation current command value calculation means for calculating an excitation current command value based on the first command value and the second command value, and an actual rotational speed of the servo motor are input. A third calculation means for calculating a third command value based on the actual rotation speed and a preset base rotation speed, an excitation current command value calculated by the current command calculation section, and the torque command Value, the excitation current command value, the torque command value, a constant representing the excitation current command value when the rated torque is output at the base rotational speed, the d-axis reactance, the q-axis reactance, the rated voltage, and the induced voltage. On the basis of the following formula , the rated torque τ _{0 includes the} magnet torque and the reluctance torque:
τ ₀ = Pm × Φf × I ₀ × (1-λ ⁻¹ × Id0_) × √ (1-Id0 — ² )
(Where Pm is the number of poles, I ₀ is the two-phase rated current, Id0_ is a constant obtained by normalizing the excitation current command value when the rated torque is output at the base rotational speed, and Φf and λ ⁻¹ are respectively It shall be represented by
Φf = E ₀ / (Pm × ω ₀ )
λ ⁻¹ = (Xq−Xd) × (V ₀ / E ₀ )
Here, E ₀ is an induced voltage, ω ₀ is a base rotational speed, Xq is a q-axis reactance, Xd is a d-axis reactance, and V ₀ is a rated voltage. )
Derived from
Iq1 = τ * × (1-λ− ¹ × Id0) × √ (1-Id0 ² ) / (1-λ− ¹ × Id *)
(Here, Iq1 is the fourth command value, τ * is the torque command value, and Id * is the excitation current command value.)
And a fourth calculation means for calculating a fourth command value, a torque divided current command value calculation means for calculating a torque divided current command value based on the third command value and the fourth command value, and It is characterized by having .

In the servo motor control device according to the present invention, the current command calculation unit further has a relationship between the d-axis reactance and the excitation current command value and a relationship between the q-axis reactance and the torque current command value in advance. A table in which these data are measured and stored, and the second calculation means inputs the excitation current command value and the torque current command value calculated by the current command calculation unit, and the excitation current The d-axis reactance corresponding to the command value and the q-axis reactance corresponding to the torque component current command value are read from the table, the excitation current command value and the torque component current command value, and the read d-axis reactance and q axis. The second command value is calculated based on the reactance, the rated voltage, and the induced voltage .

In the servo motor control device according to the present invention, the second calculation means inputs the excitation current command value and the torque component current command value calculated by the current command calculation unit, and d corresponding to the excitation current command value. The axis reactance and the q-axis reactance corresponding to the torque current command value are read from the table, the torque command value, and a constant representing the excitation current command value when the rated torque is output at the base rotational speed, The second command value is calculated based on the third command value calculated by the third calculation means, the read d-axis reactance and q-axis reactance, and the rated voltage and the induced voltage. To do.

  As described above, according to the present invention, since the excitation current command value is calculated without using the current phase angle, there is no need to measure the current phase angle in advance. Further, since the torque component current command value is calculated without using the torque component current feedback, no measurement error or detection delay due to the torque component current feedback occurs.

  In addition, by performing a linearization calculation in consideration of the reluctance torque, it is possible to obtain a torque current command value proportional to the torque command value, so that the reluctance torque can be effectively utilized. Moreover, since the excitation current command value is calculated using the actual voltage, the terminal voltage suppression control of the servo motor can be realized.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a system configuration diagram showing a servo motor control system including a servo motor control apparatus according to the present invention. The servo motor control system 1, in addition to the configuration of the conventional servo motor control system 100 includes a voltage converter 3 in that it includes a voltage command calculation unit 2 according to the present invention instead of the current command calculator 103 This is different from the conventional servo motor control system shown in FIG. In the following, in FIG. 1, the same reference numerals as those in FIG.

