JPH1025044A - Speed control device for roll drive motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify constitution without spoiling speed control accuracy in practical use by operating a plurality of induction motors of at least the previous section in two sections by means of one variable speed control device in parallel. SOLUTION: A power transducer 26 outputs alternating current of variable voltage and variable frequency based on torque reference τ* output from a speed control amplifier 17 and frequency reference Fo obtained through an adder 33, and operates a master motor 3a and helper motors 3b, 3c in parallel. It is at least provided with the function capable of supplying power of the same frequency and voltage against the three induction motors and driving them. Because a plurality of the induction motors 3a, 3b, 3c of the previous section are operated in parallel by one variable speed control device 8A of the previous section, the constitution can be remarkably simplified compared with a customary device having a variable speed control device for every driving motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control device for a roll drive motor for controlling the speed of a roll drive motor of a group of rolls for continuously feeding a roll material such as paper, film, steel plate or the like.

[0002]

2. Description of the Related Art FIG. 5 is a schematic diagram showing a part of a production line for continuously feeding a roll material, and a speed control device for conveying rolls constituting the production line. In the figure,
The material 1 is fed in the direction indicated by the arrow A by the transport rolls 2a, 2b, and 2c that form a group of rolls in the former section and the transport roll 4 that forms a group of rolls in the latter section. Of these transport rolls, the transport rolls 2a, 2b, 2c constituting the preceding section are driven by induction motors 3a, 3b, 3c, respectively, and the transport roll 4 constituting the subsequent section is driven by the induction motor 5.

The above-mentioned induction motors 3a, 3b, 3c, 4
Among them, in the former section, the transport roll 2a has the highest mechanical coupling with the material 1, and in the latter section, the transport roll 4 has the mechanical coupling as compared with other induction motors not shown. The degree is the largest. Therefore, in the following description, the induction motor 3a is the master motor 3a, and the induction motors 3b, 3c are the helper motors 3b, 3c.
c, Induction motor 5 is also referred to as master motor 5.

A speed detector 6a for detecting the speed of the master motor 3a is provided with helper motors 3b and 3b.
The speed detectors 6b and 6c are also connected to c, respectively, and further, the speed detector 7 is connected to the master motor 5. On the other hand, when the speed reference ω _{REF of the} line that conveys the material 1 is given, the master motors 3 are set so that appropriate tension acts on the material 1 between the conveyance rolls.
a, a front section speed setting device 11 is provided corresponding to the helper motors 3b and 3c, and a rear section speed setting device 12 is provided corresponding to the master motor 5. Therefore,
The variable speed control device 8a controls the speed of the master motor 3a such that the speed detection value of the speed detector 6a matches the speed reference ω _N1 * set by the speed setting device 11, and similarly, the variable speed control device 8b controls the speed of the helper motor 3b so that the speed detection value of the velocity detector 6b matches the speed reference omega _N1 *, variable speed controller 8c also speed reference omega _N1 * the speed detector 6c of the speed detection value The speed of the helper motor 3c is controlled so that the values of. In addition, the rear section variable speed controller 9 sets the speed reference ω set by the speed setter 12.
The speed of the master motor 5 is controlled so that the speed detection value of the speed detector 7 matches _N2 *.

[0005]

In the conventional transport roll speed control device described above, a speed detector and a variable speed control device are required for each transport roll constituting the transport roll group. At the same time, there has been a problem that the facility cost has been inevitably increased and the economical efficiency has deteriorated.

On the other hand, in this type of transfer device, a speed difference is generated between the front section and the rear section, and the load amount of the master motor 3a of the front section changes due to the speed difference, but the helper motors 3b, 3c Since the motor is not affected by the speed difference, a load imbalance may occur between these motors, causing a stall phenomenon due to a change in slip frequency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a first object of the present invention is to provide a speed control device for a roll drive motor which can simplify the configuration without impairing practical speed control accuracy. To provide.

Another object of the present invention is to provide a roll drive motor speed control device capable of reliably preventing a motor stall phenomenon.

[0009]

SUMMARY OF THE INVENTION According to the present invention, when controlling the speed of an induction motor that drives each of the transport roll groups of a front section and a rear section for feeding a roll material according to different speed standards, at least a plurality of the front sections are controlled. Since one induction motor is operated in parallel by one variable speed controller, the configuration can be significantly simplified as compared with a conventional device having a variable speed controller for each drive motor.

