![background image](http://html.mh-extra.com/html/abb/relion-615-series/relion-615-series_technical-manual_2395520.webp)
GUID-9AACAC66-BF72-430C-AAC7-2E52C3DC4487-ANSI V1 EN
Figure 256:
Operation logic of instantaneous high stage
Reset of the blocking signals (de-block)
All three blocking signals, that is, waveform and second and fifth harmonic, have a
counter, which holds the blocking on for a certain time after the blocking conditions have
ceased to be fulfilled. The deblocking takes place when those counters have elapsed. This
is a normal case of deblocking.
The blocking signals can be reset immediately if a very high differential current is
measured or if the phase difference of the compared currents (the angle between the
compared currents) is close to zero after the automatic vector group matching has been
made (in a normal situation, the phase difference is 180 degrees). This does not, however,
reset the counters holding the blockings, so the blocking signals may return when these
conditions are not valid anymore.
External blocking functionality
87T has three inputs for blocking.
•
When the
BLOCK
input is active ("TRUE"), the operation of the function is blocked
but measurement output signals are still updated.
•
When the
BLK_OPR_LS
input is active ("TRUE"), 87T operates normally except
that the
OPR_LS
output is not active or activated in any circumstance. Additionally,
the
TRIP
output can be activated only by the instantaneous high stage (if not blocked
as well).
•
When the
BLK_OPR_HS
input is active ("TRUE"), 87T operates normally except
that the
OPR_HS
output is not active or activated in any circumstance. Additionally,
the
TRIP
output can be activated only by the biased low stage (if not blocked as well).
4.3.2.5
Application
87T is a unit protection function serving as the main protection for transformers in case of
winding failure. The protective zone of a differential protection includes the transformer,
Section 4
1MAC059074-MB A
Protection functions
514
615 series ANSI
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: ......