GE Industrial Solutions 6KCV300WPD - Manual (Page 71)

Control Description
0
1
otherwise
Functionalities are all enabled: diameter and thickness are estimated from line speed
and winder motor speed (WMotSpd)
Diameter and thickness estimation are disabled, but diameter is updated according to
actual thickness. This is used during speed match and when torret is rotating. In this
case material path is changing so diameter estimation has to be disabled, however
, diameter is increasing (or decreasing if unwind) of thickness.
If thickness estimation is disabled (when or Tau2 are set to see
below) and thickness is zero (when is set to 0) this case is
cal to
Functionalities are all disabled: estimated diameter and thickness are constant.
This case is identical to Control=1 when thickness estimation is disabled (when Taul
or Tau2 are set to
see below) and thickness is zero (when
is set to 0).
Unwind input indicates direction of winding: rewinder and diameter increase when unwind = 0, unwinder
and diameter decrease when unwind = 1.
Diamobs block can control increment or decrement of diameter according to direction of winding: rewinding
or unwinding. For this
(Increment and Decrement Disabling) and Unwind (Unwinder)
inputs are provided. The meanings of these inputs are described in the following table:
0
Unwind Description
Estimated diameter is
different from 0
different from 0
0 Estimated diameter can only increase (rewinder)
different 0 Estimated diameter can only decrease
Diamobs is a algorithm with two time constants: Taul and Tau2 These inputs determine time that
observer takes to estimate diameter and thickness.
The simplest case is when user needs to estimate only diameter: must be set to le9 Taul is
diameter estimation time constant. It represents the same concept of time constant in electronic analog circuits
and it is equivalent to the product of and Capacitance. It is the time that estimated value takes to
reach 63% of its steady state value. After four times time constant reaches steady state value (98%).
More complex case is when user needs to estimate both variables: diameter and thickness. This is the case
when material is very thick.
If for example user wants to estimate diameter with a time constant of 2 and thickness with a time
constant of 10 he has to set Taul to 2 and Tau2 to 10 to 2 and
Taul to 10 is exactly equivalent).
In general terms the least value between Taul and is the time constant of diameter estimation while the
largest value is the time constant of thickness estimation.
Diamobs can estimate diameter and thickness with accuracy depending on winder motor speed (WMotSpd):
the higer winder motor speed, the more accuracy estimation will be. When winder motor speed is close to
zero, estimations have to stop. For this purpose two winder motor speed thresholds are provided (WMotThrl
and WMotThr2). When WMotSpd is below WMotThrl estimation is disabled. When WMotSpd is above
estimation is completely enabled. When WMotSpd is between WMotThrl and
time constants start very high and decrease until Taul and when WMotSpd reaches WMotThrl.
WMotThrl must be below WMotThr2.
WMotThrl and WMoThr2 values depends on speed sensor accuracy and on sample time of the control. The
less
sensor and the shorter sample time, the higher thresholds have to be.
6 1