ABB RELION RET670 Applications Manual page 359

1MRK 504 163-UUS A
Transformer protection RET670 2.2 ANSI
Application manual
RFRevPG
PHS
PHS
RFPG
Zm
X1
RFPG
Zm
R1
ANSI08000435 V1 EN-US
Figure 167: Relation between measuring zone and FRPSPDIS (21) characteristic
Reactive reach
The reactive reach in forward direction must as minimum be set to cover the measuring
zone used in the Teleprotection schemes, mostly zone 2. Equation
equation 242 gives the minimum recommended reactive reach.
These recommendations are valid for both 60 and 90 deg. characteristic angle.
³ ×
X1 1.44 X1
PHS Zm
EQUATION1309 V1 EN-US
+
R PG 1 RN
PHS PHS
(Minimum setting)
X
RFFwdPG
PHS
R1 +RN
Zm
RFPG
Zm
Zm
+XN
Zm Zm
φ
loop
φ
loop
X1 +XN
Zm
RFPG
Zm
+RN
Zm
Impedance protection
-
R PG 0
= PHS
RN
PHS
3
X1 +XN
PHS
90°
R
(Ohm/loop)
Zm
X1 +XN
PHS
ANSI08000435-1-en.vsd
GUID-8C693495-10FA-47D5-BEFC-E72C8577E88B v1
241 and
Section 8
R PG 1
PHS
PHS
PHS
(Equation 241)
353