Siemens SIPROTEC 7SS522 V4.6, Руководство пользователя

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Circuit Breaker Failure Protection
117
7SS52 V4 Manual
C53000-G1176-C182-3
5.3.5 Bay-Specific Functions (BU)
All parameters of the breaker failure protection function can be set separately for each
feeder. Thus the function can be matched to different types of bays (e.g. line, trans-
former) or short-circuit conditions (e.g. low-current faults).
5.3.5.1 Triggering and Releasing the Breaker Failure Protection
The parameter
BF BI MODE
(
XX14/CU
) is used to specify whether the breaker failure
protection function will be triggered exclusively by the feeder-selective binary input (1-
channel) or only after evaluation of a second binary input (">
CBF release
" (
FNo.
7615/BU
) or ”
>CBF rel.3p
. ” (
FNo. 7622/BU
)) (2-channel). Normally the function
is released by pickup of the feeder protection. Triggering by 2 channels gives the
breaker failure protection extra reliability. Together with every TRIP command, a
transfer trip is generated.
Apart from triggering and releasing, there is also the pulse mode for breaker failure
protection. For more information on the pulse mode, please refer to page 123 and Fig-
ure 5-22, page 121.
If a binary input for triggering the breaker failure protection ("
>CBF L1
" (
FNo. 7611/
BU
), "
>CBF L2
" (
FNo. 7612/BU
) , "
>CBF L3
" (
FNo. 7613/BU
) or "
>CBF 3-pole
"
( FNo. 7621/BU )) is activated erroneously, a feeder current above the threshold for the
breaker failure protection is apt to cause a spurious trip of the busbar.
The following monitoring measures can be taken to detect this kind of errors in time:
•
If a triggering signal is present for more than 15 s, the faulty binary input is blocked
and the annunciation
"
BF-BIErr $00 Lx
" (
FNo. 176.1091, 176.1092,
176.1093/CU
) or "
BFBIErr $00 3P
" (
FNo. 176.1094/CU
) is output.
•
If the release signal for the breaker failure protection is present for longer than the
time set in the parameter
T-BF rel sup
(
XX27/CU
), the breaker failure protection
is blocked and the annunciation "
BFRlErr $00 1P
" (
FNo. 176.1101/CU
) or
"
BFRlErr $00 3P
" (
FNo. 176.1102/CU
) is output. As long as the release signal
is present, the breaker failure protection of this feeder is blocked.
•
If a 1-pole or 3-pole triggering signal is present but no release signal arrives within
a settable time
T-BF 2chan
(
128/CU
), the breaker failure protection is selectively
blocked and the annunciation "
BF-BIErr $00 Lx
" (
FNo. 176.1091,
176.1092, 176.1093/CU
) or "
BFBIErr $00 3P
" (
FNo. 176.1094/CU
) is
output.
Figure 5-17 Characteristics of the breaker failure protection
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