The servo motor control apparatus according to the present invention corresponds to a portion of the configuration of the servo motor control system 1 excluding the servo motor 115 and the speed detector 116. The voltage converter 3 inputs three-phase AC voltages U, V, and W supplied to the servo motor 115, performs 3φ / dq voltage conversion, generates excitation voltage feedback and torque component voltage feedback, and generates an actual voltage V ( Excitation voltage feedback) is output to the current command calculation unit 2. The current command calculation unit 2 inputs the torque command value τ *, the actual rotational speed ω that is the motor speed, and the actual voltage V, and uses the d-axis reactance Xd and the q-axis reactance Xq, and the excitation current command value Id * and Motor control is realized by calculating the torque component current command value Iq *. In the first embodiment described below, fixed values set in advance are used as the d-axis reactance Xd and the q-axis reactance Xq. In the second embodiment, the relationship between the d-axis reactance Xd and the excitation current command value Id * and the relationship between the q-axis reactance Xq and the torque current command value Iq * are measured in advance and stored in a table. The values in the table are used as the d-axis reactance Xd and the q-axis reactance Xq. In the third embodiment, table values are used as the d-axis reactance Xd and the q-axis reactance Xq as in the second embodiment, and the excitation current command value Id * is calculated so that there is no scan delay. Hereinafter, the first embodiment, the second embodiment, and the third embodiment will be described in detail. Hereinafter, the symbol * indicates a command value.

First, the first embodiment will be described.
FIG. 2 is a block diagram showing a first embodiment of a current command calculation unit used in the servo motor control apparatus according to the present invention. The current command calculation unit 2-1 includes an I calculator 11, an Id 1 calculator 12, an adder 13, a subtractor 14, a PI controller 15 with limit, an Iq 1 calculator 16, a multiplier 17, an absolute value converter 18, A proportional output device 19 with a limit and a divider 20 are provided. The current command calculation unit 2-1 receives the torque command value τ * from the PI controller 102 shown in FIG. 1, the actual rotational speed ω from the speed detector 116, and the actual voltage V from the voltage converter 3, respectively. An excitation current command value Id * and a torque component current command value Iq * are calculated from λ and λ ⁻¹ calculated using the d-axis reactance Xd and the q-axis reactance Xq which are preset fixed values, and the excitation current The command value Id * is output to the subtractor 104, and the torque current command value Iq * is output to the subtractor 108. When this current command calculation unit 2-1 and the current command calculation unit 103 shown in FIG. 6 are compared, the difference is that the current command calculation unit 2-1 inputs the actual voltage without inputting the torque current feedback Iq. To do.

Ｉｄ１演算器１２は、Ｉ演算器１１から電流値Ｉを入力し、以下の演算を行い、Ｉｄ１を出力する。

ここで、式（２）のλ，λ^−２は、以下の式により演算された値である。この場合、ｄ軸リアクタンスＸｄ及びｑ軸リアクタンスＸｑは、予め設定された固定値である。

ここで、Ｖ_０は定格電圧、Ｅ_０は誘起電圧であり、それぞれ予め設定された固定値である。 The I calculator 11 inputs the excitation current command value Id * from the adder 13 and the torque current command value Iq * from the multiplier 17, respectively, performs the following calculation, and outputs the current value I.

The Id1 calculator 12 receives the current value I from the I calculator 11, performs the following calculation, and outputs Id1.

Here, λ and λ ⁻² in equation (2) are values calculated by the following equation. In this case, the d-axis reactance Xd and the q-axis reactance Xq are preset fixed values.

Here, V ₀ is a rated voltage, and E ₀ is an induced voltage, which are preset fixed values.

The subtractor 14 receives the rated voltage V ₀ and the actual voltage V from the voltage converter 3, subtracts the actual voltage V from the rated voltage V ₀ , and outputs a deviation that is a result of the subtraction. The PI controller 15 with a limit receives the deviation from the subtracter 14, performs a proportional-integral calculation so as to be within a predetermined setting range, and outputs the result Id2.

  The adder 13 receives Id1 from the Id1 calculator 12 and Id2 from the PI controller 15 with limit, adds Id1 and Id2, and outputs an excitation current command value Id * that is the addition result.

ここで、Ｉｄ０とは、基底回転数ω_０で定格トルクを出力するときの励磁電流指令値Ｉｄ＊であり、以下の式により予め設定された固定値である。また、λ^−１は式（３）により演算される値である。

ここで、λ，λ^−２は式（３）により演算される値である。 On the other hand, the Iq1 calculator 16 receives the excitation current command value Id * from the adder 13, the torque command value τ * from the PI controller 102, and Id0 which is a preset fixed value, and performs the following calculation. And output Iq1.