In this case, the sensorless vector control is effective. However, the roll material may be operated in a low speed range in feeding the roll material. At this time, the control accuracy is reduced due to the sensorless speed detection. There was something. In view of this, only the motor that drives the roll having the largest degree of mechanical coupling with the roll material is provided with speed detection means for detecting the speed, and the variable speed control device sets the detection speed of this speed detection means to the value of the preceding section. By calculating the output torque reference so as to match the speed reference, good control accuracy can be ensured even at a low speed without impairing the simple configuration.

[0011] Further, as a variable speed control device, an output of acceleration / deceleration rate means for outputting a time-based variation of the speed reference of the preceding section to a predetermined magnitude, and a droop characteristic setting for setting an initial speed of the motor. When the speed is compensated by adding the output of the means, the lower limit limiter outputs directly to the output side of the drooping characteristic setting means when the magnitude is larger than a predetermined value, and outputs the predetermined value when the magnitude is smaller than the predetermined value. Is provided to prevent a stall phenomenon at the time of starting or changing the speed.

Note that this stall phenomenon occurs not only at the time of starting but also at the time of acceleration / deceleration. Therefore, acceleration / deceleration torque bias setting means for setting a torque bias value at the time of acceleration / deceleration, acceleration / deceleration determination means for determining whether acceleration or deceleration is being performed based on the output of the acceleration / deceleration rate means, and During acceleration, the torque is added to the output torque reference as the corrected new output torque reference, and during deceleration, the torque bias value is subtracted from the output torque reference as the corrected new output torque reference. By providing the compensation means, it is possible to prevent a stall phenomenon at the time of acceleration / deceleration.

Further, by providing the variable speed control device with both a torque compensation function and a function of a lower limiter for the output of the drooping characteristic setting means, the variable speed control device can be used throughout starting, changing speeds, and accelerating / decelerating. Thus, the stall phenomenon can be reliably prevented.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings. FIG. 1 is a block diagram showing a schematic configuration of the first embodiment of the present invention together with a motor to which the present invention is applied. In the figure, the same elements as those in FIG. 5 showing the conventional device are denoted by the same reference numerals, and the description thereof will be omitted. Here, when the preceding section speed setting device 11 outputs the speed reference ω _N1 * based on the speed reference ω _REF of the transport line and adds the speed reference ω _N1 * to the preceding section variable speed controller 8A, the former section variable speed controller 8A becomes the master motor. 3
a, the configuration is such that the helper motors 3b, 3c are driven in parallel, which is different from the configuration in FIG.

FIG. 2 shows a front section variable speed control device 8A.
FIG. 3 is a block diagram showing a detailed configuration of FIG. In the figure,
The acceleration / deceleration rate circuit 13 is a section speed setting unit 11 for the preceding stage.
The speed reference ω _N1 * is input and the rate of change is limited to a predetermined value and output. Further, a drooping characteristic setting device 14 for setting the initial speed of each motor in the preceding section is provided, and the drooping characteristic reference and the speed reference output from the acceleration / deceleration rate circuit 13 are added by the adder 31, and the final The speed reference ω _N1X * is obtained. Adder 32
Is the speed reference ω _N1X * as a first input, the speed detection value ω _N1X detected by the _sensorless speed detection circuit 27 as a second input, and the output of a drooping characteristic circuit 16 described later as a third input. The speed detection value ω _N1X is subtracted from the reference ω _N1X *, and further, the output of the drooping characteristic circuit 16 is subtracted and added to the speed control amplifier 17.

The speed control amplifier 17 has a torque reference τ for _setting the deviation of the detected speed value ω _{N1X from} the speed reference ω _N1X * to zero.
* Is output. The drooping characteristic circuit 16 is for compensating the drooping characteristic of the speed based on the increase of the output torque reference τ *. For example, if the drooping characteristic is 3%, when the torque reference τ * is 100%, the drooping characteristic circuit 16 corresponds to 3%. The compensation amount based on the speed is obtained and added to the adder 32. With this speed control amplifier 17, the steady load torque τ * in the preceding section can be determined.

