Service
Formation
Variable Speed Drives application note
Winder / Unwinder
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2
1
Winder/Unwinder Application
I. Introduction
II. Types of Winders/
Winders/Unwinders
III. Tension control
IV. Basic functions
V. The controller inside offer
VI. Appendix
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 2
Introduction
Winder/Unwinder systems are very frequently used in the industry
The allow to wind or unwind tapes or wires of all kind of material (paper,
metals, fiber, plastic film ).
Basically, you can find them at the beginning (feeding) or at the end
(storage) of a transformation process.
The system must ensure, for example, steady winding with regulated
tension whatever the line speed and the bobbin diameter.
The principals are various, but common functions can be isolated :
tension regulation of the material or linear line speed, start/stop control ...
The actual speed drives are effective enough to take into account theses
functions.
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 3
Winder/Unwinder Applications
I. Introduction
II. Types of Winders/
Winders/Unwinders
III. Tension control
IV. Basic functions
V. The controller inside offer
VI. Appendix
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 4
Types of Winders/Unwinders
Surface winding system
Winder
Line
Regulated tension
Nip rolls
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Types of Winders/Unwinders
Central winding system
Winder
Line
Regulated Tension
Nip
rolls
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Types of Winders/Unwinders
Roll system
Unwinder
Rider
roll
Tension
Winder
rear front
roll roll
Tension
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 7
Winder/Unwinder Applications
I. Introduction
II. Types of Winders/
Winders/Unwinders
III. Tension control
IV. Basic functions
V. The controller inside offer
VI. Appendix
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 8
Tension control
In order to illustrate the basics, we take the case of a simple
Winder/Unwinder with a central winding system.
We distinguish 4 types of basic functions:
Feeding or releasing of the film --> line speed regulation.
Winding --> tension control.
Unwinding --> speed control or tension control
Breakdown or stuck of the machine --> speed control + fast stop
In order to manage theses different cases, you must know or calculate the
following parameters:
Line speed
Bobbin diameter
Tape tension
Bobbin inertia
Mechanical losses ...
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Tension control
Tension torque
constant tension
r
In steady state, ignoring the frictions, if the bobbin is
pulled by its axis and directly linked to the motor then :
to obtain continuous Tension on a product :
the motor Torque must be proportional to the radius.
Cm : Motor torque (N.m)
r : radius (m)
t : tension (N)
Cm = r * t
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Tension control
Line speed
Constant line speed
In the same case
1
if the line Speed is contant :
the motor Speed is proportionally inverted to
the radius.
r1 start r2
V
V : line speed in m/s =
: motor speed (rad/s)
r : radius (m)
r1 + r2
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Tension control
Relation torque/speed
For winding and unwinding the motor works
with :
Continuous power,
Speed and Torque variable
P = continuous
Start
Start of
of winding
winding
or
or end
end ofof unwinding
unwinding
que
r
To
Mo
tor
Sp
ee
d
End
End ofof winding
winding or
or
start of unwinding
start of unwinding
Empty
reel Bobbin Radius
Radius min Radius max
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Tension control
Total resistant torque
Continuous tension f
k
r In order to estimate the motor torque in steady
M
state you must also take into account the continuous
and variables losses of the system linked to the
frictions, various efficiency and eventually to a reducer.
Theses resistant parasite torques are generally
measured or estimated by an empty test with different
Cm : Motor torque (N.m)
speeds.
r : radius (m)
t : tension (N)
: output
f : friction
k : reduction ratio (r * t ) + Crcte + Crf (V ) )
Cm =
k
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Tension control
Relation restistant torque /resulting speed
e
rqu
r to
t o
Start
Start of
of winding
winding Mo ue
or end of
or end of unwinding
unwinding
r q
io n to
e ns
T
Mo
tor
sp
ee
d
End
End ofof winding
winding or
or
Constant losses start
start of
of unwinding
unwinding
Variable losses
Empty reel
Bobbin radius
Radius min Radius max
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Tension control
Accelerating torque
traction constante
In transitory state (acceleration/deceleration) it is also
k suitable to adapte the torque relating to the inertias to
r
M drive.
Jb Two types of inertias exist :
Jm
Jf - fix for the motor, the reducer, the empty reel
- variable for the bobbin (related to the radius)
Cm : permanent motor torque (N.m)
Ca : Accelerating motor torque (N.m) J md + J b d
Cmt : Transitory motor torque (N.m) Ca = ( + Jm ) *
r : radius (m) 2
Jmd : empty reel inertia (kg.m) k dt
Jb : bobbin inertia (Kg.m)
Jm : motor inertia + reducer (Kg.m)
Cmt = Cm + Ca
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Tension control
Calculation of bobbin inertias
L 1/ empty reel inertia (fixe)
1 2
J md = m md .rmd
r 2
empty reel 2/ bobbin inertia (variable)
r1Start 1
Jb = m b .( r12 + r22 )
r2Fin 2
Roller mass : m = .L . . r
m : Roller mass (kg)
3
: Mass Volume (Kg/m )
L : Roller length (m)
r : Roller radius (m)
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Tension control
Motor sizing
Accelerating torque for the motor
1
C a = JT . .
t
Useful power of the motor 1
Pu = T . V .
