JPS60191649A - Controlling system for drawing speed of billet in continuous casting installation - Google Patents

Abstract

PURPOSE:To control the drawing speed of a continuous casting installation with high accuracy by controlling independently driving of respective motors for drawing, providing functions for correcting roll diameters to respective speed feedback circuits and balancing the load of the respective motors. CONSTITUTION:The deviation between a common speed command signal VS of a linear commander 12 and the speed feedback signal VF of a speed controller for respective motors M1-Mn is inputted to a speed controller 101. On the other hand, the deviation between the speed feedback signal VR detected by a driving control device for a reference roll and the speed feedback signal VF for the motors M1-Mn is inputted to an integrator 13. The output signal TS thereof is applied as a common torque command to each driving control device. The driving control devices control the speeds of the motors M1-Mn by outputting the sum of the output signal TS from the integrator 13 and the output signal TP from the speed controller as a torque command. The speed change owing to a fluctuation of the roll diameter is thus automatically corrected and the casting speed is controlled with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improvement in the method of controlling the speed of slab withdrawal in continuous equipment.

[Prior art and its problems]

Figure 1 shows a cross-sectional view of a known slab drawing device, in which molten copper is poured into a mold 3 from a ladle 1 via a tundish 2, and is cooled and solidified inside the mold to form a piece. . Then, the - piece 4 is pulled out and conveyed to the roller table 7 by non-driving rolls marked with ◯ marks arranged on both sides of the passage and driving rolls marked with 0 marks driven by the city moving rock.

FIG. 2 shows a conventionally known control circuit for driving each of the drive rolls by a dedicated drive control device, and its construction and operation will be fully explained as follows.

That is, in the conventional method, a common speed command signal VS obtained by inputting the casting speed setting value from the speed setting device 11 to the total linear command device 12, and a speed detection pulse generator PLO connected to the electric motor. The deviation of the output signal from the speed command signal VF obtained through the /J Lus speed converter 106 of the drive control device provided exclusively for the motor is input to the speed controller 101 having a proportional gain characteristic. A system was adopted in which the speed of each drive roll was controlled independently.

In the conventional system, the current control section was lacking.

That is, the output signal of the speed controller 101 is converted into a torque command by the 3-phase instantaneous current command converter 102, and the AC instantaneous current command i+ of each phase of the twh machine is transferred. 'sK conversion, the command value and the motor primary current instantaneous value iF detected by the current detector 105.
By inputting the deviation from s to the total three-phase current controller 103, current control of each phase is performed, and this three-phase current controller 1
A system was adopted in which the output signal of 03 was applied to the VL motor 4 using the power converter 104 to apply the necessary pressure and frequency to operate the electric motor at the specified range and torque.

Therefore, in this method, the multi-layer controller 101 is set to a low proportional gain, and the speed of l:vs' is controlled as the total drooping time, and the vc is controlled so as to balance the entire load of the valley'α However, each drive roll is subjected to a large reaction force due to the static pressure of the unsolidified iron inside the piece 4, so the rolls are likely to wear out, and if the wear becomes too large, it will cause damage to the rolls. The load becomes unbalanced, which not only adversely affects the slab Vc, but also changes the casting speed. The problem was that it made my friend worse.

[Aim of non-invention]

The present invention was developed to solve the above-mentioned problems, and it is possible to balance the load of the Taniden yIJ machine and achieve a high casting speed control with a universal system for controlling the pulling speed of the diagonal. Required if the purpose is to provide.

[Summary of the invention]

In the present invention, each electric motor is controlled by a dedicated drive control device having an independent speed control system, and the quick feedback circuit wrVc of each drive control device has a function of automatically correcting the wear of the roll diameter of the drive roll. Control is performed to match the relationship between the preparatory speed reference roll and other g#I rolls, and the load of the motor is restrained to achieve high-accuracy speed control. It is characterized in that 1+lI control is performed.

[Example of the present invention]

The inventive embodiment shown in FIG. 3 will be described below.

In this embodiment, one drive roll is selected from all the drive rolls, the electric motor that drives it is temporarily Ml, and this i
Pulse signal generator PLO attached to t @ +fi @
The speed detected by , shall be the reference speed of the full extraction drive device.

Then, the casting speed setting value from the speed setting device 11 is input to the linear command device 12, and the output signal of the straight scarlet command device 12 is used as the common speed command signal VS for the drive control device of each electric motor M1 to Mn @tXsx...X Give to Yun. Common speed command signal
vB, speed feedback signal 1i+, output/signal VF of device 107
A speed controller 101 with a proportional gain that lowers the deviation signal from the
Vc is input, and the speed controller 101 receives a torque command signal TPt.
- Output.

'4 If the roll driven by the excitation amount 3 is selected as the reference roll for speed control, the other drive 41 ii
Control itt signal switch 219, 319. n is normally used when VC is in an open condition.

The following VC control is performed until the tip aS of the piece 4 passes the measure roll MR and the speed reference roll diameter correction calculator 191C outputs the first roll diameter correction.

