![background image](http://html.mh-extra.com/html/abb/relion-615-series/relion-615-series_technical-manual_2395369.webp)
To satisfy the sensitivity requirements, basic ground-fault protection
(based on fundamental frequency phasors) should always be used in
parallel with the 67NIEF function.
The Fault indication logic module determines the direction of the fault. The fault direction
determination is secured by multi-frequency neutral admittance measurement and special
filtering techniques. This enables fault direction determination which is not sensitive to
disturbances in measured IG and VG signals, for example, switching transients.
When
Directional mode
setting "Forward" is used, the protection operates when the fault
is in the protected feeder. When
Directional mode
setting "Reverse" is used, the protection
operates when the fault is outside the protected feeder (in the background network). If the
direction has no importance, the value "Non-directional" can be selected. The detected
fault direction (FAULT_DIR) is available in the monitored data view.
In the "Transient EF" mode, when the start transient of the fault is detected and the VG
level exceeds the set
Voltage start value
, Timer 1 is activated. Timer 1 is kept activated
until the VG level exceeds the set value or in case of a drop-off, the drop-off duration is
shorter than the set
Reset delay time
.
In the "Intermittent EF" mode, when the start transient of the fault is detected and the VG
level exceeds the set
Voltage pickup value
, the Timer 1 is activated. When a required
number of intermittent ground-fault transients set with the
Peak counter limit
setting are
detected without the function being reset (depends on the drop-off time set with the
Reset
delay time
setting), the
PICKUP
output is activated. The Timer 1 is kept activated as long
as transients are occurring during the drop-off time defined by setting
Reset delay time
.
Timer 1
The time characteristic is according to DT.
In the "Transient EF" mode, the
TRIP
output is activated after
Trip delay time
if the
residual voltage exceeds the set
Voltage pickup value
. The
Reset delay time
starts to elapse
when residual voltage falls below
Voltage pickup value
. If there is no
TRIP
activation, for
example, the fault disappears momentarily,
PICKUP
stays activated until the the
Reset
delay time
elapses. After
TRIP
activation,
PICKUP
and
TRIP
signals are reset as soon as
VG falls below
Voltage pickup value
.
1MAC059074-MB A
Section 4
Protection functions
615 series ANSI
363
Technical Manual
Содержание Relion 615 series
Страница 1: ... RELION PROTECTION AND CONTROL 615 series ANSI Technical Manual ...
Страница 2: ......
Страница 39: ...Section 17 Glossary 1181 Table of contents 615 series ANSI 33 Technical Manual ...
Страница 40: ...34 ...
Страница 64: ...58 ...
Страница 210: ...3 19 4 Settings Section 3 1MAC059074 MB A Basic functions 204 615 series ANSI Technical Manual ...
Страница 216: ...210 ...
Страница 884: ...878 ...
Страница 1038: ...1032 ...
Страница 1136: ...1130 ...
Страница 1172: ...1166 ...
Страница 1180: ...1174 ...
Страница 1186: ...1180 ...
Страница 1192: ...1186 ...
Страница 1193: ...1187 ...
Страница 1194: ......
Страница 1195: ......