JPH01291681A - Motor controller - Google Patents

Abstract

PURPOSE:To suppress the speed variation in switching from a current control mode to a speed control mode by substituting the speed target value immediately before the current control mode to a speed actual value. CONSTITUTION:Usually contacts 21A and 35 are opened and 21B is closed. Thus, the output of a current limit regulation circuit 32 becomes zero by a lower limiter 33 and the operation is in a speed control mode. When a lengthy material 2 is interlocked into a carrier roll 4, the contacts 21A and 35 are closed and 21B is opened. The output of a speed regulation circuit 13 is suppressed by that of a current limit regulation circuit 32. When the lengthy material 2 goes through the carrier roll 3, the contact 21B is closed and it is in a speed control mode. At this time, the output of the current limit regulation circuit 32 immediately before is stored into a speed correction memory 34 and a speed target value signal N* is added to be a new speed target value. When the lengthy material 2 goes through the carrier roll 4, the contacts 21A and 35 become opened and return to the original speed target value.

Description

DETAILED DESCRIPTION OF THE INVENTION C. Industrial Application Field The present invention relates to an electric motor 27J device that can smoothly switch from speed control to current control or vice versa while the electric motor is in operation.

[Conventional technology]

When transporting long materials such as paper rolls or steel strips to other locations, such as winding machines, a large number of transport rolls are used. In this case, the electric motor that drives each transport roll must be If not controlled, the long material may sag between the conveyor rolls, causing wrinkles in the long material, or a large tension may be applied to the long material, causing it to stretch or be cut. This will cause inconvenience.

FIG. 2 is a model diagram showing the relationship between the position of a long material and the control mode of each transport roll. Since the long material designated by numeral 2 is transported in the direction of the arrow from right to left, first The case where the sheet passes through the conveyance roll 3 and then the second conveyance roll is shown.

In this FIG. 2 (A), the long material 2 is being transported by the first transport roll 3, but it has not yet arrived at the first transport roll 3, and at this time, the first transport roll 3 is It is being operated in speed control mode to convey the long material 2 at a predetermined speed, and the second conveying row J4 is rotating the rolls in order to relieve the sillage and cracks when the long material 2 is bitten. The speed is controlled so that the circumferential speed of the elongated material 2 is equal to the transport speed of the elongated material 2.

FIG. 2(B) shows a state in which the long material 2 is caught in the second conveyance roll 4, and the first conveyance roll 3 is still sending out the long material 2 by speed control. If the second conveyance roll 4 is also operated under speed control, both conveyance rolls 3 and 4 will interfere with each other and become uncontrollable, so the second conveyance roll 4 is switched to current control mode and is operated under torque control.

In Figure 2 (c), the long material 2 is the first! Since it is difficult to maintain the conveying speed of the long material 2 at the target value until the first conveying roll 3 is operated under current control with the M conveying roll 3 being unloaded, the speed control mode is set. I will be returning it. Note that the 1111th feed roll 3 continues to operate in the speed control mode in preparation for the arrival of the next long material 2.

FIG. 2(D) shows a state in which the long material 2 has also been removed from the second conveyance roll 4, and both conveyance rolls 3 and 4 are operating in the speed control mode.

FIG. 3 is a circuit diagram showing a conventional example that implements the control mode shown in FIG. 2.

In the conventional example circuit shown in FIG. 3, the first conveyance roll 3 that conveys the long material 2 is driven by the first motor 5 and operates at a constant speed, but the second conveyance roll 4 is driven. The second motor 8 is controlled as follows. Furthermore, code 6
is an AC power supply, and the operation of the second motor 8 is controlled by controlling the phase of the AC power from the AC power supply 6 using a thyristor device 7.

In other words, the speed target value signal N0 set by the speed setter 11
and the speed actual value signal N from the speed transmitter 11412 connected to the second motor 8 and detecting its speed, and convert this deviation into the speed t configured by a proportional-integral calculator.
When input to the A-node circuit 13, this speed adjustment circuit 13 outputs a control signal that makes the input deviation zero, so this control signal and the actual current value of the second motor 8 obtained by the current detector 14 By calculating the deviation from the signal I and inputting this deviation to the current 11-node circuit 15 composed of a proportional-integral calculator, a control signal that makes the input deviation zero is extracted from the current tJR node circuit 15, and as described above. The signal is given to the thyrisk device 7, and the phase of this thyrisk device 7 is controlled.

When the long material 2 is in the state shown in FIG. 2(A), that is, when it is not yet bitten by the second transport roll 4, the contact 21A is always open and the normally closed contact 21B is closed. , a limiter 25 installed on the output side of the speed adjustment circuit 13 outputs the output signal from the limiter 25 to the current setting device 2.
Current target value signal 4 set by 4 and current correction setting device 2
The value of 1 + ΔI is limited so as not to exceed the sum of the current correction signal Δ■ set by the second motor 8.
Since the current limit value of the second
Motor 8 is operating in speed control mode.