That is, the roll diameter correction value ΔPl held in the roll diameter correction calculator 111 and the roll ladder correction value switching linear command unit 118 are stored as the calculation results from the previous casting. The adder 114 sets the current Norms frequency value F1 to %F1+ as an initial value at the start of speed control.
% speed feedback −1t by calculating Δpl=pm
t-The reference pulse frequency P1 to be determined is determined and the following control is started.

First of all, the pulse signal generators PI and G are attached to the electric number machine MtK.

The signal is input to the pulse frequency converter 106, and its pulse frequency aP is detected. The above-mentioned P and Pt are input to the speed feedback amount calculation unit 107, and the deviation signal between the speed command values Vs and V7 is inputted to the integrator 3 after being calculated based on the speed feedback amount Vyk following formula % formula %.

Then, the output signal of the integrator 13 is set as an all-common torque command 1δ and is applied to each drive control device XjJ1 to X3n.

Then, the signal obtained by adding T8 and TP is converted into a torque command 3-phase instantaneous [
Input to the ft command converter 102, ! The TP torque command value is taken as the command value, and is converted into the three-phase adjacent current command value of the vj conductive motor corresponding to this command. Then, the output signal t of the torque command three-phase instantaneous current command converter 102 is set as the current command, and the deviation signal from the motor primary side current feedback signal detected by the current detector 105iC is sent to the three-phase current controller 10m. The output signal of the three-phase current controller 103 is input to the power converter 104 to generate the required frequency and voltage t to operate the motor at the commanded speed and torque. - Speed control of the motor by applying it to the main circuit of the motor
-Start.

When the tip 8 of the piece 4 passes the roll driven by the electric motor M, speed control with automatic correction of the roll diameter begins as follows.

That is, each time the signal contact 110 closes at regular intervals, the output signal 'f2fTI:1-' of the speed controller 101 is input to the roll diameter correction calculator 111.
performs one addition/subtraction for rc crawl correction.

That is, in the roll diameter correction calculator 111, Tp >Δ'I
'(If it is 1, ΔF1 is added to the /arm pulse frequency correction signal ΔF, which has been held since the previous mouth.

Then, 'I'P (- is subtracted. The roll diameter correction calculator 111 outputs ΔF, t-, and the ΔF signal is passed through the signal input limiter 113t-.
The adder 114 calculates the roll diameter correction calculation result ΔFIK, P1+Δ
IF s w = IF m is calculated, and the output signal Fst'' is inputted to the speed feedback amount calculator 107 and s [l
The speed feedback signal of Ij41AMl is corrected.

- Each time the signal contact 110 is closed as described above, -
The speed feedback amount V? until the condition ΔTo<Tp<ΔTO is satisfied. The speed is gradually corrected and speed control is performed.

When the tip 8 of the piece 4 passes the measure roll MPt, the roll p connected to the electric HA Ml is
- The diameter of the hole is corrected.

The slab length measurement start signal contact 18 is closed, and the measure roll slab length measurement counter 15 and drive roll length measurement counter 17 are connected.
starts counting.

The comparator 16 detects whether the measure roll slab length measurement counter 15 matches the set length 46, and the comparator 16 instructs the reference roll diameter calculator 19 to calculate the roll diameter reference value. The reference shaft diameter calculator 19 measures the drive roll slab length counter 17 at the moment commanded by the comparator 16. The pulse frequency FI11 set by the new roll reference pulse frequency setter 115 is input to the multiplier 116. Then, calculate Fo(2).

1° At this time, the signal switch 111 is set to 0-5 human circuit, and the output signal of the multiplier 116 is changed to the roll diameter correction switching linear command unit 11.
Enter in B.

In the roll diameter correction switching linear command unit 118, the value of the previous calculation result, F, which is internally held, is as follows.
*7'C The VC is gradually changed linearly toward the roll diameter base preparation value obtained by the calculation, thereby preventing rapid changes in the speed feedback tvν.

The output signal F1 of the roll diameter correction switching direct a command unit 118 and the roll diameter correction value ΔF, which is the calculation result by the roll diameter correction calculator 111, are input to the adder 114, and bPl+ΔF,
=P, and calculates F snow to the velocity feedback amount calculator 10.
7 and the VF is corrected. In this way, speed control is performed using the electric wJ machine Ml as the reference speed.

Next, the drive control of the other electric motors M, to Mn will be explained in detail.

Other driving side #! The control circuits Xs to Xln of the device have exactly the same circuit configuration as the drive controller WtX*s of the reference motor mMt. Hereinafter, when the speed of the reference electric motor M is being controlled as a speed reference roll.

The details of the control performed on the other electric motors Mfi to MnK will be explained using the electric motor Mst as an example.

In the control device XU of the telephone machine M, the signal switch 111
Control is performed with the circuit O-8 closed, and the other signal switchers 319...n kept open.

The speed control with the roll diameter automatic correction function in the case of the electric roll machine M3 is based on the control of the electric motor M1 that drives the speed reference roll, except for the roll diameter correction control by the measure roll MR and 15 to 19. This is similar to the control of aM1.

