Siemens siprotec 7SA522 User Manual

1 Introduction
26
7SA522 Manual
C53000-G1176-C155-3
• Two sets of earth impedance compensation
Power Swing Sup-
plement (optional)
• Power swing detection with dZ/dt measurement with three measuring systems
• Power swing detection up to a maximum of 7 Hz swing frequency;
• In service also during single-pole dead times
• Settable power swing programs
• Prevention of undesired tripping by the distance protection during power swings
• Tripping for out-of-step conditions can also be configured
Teleprotection Sup-
plement
• Different procedures may be set:
• Permissive Underreach Transfer Trip = PUTT (via a separately settable overreach
zone);
• Comparison schemes (Permissive Overreach Transfer Trip = POTT or blocking
schemes, with separate overreach zone);
• Suitable for lines with two or three ends
• Phase segregated transmission possible in lines with two ends
• Optionally signal exchange of the devices via dedicated communication links (in
general optical fibres) or a communication network, in this case a phase-segregat-
ed transmission with two or three line ends and continuous monitoring of the com-
munication paths and the signal propagation delay with automatic re-adjustment.
Earth Fault Protec-
tion (optional)
• Time overcurrent protection with maximally three definite time stages (DT) and one
inverse time stage (IDMT) for high resistance earth faults in earthed systems
• For inverse time protection a selection from various characteristics based on
several standards can be made
• The inverse time stage can also be set as fourth definite time stage
• High sensitivity (depending on the version from 3 mA);
• Phase current stabilization against fault currents during current transformer satura-
tion
• Second harmonic inrush restraint
• Optionally earth fault protection with zero sequence voltage tripping time or inverse
time tripping
• Each stage can be set to be non-directional or directional in the forward or reverse
direction
• Single-pole tripping enabled by integrated phase selector
• Direction determination with automatic selection of the larger of zero sequence
voltage or negative sequence voltage (U
0
, I
y
or U
2
), with zero sequence system
quantities (I
0
, U
0
), with zero sequence current and transformer starpoint current (I
0
,
I
Y
). or with negative sequence system quantities (I
2
, U
2
) or with zero sequence
power (3I
0
· 3U
0
);
• One or more stages may function in conjunction with a signal transmission supple-
ment; also suited for lines with three ends
• Instantaneous tripping by any stage when switching onto a fault

Siemens siprotec 7SA522 Specifications

General

Brand	Siemens
Model	siprotec 7SA522
Category	Protection Device
Language	English