JPH07243188A - Control device for electric motor for paper machine - Google Patents

Abstract

PURPOSE:To obtain a control device for an electric motor for a paper machine capable of lightening a burden of an operator following a ratio setting operation in change of paper width and maintaining an excellent burden sharing state up to the whole width. CONSTITUTION:In the case in which the torque standard of a first control means to regulate the speed of one electric motor is inputted to a ratio setting means, the ratio is multiplied and the multiplied value is used as the torque standard of a second control means to regulate the other electric motor, the ratio of the ratio setting means is changed and set by a calculating means in such a way that a tension sharing ratio after change of paper width is equal to a tension sharing ratio before the change. A ratio setting means capable of changing a set state by a manual operation to one by an electric signal is preferably used as the ratio setting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a motor for a paper machine, which independently drives a pair of rolls for nipping and transporting a paper which is shifted from a narrow width to a full width.

[0002]

2. Description of the Related Art In the paper manufacturing process using a paper machine,
There is a step of independently driving a pair of rolls arranged above and below or to the left and right by an electric motor, and transporting the paper from the front stage to the rear stage while sandwiching the paper between these rolls.
Generally, such conveyance is performed in a press part (4P part or smoother part), which is the final stage of the wet part, and a size part in an online coater machine.

FIG. 3 is a block diagram showing the construction of a conventional controller for a motor for driving a paper machine, which is applied to a roll driving motor in these steps. The electric motors 1 and 2 are configured to independently drive a pair of rolls 3 and 4 arranged vertically, and the paper 5 is conveyed from the front stage to the rear stage while being sandwiched by the rolls 3 and 4. .

In this case, the speed reference generator 6 for setting the paper speed reference V _REF corresponding to the electric motor 1, the set speed reference V _REF and the actual speed, that is, the speed feedback signal V _FB become equal. Thus, the speed control device 9 for controlling the current of the electric motor 1 and the speed detector 10 for detecting the speed of the electric motor 1 to obtain the speed feedback signal V _FB are provided. Of these, the speed control device 9 uses the speed reference V
A speed control circuit 7 that generates a torque reference τ _1REF that attempts to reduce the deviation between _REF and the speed feedback signal V _FB to zero.
And a torque control circuit 8 for controlling the current of the electric motor 1 so that the generated torque reference τ _1REF and the electric motor output torque (hereinafter also referred to as torque feedback) τ _1FB detected by a known device (not shown) become equal. It consists of and.

In addition, corresponding to the electric motor 2, the torque reference
A ratio setter 11 that inputs _1REF , multiplies the ratio k determined by an external setting operation, and outputs the _result , and a speed that controls the current of the electric motor 2 based on the torque reference τ _2REF output from the ratio setter 11. A control device 12 is provided. The speed control device 12 mainly uses the torque reference τ
_The torque control circuit 13 controls the current of the electric motor 2 so that _2REF and torque feedback τ _2FB detected by a known device (not shown) become equal.

With this configuration, for example, the torque reference τ
_{When 1REF} is 100%, the output of motor 1 is 100%
If the set ratio of the ratio setter 11 is 1, the torque reference τ _2REF is also 100%, so the output of the electric motor 2 is also controlled to 100%. The output 100% is the rated output of the electric motors 1 and 2. If both have the same rating, the output is the same, and if the rated output of the electric motor 2 is 1/2 that of the electric motor 1. , The electric motor 2 is 10
Even if the output is 0%, the output is 1/2 that of the electric motor 1.

Originally, even when the two rolls are individually driven, if the peripheral speeds of the rolls can be made to be exactly the same, no problem will occur when the paper is sandwiched and conveyed by these rolls. However, in practice, an error occurs due to a setting error or a difference in control accuracy, and since each of the control devices outputs the torque so as to match the speed reference given to it while including this error, the paper The rolls interfere with each other when they are conveyed by sandwiching them, and control is not performed well.

The apparatus shown in FIG. 3 solves this problem. One roll 3 is a master roll and the other roll 4 is a slave roll, and the speed control device 12 on the slave roll side is on the master roll side. The output torque of the electric motor 2 that drives the roll 4 is controlled based on the torque reference τ _1REF of the speed control device 9. Therefore, the speed control device 9 and the speed control device 12 perform load sharing control. The ratio setter 11 is for correcting a difference in mechanical loss between rolls and a difference in electric motor characteristics. FIG. 4 is a diagram showing the relationship between the setting range of the ratio setter 11 that performs load sharing and the output of the master-side electric motor and the output of the slave-side electric motor that use the set ratio as a parameter. In the figure, the straight line a shows the case where the load sharing ratio between the master side and the slave side is set to 2: 1 (k = 0.5), and the straight line b shows the load sharing ratio between the master side and the slave side at 1: 2 ( k = 2.0), and the straight line c shows the case where the master-side and slave-side load sharing rates are set to 1: 1 (k = 1.0). The ratio setter 11 can adjust the load sharing rate on the master side and the slave side from 2: 1 to 1: 2.

