8.6.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Additional distance protection
directional function for earth faults
ZDARDIR
S00346 V1 EN
-
8.6.2 Application
The phase-to-ground impedance elements can be supervised by a phase unselective
directional function based on symmetrical components (option).
8.6.3 Setting guidelines
AngleRCA and AngleOp: these settings define the operation characteristic. Setting
AngleRCA is used to turn the directional characteristic, if the expected fault current angle
does not coincide with the polarizing quantity to produce the maximum torque. The angle
is positive, if operating quantity lags the polarizing quantity and negative if it leads the
polarizing quantity. The setting AngleOp (max. 180 degrees) defines the wideness of the
operating sector. The sector is mirror-symmetric along the MTA (Maximum Torque
Axis).
Directional elements for ground-faults must operate at fault current values below the
magnitude of load currents. As phase quantities are adversely affected by load, the use of
sequence quantities are preferred as polarizing quantities for the ground directional
elements. Optionally six modes are available:
• Zero-sequence voltage polarized (-V
0
)
• Negative-sequence voltage polarized (-V2)
• Zero-sequence current (I
0
)
• Dual polarization (-V
0
/I
0
)
• Zero-sequence voltage with zero-sequence current compensation (-V0Comp)
• Negative-sequence voltage with negative-sequence current compensation (-
V2Comp)
The zero-sequence voltage polarized ground directional unit compares the phase angles of
zero sequence current I
0
with zero sequence voltage -V
0
at the location of the protection.
The negative-sequence voltage polarized ground directional unit compares
correspondingly I
2
with -V2.
1MRK 506 369-UUS - Section 8
Impedance protection
Line distance protection REL670 2.2 ANSI 301
Application manual
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