JP2000343117A - Coiler driving system controlling method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a stable wind up of a coiler by designing a common converter capacity to be the lowest required level in a coiler driving system for winding up a rolled steel plate and, by restraining an overload condition where the capacity is exceeded. SOLUTION: A consumed electricity current of a common converter 1 is detected by an electric current detector 5 and is compared with a rated current with a comparator 6. When the consumed electric current reaches or exceeds the rated current, an instruction is outputted. A tensile force setter 7 or a velocity setter 8 gradually lowers the setting value based on the instruction so as to output an electric current instruction or a velocity instruction to inverters 2, 3, 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a common converter type coiler drive system in a winding device for winding a rolled steel sheet into a coil and an apparatus therefor.

[0002]

2. Description of the Related Art In a rolling process of a rolled steel sheet, a rolled rolled steel sheet is wound by a mandrel of a winding device. A pinch roll for restraining the rolled steel sheet is provided immediately before the mandrel. The mandrel motor and the pinch roll motor of such a winding device include an inverter device, and speed control is performed so that one of them has a predetermined winding speed, and the other has a current control that has a predetermined winding tension. I do. Such a winding control device is provided with a common converter (common converter) for converting the power on the primary side of the inverter into a direct current, and is electrically coupled. The common converter converts AC power into DC and supplies DC current to an inverter of a drive motor for the mandrel and pinch roll. The inverter converts DC into AC of a desired frequency or raises or lowers the converted AC to a required voltage and supplies the AC to a mandrel motor and a pinch roll drive motor in accordance with a set value, a load, and the like. , Output and the like.

In such a winding device, a mandrel motor pulls a rolled steel plate to generate power, while a pinch roll motor is pulled to regenerate. Therefore, it is theoretically sufficient for the common converter to have a power capacity of the difference between the two.

[0004] The mandrel motor is controlled by the current and frequency of the inverter, and when the rotation speed of the motor exceeds a predetermined upper limit value or when the motor current falls below a predetermined lower limit value, the material feeding speed is reduced. The technology is disclosed in
No. 11,351. This relates to the control of the mandrel motor alone.

Japanese Unexamined Patent Publication (Kokai) No. 59-225816 discloses that the actual tension of a winding device driven at a current value corresponding to a set tension is detected, and the detected tension is converted into a control signal of a motor current value. A technique for equalizing the tension and the set tension is disclosed. This is a technique for removing the influence on the fluctuation of the tension due to the change in the diameter of the winding coil, and preventing the occurrence of uneven winding, waist breaks and winding defects.

Similarly, a current control circuit for inputting a current reference signal corresponding to the output of the tension setter and changing the number of revolutions to control the tension to a target value is provided. JP-A-60-15019 discloses a technique for controlling the winding tension to a target value by using a deviation signal by comparing the above-mentioned values. This is a technique relating to tension control of an andrel motor.

[0007] The above prior art relates to the basic technology which is the basis of the tension control of the andrel motor of the present invention.

[0008]

The present invention relates to the control of a coiler drive system provided with a common converter in which a mandrel motor and a pinch roll motor inverter are connected in parallel.

If the mandrel motor and the pinch roll motor generate only the tension of the rolled steel sheet, the regenerative power of the pinch roll motor recovers a part of the power running power of the mandrel motor and reduces the required power. All that is needed is a common converter capacity that is slightly larger than the power difference.

However, actually, the acceleration of the line speed,
In some cases, electric power required for bending force of a rolled steel sheet or the like is required as electric power other than generation of tension. In such a case, the capacity of the common converter may be insufficient. In this case, in the worst case, the power supply is cut off from the viewpoint of protection of the common converter, and the line must be stopped even during rolling, which may not be able to avoid adverse effects on the operation. Was. For this reason, conventionally, since the common converter capacity is determined in consideration of all possible and unpredictable factors and safety is considered, it has not been possible to make the common converter as economical as possible.

The present invention is designed to suppress the capacity of the common converter in such a coiled steel drive system of the rolled steel sheet to the minimum necessary, suppress an overload state exceeding the capacity, and provide a stable winding of the winding device. It is an object of the present invention to provide a method and a device for realizing the taking.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its technical means is a coiler having a common converter in which inverters of a mandrel motor and a pinch roll motor are connected in parallel. In a drive system control method, a permissible upper limit of power consumption of a common converter is detected, and a set tension or a winding speed of a rolled steel sheet is reduced based on the detected upper limit. By adopting this control method, the required capacity of the common converter can be minimized, and the most economical system can be realized.