Incidentally, at the point A on the straight line a, the motor 1 on the master side outputs 50% torque, and correspondingly, a 25% torque reference is given to the motor 2 on the slave side. Further, at the point B on the straight line b, the motor 1 on the master side outputs 50% torque, and correspondingly, a torque reference of 100% is given to the motor 2 on the slave side. In practice, the master roll and slave roll apply pressure to the paper and convey it from the front stage to the rear stage.Therefore, in a stable state, the total torque required for tension is constant. If the sharing ratio is changed by 11, the load is transferred from the master roll to the slave roll (or from the slave roll to the master roll), and the load is controlled to a balanced point on the set ratio straight line.

By the way, in the manufacture of paper by a paper machine, a characteristic work called paper passing is performed. That is, in the paper machine line, when the paper is passed through, the paper is first passed through a narrow width up to a certain section and then widened (usually referred to as full width, hereinafter referred to as full width). Then, this work is sequentially repeated to pass the paper to the final stage (winding device).

Even in the section where the apparatus shown in FIG. 3 is provided, the paper is first passed through with a narrow width, and generally, the speed reference V _REF is adjusted to be slightly larger than that in the preceding step so as to give proper tension to the paper. To be done. Further, the load sharing rate of each roll at that time is also appropriately set by the ratio setting device 11. Then, since the paper spreads from the narrow width to the full width in a stable state after the adjustment is completed, the speed reference V _REF is adjusted again and the load sharing ratio is set by the ratio setting unit 11 again at that time.

[0012]

The output torque of the above-mentioned electric motor is mainly divided into a tension component and a mechanical loss component.
The proper setting of the load sharing ratio by the ratio setting device 11 is nothing but the proper ratio of the tension of the motor on the master roll side to the tension of the motor on the slave roll side. In general, it is desirable that the tension ratios of the two electric motors are the same in both narrow width and full width.

However, the conventional controller for the electric motor for a paper machine shown in FIG. 3 does not consider that the mechanical loss varies depending on the electric motor and the rating. For this reason,
If the setting state of the ratio setter 11 is kept the same, the load sharing ratio when the paper is conveyed in the narrow width and the load sharing ratio when the paper is conveyed in the full width are different, which is why In addition, when the width is changed from the narrow width to the full width, it is necessary to manually perform the ratio setting operation again, which increases the burden on the operator and at the same time, there is a fear of erroneous setting.

The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the burden on the operator due to the ratio setting operation at the time of shifting the paper width and to maintain a good load sharing state until the full width. An object of the present invention is to obtain a control device for an electric motor for a paper machine that can be used.

[0015]

DISCLOSURE OF THE INVENTION The present invention is a controller for a motor for a paper machine, which independently drives a pair of rolls for nipping and transporting a paper which is made to shift from a narrow width to a wide width. First control means for creating a torque reference corresponding to the difference between the set speed reference and the detected actual speed, and controlling the current of one of the electric motors so that the torque reference and the detected output torque are equal. And a torque reference generated by the first control means, a ratio setting means for multiplying and outputting a ratio determined by an external setting operation, a torque reference output from the ratio setting means, and a detected output. The second control means for controlling the current of the other electric motor so that the torque becomes equal to each other and the output torque of each electric motor before the paper width transition calculates the tension of the output torque of each electric motor after the paper width transition. With, when the paper width of the transition, and a calculating means for tension sharing ratio after migration to change setting the ratio of the ratio setting means to be equal to the tension sharing ratio before migration.

Preferably, the ratio setting means has a setting function by manual operation and a setting function by electric signal, and the setting state by manual operation can be changed by an electric signal.

[0017]

According to the present invention, the second reference means for controlling the other electric motor by inputting the torque reference of the first control means for controlling the speed of one of the electric motors to the ratio setting means, and multiplying the ratio by the torque reference. In the case of the torque reference of, the calculation unit changes and sets the ratio of the ratio setting unit so that the tension sharing ratio after the paper width transition becomes equal to the tension sharing ratio before the transition.
It is possible to reduce the burden on the operator due to the ratio setting operation and to maintain a good load sharing state up to the full width.

In this case, by using as the ratio setting means a setting state that can be manually set can be changed by an electric signal, the introduction of the calculating means can be facilitated.

[0019]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, the same elements as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. This device is a ratio setter configured to be able to change the setting state by manual operation instead of the ratio setter 11 shown in FIG. 3 by an electric signal.
11a is used, the tension of output torque of each electric motor after paper width transition is calculated based on each output torque of electric motors 1 and 2 before paper width transition, and at the time of paper width transition, the tension share ratio after transition is calculated. The configuration differs from the device shown in FIG. 3 in that a calculation device 14 for changing and setting the ratio of the ratio setting means so as to be equal to the tension sharing ratio before the shift is newly provided. The arithmetic unit 14 is adapted to input a signal from the contact a which is closed at the time of shifting from the narrow width to the full width, and execute the calculation and the setting operation.