On the other hand, the sensorless speed detecting circuit 27 detects the fundamental wave component of the output voltage to the induction motor and calculates its speed. _N1X is added to the adder 32 and further to the rotation frequency calculator 25. The rotation frequency calculator 25 calculates the electric rotation frequency FR based on the detected speed value ω _N1X and adds the electric rotation frequency FR to the adder 33. Also, based on the output of the speed control amplifier 17, that is, the torque reference τ *, the slip frequency calculator 2
4 calculates the slip frequency FS and adds it to the adder 33.
The adder 33 outputs a frequency reference F ₀ by adding the frequency FS slip and rotational frequency FR.

Next, the power converter 26 is connected to the speed control amplifier 1
7 outputs a variable voltage and a variable frequency alternating current based on the torque reference τ * output from the controller 7 and the frequency reference F ₀ obtained through the adder 33, and the master motor 3a and the helper motors 3b and 3c are operated in parallel. I do. The power converter 2
The details of 6 are publicly known from literatures and the like, and the description thereof will be omitted. However, at least three induction motors are supplied with power having the same frequency and voltage to drive them. ing.

Thus, according to the first embodiment shown in FIG. 2, a plurality of induction motors 3a, 3 in the preceding section are provided.
Since b and 3c are operated in parallel by one front section variable speed control device 8A, the configuration can be greatly simplified as compared with a conventional device having a variable speed control device for each drive motor. it can.

By the way, as a speed detecting means of the sensorless vector control, a method of calculating from a voltage on dq axis stationary coordinates is generally used. However, in this method, speed detection accuracy at the time of low speed operation is low. Therefore, low speed operation is necessary,
In addition, when high speed control accuracy is required, there is a case where sensorless control is not suitable. Also, the master motor 3
The load of a has a strong mechanical coupling with the material 1, so that the load varies depending on the speed difference with the subsequent section. However, the helper motors 3 b and 3 c have a low mechanical coupling with the material 1, so that The load imbalance between the master motor 3a and the helper motors 3b and 3c constantly occurs because the speed difference between the master motor 3a and the helper motors 3b and 3c is not affected. Due to the imbalance of the load, the slip frequency required by each of the induction motors operated in parallel changes, so that the motor may stall.

FIG. 3 is a block diagram showing a schematic configuration of a second embodiment of the present invention which also solves these problems, together with an electric motor to which the present invention is applied. In the figure, the same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. here,
Of the master motor 3a and the helper motors 3b and 3c operated in parallel by the front section variable speed control device 8B, the transport roll 2a which is easily affected by the rear section.
Is actually detected by the speed detector 6 only the speed of the master motor 3a that drives the motor. The speed detector 6 has the function of the sensorless speed detection circuit 27 shown in FIG. 2, and has a different internal configuration from the former section variable speed controller 8A shown in FIG. To the speed detection value.

FIG. 4 shows a front section variable speed control device 8B.
3 is a block diagram showing a detailed configuration of the third embodiment. The same elements as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. In addition,
The preceding section variable speed control device 8B shown in FIG.
Although it also includes a slip frequency calculator 24, a rotation frequency calculator 25, and an adder 33 shown in FIG. 2, these elements are omitted for simplification of the drawing, and the output of the speed detector 6 is further shown. As ω _N1X .

In FIG. 4, the drooping characteristic setting unit 14
Is provided with a lower limiter 15. The lower limiter 15 outputs the value as it is when the size of the drooping characteristic setter 14 is larger than the predetermined value, and outputs the predetermined value when it is smaller than the predetermined value. It is set to the maximum speed fluctuation amount when pulled by the section and accelerated. Then, the drooping characteristic speed reference ω _DRP * obtained via the lower limiter 15 and the speed reference ω _N1A * obtained via the acceleration / deceleration rate circuit 13 are added by the adder 31 to obtain the final speed reference. ω _N1X * is obtained. The lower limiter 15 is designed such that its output value becomes zero when the drooping characteristic setter 14 is not operating.

A speed generator ω _N1A * obtained via the acceleration / deceleration rate circuit 13 is input, and a function generator 18 for obtaining a mechanical loss torque τ _M * corresponding to the speed reference ω _N1A * is provided. The mechanical loss torque τ _M * output from the function generator 18 is added to the adder 36. On the other hand, to the inertia compensation according to the speed reference omega _N1A * change of obtained via the acceleration and deceleration rate circuit 13, the inertia compensation setter 19 for setting the inertia moment GD ² speed control target is provided, the speed reference ω _N1A * differentiator 20
And the set value GD ² of the inertia compensation setting unit 19 are multiplied by the multiplier 21, and the acceleration / deceleration torque τ _ACC * output from the multiplier 21 is added to the adder 35. Further, the acceleration / deceleration torque bias setting unit 22 is set with a baise torque τ _B * that increases the output torque during acceleration and decreases the output torque during deceleration. To determine whether the vehicle is accelerating or decelerating.
, And the relay contact is closed during deceleration to be added as a subtraction input of the subtractor 34.

