JP3246101B2 - Automatic field current measurement method for DC shunt motor automatic controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic control device for a DC motor, and more particularly to an automatic control device for a field motor which does not cause overvoltage or hunting in a field current supply circuit. Can supply magnetic current automatically,
The present invention relates to a method for automatically measuring a field current for a DC shunt motor automatic controller that is optimal for creating a rotation speed versus a field current table.

[0002]

2. Description of the Related Art A conventional industrial machine, for example, an automatic control device for a DC shunt motor (hereinafter abbreviated as a motor) such as a thyristor leonard used for driving a rolling roll of a hot rolling machine or a drawing roll in a continuous casting machine. The control of the field current is configured, for example, as shown in FIG. In FIG. 6, reference numeral 11 denotes a control device including the field current control function, which outputs a rotational speed command of the electric motor 6 coupled to a load 20, for example, a rolling roll of a hot rolling device. The armature voltage control function 12
The armature voltage is created in the
A. The armature voltage control function 12 includes a servo function and a power output function, and maintains an armature voltage appropriately and supplies an armature current corresponding to a load. The rotation speed command is compared with a rotation speed signal of the motor 6 transmitted from a rotation speed sensor 7 which is coupled to the motor 6 and measures the rotation speed. 14 is input. The output of the amplifying function 14 is compared with a field current value supplied to a field winding 6F of the electric motor 6, and a deviation component is input to a second amplifying function 15 having an integrating function. The output of the amplification function 15 is power-amplified by the third amplification function 19 and supplies a field current to the field winding 6F. This field current value is fed back to the input of the second amplification function 15 as described above.

[0003]

According to the field current control method as described above, since the amplification function having the two-stage integration function is connected, the response delay is large, and therefore the load fluctuation is reduced. At times, there is a problem that the supply field current value may overshoot. The present invention solves the above-mentioned problems (problems) of the prior art, and provides an electric motor (DC shunt motor) with good responsiveness and optimal rotation for an automatic control device of a DC shunt motor that enables stable rotation speed control. It is an object of the present invention to provide a method of automatically measuring a field current for a DC shunt motor automatic controller for creating a speed versus field current table.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method of automatically measuring a field current for a DC shunt motor automatic control device according to the present invention comprises: For the DC shunt motor in a loaded state, the armature of the DC shunt motor supplies a voltage preset according to the rotation speed from the base rotation speed to the maximum rotation speed of the DC shunt motor, A rotation speed command value that automatically changes at a constant pitch from the base rotation speed to the maximum rotation speed is input to a control element configured by an amplification function having an integration function, and the DC current is used as a field current value as an operation amount. Automatically controls the rotation speed of the shunt motor,
The field current value at each command rotation speed of the DC shunt motor at the constant pitch is automatically measured, and the field current value corresponding to each command rotation speed is automatically recorded sequentially.

[0005]

