Siemens siprotec SJ62 User Manual page 286

Connection, Multi-
ple-phase
Connection, Single-
phase
Operating Modes
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
Figure 2-101 Bus coupler
The synchronism check of 7SJ64 usually cooperates with the integrated automatic re-
closing system and the control functions of the control function. It is also possible to
employ an external automatic reclosing system. In such a case signal exchange
between the devices is accomplished via binary inputs and outputs.
The configuration decides whether the synchronism check is carried out only for auto-
matic reclosing or only for circuit breaker control or both. It is also possible to specify
different release criteria for automatic close or control close. Synchronous connection
is always accomplished via the integrated control.
The release command for closing under satisfied synchronism conditions can be de-
activated by parameter 6x13 25 Synchron. The disabled closing release can, how-
ever, be activated via binary input („>25 synchr."). It is intended for special appli-
cations (see„de-energized switching").
For comparing the two voltages the synchronism check takes the reference voltage V
and an additional voltage to be connected V
the multi-phase system, usually the three phase-ground voltages. The voltage to be
synchronized V is assigned to the single-phase connection and may be any phase-
2
ground or phase-phase voltage.
The device can also be connected in V-connection using two phase-phase voltages.
In that case, a phase-to-phase voltage must be connected to the voltage to be syn-
chronized V . Please observe also that a V-connection does not allow the zero se-
2
quence voltage to be determined. The functions „Directional Time Overcurrent Protec-
tion Ground", „Directional Ground Fault Detection" and „Fuse-Failure-Monitor (FFM)"
must be disabled.
If there is only one primary voltage to represent the reference voltage V
can be informed of this fact via the power system data. Also in this case the synchro-
nism check can be fully applied.
The synchronism check can be operated in two modes:
• Synchrocheck
• Synchronous / Asynchronous
Synchronous power systems exhibit small differences regarding phase angle and
voltage magnitude. Before connection it is checked whether conditions are synchro-
nous or not. If synchronism prevails the system is energized, with asynchronous con-
2.19 Synchronism and Voltage Check 25 (7SJ64 only)
. The reference voltage V
2
1
is derived from
1
, the device
1
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