Here, Id0 is the excitation current command value Id * when the rated torque is output at the base rotational speed ω ₀ , and is a fixed value set in advance by the following equation. Also, λ ⁻¹ is a value calculated by equation (3).

Here, λ and λ ⁻² are values calculated by the equation (3).

The absolute value converter 18 receives the actual rotational speed ω from the speed detector 116, performs absolute value conversion, and outputs the absolute value of the actual rotational speed ω. The proportional output device 19 with a limit inputs the absolute value of the actual rotational speed ω from the absolute value converter 18, and when the absolute value is smaller than a predetermined value, a constant value is obtained. Outputs each value proportional to the value. The divider 20 receives the output from the limited proportional output device 19 as a base rotation speed ω ₀ which is a preset fixed value, divides the output by ω ₀ , and obtains Iq2 as a result of the division. Output.

  The multiplier 17 receives Iq1 from the Iq1 calculator 16 and Iq2 from the divider 20, multiplies Iq1 and Iq2, and outputs a torque current command value Iq * as a result of the multiplication.

By the way, the above-described equation (4) for calculating the torque component current command value Iq1 is an equation in which the reluctance torque is considered in the rated torque τ ₀ . Hereinafter, Formula (4) will be described in detail. Torque component current command value Iq1 (in the following description, Iq *) is generally calculated by the following equation. In the description up to deriving Expression (4), _ (underscore) is added to the normalized data. Further, τ, Iq, Id, Ld, and Lq respectively indicate torque, torque component current command value, excitation current command value, d-axis inductance, and q-axis inductance before normalization.
Iq = τ / (((Ld−Lq) × Id + Φf) × Pm)
= Τ / ((Φf− (Lq−Ld) × Id) × Pm)
Here, Lq and Ld are normalized by I ₀ (2-phase rated current) = (3/2) × I ₁ (3-phase rated current) and V ₀ (rated voltage),
Lq = Lq_ × V ₀ / I ₀
Ld = Ld_ × V ₀ / I ₀
And Further, Iq and Id are normalized by I ₀ ,
Iq = Iq_ × I ₀
Id = Id_ × I ₀
And Also, normalize τ by τ ₀ (rated torque),
τ = τ_ × I ₀ × τ ₀
And Moreover, when Φf uses E ₀ (induced voltage (reverse phase electromotive voltage)),
Φf = E ₀ / (Pm × ω ₀ )
And
Iq_ = τ_ × (τ ₀ / I ₀ ) / ((E ₀ / (Pm × ω ₀ ) − (Lq_−Ld_) × (V ₀ / I ₀ ) × Id_ × I ₀ ) × Pm)
= Τ_ × (τ ₀ / I ₀ ) / ((E ₀ / ω ₀ ) − (Lq_−Ld_) × V ₀ × Pm × Id_)
Here, from equation (3),
λ ⁻¹ = (Lq_−Ld_) × Pm × ω ₀ / (E ₀ / V ₀ )
Then,
Iq_ = τ_ × (τ ₀ ω ₀ / E ₀ I ₀ ) / (1-λ ⁻¹ × Id_)
(Τ ₀ ω ₀ / E ₀ I ₀ ) remains.

When the rated torque τ ₀ is only the magnet torque, τ ₀ = Pm × Φf × I ₀ and (τ ₀ ω ₀ / E ₀ I ₀ ) = 1. The torque component current command value Iq * is calculated by the following formula by the current command calculation unit 103 of FIG. 6 described in the background art.
Iq_ = τ_ × (τ ₀ ω ₀ / E ₀ I ₀ ) / (1-λ ⁻¹ × Id_)
That is, using * indicating the command value,
Iq * = τ * × (τ ₀ ω ₀ / E ₀ I ₀ ) / (1-λ ⁻¹ × Id *)
It becomes.

