JP2001178167A - Protective system for excessive speed of acr control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control an abnormal rise in rotation of a motor due to a drop in a load or due to cutoff of the load. SOLUTION: In ACR control operation, the difference between an ACR setting operation 5 and a current detection is computed and amplified by a current-controlled amplifier 8, so as to control the motor. ACR control parts 1 to 3 are installed. An ACR/ASR changeover unit 4, by which a current command from an ASR control amplifier 3 and the ACR setting operation 5 are changed over, is installed. A speed setting operation and a speed detection are compared by a comparison amplifier 14. When the speed detection becomes a value or larger which is decided by the speed setting operation, an excessive speed is detected and outputted. The changeover unit 4 is changed over, and an ASR control operation is performed. Thereby, the excessive speed is suppressed. In the ASR control operation, the speed setting operation is voltage-divided by a resistor 13 so as to be added to an adder 2 for deviation detection, and the ASR control operation is performed by the speed setting operation which is a slightly higher. A comparison amplifier 15 compares the ACR setting operation with a current detection value, and whether the load is returned normally is detected. When the load becomes normal, the changeover unit 4 is changed over to the side of the ACR setting operation, so as to be returned to the original ACR control operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overspeed protection control system of ACR control for preventing overspeed when a load is lost during motor current (torque) control.

[0002]

2. Description of the Related Art When processing a continuous material such as an iron plate or cloth, as shown in FIG. 2, a roller R1 for drawing out a material W, and rollers R2 to Rn for rolling, dividing, etc. are connected to motors M1 to M1, respectively.
It is driven by Mn. Since the motor shafts of the motors M1 to Mn are connected via the material W, speed control (ASR control) is performed using one of the motors as a reference for the line speed.
Then, the speed is tuned by controlling the current (torque) of other motors (ACR control).

[0003]

As shown in FIG. 4, the control block of the motor is a speed control amplifier for performing PI calculation of the deviation between the line speed value set by the line speed setting device 1 and the speed detection value fed back. ACR / AS for switching between a current command value from the speed amplifier 3 and a current (torque) set value (ACR set value) from the ACR setter 5
An R switching unit 4 and a current control amplifier 8 for calculating and amplifying a difference between a current command (set) value from the switching unit 4 and a current detection value detected by the current detector CT1 and adjusted by the variable resistor 6. ing. In the case of ASR control, the switching unit 4 is inserted into the current control amplifier 8 to control the motor using the current control amplifier 3 and the current control amplifier 8 so that the speed deviation is eliminated. In the case of ACR control, the switching unit 4 is switched to the ACR setting unit 5 side to disconnect the speed amplifier 2 for control. In the ACR control, only the current control by the current control amplifier 8 is performed, so that the speed control becomes impossible.

[0004] In the line of FIG.
R control, when the motor M2 is operating as ASR control, when the material W is lost or broken at the point A as shown in FIG. 3 or when the roll R1 is raised due to the deflection of the material W. No load is applied to M1, and the speed increases to the maximum speed regardless of the line speed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an overspeed protection for ACR control capable of suppressing an abnormal increase in motor rotation due to a load reduction or a load cut in ACR control. It is to provide a control method.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an overspeed protection system for ACR control in which a difference between an ACR set value and a current detection value is arithmetically amplified by a current control amplifier to control a motor. Speed control amplifier for calculating and amplifying the difference between the speed control value and the speed detection value; ACR / ASR switching means for switching the input of the current control amplifier to an ACR set value or a current command value output from the speed control amplifier; A speed comparison means for comparing the detected values to detect an overspeed and switching the ACR / ASR switching means to a speed control amplifier side.

A means for increasing a speed command value input to a speed control amplifier upon detection of the overspeed;
A current comparison means for comparing the CR set value with the current detection value to detect that the load has returned to the original state and returning the ACR / ASR switching means to the original ACR set value side is provided. Automatically return to

This method is suitable for controlling a motor in a line in which a continuous material is controlled by a large number of motors.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS AC according to an embodiment of the present invention
FIG. 1 shows a control block of the overspeed protection control system of the R control. In the figure, the same components as those shown in FIG. 4 in the related art are denoted by the same reference numerals, and the description thereof will not be repeated.

Reference numeral 11 denotes a speed increase setting circuit connected between the speed setting device 1 and the speed deviation detecting adder 2, which is constituted by a series circuit of a switch 12 and a voltage dividing variable resistor 13, and the switch 12 is turned on. Then, a voltage obtained by dividing the speed set value of the speed setter 1 by the variable resistor 13 is input to the speed deviation detecting adder 2 to increase the speed set value.

Reference numeral 14 denotes a comparison amplifier for comparing the set speed value with the detected speed value to be fed back to detect an overspeed of the motor. The feedback amount becomes larger than the set speed value, and the magnitude of the feedback amount is stored in the comparison amplifier 14. When the set value is reached, the signal is output to the ACR / ASR switching unit 4 so that the switching unit 4 is switched to the speed control amplifier 3 (ASR side) to perform ASR control, and the switch 12 of the speed increase setting circuit 11 is turned on. Is configured.

