This gives 20 % more total band for regulating, and this setting ensures that the voltage
remains within the voltage window after a tap change operation. You can increase the regulating
sensitivity by setting a smaller window; however, this is not advised.
Next, the window must be set into the voltage regulator: divide the calculated
U>/<
window
by two, and
then set the result as the value for the parameters
U> setting (+U
TGT
) and U< setting (-U
TGT
). If the
values for both window settings are equal, the regulator has same sensitivity for both overvoltage and
undervoltage situations. The voltage windows as well as all other setting parameters are in relation
to the set target voltage
U
TGT
. If the target voltage is changed, the voltage window setting
parameters change as well to follow the new target voltage.
The following three images present various situations with the setting of the voltage window.
Figure. 5.4.4 - 173. Tight voltage window (window not reached).
In this example situation the set voltage window is too tight compared to the tap effect. The AVR cannot
reach the target window and thus lowers the voltage. Eventually a stable voltage may be found but the
next tap change request will cause similar fluctuation and the cycle begins again.
Figure. 5.4.4 - 174. Tight voltage window (window reached but voltage near the limit).
A
AQ
Q-T215
-T215
Instruction manual
Version: 2.04
271
