MR ETOS TD, Руководство по эксплуатации

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9 Visualization
Maschinenfabrik Reinhausen GmbH 2020 187 4453918/14 EN ETOS
®
TD
9.21.1.3 Circulating reactive current minimization without CAN bus
communication
With this method, you can operate several voltage regulators without a com-
munication connection (CAN bus) in parallel with circulating reactive current
minimization.
Desired cosφ
Desired cosφ
U, I, (cosφ)
T1: U, I, (cosφ)
T2: U, I, (cosφ)
M AVR M AVR
T1 T2
Figure 126: Circulating reactive current minimization without CAN bus communication
The circulating reactive current is calculated using the desired power factor
parameter, the desired load stress type parameter, and the measured trans-
former current. An extra control deviation proportional to circulating reactive
current is added to the independently regulating voltage regulators as a cor-
rection for the control deviation determined on the basis of the measurement
voltage. This extra control deviation depends on how much the measured
power factor deviates from the desired power factor.
To use the power factor method, you need to know the conditions of your
network in order to correctly set the device parameters.
The power factor method is suited to transformers connected in parallel with
a similar nominal output and short-circuit voltage U
K
and to vector groups
with the same and different step voltages. This does not require any informa-
tion about the tap position.
For the circulating reactive current minimization parallel operation method
without CAN communication, you have to set the following parameters:
▪ Activating parallel operation
▪ Parallel operation method: Power factor
▪ Circulating reactive current sensitivity
▪ Circulating reactive current blocking limit
▪ Desired power factor
▪ Desired load stress type
▪ Parallel operation error delay time