On the other hand, when the rated torque τ ₀ is the magnet torque and the reluctance torque, that is, when the reluctance torque is considered in the rated torque τ ₀ ,
_{τ 0 = Pm × Φf × I} 0 × (1-λ -1 × Id0 _) × √ (1-Id0 _ 2)
And
_{(Τ 0 ω 0 / E 0} I 0) = (1-λ -1 × Id0 _) × √ (1-Id0 _ 2)
It becomes. In other words,
Iq_ = τ_ × ((1- λ -1 × Id0 _) / (1-λ -1 × Id _)) × √ (1-Id0 _ 2)
It becomes. Here, the * indicates a command value, the Iq_ and Iq *, the τ_ and tau *, and Id0 the id_, when a and Id * id_, the torque current command in consideration of the reluctance torque to the rated torque tau ₀ The equation for calculating the value Iq * (Iq1) is the aforementioned equation (4). This means that the Iq1 calculator 16 calculates the torque current command value Iq1 in consideration of the reluctance torque in the rated torque τ ₀ .

Thus, according to the first embodiment of the present invention, the current command calculation unit 2-1 of the servo motor control device inputs the torque command value τ *, the actual rotational speed ω, and the actual voltage V, The excitation current command value Id * and the torque current command value Iq * are calculated using the preset d-axis reactance Xd and q-axis reactance Xq. The d-axis reactance Xd and the q-axis reactance Xq are specification values of the servo motor 115, for example, values specified in advance from the manufacturer of the servo motor 115 at the time of purchase. Thus, the current command calculation unit 2-1 does not calculate using the current phase angle, so there is no need to set the current phase angle in advance. That is, since it is not necessary to perform a load test for characteristic confirmation for measuring the current phase angle, it is possible to save time and effort for performing the load test.

  Further, since the current command calculation unit 2-1 does not perform calculation using the torque component current feedback Iq, no measurement error or detection delay due to the torque component current feedback Iq occurs.

In addition, since the Iq1 calculator 16 of the current command calculation unit 2-1 calculates Iq1 by the above-described formula (4), it can perform a linearization calculation on the torque command value τ *, A calculation considering the reluctance torque can be performed on the rated torque τ ₀ . Therefore, the reluctance torque can be effectively utilized. In this case, when the servo motor 115 is small, a large torque can be obtained by effectively utilizing the reluctance torque, so that rapid acceleration / deceleration of the motor can be realized. Therefore, it is suitable not only for a servo motor control apparatus but also for an automobile mission test apparatus that requires rapid acceleration / deceleration control, for example.

  In addition, since the current command calculation unit 2-1 calculates the excitation current command value Id * based on the actual voltage V, continuous terminal voltage suppression control of the servo motor 115 can be realized. That is, the three-phase AC voltages U, V, and W do not exceed the motor rated voltage.

Next, a second embodiment will be described.
In the first embodiment described above, the d-axis reactance Xd and the q-axis reactance Xq shown in Expression (3) are preset fixed values. These fixed values are specified by the manufacturer of the servo motor 115, but the manufacturer cannot always grasp these values accurately, so it cannot be said to be an accurate value. Therefore, in the second embodiment, in the test operation mode, the relationship between the d-axis reactance Xd and the excitation current command value Id * and the relationship between the q-axis reactance Xq and the torque current command value Iq * are preliminarily determined. The measurement was stored in a table, and the d-axis reactance Xd and the q-axis reactance Xq stored in the table were used in the actual operation mode.

  FIG. 3 is a block diagram showing a second embodiment of the current command calculation unit used in the servo motor control apparatus according to the present invention. The current command calculation unit 2-2 includes a table 21 and a λ calculator 22 in addition to the configuration of the current command calculation unit 2-1 illustrated in FIG. In FIG. 3, the same reference numerals as those in FIG. 2 are given to portions common to FIG. 2, and detailed description thereof is omitted.

ここで、Ｐ_０は同定定数、cemfは誘起電圧Ｅ_０である。このようにして、試運転モードのときにテーブル２１が作成される。 First, when the servo motor control device is in the test operation mode, the current command calculation unit 2-2 receives the excitation current feedback Id and the torque component current feedback Iq from the 3φ / dq converter 113, and the excitation voltage feedback Vd from the voltage converter 3. And the actual voltage ω are input from the speed detector 116 (not shown). The means (not shown) of the current command calculation unit 2-2 identifies the resistance value r and the d-axis reactance Xd by no-load operation or the operation of the servo motor 115 alone, and determines the q-axis reactance Xq as the above-described resistance value r. And d-axis reactance Xd is used for identification by normal load operation. That is, the means (not shown) of the current command calculation unit 2-2 performs the following calculation by sequentially identifying parameters by the least square method, measures the resistance value r, the d-axis reactance Xd, and the q-axis reactance Xq, and the d-axis reactance. The relationship between Xd and the excitation current command value Id * and the relationship between the q-axis reactance Xq and the torque current command value Iq * are obtained and stored in the table 21.

