ABB RET670 Applications Manual page 370

Section 3
IED application
364
tP2 = 10 ms
Consider RLdInFw = 75.0Ω.
Do not forget to adjust the setting of load encroachment resistance
RLdFwd in Phase selection with load encroachment (FDPSPDIS, 21 or
FRPSPDIS, 21) to the value equal to or less than the calculated value
RLdInFw. It is at the same time necessary to adjust the load angle in
FDPSPDIS (21) or FRPSPDIS (21) to follow the condition presented in
equation 309.
Index PHS designates correspondence to FDPSPDIS (21) or
FRPSPDIS (21) function and index PSD the correspondence to
ZMRPSB (68) function.
é
tan(
³
arctan
LdAngle
ê
PHS
ë
EQUATION1737-ANSI V1 EN
Consider equation 310,
= °
j 25
=
LdAngle
max
PSD
EQUATION1739-ANSI V1 EN
then it is necessary to set the load angle in FDPSPDIS (21) or FRPSPDIS (21) function
to not less than equation 311.
é
tan(LdAngle
³
LdAngle arctan
ê
PHS
ë
EQUATION1738-ANSI V1 EN
It is recommended to set the corresponding resistive reach parameters in reverse
direction (RLdOutRv and kLdRRv) to the same values as in forward direction, unless
the system operating conditions, which dictate motoring and generating types of
oscillations, requires different values. This decision must be made on basis of possible
system contingency studies especially in cases, when the direction of transmitted
power may change fast in short periods of time. It is recommended to use different
setting groups for operating conditions, which are changing only between different
periods of year (summer, winter).
ù
LdAngle )
PSD
ú
û
KLdRFw
ù
)
=
PSD arctan
ú
û
kLdRFw
1MRK504116-UUS C
°
é ù
tan(25 )
= °
37.5
ê ú
ë û
0.61
Application manual
(Equation 309)
(Equation 310)
(Equation 311)