![ABB 650 series Скачать руководство пользователя страница 113](http://html.mh-extra.com/html/abb/650-series/650-series_technical-manual_2503113.webp)
en05000190.vsd
0.5 kA
30
210
60
240
90
270
120
300
150
330
180
0
HV s ide contribution to the total negative s equence differential current in kA
Directional limit (within the region delimited by ± 60 degrees is internal fault)
1.0 kA
1.5 kA
definitely
an internal
fault
Internal fault
declared 7 ms
after internal
fault occured
trip co mmand
in 12 ms
excurs ion
from 0 degrees
due to CT
s aturation
external
fault
region
35 ms
Directional Comparis on Criterion: Internal fault as s een from the HV s ide
IEC05000190 V1 EN
Figure 35:
Operation of the internal/external fault discriminator for internal fault with
CT saturation
It shall be noted that additional security measures are implemented in the internal/external
fault discriminator algorithm in order to guarantee proper operation with heavily saturated
current transformers. The trustworthy information on whether a fault is internal or
external is typically obtained in about 10ms after the fault inception, depending on the
setting
IminNegSeq
, and the magnitudes of the fault currents. During heavy faults,
approximately 5ms time to full saturation of the main CT is sufficient in order to produce
a correct discrimination between internal and external faults.
6.1.3.9
Unrestrained, and sensitive negative sequence protections
Two sub functions are based on the internal/external fault discriminator and have the
ability to trip a faulty power transformer, are parts to the traditional power transformer
differential protection.
The unrestrained negative sequence differential protection
The unrestrained negative sequence protection is activated if one or more pickup signals
have been set by the traditional differential protection algorithm. This happens because
one or more of the fundamental frequency differential currents entered the operate region
1MRK 502 048-UUS A
Section 6
Differential protection
107
Technical manual
Содержание 650 series
Страница 1: ...Relion 650 series Generator protection REG650 ANSI Technical manual ...
Страница 2: ......
Страница 44: ...38 ...
Страница 62: ...56 ...
Страница 68: ...62 ...
Страница 156: ...150 ...
Страница 198: ...192 ...
Страница 512: ...506 ...
Страница 644: ...638 ...
Страница 714: ...708 ...
Страница 777: ...771 ...