Siemens Sinamics S120 Function Manual page 696

Applications
11.4 DCC axial winder
1. TTCU block: Winding hardness characteristic
2. DCA block: Diameter calculator
3. INCO block: Dynamic calculation of the moment of inertia for torque pre-control and Kp
Operating principle
To maintain a constant tension of the continuous web, the drive torque is increased linearly
as the wound roll diameter increases - or is decreased linearly as the diameter decreases.
To protect the material being wound, the tension is reduced according to a characteristic as
the wound roll diameter increases.
The calculation of the continuously changing moment of inertia permits a torque pre-control
during a steady decrease or increase of the winder speed.
By using an encoder, a speed controlled operation of the winder is possible. The winder can
be operated without an encoder by controlling the tension torque, with two scaling
parameters p1552 and p1554 for tension torque limitation (see torque limitation).
694
The block is used for defining the tension setpoint as a function of the actual diameter of
the roll being wound. The setpoint is adjusted according to a selectable characteristic
curve.
The DCA (Diameter Calculator) is used to determine the actual diameter of a roll being
wound based on the path velocity and the motor speed. The calculated diameter is
checked for plausibility.
adaptation of the speed controller
(see figure "Axial winder setup", abbreviations refer to block description).
The block calculates the mass moment of inertia of a wound roll, referred to the motor
side. In addition to the diameter (from DCA), the block also contains information on the
geometry and material properties of the winder and the winding product.
The static mass moment of inertia referred to the motor side is passed to the DCC block
via the parameter r1493. The result is fed back to the basic system via the scaling
parameter p1497 (referred to the static moment of inertia).
DEN SCL
OFS
n :
1
M
b
Figure 11-6 Axial winder setup
DMIN
D
n
2
DMAX
GF = n /n
1 2
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
V
W
n :
1
n :
2
M :
b
Drive functions