Distance Protection Zone, Quadrilateral Characteristic, Separate Settings Zmrpdis (21), Zmrapdis (21) And Zdrdir (21D) - ABB RELION RET670 Applications Manual

Section 8
Impedance protection
8.9
320
2
V
=
Zload min
S
EQUATION1753-ANSI V1 EN-US
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 198:
æ ö
P max
=
LdAngle a cos
ç ÷
è S max ø
EQUATION1623-ANSI V1 EN-US
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 199:
= ×
RLd ZLoad cos( LdAngle )
EQUATION1624-ANSI V1 EN-US
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.
Distance protection zone, quadrilateral characteristic,
separate settings ZMRPDIS (21), ZMRAPDIS (21)
and ZDRDIR (21D)
1MRK 504 163-UUS A
(Equation 197)
(Equation 198)
(Equation 199)
GUID-7308DB86-32CE-4615-95DC-92BEEF69E184 v1
Transformer protection RET670 2.2 ANSI
Application manual