Siemens SIPROTEC 7SD80 User Manual

Functions
2.2 Phase Comparison Protection and Ground Differential Protection
SIPROTEC, 7SD80, Manual
E50417-G1140-C474-A1, Release date 09.2011
57
The following figure shows the pickup behavior of the phase comparison protection in resonant-grounded or
isolated systems.
Figure 2-9 Phase comparison protection in resonant-grounded/isolated systems
You will find the logic diagram for the general pickup of the differential protection and the differential protection
tripping in Section 2.2.5.
2.2.2.2 Setting Notes
General
The phase comparison protection can be switched ON or OFF at address 1201 87L PCC-Prot.. This requires
the differential protection to be set to Enabled at address 112 87 DIFF.PROTEC..
For cables and long lines, the capacitive charging current is decisive for determining the pickup values. The
charging current is calculated as follows:
I
C
=2π · f
Nom
· C
B
' ·s·V
Nom
/√3
where
I
C
charging current in A
f
Nom
rated power system frequency in Hz
C
B
' referred rated capacitance of the line in F/km
V
Nom
rated system voltage in V
s line length in km

Siemens SIPROTEC 7SD80 Specifications

General

Brand	Siemens
Model	SIPROTEC 7SD80
Category	Protection Device
Language	English