ABB RELION 670 Series Technical Manual page 568

Section 8
Current protection
delay characteristic which matches the heating characteristic of the generator
defined in standard IEEE C50.13.
where:
I
2
t
K
NS2PTOC (46I2) has a wide range of
tripping for negative sequence currents down to the continuous capability of a generator.
In order to match the heating characteristics of the generator a reset time parameter can be set.
A separate definite time delayed output is available as an alarm feature to warn the operator of a
potentially dangerous situation.
8.14.3 Function block
I3P*
BLOCK
BLKST1
BLKST2
BLKTR
ANSI08000359 V3 EN-US
Figure 298: NS2PTOC (46I2) function block
8.14.4 Signals
Table 299: NS2PTOC (46I2) Input signals
Name
I3P
BLOCK
BLK1
BLK2
BLKTR
562
is negative sequence current expressed in per unit of the rated generator
current
is operating time in seconds
is a constant which depends of the generators size and design
NS2PTOC (46I2)
TRIP
TR1
TR2
START
ST1
ST2
ALARM
NSCURR
ANSI08000359.vsdx
Type Default
GROUP -
SIGNAL
BOOLEAN 0
BOOLEAN 0
BOOLEAN 0
BOOLEAN 0
K settings and the sensitivity and capability of detecting and
Description
Group connection for neg seq.
Block of function
Block of step 1
Block of step 2
Block of trip signals
1MRK 502 066-UUS B
2
=
I t K
as
2
GUID-7071A62D-AB87-43C4-922A-1DD2E6DD5623 v2
PID-3854-INPUTSIGNALS v5
Technical manual