General - Siemens SIPROTEC 7RW80 Manual

2.7 SYNCHROCHECK 25
When connecting two sections of a power system, the synchrocheck function verifies that the switching does
not endanger the stability of the power system
Applications
• Typical applications are, for example, the synchronization of a feeder and a busbar or the synchronization
of two busbars via tie-breaker.
2.7.1

General

Synchronous power systems exhibit small differences regarding frequency and voltage values. Before connec-
tion it is to be checked whether the conditions are synchronous or not. If the conditions are synchronous, the
system is energized; if they are asynchronous, it is not. The circuit breaker operating time is not taken into con-
sideration. The synchrocheck function is activated via address 161 SYNCHROCHECK.
For comparing the two voltages of the sections of the power system to be synchronized, the synchrocheck func-
tion uses the reference voltage V
If a transformer is connected between the two voltage transformers as shown in the example Figure 2-21, its
vector group can be adapted in the 7RW80 relay so that there is no external adjustment required.
Figure 2-21
SIPROTEC, 7RW80, Manual
C53000-G1140-C233-1, Release date 10.2010
and an additional voltage to be connected V
1
Infeed
Functions
2.7 SYNCHROCHECK 25
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