max1
min
155.75
75.8
91.5
2 tan
2 tan
2
2
d
-
=
=
=
W
æ
ö
æ
ö
×
×
ç
÷
ç
÷
è
ø
è
ø
S
in
Z
RLdInFw
EQUATION1350 V1 EN-US
(Equation 439)
max1
75.8
0.61
123.5
=
=
=
RLdInFw
kLdRFw
RLdOutFw
EQUATION1351 V1 EN-US
(Equation 440)
Also check if this minimum setting satisfies the required speed for detection of consecutive
oscillations. This requirement will be satisfied if the proposed setting of
tP2 time remains
higher than 10 ms, see equation
.
max
91.5
64.5
2
10.7
360
7 360
In
Out
sc
tP
ms
f
d
d
-
° -
°
=
=
=
×
°
×
°
EQUATION1352 V1 EN-US
(Equation 441)
The final proposed settings are as follows:
RLdOutFw = 123.5Ω
kLdRFw = 0.61
tP1 = 30 ms
tP2 = 10 ms
Consider RLdInFw = 75.0Ω.
Do not forget to adjust the setting of load encroachment resistance
RLdFw in
Phase selection with load encroachment (FDPSPDIS or FRPSPDIS) 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 or FRPSPDIS to follow the
condition presented in equation
.
Index PHS designates correspondence to FDPSPDIS or FRPSPDIS function and
index PSD the correspondence to ZMRPSB function.
(
)
tan
arc tan
³
PSD
PHS
ArgLd
ArgLd
kLdRFw
EQUATION1353 V2 EN-US
(Equation 442)
Consider equation
max
25
PSD
ArgLd
j
=
=
°
EQUATION1354 V1 EN-US
(Equation 443)
Section 7
1MRK 505 343-UEN B
Impedance protection
370
Application manual
Summary of Contents for Relion 670 series
Page 1: ...RELION 670 SERIES Line differential protection RED670 Version 2 1 IEC Application manual...
Page 2: ......
Page 40: ...34...
Page 64: ...58...
Page 150: ...144...
Page 406: ...400...
Page 472: ...466...
Page 494: ...488...
Page 512: ...506...
Page 524: ...518...
Page 604: ...598...
Page 686: ...680...
Page 718: ...712...
Page 722: ...716...
Page 758: ...752...
Page 759: ...753...