Thus, during acceleration, the subtractor 34 outputs a positive Baise torque τ _B *, and conversely, during deceleration, the subtractor 34 outputs a negative Baise torque τ _B *. The adder 35 adds the bias torque τ _B * and the acceleration / deceleration torque τ _ACC * output from the multiplier 21. Further, the output of the adder 35 and the mechanical loss torque τ _M * output from the function generator 18 are added by the adder 36. Accordingly, the adder 36 _outputs τ _M * + τ _ACC *
± τ _B * are output as torque compensation values, and these are added to the output τ _S * of the speed control amplifier 17 by the adder 37, and the power converter 26 (FIG.
See also).

As described above, when the speed of the rear section is increased by the rear section speed setting device 12, the master motor 3a of the front section is pulled by the rear section and accelerated because of a large degree of mechanical coupling with the material 1. However, according to the preceding section variable speed control device 8B shown in FIG. 4, the droop characteristic setting reference ω _DRP * output from the droop characteristic setting device 14 is larger than the speed change of the succeeding section. The section torque reference τ * does not constantly drop below the mechanical loss compensation torque τ _M *, and the helper motor 3b,
Since the minimum torque required to maintain the speed of 3c is output, the stall phenomenon of the helper motors 3b and 3c is eliminated.

Further, the acceleration and deceleration torque tau _ACC that actually required is during deceleration *, during acceleration bias torque tau _B * of power running direction, adds regeneration the direction of the bias torque tau _B * respectively decelerating The master motor 3
Even if the speed of “a” fluctuates due to the speed fluctuation of the subsequent section, a torque reference τ * that is equal to or more than the torque required for accelerating and decelerating the helper roll group is applied to the power converter 26. The stall phenomenon of 3b and 3c is eliminated.

In the second embodiment, the function of coping with the speed change of the subsequent section by the droop characteristic setting reference ω _DRP * of the lower limiter 15 and the acceleration / deceleration torque bias setter 22 and the acceleration / deceleration mode detector 23 are used. Although both functions corresponding to acceleration and deceleration of the subsequent section are provided by the bi-ice torque τ _B *, the helper motor 3b,
This is effective for eliminating the stall phenomenon 3c.

Further, in the above embodiment, the induction motors 3a, 3b, 3c of the preceding section are controlled by one preceding section variable speed control device 8A or 8B. The motor to be driven may be a part or all of the roll drive motor constituting the preceding section. In short, a plurality of induction motors are driven by one preceding section variable speed control device. Thereby, simplification of the configuration is achieved.

The configuration in which a plurality of motors are driven by one variable speed control device is not limited to the preceding section, but can be applied to the following section if necessary.

[0031]

As is apparent from the above description, according to the present invention, when controlling the speed of the induction motors for driving the respective transport roll groups of the front section and the rear section according to different speed standards, at least the front section is controlled. Since a plurality of induction motors are operated in parallel by one variable speed control device, the configuration can be significantly simplified as compared with a conventional device.

In this case, the speed control means is provided only for the motor driving the roll having the largest mechanical coupling with the roll material, and the feedback control is performed. Also, good control accuracy can be secured.

As a variable speed control device, a lower limiter is provided on the output side of the drooping characteristic setting means for outputting the value as it is when the size is larger than a predetermined value and outputting the predetermined value when the size is smaller than the predetermined value. Thus, the stall phenomenon at the time of starting can be suppressed.

Further, acceleration / deceleration torque bias setting means for setting a torque bias value during acceleration / deceleration is provided, and this torque bias value is added to an output torque reference during acceleration.
By deducting the torque bias value from the output torque reference during deceleration and using the corrected new output torque reference, a stall phenomenon during acceleration / deceleration can be prevented.

Further, by providing the variable speed control device with both a torque compensating function and a function of a lower limiter for the output of the drooping characteristic setting means, the variable speed control device can be used for all of starting, changing speed, and accelerating / decelerating. Thus, the stall phenomenon can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of the present invention, together with an electric motor to which the first embodiment is applied.

