Schweitzer Engineering Laboratories SEL-421-4 - Autoreclose and Synchronism-Check Example; Figure 6.37 500 Kv Power System

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 Figure 6.37. This example shows the settings for the SEL-421 at Station
S protecting Line 1 in Figure 6.38 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 (SELOGIC Equation) 3PT AND Z1P
79SKP Skip Reclosing Shot (SEL
OGIC Equation) NA
3P1CLS
a
Three-Pole BK 1 Reclose Supervision (SELOGIC 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
Z
1L1
,
Z
0
L
1
Z
1L2
,
Z
0
L
2
Z
1
S
,
Z
0
S
Z
1
R
,
Z
0
R
Z0
M
VY
VBZ
VAZ
S
(
Moscow
)
R
(
Pullman
)
S
EL-42
1
C
B
2
C
B
1
B
US
1
B
US
2