Next, the state shown in FIG. 2(b), that is, the second conveyance roll 4
When a long piece of material is caught, the normally closed contact 21B opens and the limiter 25 acts to prevent the output signal of the speed adjustment circuit 13 from exceeding the current target value signal I3, and the normally open contact 21A opens. Since the circuit is closed, the speed correction signal ΔS set by the speed correction setter 22 is added to the speed target value signal N9 and input to the speed adjustment circuit 13.

That is, when the second motor 8 is in the current control mode in the state shown in FIG. 2(b), the speed adjustment circuit 13 is saturated,
By changing the limit value of the output signal, the output signal of the speed adjustment circuit 13 is used as the current target value signal.

[Problem to be solved by the invention]

As mentioned above, the second motor 8 switches from the speed control mode to the current control mode in accordance with the position of the long material 2, but if the long material 2 is pulled out of the first conveyor roll 3, For example, the second motor 8 has to switch back to speed control mode.

By the way, when in the current control mode, the speed adjustment circuit 13
Since this is in a saturated state, it is not possible to shift to the speed control mode until the saturation of this is released, and therefore, the second motor 8 is This had the disadvantage of causing speed fluctuations.

SUMMARY OF THE INVENTION An object of the present invention is to enable smooth and prompt switching of an electric motor operating in current control mode to speed control mode without causing speed fluctuations.

[Means to solve the problem]

In order to achieve the above object, the electric motor control device of the present invention provides a speed adjusting means for outputting a signal that controls the deviation between the speed target value signal of the electric motor and the actual speed value signal fed back from the electric motor to zero. and current regulating means for outputting a signal for controlling the deviation between the speed regulating means output signal and the current actual value signal fed back from the motor to zero, and controlling the electric motor according to the output signal of the current regulating means. In a motor control device that performs speed control operation or current control operation, a current target is set to a value larger than a current limit value of the motor during speed control operation of the motor, and is switched to a predetermined value during current control operation. a current limit adjustment circuit that inputs a deviation between a value signal and the output signal of the speed adjustment means; a means for limiting a lower limit value of the output signal of the current limit adjustment means to zero; a circuit for feeding back to the input side of the means; a memory means for storing the output signal of the lower limit value limiting means; and means for adding the output signal of the memory means to the speed target value signal when the motor is operated under current control. and means for adding a constant value to the speed target value signal when the electric motor is operated under current control.

[Effect]

In the present invention, when switching an electric motor operating in current control mode to speed control mode, the actual speed value signal of the electric motor immediately before the end of current control is converted into a speed target value signal and given to the current adjustment means. This is intended to suppress the occurrence of speed fluctuations when transitioning from current control mode to speed control mode.

〔Example〕

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

In FIG. 1, a first transport roll 3 that transports a long material 2 in the direction of the arrow (that is, from right to left), a first motor 5 that drives this, a second transport roll 4, and a second motor that drives this
The functions of the motor 8, the AC power supply 6 that supplies power to the second motor 8, and the SIRISK device 7 are the same as in the conventional circuit shown in FIG. 3, and therefore a description thereof will be omitted. Further, a speed setter 11, a speed transmitter 12, and a speed 1! installed to control the second motor 8 are installed. node circuit 1
3. The functions of the current detector 14, current adjustment circuit 15, normally open contact 21A, normally closed contact 21B, speed correction setting device 22, current correction setting device 23, and current setting device 24 are also the same as those already described in FIG. Since the circuit is the same as the example circuit, a description thereof will be omitted.

In this invention, an inverting circuit 31 for inverting the output signal of the speed j[flff circuit 13, and ':! A current limiter consisting of a proportional-integral calculator that calculates the deviation between the L flow target value signal I'' or this (9) plus the current correction signal ΔI and the output signal of the inverting circuit 31, and inputs this deviation. An adjustment circuit 32, a circuit that limits the lower limit of the output signal of the current limiter 32 to zero, a circuit that feeds back the output signal ΔN of the lower limiter 33 to the input side of the speed adjustment circuit 13, A speed correction memory 34 for storing the output signal ΔN of the mink 33 and a normally open contact 35 for adding the output signal of the speed correction memory 34 to the speed target value signal N0 are provided.

The operation of the present invention is as follows. In other words, Figure 2 (a)
In the state shown in , the second motor 8 that drives the first transport roll 3 is controlled with the normally open contacts 21A and 35 open and the normally closed contact 21B closed, so that the current target value signal I The current correction signal Δl is added to *, and this
The value of 4+ΔI is larger than the limiting current of the second motor 8. On the other hand, since the output of the speed adjustment circuit 13 is normally a value smaller than this limit 1 iti, the output of the current limit adjustment circuit 32 is always set to zero by the lower limiter 33, so that the speed li! The value of ΔN fed back to the node circuit 13 is also zero, and the deviation between the speed target value signal N0 and the speed actual value signal N is input to the speed adjustment circuit 13, and the operation in the speed control mode is becomes.