The operation of this embodiment configured as described above will be described below. The arithmetic unit 14 has a built-in memory, and the mechanical loss components of the electric motors 1 and 2 including the driven rolls are stored in the memory before passing the narrow width sheet. As shown in FIG. 2, the electric motor 1 that drives the roll 3
The master motor M _M, when the electric motor driving the roll 4 and the slave electric motor M _S, the rated output of the master electric motor M _M is 200 KW, the rated output of the slave electric motor M _S is also 200 KW. Also, the master motor M _M
The mechanical loss of the slave electric motor M _S is 25 KW. The narrow paper width is 1000 mm, and the full width paper width is 7000 mm.

First, the paper is passed in a narrow width, and the ratio setter 11
It is assumed that the tension with the preceding stage is appropriate and the most stable state is obtained by adjusting. At this time, the torque feedback τ _1FB on the master motor M _M side is 25% (200 KW × 0.
25 = 50 KW), and the torque feedback τ _2FB on the slave motor M _S side is 22.5% (200 KW × 0.225 =
45 kW). Ratio setter 11 in this state
The ratio k of a is k = 22.5% / 25% = 0.9. Further, the tension component T _HM of the master electric motor M _{M and} the tension component T _HS on the slave electric motor M _S side are as follows.

T _HM = 50KW-30KW = 20KW (1) T _HS = 45KW-25KW = 20KW (2) Next, it is assumed that the contact a is closed and the sheet passing state is changed from narrow width to full width. . The required tension component T _ZM of the master electric motor M _{M and} the required tension component T _ZS of the slave electric motor M _S in this full width are as follows.

[0023] T _ZM = T _HM × (full width / narrow) = 20KW × (7000/1000) = 140KW ... (3) T ZS = T HS × ( full width / narrow) = 20KW × (7000/1000) = 140 kW (4) The speed is constant even if the width is changed from the narrow width to the full width. At this time, if the set ratio of the ratio setter 11a is maintained at 0.9, the torque reference τ _2REF on the slave motor M _S side is as follows.

Τ _2REF = τ _1REF × 0.9 = ( _140KW + 30KW) × 0.9 = 153KW (5) Therefore, the tension component on the slave motor M _S side is T _ZS as shown in the following formula: T _ZS = 153 KW- 25 kW = 128 kW (6)

As a result, the balance of tension between the pair of rolls 3 and 4 is lost. The arithmetic unit 14 calculates the ratio k of the ratio setter 11a by the following equation.

[0026]

[Equation 1] Then, the arithmetic unit 14 gives the above-mentioned ratio k = 0.97 to the ratio setter 11a to change the set ratio from 0.9 to 0.97.
Change to. As a result, it is possible to shift from the narrow width to the full width without breaking the balance of the tensions of the upper and lower rolls 3 and 4.

The calculation results of the above equations (1) to (7) are summarized as follows.

[0028]

[Table 1]

[0029]

As is apparent from the above description, according to the present invention, the torque reference of one electric motor is input to the ratio setting means, and the ratio is multiplied here to control the other electric motor. In this case, since the tension sharing ratio after the paper width transition is made equal to the tension sharing ratio before the paper width transition, the operator's load associated with the ratio setting operation should be reduced and a good load sharing state should be maintained until full width. You can

In this case, it is possible to facilitate the introduction of the calculating means by using, as the ratio setting means, a setting state that can be manually set and changed by an electric signal.

[Brief description of drawings]

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

FIG. 2 is an explanatory view showing a state at the time of shifting the paper width to explain the operation of the present invention.

FIG. 3 is a block diagram showing the configuration of a conventional controller for a paper machine electric motor.

FIG. 4 is a diagram showing a relationship between an output of a master side electric motor and an output of a slave side electric motor using a setting ratio of a ratio setter constituting a conventional controller for a paper machine electric motor as a parameter.

[Explanation of symbols]

 1, 2 electric motor 3, 4 roll 6 speed reference generator 7 speed control circuit 8, 13 torque control circuit 9, 12 speed control device 11a ratio setting device 14 arithmetic device

Claims (2)

[Claims] 1. A control device for a motor for a paper machine, which independently drives a pair of rolls for nipping and transporting a paper which is made to shift from a narrow width to a wide width, and which is detected as a preset speed reference. A first reference means for controlling the current of one of the electric motors so that a torque reference corresponding to the difference with the actual speed is created, and the detected output torque is equal to the torque reference. The torque reference produced by the means is input, the ratio setting means for multiplying and outputting the ratio determined by the setting operation from the outside, and the torque reference output from the ratio setting means and the detected torque feedback become equal. Second control means for controlling the current of the other electric motor and the output torque of each electric motor before the paper width transition calculates the tension of the output torque of each electric motor after the paper width transition And a controller for changing the ratio of the ratio setting unit so that the tension sharing ratio after the shift becomes equal to the tension sharing ratio before the shift when the paper width shifts. . 2. The papermaking machine according to claim 1, wherein the ratio setting means has a setting function by manual operation and a setting function by electric signal, and the setting state by manual operation can be changed by an electric signal. Control device for electric motors for machines.