[0013] The apparatus of the present invention capable of suitably carrying out the above method comprises a mandrel for winding a rolled steel sheet, a pinch roll for restraining the rolled steel sheet immediately before the mandrel,
A detector for detecting power consumption of a common converter in a controller for a coiler drive system including an inverter for controlling a mandrel motor and an inverter motor, respectively, and a common converter in which the inverters are connected in parallel; A controller for comparing the value with the rated capacity of the common converter, and a controller for reducing the set tension or the winding speed of the rolled steel sheet based on the comparison value of the comparator, the control of the coiler drive system, comprising: Device.

The present invention takes measures to reduce the capacity of the common converter to the minimum necessary to improve the economical efficiency of the device, while preventing overload of the common converter.
Since the required power of the motor is the product of the torque and the rotation speed,
The power can be reduced by reducing the torque by reducing the set tension or reducing the rotation speed by reducing the winding speed. Therefore, the overload of the common converter can be prevented, and the design can be made economical.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a common converter type coiler drive system according to an embodiment of the present invention, and FIG. 2 is a control flowchart thereof. Rolled steel plate 21 is pinch roll 2
It is wound around the mandrel 23 through 2 and 23. The motors of the upper pinch roll 22, the lower pinch roll 23, and the mandrel 23 include inverters 2, 3, and 4, respectively.
These inverters are coupled to common converter 1 in parallel. The common converter 1 converts the tributary power supply 13 into a direct current and supplies the direct current to the inverters 2, 3, and 4. The inverters 2, 3, and 4 control the pinch roll motor and the mandrel motor to control the tension and speed of the rolled steel sheet 21 based on the commands from the tension setting device 7 and the speed setting device 8, respectively.

The power consumption of the common converter 1 is detected by the power detector 5, and the detected value W is compared with the rated power W ₀ of the common converter 1 by the comparator 6. If the detected value W of the power consumption of the common converter 1 is less than the rated power W ₀ , the winding is continued under the same condition. When the detected value W of the power consumption reaches or exceeds the rated power W ₀ ,
A command is output to the tension setting device 7 or the speed setting device 8 so as to reduce the tension or the speed. The tension setting device 7 or the speed setting device 8 gradually decreases the tension setting value 11 or the speed setting value 12 based on this command, and
Output a current command or speed command. This control, the detected value W of the power consumption of the common converter is executed until less than rated power W _0. Reducing the reduced amount detection value W of the power consumption of the common converter 1 for setpoint When becomes less than the rated power W _0, return to the original tension setting value or the speed setting value. With the above control, stable winding was achieved.

[0018]

As described above, the control method of the common converter type coiler drive system of the present invention is configured as described above, so that the common converter can be designed to have a minimum capacity, and the overload portion is separately provided. This has an excellent effect of being able to be eliminated by the above measures.

[Brief description of the drawings]

FIG. 1 is a control system diagram of a common converter type coiler drive system of an embodiment.

FIG. 2 is a control flowchart.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Common converter 2, 3, 4 Inverter 5 Power detector 6 Comparator 7 Tension setting device 8 Speed setting device 11 Tension setting value 12 Speed setting value 13 Power supply 21 Strip steel plate 22 Upper pinch roll 23 Lower pinch roll 24 Mandrel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F105 AA08 AB11 BA01 BA10 DA05 DA15 4E026 AA12 AA18 BA04 BA15 5H572 AA05 BB02 BB10 CC01 CC05 DD02 EE04 FF01 FF05 FF08 GG02 GG04 HB07 HC01 HC04 HC09 LL22 LL38 LL50

Claims (2)

[Claims] 1. A method for controlling a coiler drive system including a common converter in which inverters of a mandrel motor and a pinch roll motor are connected in parallel, wherein an allowable upper limit of power consumption of the common converter is detected. A method for controlling a coiler drive system, wherein a set tension or a winding speed is reduced. 2. A mandrel for winding a rolled steel sheet, a pinch roll for restraining the rolled steel sheet immediately before the mandrel, an inverter for controlling a mandrel motor and an inverter motor, respectively, and a common converter in which these inverters are connected in parallel. A controller for detecting power consumption of the common converter, a comparator for comparing a detection value of the detector with a rated capacity of the common converter, and a comparator for detecting power consumption of the common converter based on a comparison value of the comparator. A controller for controlling a set tension or a winding speed of a rolled steel sheet, the control device for a coiler drive system.