Here, P ₀ is an identification constant, and cemf is an induced voltage E ₀ . In this way, the table 21 is created in the trial operation mode.

FIG. 4 is a graph showing the relationship between the d-axis reactance Xd and the excitation current command value Id * and the relationship between the q-axis reactance Xq and the torque component current command value Iq *. The means (not shown) of the current command calculation unit 2-2 stores the data shown in FIG. In FIG. 4, it can be seen that the d-axis reactance Xd changes when the excitation current command value Id * changes, and the q-axis reactance Xq also changes when the torque current command value Iq * changes.

When the servo motor control device is in the actual operation mode, the excitation current command value Id * and the torque component current command are used using the d-axis reactance Xd and the q-axis reactance Xq stored in the table 21 with the configuration shown in FIG. The value Iq * is calculated. This will be specifically described below.

Returning to FIG. 3, the λ calculator 22 reads the d-axis reactance Xd from the table 21 on the basis of the excitation current command value Id * from the adder 13, and sets the torque component current command value Iq * from the multiplier 17. Based on this, the q-axis reactance Xq is read from the table 21. The λ calculator 22 performs the following calculation and outputs λx.

The Id1 calculator 12 receives the current value I from the I calculator 11 and λx from the λ calculator 22, performs the following calculation, and outputs Id1.

  The adder 13 receives Id1 from the Id1 calculator 12 and Id2 from the PI controller 15 with limit, adds Id1 and Id2, and outputs an excitation current command value Id * that is the addition result.

尚、λ^−１は、図示しない同定回路により式（３）により演算される固定値であり、最大位相制御における値である。 On the other hand, the Iq1 calculator 16 receives the excitation current command value Id * from the adder 13, the torque command value τ * from the PI controller 102, Id0 which is a preset fixed value, and λx from the λ calculator 22. Each is input, the following calculation is performed, and Iq1 is output.

Note that λ ⁻¹ is a fixed value calculated by Expression (3) by an identification circuit (not shown), and is a value in the maximum phase control.

  The multiplier 17 receives Iq1 from the Iq1 calculator 16 and Iq2 from the divider 20, multiplies Iq1 and Iq2, and outputs a torque current command value Iq * as a result of the multiplication.

As described above, according to the second embodiment of the present invention, the current command calculation unit 2-2 of the servo motor control device receives the torque command value τ *, the actual rotational speed ω, and the actual voltage V, respectively, and d An excitation current command value Id is obtained from a table 21 in which the relationship between the shaft reactance Xd and the excitation current command value Id * and the relationship between the q-axis reactance Xq and the torque current command value Iq * are measured and stored in advance. The d-axis reactance Xd and the q-axis reactance Xq are read according to * and the torque current command value Iq *, and the excitation current command value Id * and the torque current command value Iq * are calculated using these values. . As a result, for example, it is possible to cope with fluctuations in the q-axis reactance Xq due to magnetic flux saturation. In addition to the same effects as in the first embodiment, a more appropriate excitation current command value Id * and torque component current command can be obtained. The value Iq * can be calculated. Further, when realizing the torque linearization according to the equation (9), the accuracy of the linearization can be further improved.

Further, in the test operation mode, the current command calculation unit 2-1 has a relationship between the d-axis reactance Xd and the excitation current command value Id *, and a relationship between the q-axis reactance Xq and the torque current command value Iq *. Was measured in advance and stored in the table 21. Thereby, the d-axis reactance Xd and the q-axis reactance Xq necessary for servo motor control can be measured for each servo motor, and control using appropriate values can be realized.