Since the present invention is constructed and functions as described above, a table for recording field current values corresponding to respective command rotational speeds can be easily created. Therefore, by reading out the field current value from the table created based on the present invention in accordance with the rotation speed command signal of the electric motor and using it as a field current control signal, a stable and responsive motor (DC The rotation speed of the shunt motor can be controlled.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for automatically measuring a field current for an automatic control device of a DC shunt motor (abbreviated as a motor) according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of a functional configuration to which the present invention is applied, and the same reference numerals are given to the same component functions as those of FIG. 6 described in the related art. Also, among the respective element functions shown in FIG. 1, the mechanism device and the armature 6A of the electric motor 6,
Except for the power supply for supplying a current to the field winding 6F and the analog signal part of the current value measurement signal, the functions incorporated in the computer are shown. In FIG. 1, reference numeral 1 denotes a control function for system control including a rotation speed control function of the electric motor. The motor 6 is set in a no-load state, and the control function 1
When the rotation speed control function is set to the measurement mode, a measurement start signal is output to the measurement signal creation function 2.
The measurement start signal output from the control function 1 is input to the armature voltage control function 10. Armature voltage control function 10
As a result, an armature voltage of a preset predetermined value covering from the base rotation speed to the maximum rotation speed of the electric motor 6 is created and supplied to the armature winding 6A of the electric motor 6. The rotation speed command signal output from the measurement signal creation function 2 is coupled to the motor 6 and compared with the rotation speed signal of the motor 6 transmitted from the rotation speed sensor 7 for measuring the rotation speed.
The deviation component is input to a first amplification function 4 having an integration function. The rotation speed command signal is also input to the recording function 3. The output of the first amplifying function 4 is compared with the field current value supplied to the field winding 6F of the electric motor 6, and the deviation component is set to the second value.
Are input to the amplification function 5. The output of the amplifying function 5 creates a gate signal by a gate signal creating function 8 and inputs this gate signal to an output function 9 having a thyristor rectifier circuit to control the thyristor. Output function 9 is field winding 6F
Is supplied with a field current. This field current value is fed back to the input of the second amplification function 5 as described above. The field current value is input to the recording function 3. FIG. 1 omits illustration of circuit relationships that are not directly related to the description of the present invention, such as a load mechanism and a power-related circuit coupled to the electric motor 6 and its component devices.

The operation of the configuration function shown in FIG. 1 will be described with reference to FIGS. 2, 3 and 4. FIG. 2 shows the operation flow, FIG. 3 shows the time on the horizontal axis, and the vertical axis shows the rotational speed command signal output from the measurement signal generation function 2 corresponding to the time flow shown on the horizontal axis. I have. When the control function 1 is set to the measurement mode, the control function 1 outputs a measurement start signal to the measurement signal creation function 2 and the armature voltage control function 10. Measurement signal creation function 2 with measurement start signal input
Figure 2, as shown in FIG. 3, the first amplification function 4 having a recording function 3 and the integrating function the rotational speed command signal indicative of the rotational speed n ₁ to specify the base rotational speed of the motor at time t ₁ Output to The first amplification function 4 compares a rotation speed command signal at its input portion with a rotation speed signal of the electric motor 6 transmitted from the rotation speed sensor 7, and amplifies and integrates a deviation component. An output signal of the first amplification function 4 is input to a second amplification function 5 having an integration function. The second amplifying function 5 compares an output signal of the first amplifying function 4 with a field current value supplied to a field winding 6F of the electric motor 6 at an input section, and amplifies and integrates a deviation component. . The output of the amplifying function 5 creates a gate signal in accordance with a condition set in advance by a gate signal creating function 8 and inputs it to an output function 9 having a thyristor rectifier circuit to control the thyristor. The output function 9 supplies a field current to the field winding 6F. This field current value is fed back to the input of the second amplification function 5 as described above. The armature voltage control function 10 to which the measurement start signal is input has a thyristor rectifier circuit for supplying a predetermined voltage and current to the armature winding 6A of the electric motor 6 and a feedback control function. The armature voltage of the value is supplied to the armature winding 6A of the electric motor 6. Accordingly, the motor 6 is stably rotated at a rotational speed n _1. Since the field current value is also input to the recording function 3, the recording function 3
By corresponding recording the rotational speed command signal n ₁ being fed. Further, the measurement signal creation function 2 outputs the rotation speed command signal n ₂ at time t ₂ and records the rotation speed command signal n ₂ in the recording device in the same manner as described above. Also, the rotation speed command signal n ₂
The field current value supplied to the electric motor 6 rotating according to the above is recorded in the recording device 3 in accordance with the rotational speed n ₂ . Maximum rotational speed n of the motor 6 at time t _n the above-described operation is continuously
_n is output from the measurement signal creation function 2, and the field current value at the rotation speed is recorded in the recording function 3 together with the rotation speed. When the field current value at the maximum rotational speed n _n is recorded together with the rotational speed signal, the measurement mode is completed. Therefore, the rotation speed n of the electric motor as shown in FIG.
Field current characteristic curve from ₁ to n _n is recorded in the measurement pitch in accordance with the set conditions in the measurement signal creation function 2,
A table showing the rotation speed versus field current characteristics is created and recorded in the recording function 3. The recording rotation speed pitch of the rotation speed versus field current characteristic table recorded in the recording function 3 is determined by the control accuracy of the motor rotation speed required during the actual operation of the system. The field current value at the gap rotation speed may be obtained by a calculation process using linear approximation.

