Siemens SIPROTEC 7SJ80 User Manual

[7sj80_prot-lo-qvp, 1, en_US]
Figure 2-52
Logic diagram of the QU protection
Reconnection
The release for reconnecting the generating facility is given under the following conditions:
•
All 3 phase-to-phase voltages are above the parameterized threshold value.
•
The power system frequency is within the parameterized range.
•
The delay time of the protection function has elapsed. The delay time is started by the first trip signal of
any stage of the voltage or frequency protection.
The release criteria for reconnection can be set. The following parameters are used:
•
Threshold for the release voltage at the power system connection point
•
Frequency deviation in positive and negative direction
•
Reconnection release can be delayed by a settable time.
You also define whether the tripping of the circuit breaker at the power system connection point is included in
the formation of the release signal. The tripping of the protection stages of voltage and frequency protection
is always included.
The following figure shows the logic diagram of the QU protection for reconnection.
Functions
2.9 Undervoltage-controlled reactive power protection (27/Q)
SIPROTEC 4, 7SJ80, Manual 143
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