Additional Distance Protection Directional Function For Ground Faults Zdardir (21D) - ABB REL650 Applications Manual

1MRK 506 334-UUS A
6.4
6.4.1
Application manual
2
V
=
Zload min
S
EQUATION1753-ANSI V1 EN
Where:
V is the minimum phase-to-phase voltage in kV
S is the maximum apparent power in MVA.
The load angle LdAngle can be derived according to equation 70:
æ ö
P max
=
LdAngle a cos
ç ÷
è S max ø
EQUATION1623-ANSI V1 EN
where:
Pmax is the maximal active power transfer during emergency conditions and
Smax is the maximal apparent power transfer during emergency conditions.
The RLd can be calculated according to equation 71:
= ×
RLd ZLoad cos( LdAngle )
EQUATION1624-ANSI V1 EN
The setting of RLd and LdAngle is by default set to 80 ohm/phase and 20 degrees. Those
values must be adapted to the specific application.
Additional distance protection directional function for
ground faults ZDARDIR (21D)
Identification
Function description
Additional distance protection
directional function for ground faults
Impedance protection
IEC 61850 IEC 60617
identification identification
ZDARDIR
S00346 V1 EN
Section 6
(Equation 69)
(Equation 70)
(Equation 71)
ANSI/IEEE C37.2
device number
21D
149