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6.141
Date Code 20171021
Instruction Manual
SEL-421 Relay
Protection Applications Examples
Autoreclose and Synchronism-Check Example
Autoreclose and Synchronism-Check Example
Use the SEL-421 to provide automatic reclosing and synchronism check for
overhead transmission lines. This application example is for double-ended
500 kV parallel lines with SEL-421 protection at each end of the first circuit as
shown in
. This example shows the settings for the SEL-421 at Station
between Buses S (Moscow) and R (Pullman).
First set the autoreclose logic, and then set the synchronism-check function.
3PMRCD
Manual Close Reclaim Time Delay (1–99999 cycles)
900
BK1CLSD BK1 Reclose Supervision Delay (OFF, 1–99999 cycles)
300
Three-Pole Reclose (Group)
3POID1
Three-Pole Open Interval 1 delay (1–99999 cycles)
30
3PFARC
Three-Pole Fast Automatic Reclose Enable (SEL
OGIC
Equation) NA
3PRCD
Three-Pole Reclaim Time Delay (1–99999 cycles)
900
3PRI
Three-Pole Reclose Initiation (SEL
OGIC
Equation)
3PT AND Z1P
79SKP
Skip Reclosing Shot (SEL
OGIC
Equation)
NA
3P1CLS
a
Three-Pole BK 1 Reclose Supervision (SEL
OGIC
Equation)
DLLB1
Voltage Elements (Group)
EVCK
Reclosing Voltage Check (Y, N)
Y
27LP
Dead Line Voltage (1.0–200 V secondary)
15.0
59LP
Live Line Voltage (1.0–200 V secondary)
50.0
27BK1P
Breaker 1 Dead Busbar Voltage (1.0–200 V secondary)
15.0
59BK1P
Breaker 1 Live Busbar Voltage (1.0–200 V secondary)
50.0
a
This setting cannot be set to NA or logical 0.
Table 6.39
Settings for Autoreclose Example (Sheet 2 of 2)
Setting
Prompt
Entry
Figure 6.37
500 kV Power System
Z1L1, Z0L1
Z1L2, Z0L2
Z1S, Z0S
Z1R, Z0R
Z0M
VY
VBZ
VAZ
S (Moscow)
R (Pullman)
SEL-421
CB2
CB1
BUS 1
BUS 2
Summary of Contents for SEL-421-4
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