JPS6324906B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a system for conveying a strip of material (aluminum foil, steel plate, copper plate, paper, etc.) via a plurality of electric motors. In such a system, motors other than the master motor that determines the conveyance speed are subject to a certain load, which is determined by the system and the type of material.
For example, it is operated with a constant material tension applied, but it is desirable that this type of load remains constant even when the conveying speed is accelerated or decelerated.

[Prior art and its problems]

Fig. 1 is a configuration diagram showing a conventional example of a belt-shaped material conveyance system, Fig. 1A is a waveform diagram for explaining the function of the timing calculator in Fig. 1, and Fig. 1B is a diagram showing the material conveyance speed and armature back electromotive force. FIG. 3 is a characteristic diagram showing the relationship between voltage and field flux. In Fig. 1, 1 is a strip material, 2 is an electric motor, 2' is a master electric motor, 3,
3' is a thyristor converter, 4 and 4' are field windings,
5, 5' are field thyristor converters, 6, 6 are field current control devices (FCR), 7, 7' are armature current control devices (current regulators; ACR), 8 are load setting devices, 9 is a speed regulator (ASR), 10 is an acceleration/deceleration speed calculator, 11 is a material conveyance speed setting device, 12 is a looper, 13 is a bridle, 14 is a winder, 15 is a
GD ² (motor inertia) calculator, 16 is speed generator,
20 is a field flux compensation calculator, 21 is a timing calculator, and 22 is a differentiator.

That is, FIG. 1 shows an example in which a strip material 1 such as a steel plate or a copper plate is wound up by a winding machine 14 via various rollers such as a looper 12 and a bridle 13. Roopa 12, bridle 13
, etc. are respectively coupled to electric motors 2 and 2', where 2' acts as a master motor and determines the conveyance speed V _L of the material 1, and the other electric motor 2 determines the tension or tension difference of the material 1 to a predetermined value. control so that
Therefore, in each electric motor 2, the current control device 7 controls the thyristor converter 3, and the field current control device 6 controls the field thyristor converter 5. In addition, similar control is carried out on the master motor 2', and speed control is also carried out by a speed regulator 9, and furthermore, the conveying speed set value (or actual speed value _VL ) V _L ^* is differentiated by a differentiator 22. Then, by inputting the output (dV _L ^* /dt) to the timing calculator 21 and making a predetermined adjustment, the acceleration/deceleration torque is compensated. In other words, the 1st A
As shown in the figure, if the output of the circuit 10 that calculates the command value based on the speed setter 11 is represented by the solid line in A of the figure, the actual speed value obtained as a result of control based on the speed command value is: Since a time delay occurs as shown by the broken line in A of the figure, the acceleration/deceleration torque of the master motor as shown in B of the figure, that is, its armature current pattern, and the waveform of the acceleration/deceleration torque of the other motors as shown in C of the figure Therefore, the timing calculator 21 adjusts these waveforms so that they match. However, such adjustment is not necessarily easy, and therefore has the disadvantage that material tension tends to fluctuate. In addition, when controlling each electric motor in both a constant torque (constant magnetic flux) region and a constant output region (weakening magnetic flux region) as shown in Fig. 1B, the first
A field flux compensation computing unit indicated by the reference numeral 20 in the figure is required.

[Purpose of the invention]

This invention has been made in view of the above, and it is possible to generate the master electric motor acceleration/deceleration torque that determines the conveyance speed of the strip material and the acceleration/deceleration torque necessary for other electric motor groups without using a differentiator or a timing calculator. By matching the timing and compensating for field changes without using a special calculator,
Easy and highly accurate constant load (constant tension) even during acceleration and deceleration
The purpose is to enable driving.

[Key points of the invention]

Among the motor groups that transport strip-shaped materials, the master motor speed control device that determines the transport speed is equipped with a state observation device that estimates and calculates the armature current equivalent to the load torque of the master motor from the actual values of the speed and armature current. A current adjustment calculation is performed based on the armature current equivalent to the load torque obtained via the observation device and the armature current equivalent to the acceleration/deceleration torque obtained via the speed regulator. The main feature is that a corresponding armature current is applied to the current regulator of each motor to control it.

[Embodiments of the invention]

FIG. 2 is a configuration diagram showing an embodiment of this invention.
Figure A is a configuration diagram showing a specific example of a state observation device.
As is clear from FIG. 2, this embodiment is different from the conventional example shown in FIG.
9 output to other motor's current regulator (ACR) 7
The other features are the same as the conventional example.

