Siemens SIPROTEC 4, User Manual, Page: 290 / 734

[synchronisierfunktion-querkupplung-260602-kn, 1, en_US]
Figure 2-125 Bus coupler
The synchronizing feature of 7SJ62/64 usually coordinates with the integrated automatic reclosing 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 automatic 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 deactivated by parameter
6x13
25 Synchron
. The disabled closing release can, however, be activated via binary input (
>25
synchr.
). It is intended for special applications (see De-energized switching).
Connection, Multiple-phase
For comparing the two voltages, the synchronization function uses the reference voltage V
1
and an additional
voltage to be connected V
2
. The reference voltage V
1
is derived from the multi-phase system, usually the three
phase-to-ground voltages. The voltage to be synchronized V
2
is assigned to the single-phase connection and
may be any phase-to-ground or phase-to-phase voltage.
The device can also be connected in open delta Voltage connection using two phase-phase voltages. In this
case, a phase-to-phase voltage must be connected to the voltage to be synchronized V
2
. Furthermore, it
should be noted that in case of a open delta voltage connection, zero sequence voltage cannot be detected.
The functions “Directional Overcurrent Protection Ground”, “Directional Ground Fault Detection” and “Fuse
Failure Monitoring (FFM)” must be either removed or switched off.
Connection, Single-phase
If there is only one primary voltage to represent the reference voltage V
1
, the device can be informed of this
fact via the Power System Data 1. Also in this case the synchronization function can be fully applied.
Operating Modes
The synchronism check can be operated in two modes:
•
Synchrocheck (7SJ62 and 7SJ64)
•
Synchronous / Asynchronous (only 7SJ64)
Synchronous power systems exhibit small differences regarding phase angle and voltage magnitude. Before
connection it is checked whether conditions are synchronous or not. If synchronism prevails the system is
energized, with asynchronous conditions it is not. The circuit breaker operating time is not taken into consid-
eration. The
SYNCHROCHECK
mode is used. It corresponds to the classic synchrocheck function.
On the other hand, asynchronous systems include bigger differences and the time window for switching
passes relatively quick. It is useful to consider the operating time of the circuit breaker. The
ASYN/SYNCHRON
mode is used.
Functions
2.21 Synchronization Function
290 SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016