7.11 Out-of-step protection OOSPPAM (78)
GUID-667DAF85-B87B-47AA-9EAA-CD349E66F22F v3
7.11.1 Identification
GUID-BF2F1533-BA39-48F0-A55C-0B13A393F780 v2
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Out-of-step protection OOSPPAM
78
7.11.2 Functionality
GUID-BF2F7D4C-F579-4EBD-9AFC-7C03296BD5D4 v7
The out-of-step protection OOSPPAM (78) function in the IED can be used for both generator
protection and as well for line protection applications.
The main purpose of the OOSPPAM (78) function is to detect, evaluate, and take the required
action during pole slipping occurrences in the power system.
The OOSPPAM (78) function detects pole slip conditions and trips the generator as fast as
possible, after the first pole-slip if the center of oscillation is found to be in zone 1, which normally
includes the generator and its step-up power transformer. If the center of oscillation is found to
be further out in the power system, in zone 2, more than one pole-slip is usually allowed before the
generator-transformer unit is disconnected. A parameter setting is available to take into account
the circuit breaker opening time. If there are several out-of-step relays in the power system, then
the one which finds the center of oscillation in its zone 1 should operate first.
Two current channels I3P1 and I3P2 are available in OOSPPAM function to allow the direct
connection of two groups of three-phase currents; that may be needed for very powerful
generators, with stator windings split into two groups per phase, when each group is equipped
with current transformers. The protection function performs a simple summation of the currents
of the two channels I3P1 and I3P2.
7.11.3 Function block
GUID-CB98C615-8A93-438D-9DF0-542F333198AC v4
OOSPPAM (78)
I3P1*
I3P2*
V3P*
BLOCK
BLKGEN
BLKMOT
EXTZ1
TRIP
TRIPZ1
TRIPZ2
PICKUP
GENMODE
MOTMODE
R
X
SLIPFREQ
ROTORANG
VCOSPHI
ANSI14000055-1-en.vsd
ANSI12000188 V2 EN-US
Figure 199: OOSPPAM (78) function block
1MRK 502 066-UUS B Section 7
Impedance protection
375
Technical manual
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