
3.44
SEL-311C Relay
Instruction Manual
Date Code 20060320
Distance, Out-of-Step, Overcurrent, Voltage, Synchronism Check, and Frequency Elements
Synchronism Check Elements
Synchronism Check Elements
Enable the two single-phase synchronism check elements by making the
enable setting:
E25 =
Y
and
show examples where synchronism check can be
applied. Synchronism check voltage input
VS
is connected to a potential
transformer secondary on one side of the circuit breaker, on any desired phase
or between any two phases. The other synchronizing phase (
VA
,
VB
,
VC
,
VAB
,
VBC
, or
VCA
) taken from a potential transformer secondary on the other side of
the circuit breaker is selected by setting SYNCP.
The two synchronism check elements use the same voltage magnitude
window (to ensure healthy voltage) and slip frequency settings (see
). They have separate angle settings (see
Fixed Angle
Synchronism Check
To implement a simple fixed-angle synchronism check scheme, set TCLOSD
= OFF and 25SF = 0.500. With these settings, the synchronism check is
performed as described in the top of
If there is the possibility of a high slip frequency, exercise caution if
synchronism check elements 25A1 or 25A2 are used to close a circuit breaker.
A high slip frequency and a slow breaker close could result in closing the
breaker outside the synchronism check window. Qualify the breaker close
command with a time delay, such as:
SV1 =
25A1
CL =
CC * SV1T
Set SV1PU with enough pickup delay to ensure that the slip frequency is low
enough for the circuit breaker to close within the synchronism check window.
Dynamic
Synchronism Check
The remainder of this discussion assumes TCLOSD is
not
set to OFF. With
TCLOSD not set to OFF, the synchronism check is performed as described in
either the top or bottom of
, depending on the slip frequency.
If the voltages are static (voltages
not
slipping with respect to one another),
the two synchronism check elements operate as shown in the top of
. The angle settings are checked for synchronism check closing.
If the voltages are
not
static (voltages slipping with respect to one another),
the two synchronism check elements operate as shown in the bottom of
. The angle difference is compensated by breaker close time, and
the breaker is ideally closed at a zero degree phase angle difference, to
minimize system shock.
These synchronism check elements are explained in detail in the following
text.
Содержание SEL-311C
Страница 1: ...20060320 SEL 311C Relay Protection and Automation System Instruction Manual PM311C 01 NB ...
Страница 22: ...This page intentionally left blank ...
Страница 42: ...This page intentionally left blank ...
Страница 68: ...This page intentionally left blank ...
Страница 128: ...This page intentionally left blank ...
Страница 294: ...This page intentionally left blank ...
Страница 330: ...This page intentionally left blank ...
Страница 402: ...This page intentionally left blank ...
Страница 406: ...This page intentionally left blank ...
Страница 454: ...This page intentionally left blank ...
Страница 574: ...This page intentionally left blank ...
Страница 592: ...This page intentionally left blank ...
Страница 616: ...This page intentionally left blank ...
Страница 648: ...This page intentionally left blank ...
Страница 652: ...This page intentionally left blank ...
Страница 678: ...This page intentionally left blank ...
Страница 682: ...This page intentionally left blank ...
Страница 722: ...This page intentionally left blank ...
Страница 724: ...This page intentionally left blank ...
Страница 732: ...This page intentionally left blank ...
Страница 748: ...This page intentionally left blank ...