Sel 411L - Figure 3.105 Swing Signature Detector Logic

P.3.168
SEL-411L Relay Protection Manual Date Code 20151029
Protection Functions
Out-of-Step Logic (Zero Settings)
Figure 3.105 Swing Signature Detector Logic
Reset Conditions
Function
The Reset Conditions logic corresponding to the block with the same name in
Figure 3.101 is shown in Figure 3.106.
As shown in Figure 3.101, the OSB function will reset under the following
conditions.
1. The SCV1 magnitude will be greater than 0.85 or the positive-
sequence impedance Z1 will be outside the starter zone for
more than 0.5 s or the OST function will be enabled and Z1
will stay outside Zone 7 for more than 30 cycles.
2. The slow derivative dSCV1_S will be smaller than 0.0026
(pu V/cyc) for more than 10 cycles under a no-fault condition.
AND 2
AND 4
OSBA
OSBB
OSBC
Z2G
OOSB2 = Y
Z3G
OOSB3 = Y
Z4G
OOSB4 = Y
Z5G
OOSB5 = Y
Z2P
OOSB2 = Y
Z3P
OOSB3 = Y
Z4P
OOSB4 = Y
Z5P
OOSB5 = Y
67QUBF
SPO
| dSCV1_Unflt
k–16
|
| dSCV1_Unflt
k–17
|
| dSCV1_Unflt
k–23
|
dSCV1_Unflt
max
0.05 • dSCV1_Unflt
max
0.001
2
AND 3
•
•
•
0.125
CYC
0.5
CYC
Reset Timer
0
8
CYC
SSDAND 1