Siemens SIPROTEC 7SJ80 User Manual

[7sj80-anschl-rueckleist-schutz-20061205, 1, en_US]
Figure 2-104
Wiring diagram for a 7SJ80 as reverse power protection
Implementation of the Reverse Power Protection
General
The names of messages can be edited in DIGSI and adjusted accordingly for this example. The names of the
parameters are fixed.
Determination of the Reverse Power
The reverse power protection evaluates the active power from the symmetrical components of the funda-
mental harmonics of the voltages and currents. The evaluation of the positive sequence systems causes
reverse power determination to be independent of the asymmetries in currents and voltages and reflects the
real load of the driving end. The calculated active power value corresponds to the total active power. The
connection in the example illustrates positive measurement of power in the direction extending from the
busbar to the transformer of the device.
Functional Logic
The following logic diagram depicts the functional logic of the reverse power protection.
2.19.2
Functions
2.19 Reverse-Power Protection Application with Flexible Protection Function
256 SIPROTEC 4, 7SJ80, Manual
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