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