Siemens SIPROTEC 7SJ80 User Manual

Synchrocheck
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.
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
consideration. 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
function uses the reference voltage V
1
and an additional voltage to be connected V
2
.
If a transformer is connected between the two voltage transformers as shown in the following example, its
vector group can be adapted in the 7SJ80 relay so that there is no external adjustment required.
[synchro-fkt-einspeis-061115, 1, en_US]
Figure 2-112 Infeed
2.20
2.20.1
Functions
2.20 Synchrocheck
SIPROTEC 4, 7SJ80, Manual 261
E50417-G1140-C343-A8, Edition 12.2017

Siemens SIPROTEC 7SJ80 Specifications

General

Rated Frequency	50/60 Hz
Rated Current	1 A / 5 A
Operating Temperature	-25°C to +55°C
Storage Temperature	-40°C to +70°C
Current Transformer Inputs	4
Application	Protection of feeders, motors, transformers, and generators
Rated Voltage	100-240 V AC/DC
Communication Protocols	IEC 61850, Modbus, DNP3, IEC 60870-5-103
Display	Graphical LCD
Mounting	Flush mounting
Protection Functions	Overcurrent, Earth fault
Communication Interfaces	Ethernet, RS485
Housing	Plastic
Weight	Approx. 1.5 kg