Sizing, power of the motor P = C r 2 . 1
Ca : Motor Accelerating torque (N.m)
Jt : total inertia of the motor (kg.m)
Jb : bobbin inertia (Kg.m)
Jm : motor inertia + reducer (Kg.m)
: motor speed (rad/s)
t : acceleration min (s)
V : line speed (m/s)
: system effieciency
Cr2 : resistant torque at the end of winding (N.m)
1 : motor speed at the start of winding (rad/s)
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 17
Winder/Unwinder Applications
I. Introduction
II. Types of Winders/
Winders/Unwinders
III. Tension control
IV. Basic functions
V. The controller inside offer
VI. Appendix
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 18
Basic functions
Basic functions of winder/unwinder with central drive.
Motor
Speed
Speed line
tension
VSD Diameter
Tension
Speed set point
reference
Regulator Tension
Torque
profile
reference
Calculation
bobbin
Inertia comp. Motor speed
radius
Frictions comp.
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Basic functions
Function radius determination
The radius is one of the key
parameters to calculate the set points
and corrections.
It can be calculated with the line
speed (encoder or analogue sensor) and
the angular speed of the bobbin (motor
encoder)
Radius = V line / bobbin
V line or measured with a diameter sensor
(ex analogue ultra-sonic 4-20mA).
measurement
bobbin
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 20
Basic functions
Tension regulation : radius calculation
integrator
Line speed
reset
Bobbin turns
counter
integrator
Bobbin axis speed (motor)
scaling Bobbin radius
scaling
Bobbin radius sensor
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Basic functions
Function tension profile
trension In reality the tension on the tape is
rarely continuous. You might, for
example, want a strong pulling at the
max beginning of the tape and less strong
square at the end.
linear constant This function allows to define the
tension profile along the building of the
bobbin. It modifies the tension set point
according to the selected profile.
Hyperbolic
Following the material you can have
min different profiles.
The profiles are only necessary for the
radius winding.
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Basic functions
Tension regulation : tension set point
Traction
T1
Gains
Gains
profile
profile
T2 max
min Rayon
Ramps
Tension set point Tension Ramps
Tension
profile
profile
Radius
Final tension set point
PI
Tension feedback scaling
Filter scaling
Filter
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Basic functions
Function Speed set point
In tension mode the bobbin follows
as closely as possible the line speed with
the necessary latitude to follow the
tension profile (Torque set point)
In speed mode the regulation of the
torque is no more active. The
winder/unwinder follows the speed set
point.
The line speed information is given by
an external sensor (encoder,
V line
tachometer..) or by the supervisor.
bobbin
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 24
Basic functions
Tension regulation : Speed set point
Tension or speed state
Drive Speed
Ramps set point
Line speed L Dead
Dead Ramps
Scaling band
Scaling band
D
Bobbin radius
Acceleration
DS
DS
??
Deceleration
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Basic functions
Function inertia compensation
During acceleration and deceleration,
Transitory motor torque if the inertia is not compensated, it
results in strong tension pulling which
Resulting may result in breaking or folding the tape.
accelerating
Torque
This function calculates the constant
and variable inertia and adapts the
Bobbin torque set point to maintain the tension
accelerating
profile.
Torque
The variable inertia varies as power 4
empty reel of the radius.
accelerating
torque Jb = k * r 4
Resistant torque
radius
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Basic functions
Tension regulation : inertia compensation
Tension set point
Limitation
Limitation
bobbin
bobbin acceleration
inertia
inertia
xxradius
radius
calculation
calculation Drive torque
set point
Constant
Constantinertia
inertia
calculation
calculation
deceleration
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Basic functions
Function friction compensation (losses)
The frictions (losses) represent the
torque which is not used for the tension
Torque
neither the drive inertia.
Total losses We distinguish 2 types of losses :
Continuous losses (statics)
Variable losses linked to speed
(dynamics)
Variable losses Theses losses are generally determined
by a real life test.
Static losses : no load torque for 10% of
Constant the speed
losses Dynamic losses : no load torque function
of the speed
Following the systems, the dynamic
losses can be proportional to speed or
Line speed not.
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Basic functions
Tension regulation : Frictions compensation
Tension set point
couple
T1
T2 max
min vitess
Limitation
Limitation
winder
Dynamic
Dynamiclosses
losses
xxspeed
speed
torque set point
Static
Staticlosses
losses
unwinder
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Basic functions
Tension regulation
Tension regulator
Tension set point
Inertia
Inertia
compensation
compensation
frictions
frictions Torque set point
compensation
compensation
Speed drive
Speed loop Torque loop
Speed set point
MM
EE
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 30
Winder/Unwinder Applications
I. Introduction
II. Types of Winders/
Winders/Unwinders
III. Tension control
IV. Basic functions
V. The controller inside offer
VI. Appendix
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 31
Winder/Unwinder Applications
I. Introduction
II. Types of Winders/
Winders/Unwinders
III. Tension control
IV. Basic functions
V. The controller inside offer
VI. Appendix
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 32
Module titre
uestions - Answers
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 33
Motion&Drive Domain
Thank
Merci you For your attention
29/08/2008 Bertrand Guarinos STIE AN Winder - Unwinder V2 Summary 34