Next, a third embodiment will be described.
In the second embodiment described above, the I calculator 11 inputs the excitation current command value Id * and the torque component current command value Iq * as feedback, and the Id1 calculator 12 calculates the excitation current command value Id1. The calculation is delayed by one scan. Therefore, in the third embodiment, the Id1 calculator 23 does not feed back and calculates the excitation current command value Id *, but calculates it by feedforward.

FIG. 5 is a block diagram showing a third embodiment of the current command calculation unit used in the servo motor control apparatus according to the present invention. This current command calculator 2-3 is shown in FIG. 3 in that it includes an Id1 calculator 23 instead of the I calculator 11 and the Id1 calculator 12 of the current command calculator 2-2 shown in FIG. The current command calculation unit 2-2 is different. In the following, in FIG. 5, the same reference numerals as those in FIG. In the test operation mode, the relationship between the d-axis reactance Xd and the excitation current command value Id * and the relationship between the q-axis reactance Xq and the torque current command value Iq * are measured in advance and stored in the table 21. In the actual operation mode, the point that the d-axis reactance Xd and the q-axis reactance Xq stored in the table 21 are used is the same as that of the second embodiment shown in FIG.

尚、λ^−１は、図示しない同定回路により式（３）により演算される固定値であり、最大位相制御における値である。 When the servo motor control device is in the actual operation mode, the Id1 calculator 23 receives the torque command value τ * from the PI controller 102, the preset fixed value Id0, and the divider 20 receives ω _Bx that is Iq2. , Λx is input from the λ calculator 22. Here, ω _Bx is a value obtained by dividing the value obtained by limiting the absolute value of the actual rotational speed ω by the base rotational speed ω ₀ by the absolute value converter 18, the proportional proportional output unit 19 and the divider 20. The Id1 calculator 23 calculates Id1 by performing the following calculation, and outputs the Id1.

Note that λ ⁻¹ is a fixed value calculated by Expression (3) by an identification circuit (not shown), and is a value in the maximum phase control.

  The adder 13 receives Id1 from the Id1 calculator 23 and Id2 from the PI controller 15 with limit, adds Id1 and Id2, and outputs an excitation current command value Id * as the addition result.

As described above, according to the third embodiment of the present invention, the current command calculation unit 2-3 of the servo motor control device receives the torque command value τ *, the actual rotational speed ω, and the actual voltage V, respectively. 21 reads out the d-axis reactance Xd and the q-axis reactance Xq in accordance with the excitation current command value Id * and the torque component current command value Iq *, and uses these values to determine the excitation current command value Id * and the torque component current command value Iq. * Was calculated. In this case, the Id1 calculator 23 does not calculate the excitation current command value Id1 by feedback input of the excitation current command value Id * and the torque current command value Iq *, but directly inputs the torque command values τ * and Id0. And calculated by feedforward. Thereby, in addition to the same effects as those of the second embodiment, servo motor control can be realized without causing a scan delay.

  The servo motor control device may be configured by a computer device including a volatile storage medium such as a CPU and a RAM, and a non-volatile storage medium such as a ROM. In this case, the arithmetic unit 11, Id1 arithmetic units 12 and 23, adder 13, subtractor 14, and PI controller with limits provided in the current command calculation units 2-1, 2-2, and 2-3 of the servo motor control device. 15, Iq1 computing unit 16, multiplier 17, absolute value converter 18, proportional output unit 19 with limit, divider 20, table 21, and λ computing unit 22, a program describing these functions is stored in the CPU. Each is realized by executing. These programs can also be stored and distributed in a storage medium such as a magnetic disk (floppy disk, hard disk, etc.), optical disk (CD-ROM, DVD, etc.), semiconductor memory, or the like.

1 is a system configuration diagram showing a servo motor control system including a servo motor control device according to the present invention. It is a block diagram which shows the 1st Example of the current command calculating part used for the servomotor control apparatus by this invention. It is a block diagram which shows the 2nd Example of the current command calculating part used for the servomotor control apparatus by this invention. It is a graph which shows the relationship between d-axis reactance Xd and exciting current command value Id *, and the relationship between q-axis reactance Xq and torque component current command value Iq * . It is a block diagram which shows the 3rd Example of the current command calculating part used for the servomotor control apparatus by this invention. It is a system block diagram which shows the conventional servomotor control system.