A comparison amplifier 15 compares the ACR set value of the ACR setter 5 with a current detection value fed back to the current control amplifier 8 via the variable resistor 16 and detects that the load has returned to its original state. When the operation of the speed increase setting circuit 11 and the load return to normal, the current detection value becomes larger than the ACR set value, and when the current value becomes the value set inside the comparator 15, an output is made to switch the switching unit 4 to the ACR side. And the output of the comparison amplifier 14 is turned off.

Next, the operation of this control method will be described. The ACR / ASR switching unit 4 is inserted into the ACR setting unit 5 (ACR side) to perform ACR control. In the ACR control, a difference between the ACR set value set by the ACR setter 5 and the current detection value detected by the current detector CT1 is detected by the adder 7, and the current control amplifier 8 calculates and amplifies the current so as to eliminate the current difference. Then, ACR control of the motor is performed by controlling a gate and the like of a motor drive circuit (not shown).

During the ACR control, the comparison amplifier 14 compares the difference between the set speed value and the detected speed value. When the motor speed increases and the detected speed value becomes larger than the set speed value and the magnitude becomes larger than a value set inside the comparison amplifier 14, the comparison amplifier 14 outputs. As a result, the overspeed of the motor is detected, the ACR / ASR switching unit 4 is switched to the speed control amplifier 3 (ASR side), and the switch 12 of the speed increase setting circuit 11 is turned on to set the speed set value by the speed deviation detecting adder. The speed set value is increased by adding the speed increase set value divided by the voltage dividing variable resistor 13, and the motor is set to ASR at a speed slightly higher than the speed set by the speed setter 1.
Control.

The overspeed is caused by the ACR control when the load is reduced or the load is cut off. When the load is not reduced or the load is cut off, the current detection value returns close to the normal value. The current detection value is higher than the set speed due to the addition of, so that the current detection value is larger than that in the normal ACR control. The comparison amplifier 15 compares the ACR set value with the current detection value. When the amount of the detected current value becomes larger than the ACR set value and becomes larger than the value set inside the comparison amplifier 14, the output is outputted. To switch the switching unit 4 to the ACR setting unit 5 side, and turn off the output of the comparison amplifier 14.
And This automatically returns to the original ACR control state from the ASR control.

According to the above embodiment, when the motor speed increases due to a load reduction or a load cut in the ACR control, the mode is automatically switched to the ASR control, so that an overspeed of the motor can be prevented. Then, when the load reduction or the load disconnection is resolved, the operation automatically returns to the original ACR control.

In the above embodiment, the motor is operated alone, but as shown in FIG. 2, a continuous material W is used by a large number of motors, one of which is subjected to ASR control and the other motors are used. In the case of the ACR control, the control of each motor to be ACR-controlled is performed in the same manner as in the above embodiment, so that the AC
Overspeed protection control of R control can be performed. In that case, the speed setting is the line speed setting.

[0018]

Since the present invention is configured as described above, the following effects can be obtained. (1) It is possible to control an abnormal decrease in the motor rotation due to a load reduction or a load cut by the ACR control. (2) If the load reduction or the load disconnection is eliminated after switching to the ASR control, the original ACR control can be automatically restored. (3) When the roll is raised and lowered again in accordance with the state of the material in order to remove the material during operation with a slitter line or the like, a large speed difference does not occur, so that the material is not damaged.

[Brief description of the drawings]

FIG. 1 is a control block diagram according to an embodiment.

FIG. 2 is a configuration explanatory view of a continuous material processing line.

FIG. 3 is an explanatory diagram of a cause of no load on a motor.

FIG. 4 is a control block diagram according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Speed setting device, line speed setting device 3 ... Speed control amplifier 4 ... ACR / ASR switching unit 5 ... ACR setting device 7 ... Current control amplifier 11 ... Speed rise setting circuit 14, 15 ... Comparison amplifier

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E024 AA01 BB06 CC03 FF01 5H550 AA03 BB08 DD01 GG03 GG05 GG08 HB18 HB20 KK02 LL01 LL22 MM05 5H572 AA05 BB07 DD01 EE04 GG02 GG04 GG07 HC07 KK01 LL01 LL01

Claims (3)

[Claims] 1. An overspeed protection system of ACR control for controlling a motor by calculating and amplifying a difference between an ACR set value and a current detection value by a current control amplifier, wherein a deviation between the speed set value and the speed detection value is determined. A speed control amplifier for arithmetic amplification and ACR / ASR for switching the input of the current control amplifier to an ACR set value or a current command value output from the speed control amplifier
Overspeed protection for ACR control, comprising: switching means; and speed comparison means for comparing an ACR / ASR switching means to a speed control amplifier by detecting an overspeed by comparing a speed set value and a speed detection value. method. 2. The apparatus according to claim 1, wherein said speed comparison means detects an overspeed to increase a speed command value input to a speed control amplifier, and said ACR set value is compared with a current detection value to determine a load value. When the ACR / ASR switching means is detected
An overspeed protection method for ACR control, comprising: current comparison means for returning to a CR set value side. 3. The ACR control overspeed protection method according to claim 1, wherein the motor is a motor in a line in which a continuous material is controlled by a plurality of motors.