Functions
2.18 Synchronism and Voltage Check (optional)
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
356
Synchronism conditions for automatic reclosure
Addresses
3510
to
3519
are relevant to the check conditions before automatic reclosure of the circuit breaker.
When setting the parameters for the internal automatic reclosing function (Section 2.17.2), it is decided with
which automatic reclosing cycle synchronism and voltage check should be carried out.
Address
3510
Op.mode with AR
determines whether closing under asynchronous system conditions is
allowed for automatic reclosure. Set this parameter to
with T-CB close
to allow asynchronous closing; the
relay will then consider the circuit breaker closing time before determining the correct instant for the close com-
mand. Remember that closing under asynchronous system conditions is allowed only if the circuit breaker
closing time is set correctly (see above under „Preconditions“)! If you wish to permit automatic reclosure only
under synchronous system conditions, set this address to
w/o T-CB close
.
The permissible difference between the voltages is set in address
3511
AR maxVolt.Diff
. The setting is
applied in Volts secondary. This value can be entered as a primary value when parameterising with a PC and
DIGSI. Depending on the VT connection these are phase-to-earth voltages or phase-to-phase voltages.
The permissible frequency difference between the voltages is set in address
3512
AR maxFreq.Diff
, the
permissible phase angle difference in address
3513
AR maxAngleDiff
.
The further release conditions for automatic reclosing are set at addresses
3515
to
3519
.
The following addresses mean:
3515
AR SYNC-CHECK
both measuring points U
sy1
and U
sy2
must be energised (
Live Volt.
Thr.
, address
3503
); the synchronism conditions are checked, i.e.
AR
maxVolt.Diff
(address
3511
),
AR maxFreq.Diff
(address
3512
) and
AR maxAngleDiff
(address
3513
). This parameter can only be altered
with DIGSI under
Additional Settings
;
3516
AR Usy1<Usy2>
the measuring point U
sy1
must be de-energised (
Dead Volt. Thr.
,
address
3502
), measuring point U
sy2
must be energised (
Live Volt.
Thr.
, address
3503
) ;
3517
AR Usy1>Usy2<
the measuring point U
sy1
must be energised (
Live Volt. Thr.
, address
3503
), measuring point U
sy2
must be de-energised (
Dead Volt. Thr.
,
address
3502
);
3518
AR Usy1<Usy2<
both measuring points U
sy1
and U
sy2
must be de-energised (
Dead Volt.
Thr.
, address
3502
);
3519
AR OVERRIDE
automatic reclosure is released without any check.
The five possible release conditions are independent of one another and can be combined.
Synchronism conditions for manual closure and control command
Addresses
3530
to
3539
are relevant to the check conditions before manual closure and closing via control
command of the circuit breaker. When setting the general protection data (Power System Data 2, Section
2.1.4.1) it was already decided at address
1151
whether synchronism and voltage check should be carried out
before manual closing. With the following setting in address
SYN.MAN.CL
=
w/o Sync-check
, no checks are
performed before manual closing.
Note
If parameter
1151
SYN.MAN.CL
is set to
with Sync-check
or
w/o Sync-check
, it is recommended to set
the software filter time under DIGSI 4 for the binary input 356
„>Manual Close“
to 50 ms.