Next, the state shown in FIG. 2(b), that is, the second conveyance roll 4
When the long material 2 is bitten in, the constant contact points 21A and 35
is closed, the normally closed contact 21B is open, and the current correction signal Δ
■ is cut off, and the second motor 8 operates in the current control mode with the current target value as “■”. At this time, the second motor 8
The speed N of is dependent on the speed of the first motor 5. That is, the second conveyance roll 4 is connected to the first conveyance roll 3 by the elongated material 2.
Therefore, the circumferential speeds of the re-conveying rolls 3 and 4 and the conveying speed of the long material 2 are equal values, and therefore the actual speed value N and the target speed value N'' of the second motor 8 are approximately equal. value.

By constantly closing the contacts 21A and 35, the speed correction signal ΔS is added to the speed adjustment circuit 13 as a new input, but at this time, the actual speed value signal N and the speed target value signal N
'' is approximately the same value, the output of the speed adjustment circuit instantaneously tries to reach the maximum value, but the current limit adjustment circuit 32 works to suppress the output to the current target value r''.

Furthermore, if the output of the speed adjustment circuit 13 becomes smaller than this current target value signal I'', the current limit adjustment circuit 13
The output ΔN of 2 also becomes smaller, but since this extra ΔN is input to the speed adjustment circuit 13, the output tends to increase again toward the maximum value. However, due to the action of the current limit adjustment circuit 32 again, the output of this speed gIj1 node circuit 13 is suppressed to the current target value ■". Thus, the change in the output of the speed jj1 node circuit 13 or the current target value ■" In response to a change in I9, the speed target value is corrected, and the current of the second motor 8 is adjusted to its target value I9.
can be controlled.

FIG. 2(C) In other words, at the moment when the long material 2 passes through the first transport roll 3, the current target value I''' is added with the current correction signal ΔI due to the normally closed contact 21B being closed, and the second motor Therefore, the output of the current limit adjustment circuit 32 is always zero due to the lower limiter 33, so this current limit adjustment circuit 32 no longer functions, and the second motor 8 starts speed control again. It will be driven in mode.

On the other hand, ΔN, which is the output of the current limit adjustment circuit 32 immediately before the long material 2 passes through the first conveyance roll 3 and the current control mode ends, is stored in the speed correction memory 34, and the speed target value signal N * is added to form a new speed target value. Therefore, in order for the long material 2 to pass through the first conveyance roll 3, the moment when the second motor 8 (for driving the second conveyance roll) shifts from the current control mode to the speed control mode, the second V
The circumferential speed of the a-feed roll 4 does not change, so the conveyance speed of the long material 2 is maintained at a constant value.

Further, in the state shown in FIG. 2(d), that is, when the elongated material 2 passes through the second conveyance roll 4, the normally open contact 21/'.

and 35 are opened, and the speed of the second conveyance roll 4 follows the original speed target value N''.

〔Effect of the invention〕

According to this invention, when switching the electric motor operating in the current control mode to the speed control mode, the speed target value immediately before the end of the current control mode is replaced with the actual speed value. This has the effect of suppressing the occurrence of speed fluctuations in the electric motor when switching to the control mode, and making it possible to smoothly and quickly shift to the speed control mode.

[Brief Description of the Drawings] Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is a model diagram showing the relationship between the position of a long material and seven control modes of each transport roll; FIG. 3 is a circuit diagram showing a conventional example that implements the control mode shown in FIG. 2. 2... Long material, 3... First conveyance roll, 4... 28th feed roll, 5... First mork, 6... AC power supply, 7... Thyristor device, 8... ...Second motor, 11
...Speed setter, 12...Speed transmitter, 13...
Speed adjustment circuit, 14... Current detector, 15... Current limit adjustment circuit, 2LA, 35... Normally open contact, 21
B... Normally closed contact, 22... Speed correction setting device, 23
... Current correction setting device, 24... Current setting device, 25.
...'J Mink, 31... Inversion circuit, 32... Current limit adjustment circuit, 33t 1 Figure 32 Figure 63 Figure

Claims (1)

[Claims] 1) a speed adjusting means for outputting a signal for controlling to zero the deviation between the speed target value signal of the electric motor and the actual speed value signal fed back from the electric motor; and current adjusting means for outputting a signal for controlling a deviation from an actual current value signal to zero, and causing the motor to operate under speed control or current control according to the output signal of the current adjusting means, inputting the deviation between the current target value signal, which is set to a value larger than the current limit value of the motor during speed control operation of the motor and switched to a predetermined value during current control operation, and the speed adjustment means output signal; Current limit adjusting means; means for limiting the lower limit value of the current limit adjusting means output signal to zero; a circuit for feeding back the lower limit value limiting means output signal to the input side of the speed adjusting means; and this lower limit value limiting means. memory means for storing an output signal; means for adding the output signal of the memory means to the speed target value signal when the motor is in current control operation; and means for adding the output signal of the memory means to the speed target value signal when the electric motor is in current control operation; 1. A motor control device comprising: means for adding a constant value to a signal.