MR ETOS ED - Page 191

9 Visualization
Maschinenfabrik Reinhausen GmbH 2020 1916385142/08 EN ETOS
®
ED
change command is issued after expiration of the set delay time T1. The
on-load tap-changer carries out a tap-change in a raise or lower direction to
return to the tolerance bandwidth.
Figure135: Behavior of the control function with delay time T1
1 Upper limit of bandwidth 4 Set delay time T1
2 Desired value 5 Control variable measured value
3 Lower limit of bandwidth 6 Bandwidth range
A Control variable is outside of the
bandwidth. Delay time T1 starts.
B Control variable returned to within
the bandwidth before delay time
T1 has expired.
C Control variable is outside of the
bandwidth. Delay time T1 starts.
D Control variable is still outside the
bandwidth after delay time T1 has
expired. Tap-change operation is
initiated.
Delay time T2
You can use this parameter to set delay time T2. Delay time T2 is used to
compensate for large control deviations faster.
The delay time T2 only takes effect if more than one tap-change operation is
required to correct the control deviation. The first output pulse occurs after
the set delay time T1. After the set tap-change delay time T2 has elapsed,
additional pulses occur in order to correct the existing control deviation.
The following requirements must be noted to set delay time T2:
▪ The delay time T2 must be greater than the switching pulse time.
▪ The delay time T2 must be greater than the maximum operating time of
the motor-drive unit.
▪ The delay time T2 must be less than the value set for delay time T1.