FIG. 2 is a block diagram showing a detailed configuration of a first-stage section variable speed control device constituting the embodiment shown in FIG. 1;

FIG. 3 is a block diagram showing a schematic configuration of a second embodiment of the present invention, together with an electric motor to which the second embodiment is applied.

FIG. 4 is a block diagram showing a detailed configuration of a preceding-stage section variable speed control device constituting the embodiment shown in FIG. 3;

FIG. 5 is a block diagram showing a configuration of a conventional roll drive motor speed control device together with a motor to which the roll drive motor is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Material 2a, 2b, 2c, 4 Conveyance roll 3a, 3b, 3c, 5 Induction motor 6,7 Speed detector 8A, 8B Front section variable speed control device 9 Rear section variable speed control device 11 Front section speed setting device 12 Rear stage Section speed setting device 13 Acceleration / deceleration rate circuit 14 Droop characteristic setting device 15 Lower limiter 16 Droop characteristic circuit 17 Speed control amplifier 18 Function generator 19 Inertial compensation setting device 20 Differentiator 21 Multiplier 22 Acceleration / deceleration torque bias setting device 23 Acceleration / deceleration Mode detector

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazufumi Ishihara 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Factory (72) Inventor Tokuo Kaneko 1-Toshiba-cho, Fuchu-shi, Tokyo Toshiba Corporation Fuchu factory

Claims (5)

[Claims] An induction motor for driving a group of transport rolls of a preceding section and a latter section for driving a plurality of transport rolls arranged in each section for feeding a roll material from a former section to a latter section by an induction motor. A speed control device for a roll drive motor for controlling the speed of an induction motor that drives a group of transfer rolls according to different speed references, wherein a variable speed control for operating at least a plurality of induction motors in at least a preceding section of the two sections in parallel. A speed control device for a roll drive motor, comprising a device. 2. A speed detecting means for detecting only the speed of an induction motor that drives a transport roll having the largest degree of mechanical coupling with a roll material among transport rolls driven by induction motors operated in parallel. The variable speed control device further includes speed control amplification means for calculating an output torque reference for the induction motor to be controlled such that the speed detected by the speed detection means matches the speed reference of the preceding section. Item 2. A speed control device for a roll drive electric motor according to item 1. 3. The variable speed control device includes: an acceleration / deceleration rate means for outputting a time-based change in speed reference of the preceding section to a predetermined magnitude, and a droop for setting an initial speed of the induction motor. A characteristic setting means, and a lower limiter for inputting a set value of the drooping characteristic setting means, outputting the value as it is when the magnitude is larger than a predetermined value, and outputting a predetermined value when the magnitude is smaller than the predetermined value; An adder for adding the output and the output of the acceleration / deceleration rate unit; and a speed control amplifier for calculating an output torque reference in accordance with a deviation between the output of the adder and the speed detected by the speed detector. The speed control device for a roll drive motor according to claim 1 or 2, wherein 4. The variable speed control device according to claim 1, wherein said variable speed control device controls acceleration and deceleration rate means for suppressing a time-based change in speed of said preceding section to a predetermined magnitude, and outputs the acceleration and deceleration rate means. Speed control amplification means for calculating an output torque reference in accordance with a deviation from the detection speed of the detection means; acceleration / deceleration torque bias setting means for setting a torque bias value during acceleration / deceleration; Acceleration / deceleration determining means for determining whether the vehicle is accelerating or decelerating, and, based on the result of the determination, adding the torque bias value to the output torque reference during acceleration to provide a corrected output torque reference, thereby decelerating. 3. The roll drive motor according to claim 1, further comprising: a torque compensating means for subtracting the output torque reference from the torque bias value to obtain a corrected output torque reference. Degree control device. 5. The variable speed control device further includes acceleration / deceleration torque bias setting means for setting a torque bias value during acceleration / deceleration, and whether the vehicle is accelerating or decelerating based on the output of the acceleration / deceleration rate means. Acceleration / deceleration discrimination means for discriminating, the torque bias value being added to the output torque reference during acceleration according to the discrimination result as a corrected output torque reference, and the output from the torque bias value being decelerated during deceleration. 4. The speed control device for a roll drive motor according to claim 3, further comprising: a torque compensating unit that sets a new output torque reference corrected by subtracting the torque reference.