Application Examples - Mitsubishi Electric A800 Plus Series Function Manual

10.4

Application examples

This section shows examples of major applications of the FR-A800-R2R inverters which have the dedicated functions for Roll
to Roll applications. Each example provides the overview and the example setting of relevant parameters.
10.4.1
Dancer feedback speed control with roll
diameter compensation for printers
This is useful for winding paper rolls for printers.
The roll diameter compensation function and the dancer feedback speed control enhance the speed and quality of winding.
Requirements for this application
High-speed winding is always required in this application. Furthermore, paper rolls must be wound with less sagging and
unevenness. Therefore, fluctuation of dancer rolls must be reduced to a minimum.
Purpose
Sagging and unevenness
prevention
Speedup
Cost reduction
Control overview
The FR-A800-R2R inverter for the intermediate roller controls the total line speed of paper rolls. The tension of the paper to be
wound is maintained constant by the dancer roll. Another FR-A800-R2R inverter is used to control the speed of the winding
roller (shaft). The inverter keeps the tension of the paper constant for winding by identifying the dancer roll in the same
position. The use of the roll diameter compensation function maintains the circumferential speed of the paper roll during
winding.
FR-A800-R2R inverters have the following additional functions as compared with the FR-A800 inverter standard models.
Additional function
Dancer feedback speed control
function
Analog output signal for dancer
tension control
Roll diameter compensation function
Tension PI gain tuning
Speed control proportional gain
compensation function
The inverter minimizes speed fluctuation to prevent sagging and unevenness.
Higher responsivity can be expected under Vector control using encoders (internal response: 300 rad/
s).
A dancer roll controller is included in the inverter.
To keep the position of the dancer roll, PID control is performed for speed control of the winding
roller.
Taper function: To change a load applied to the dancer roll, analog signals as tension control
commands are output to an electro-pneumatic converter.
After the winding roll diameter is calculated, the motor speed is controlled based on data of the
diameter so that circumferential speed of the winding roll are kept constant. This function reduces
hunting in dancer feedback speed control. Roll diameter calculators and PID calculators do not
need to be added externally.
By automatically adjusting the tension PI gain for dancer PID control, time required for adjustment
is significantly cut down.
Anyone can start the system easily.
Speed control proportional gain can be changed based on the value determined by roll diameter
calculation.
Application examples
Feature of inverter
Description
10
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APPENDIX