DESCRIPTION OF SYMBOLS 1,100 Servo motor control system 2,103 Current command calculating part 3 Voltage converter 11 I calculator 12, 23 Id1 calculator 13 Adder 14 Subtracter 15 Limited PI controller 16 Iq1 calculator 17 Multiplier 18 Absolute value Converter 19 Proportional output device with limit 20 Divider 21 Table 22 λ calculator 101, 104, 106, 108, 110 Subtractor 102, 105, 109 PI controller 107 Non-interference controller 117 dq / 3φ converter 111 Power conversion 112 Counter 113 3φ / dq converter 114 Current detector 115 Servo motor 116 Speed detector

Claims (3)

A torque command value and an actual rotational speed that is the rotation speed of the servo motor are input, and a current command calculation unit that calculates an excitation current command value and a torque-divided current command value is provided. In the servo motor control device that controls the servo motor,
The current command calculation unit is
A first calculation means for inputting a real voltage obtained by converting a voltage supplied to the servo motor and calculating a first command value based on the real voltage and a preset rated voltage;
The excitation current command value and the torque component current command value calculated by the current command calculation unit are input, the excitation current command value, the torque component current command value, preset d-axis reactance, q-axis reactance, Second computing means for computing a second command value based on the rated voltage and the induced voltage;
Excitation current command value calculating means for calculating an excitation current command value based on the first command value and the second command value;
Third calculation means for inputting a real rotation speed of the servo motor and calculating a third command value based on the real rotation speed and a preset base rotation speed;
The excitation current command value calculated by the current command calculation unit and the torque command value are input, and the excitation current command value, the torque command value, and the excitation current command value when the rated torque is output at the base rotational speed On the basis of the constant representing d, the d-axis reactance, the q-axis reactance, the rated voltage, and the induced voltage, the following equation when the rated torque τ ₀ is composed of a magnet torque and a reluctance torque:
τ ₀ = Pm × Φf × I ₀ × (1-λ ⁻¹ × Id0_) × √ (1-Id0 — ² )
(Where Pm is the number of poles, I ₀ is the two-phase rated current, Id0_ is a constant obtained by normalizing the excitation current command value when the rated torque is output at the base rotational speed, and Φf and λ ⁻¹ are respectively It shall be represented by
Φf = E ₀ / (Pm × ω ₀ )
λ ⁻¹ = (Xq−Xd) × (V ₀ / E ₀ )
Here, E ₀ is an induced voltage, ω ₀ is a base rotational speed, Xq is a q-axis reactance, Xd is a d-axis reactance, and V ₀ is a rated voltage. )
Derived from
Iq1 = τ * × (1-λ− ¹ × Id0) × √ (1-Id0 ² ) / (1-λ− ¹ × Id *)
(Here, Iq1 is the fourth command value, τ * is the torque command value, and Id * is the excitation current command value.)
A fourth computing means for computing a fourth command value using
Torque component current command value calculating means for calculating a torque component current command value based on the third command value and the fourth command value;
Servo motor control apparatus characterized by having a. In the servo motor control device according to claim 1,
The current command calculation unit further measures in advance the relationship between the d-axis reactance and the excitation current command value and the relationship between the q-axis reactance and the torque component current command value, and stores these data. Have a table
The second calculation means inputs the excitation current command value and the torque component current command value calculated by the current command calculation unit, the d-axis reactance corresponding to the excitation current command value, and the torque component current command value The q-axis reactance corresponding to the second is read from the table, and based on the excitation current command value and torque component current command value, the read d-axis reactance and q-axis reactance, and the rated voltage and induced voltage, the second A servo motor control device that calculates a command value . In the servo motor control device according to claim 2 ,
The second calculation means inputs the excitation current command value and the torque component current command value calculated by the current command calculation unit, the d-axis reactance corresponding to the excitation current command value, and the torque component current command value The q-axis reactance corresponding to is read from the table, the torque command value, a constant representing the excitation current command value when the rated torque is output at the base rotational speed, and the third calculation means calculated by the third calculation means. 3. A servo motor control device that calculates a second command value based on the command value of 3, the read d-axis reactance and q-axis reactance, and the rated voltage and induced voltage .

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