Improper analog channel configuration causes a validation error if the analog
channels are not completely configured or they do not match with certain settings.
Check the contents of this chapter and also the preprocessing blocks in this
document. The configuration can be written to the protection relay once the
mismatch is corrected.
4.12.5.5 Operation principle
The function can be enabled and disabled with the
Operation
setting. The
corresponding parameter values are "on" and "off".
The operation of CNUPTOV can be described with a module diagram. All the
modules in the diagram are explained in the next sections.
BLOCK
OPERATE
Blocking
logic
Natural
unbalance
compensati
on
START
Level
detector
t
Timer
U3P
U_A
U_B
U_C
URES
UNEUT
U
neutral
U
1
U
o
Figure 642: Functional module diagram
Natural unbalance compensation
This module calculates the natural unbalance compensation. Calculation for
compensation is initiated through the command Record unbalance, available under
the menu path Control> CNUPTOV. The function equates the operating signal to
zero and calculates
from the available known quantities.
is memorized as
. This memorized value is then used when calculating the operating quantity.
For more information, see the
Chapter 4.12.5.6 Operating quantity
section in this
manual.
If the positive-sequence voltage is available at the time of memorizing the
value, the positive-sequence voltage is also memorized as
. The function then
applies the revised compensation voltage to account for change in bus voltages
between the moment of memorizing the compensation voltage and the time of
applying it.
U U m
U
U m
unb unb= ⋅( )
( )
1
1
Figure 643: Equation
Protection functions
1MRS759142 F
1150 REX640
Technical Manual
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