Sel 411L - Figure 3.108 Dependable Power-Swing Block Detector Logic (EOOS = Y1)

P.3.170
SEL-411L Relay Protection Manual Date Code 20151029
Protection Functions
Out-of-Step Logic (Zero Settings)
In summary, for an external forward fault, the logic issues a DOSB signal if
the signal from a fault detector has lasted several cycles, no power swing has
been detected, the relay has issued no trip, and at least one of the Zone 1
phase-mho has picked up or when FZAVG asserts. For a reverse fault, the
logic issues a DOSB signal if a power swing has not been detected, the signal
from a fault detector has lasted several cycles and been cleared, the relay has
issued no trip signal, and a Zone 2 mho-phase has picked up within a time
delay.
Depending on the EOOS setting, the relay selects either the logic shown in
Figure 3.108 (EOOS = Y1) or the logic shown in Figure 3.108 (EOOS =Y).
Figure 3.108 shows the dependable power-swing block detector logic.
Figure 3.108 Dependable Power-Swing Block Detector Logic (EOOS = Y1)
DIR5 = F
DIR4 = F
Z5P
Z4P
Z3P
Z2P
OSB
OSB1
TRIP
SERCAB
SERCBC
MAB1I
XAB1I
MBC1I
XBC1I
SERCCA
MCA1I
XCA1I
MAB2I
XAB2I
MBC2I
XBC2I
MCA2I
XCA2I
Z1MAG
FZAVG
| Z1F
k
— Z1F
k — 1
| • 8 • NFREQ
| d2SCV1_UF |
2 • d2SCV1_UF_avg + 0.06
DIR3 = F
0
0.25
CYC
0
0.25
CYC
0
0.25
CYC
0.25
CYC
0
0
0.25
CYC
0
2.5
CYC
0
0.125
CYC
1.5
CYC
0
0
2.5
CYC
DOSBY1
0
1.5
CYC
0
60
CYC
1