[0008] When the measurement mode is completed and the system including the electric motor 6 is operated, the control function 1 is set to the operation mode. Further, the functional configuration shown in FIG. 1 is switched to the functional configuration shown in FIG. 5 are the same as those in FIG. In FIG. 5, when the control function 1 outputs a rotation speed command signal corresponding to the condition of the system including the electric motor 6, the recording function 3 reads out a field current value corresponding to the commanded rotation speed and feeds back the field current value. The difference signal is compared with the field current value, and the deviation signal is input to an amplification function 5 having an integration function. The output of the amplifying function 5 controls the gate signal generating function 8 and the output function 9 to output the field current to the field winding 6F.
To supply. The rotation speed command signal output from the control function 1 is input to the armature voltage control function 10, and the armature voltage control function 10 supplies a predetermined voltage to the armature winding 6A. Therefore, the electric motor 6 is driven by the load 20 at the commanded rotational speed.
Drive the rotation of.

The above description shows a basic embodiment based on the present invention, and can be variously modified. For example, in the above-described embodiment, the description has been made such that the functions other than the analog function are executed by computer processing. However, the functions may be appropriately configured by a hardware circuit. In addition, the type and state of the signal output from the control function 1 may be appropriately set according to the characteristic conditions configured in the measurement signal creation function 2 and the armature voltage control function 10. In addition, it is natural that the configuration at the time of measurement can be changed according to the configuration state of the element functions of the motor control system.

[0010]

Since the present invention functions as described above, it has the following excellent effects. The rotation speed versus field current value characteristics of the DC shunt motor can be automatically and easily measured at a constant pitch from the base rotation speed to the maximum rotation speed. Control can be performed stably with good responsiveness by the rotational speed versus field current value characteristics measured during the load operation of the DC shunt motor. By using the measured and stored rotation speed versus field current value table, there is no danger of overvoltage occurring in the field winding circuit.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram illustrating a functional configuration example to which the present invention is applied.

FIG. 2 is a schematic flowchart illustrating the present invention.

FIG. 3 is a time change diagram of a rotation speed command signal for explaining the present invention.

FIG. 4 is a graph showing a relationship between a rotation speed of a motor and a field current value for explaining the present invention.

FIG. 5 is a schematic block diagram showing a functional configuration example of a motor control device to which the rotational speed-field current value characteristic obtained by the present invention is applied.

FIG. 6 is a schematic block diagram illustrating a functional configuration example of a conventional motor control device.

[Explanation of symbols]

 1: Control function 2: Measurement signal creation function 3: Recording function 4, 5: Amplification function 6: Motor 6A: Armature winding 6F: Field winding 8: Gate signal creation function 9: Output function 10: Armature voltage Control function

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02P 5/00-5/26 H02P 7/00-7/34 G05D 13/62 G05B 23/02 301 G05D 13/62

Claims (1)

(57) [Claims] The automatic control system of claim 1 DC shunt-wound motor, against the DC shunt-wound motor unloaded condition, the DC
The base winding of the DC shunt motor is attached to the armature of the shunt motor.
Set in advance according to the rotation speed from the rotation speed to the maximum rotation speed.
Supplies a constant voltage, maximum times from the base rotational speed
Rolling the rotational speed command value for automatically changed at a constant pitch in until the speed input to the control element constituted by an amplification function having an integrating function, the linear field current value as the manipulated variable
The rotational speed of the flow shunt-wound motor is automatically controlled, the constant pitch
A DC shunt motor characterized in that a field current value at each command rotation speed of the DC shunt motor is automatically measured and a field current value corresponding to each command rotation speed is automatically recorded sequentially. Automatic field current measurement method for automatic control devices.