In other words, the circuit between O-8 of the signal switch 117 is closed, and the value of the pulse frequency PG based on the new four-wheel by the new roll reference pulse frequency setter 115 is changed to the roll diameter correction value via the signal switch 111. This is input to the switching direct melting command unit 118 and used as a reference value for determining the speed feedback amount.

When the tip 8 of the slab 4 passes the drive roll of the electric machine M, the signal contact 110 closes at regular intervals, and the diameter of the drive roll of the electric machine Mz is automatically adjusted in exactly the same way as the control of the electric motor M1. The output TP of the speed controller 101 is -ΔT
Periodic roll diameter correction calculations are continued until o<TP<ΔToe is satisfied, and the roll circumferential speed of % electric M is electric wjJ
Control is performed to synchronize with the roll circumferential speed of J machine M1.

The other electric motors M@ = Mn are also left open so that they can be controlled in the same way as M.

As mentioned above, E! A is a drive that sets the standard speed based on the pulse count results of a pulse signal generator attached to a measure roll MR installed outside the pinch roll machine, which allows easy maintenance such as central measurement of roll diameter and roll replacement. The diameter of the roll is calculated and the diameter of the speed-based drive roll is automatically corrected based on the result. Furthermore, the circumferential speed of other drive rolls is automatically synchronized with the circumferential speed of the speed-based drive roll. A single piece drawing control device in a continuous casting facility configured to correct the roll diameter is used. Therefore, the present invention can be made very large due to the steel pressure inside the slab.
When applied to slab drawing equipment where drive rolls tend to wear due to high roll pressure, the % Electric IiJ machine has a function that automatically compensates for changes in speed due to changes in roll diameter. Highly accurate casting speed control with fully balanced loads is performed, and its effects are significant.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a known single-piece drawing device. FIG. 2 is a block diagram of a conventional slab-drawing continuous layer control device, and FIG. 3 is a block diagram of an embodiment of the present invention. 4... Slab,? ...Roller table roll, 11
...Speed setter, 12...Linear command device, 13...
Integrator, 15...Measure roll slab length measurement counter,
16...Comparator, 17...Drive roll slab length measurement counter, 1B...-Slab length measurement start signal, 19...Reference roll diameter calculator, LQI...Speed controller, 102...・・・
Torque command 3-phase instantaneous current command converter, 103... 3-phase lightning controller. 104...Power converter, 105...Current detector%1
06... Pulse frequency converter % 107... Speed feedback amount calculator % 111... Roll diameter correction calculator % 1
13--Signal input limiter, 114--Adder, 11
5...New roll reference pulse frequency setter% 116.
... Multiplier, 117 ... Signal switch, 118 ... Roll diameter correction value switching direct win command device = 119, 219, 31
9. n...Signal switch 1M1~Mn...Induction motor, PLGI~PL Gn...Pulse No. 18 generator, PLGo...Pulse No. 1J generator for slab length measurement, MR
...Measure roll for measuring slab length. Special applicant: Yasukawa Koiso Seisakusho Co., Ltd.

Claims (3)

[Claims] (1) In the slab drawing control device of continuous casting equipment, which has a dedicated drive control device for each electric motor, the common speed command 11
Deviation between No. v8 and the speed feedback signal VF of the speed controller of each motor! In order to control the electric motor with drooping characteristics, the total deviation between the speed feedback signal V7 and the speed feedback signal V7, which is input to a speed controller with a low proportional gain and detected by the drive control device of the speed control reference rail, is Give it to the integrator as a human torque command, and in each drive control device, the sum of the output signal of the integrator and the output signal TP of the speed controller is used as the torque command to operate the speed controller of the Taniden machine. A slab drawing speed control system in continuous casting equipment, characterized in that the speed is controlled using the speed of the speed reference drive four as a feedback value. (2) In the slab drawing control device of continuous casting equipment where each motor has a dedicated drive control device, the deviation t between the common speed command signal V13 and the speed feedback signal VF of the speed side # of each motor - Drooping the motor The difference between the speed feedback No. 41 VF detected by the speed control reference roll drive control device and the speed feedback signal VF is input to a total integrator. Then, the output signal Ts is given to each drive-control device as a common torque command, and valley drive! In the Ij control device, the output 1 of the integrator
The sum of the TS and the output signal T2O of the speed controller is used as the torque command to control the speed side of the motor, and the overall speed is controlled as the speed total feedback 1η of the speed reference drive wheel. A device for detecting the moving speed of the slab running on the roller table of the continuous casting equipment, and using the ratio of the speed of the speed reference roll to this detection signal as a speed correction coefficient as a speed correction coefficient for driving the speed reference roll. A slab drawing speed control method in continuous tA production equipment, which features corrective control of the speed feedback amount of an electric motor control device. (3) Correction control for quick return work using the speed correction coefficient of the speed reference roll drive electric motor control device The slab drawing speed in the continuous casting equipment according to claim 2, characterized in that the correction control is carried out in all cycles. control method.