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When the bus coupler is in the open position, each section of the busbar handles
the current flow independently, that is, the instantaneous incoming current is equal
to the total instantaneous outgoing current and the difference current is negligible.
The difference current is no longer zero with a fault in the busbar and the protection
operates.
With the bus coupler in the closed position, the current also flows from one busbar
section to another busbar section. Thus, the current flowing through the bus
coupler needs to be considered in calculating differential current. During normal
condition, the summation of the current on each bus section is zero. However, if
there is a fault in any busbar section, the difference current is no longer zero and the
protection operates.
Figure 446: Differential protection on busbar with bus coupler (Single-phase
representation)
4.3.6.7
Example calculations for busbar high-impedance differential
protection
The protected object in the example for busbar differential protection is a single-
bus system with two zones of protection.
Protection functions
1MRS759142 F
780
REX640
Technical Manual
Содержание RELION REX640
Страница 1: ... RELION PROTECTION AND CONTROL REX640 Technical Manual ...
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Страница 3: ...Document ID 1MRS759142 Issued 2023 02 07 Revision F Copyright 2023 ABB All rights reserved ...
Страница 167: ...Figure 62 Signal outputs in power supply module 1MRS759142 F Basic functions REX640 Technical Manual 167 ...
Страница 184: ...Figure 84 mA channels working as mA outputs Basic functions 1MRS759142 F 184 REX640 Technical Manual ...
Страница 1868: ...Figure 989 ANSI extremely inverse time characteristics General function block features 1MRS759142 F 1868 REX640 Technical Manual ...
Страница 1869: ...Figure 990 ANSI very inverse time characteristics 1MRS759142 F General function block features REX640 Technical Manual 1869 ...
Страница 1870: ...Figure 991 ANSI normal inverse time characteristics General function block features 1MRS759142 F 1870 REX640 Technical Manual ...
Страница 1874: ...Figure 995 ANSI long time inverse time characteristics General function block features 1MRS759142 F 1874 REX640 Technical Manual ...
Страница 1875: ...Figure 996 IEC normal inverse time characteristics 1MRS759142 F General function block features REX640 Technical Manual 1875 ...
Страница 1876: ...Figure 997 IEC very inverse time characteristics General function block features 1MRS759142 F 1876 REX640 Technical Manual ...
Страница 1877: ...Figure 998 IEC inverse time characteristics 1MRS759142 F General function block features REX640 Technical Manual 1877 ...
Страница 1878: ...Figure 999 IEC extremely inverse time characteristics General function block features 1MRS759142 F 1878 REX640 Technical Manual ...
Страница 1882: ...Figure 1002 RI type inverse time characteristics General function block features 1MRS759142 F 1882 REX640 Technical Manual ...
Страница 1885: ...Figure 1004 UK rectifier inverse time characteristic 1MRS759142 F General function block features REX640 Technical Manual 1885 ...
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