Now, when the conveyance speed V _L of the line as shown in FIG. _a is obtained as the output of the speed regulator 9 of the master motor 2', while
Armature current I _L equivalent to master motor load torque
The mark (estimated value I^ _L ; P∧) represents the estimated value. ) can be obtained via the state observer 19, so all electric motors can obtain acceleration/deceleration torque at the same timing. Therefore, even when the electric motor accelerates or decelerates, the tension in each part of the material 1 can be kept substantially constant at the tension set by the setting device 8. Further, the field current is controlled by field current control devices (FCR) 6, 6' to generate a field magnetic flux φ according to the conveying speed _VL as shown in FIG. 1B.

The state observation device 19 used here is, for example,
This is known from Japanese Unexamined Patent Publication No. 55-162894, and will be explained below with reference to FIG. 2A.

In the same figure, 191 and 192 are proportional elements, 1
93, 194 are integral elements, 195 is a divider, 19
6 is a multiplier, and 197 is a function generator. Further, S is a Laplace operator, J^ is an integral time corresponding to a change in motor speed from a change in motor torque, that is, a motor starting time constant, and g ₁ and g ₂ are proportional gains. Note that 51 is a detector that detects the armature current I _a .

The function generator 197 calculates the reciprocal of the field magnetic flux, that is, the amount 1/φ, based on the armature current I _a given via the detector 51, and the divider 19
5 calculates the motor torque τ _M (∝I _a ×φ) using this quantity 1/φ and the armature current I _a . The deviation between the motor torque τ _M and the estimated load torque value τ^ _L is input to the integral element 193, and the estimated motor speed value n^ is obtained from its output. At this time, in order to estimate (simulate) the motor load torque τ _L , if the speed difference n-n^ is input to the integral element 194, then τ^ _L is n
It continues to change until n=n^, and the value of τ^ _L when n=n^ comes to match the motor load torque. In such a simulation operation,
In order to ensure that n^ always follows n stably according to the state of the controlled object, integral elements 193, 19
The value of n-n^ is fed back to the input side of 4 by giving gains g ₁ and g ₂ respectively. The gains g ₁ and g ₂ are related to the coefficients of the characteristic equation of the load torque state observer 19, and by appropriately selecting them, the response can be optimally adjusted. The load torque estimated value τ^ _L simulated in this way is multiplied by the reciprocal of the magnetic flux 1/φ in a multiplier 196, and the armature current estimate I _L (τ^ _L × 1/φ ) can be obtained. Furthermore, this estimated armature current value
I^ _L is given as a set value to the armature current regulator 7' of the master motor.

〔Effect of the invention〕

According to this invention, the speed control device of the master motor that determines the conveyance speed is provided with a state observation device that observes the load torque, and the output of the state observation device is set as the setting value of the armature current regulator of the master motor. The speed regulator output is the armature current value corresponding to the acceleration/deceleration torque, so by setting this value as the acceleration/deceleration armature current setting value for all motors,
Since the armature current setting value corresponding to the acceleration/deceleration torque of all electric motors can be automatically obtained without using conventional differentiators, timing calculators, and field flux calculators, the armature current setting value corresponding to the acceleration/deceleration torque of all electric motors can be obtained automatically. This provides the advantage that the load, such as tension, can be maintained constant with high precision.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing a conventional example of a belt-shaped material conveyance system, Fig. 1A is a waveform diagram for explaining the function of the timing calculator in Fig. 1, and Fig. 1B is a diagram showing the material conveyance speed and armature back electromotive force. A characteristic diagram showing the relationship between voltage and field magnetic flux, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 2A is a block diagram showing the state observation device in FIG. 2 in detail. Explanation of symbols, 1... Strip material, 2, 2'... Electric motor, 3, 3'... Thyristor converter, 4, 4'...
Field winding, 5,5'... field thyristor converter,
6,6'...Field current control device (FCR), 7,
7'... Armature current controller (ACR), 8... Load setting device, 9... Speed regulator (ASR), 10...
Acceleration/deceleration speed calculator, 11...Speed setter, 12...
... Looper, 13 ... Bridle, 14 ... Winder, 15 ... GD ² computing unit, 16 ... Speed generator,
19... State observation device, 20... Field flux compensation calculator, 21... Timing calculator, 22... Differentiator, 191, 192... Proportional element, 193, 19
4... Integral element, 195... Divider, 196...
Multiplier, 197...Function generator, 51...Current detector.

Claims (1)

[Claims] 1. Through a master motor having a speed control system that has a current control loop as a minor loop within the speed control loop, and a plurality of motor groups each having a current control system that controls the armature current to maintain the tension at a predetermined value. In a system for conveying a predetermined strip of material, a condition observation device is provided that estimates and calculates an armature current equivalent to a load torque based on the actual values of the armature current and speed of the master motor, The current of the master motor is adjusted based on the child current and the armature current equivalent to acceleration/deceleration torque obtained via the speed adjustment loop, and the armature current equivalent to the acceleration/deceleration torque is controlled by each current of the motor group. A belt material conveying system using multiple electric motors that maintains constant material tension even during acceleration and deceleration by applying it to the system.