![Schweitzer Engineering Laboratories SEL-421-4 Скачать руководство пользователя страница 400](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-421-4/sel-421-4_instruction-manual_1216726400.webp)
6.64
SEL-421 Relay
Instruction Manual
Date Code 20171021
Protection Applications Examples
345 kV Tapped Overhead Transmission Line Example
Station T has the greatest overreach. Use
to set Zone 3 phase-
distance element reach.
Equation 6.30
where:
Equation 6.31
Z3MP :=
50.50
.
Zone 3 Reach (OFF, 0.05–64
secondary)
Ground-Distance Elements (21MG and 21XG)
Mho Ground-Distance Element Reach
Employ each zone of mho ground-distance protection as follows:
➤
Zone 1—Instantaneous underreaching tripping
➤
Zone 2—DCB scheme tripping
➤
Zone 3—DCB scheme blocking
Zone 1 Mho Ground-Distance Element Reach
Zone 1 mho ground-distance element reach must meet the same requirement as
that for Zone 1 mho phase-distance protection; the reach setting can be no greater
than 80 percent of the protected line.
Z1MG = Z1MP = 3.2
Z1MG :=
3.20
.
Zone 1 (OFF, 0.05–64
secondary)
Zone 2 Mho Ground-Distance Element Reach
Set Zone 2 ground-distance element reach equal to Zone 2 phase-distance ele-
ment reach; this ensures that Zone 2 ground-distance elements can see faults
internal to the tapped autotransformer. Zone 2 phase-distance element reach was
set to see the largest apparent fault impedance for faults at the 138 kV terminal of
the tapped autotransformer.
Z2MG = Z2MP = 11
Z2MG :=
11.00
.
Zone 2 (OFF, 0.05–64
secondary)
Zone 3 Mho Ground-Distance Element Reach
Set Zone 3 ground-distance element reach equal to Zone 3 phase-distance ele-
ment reach; this ensures that Zone 3 ground-distance elements coordinate with
the remote Zone 2 ground-distance elements at Station R and Station T for out-
Z3MP
CTR
PTR
------------
=
%
Z per-unit
Z
base
120%
• •
200
3000
------------
0.53 1190.25 1.2
• •
•
=
50.5
=
Z
base
345kV
2
100 MVA
-------------------------
=
1190.25
=
Содержание SEL-421-4
Страница 6: ...This page intentionally left blank ...
Страница 14: ...This page intentionally left blank ...
Страница 30: ...This page intentionally left blank ...
Страница 104: ...This page intentionally left blank ...
Страница 128: ...This page intentionally left blank ...
Страница 536: ...This page intentionally left blank ...
Страница 584: ...This page intentionally left blank ...
Страница 616: ...This page intentionally left blank ...
Страница 696: ...This page intentionally left blank ...
Страница 750: ...This page intentionally left blank ...
Страница 755: ...Instruction Manual PM400 01 NB SEL 400 Series Relays Instruction Manual 20171006 ...
Страница 776: ...This page intentionally left blank ...
Страница 932: ...This page intentionally left blank ...
Страница 976: ...This page intentionally left blank ...
Страница 1024: ...This page intentionally left blank ...
Страница 1038: ...This page intentionally left blank ...
Страница 1064: ...This page intentionally left blank ...
Страница 1128: ...This page intentionally left blank ...
Страница 1206: ...This page intentionally left blank ...
Страница 1316: ...This page intentionally left blank ...
Страница 1350: ...This page intentionally left blank ...
Страница 1464: ...This page intentionally left blank ...
Страница 1468: ...This page intentionally left blank ...
Страница 1492: ...This page intentionally left blank ...
Страница 1518: ...This page intentionally left blank ...