ABB REL 356 Current Differential Protection
4-3
Measuring Elements and Operational Logic
Figure 4-3. Operating Characteristic
External fault
For an external fault, the currents will be 180
°
out of phase and of equal magnitude:
4
.
1
4
.
1
0
7
.
0
2
0
180
180
−
=
−
=
−
⋅
=
+
=
+
=
=
°
∠
+
=
+
=
°
∠
=
RES
OP
ITL
ITL
ITL
ITR
ITL
RES
ITL
ITL
ITR
ITL
OP
ITL
ITR
which, of course, is less than OTH which is a positive value (settable 0.00 – 3.98).
Internal fault
For an internal fault, the currents will be practically in phase:
where OTH should be selected so that minimum internal fault current will produce trip.
Communication Channel Options
REL356 is available with eight different communication interfaces:
·
9600 bps audiotone
·
British Telecom audiotone
·
56/64 kbps direct digital
·
56/64 kbps 820 nm multi-mode fiber
·
56/64 kbps 1300 nm single mode fiber, short reach
·
56/64 kbps 1300 nm single mode fiber, medium reach
·
56/64 kbps 1300 nm single mode fiber, long reach
·
56/64 kbps direct digital with G.703 interface
(
)
(
)
OTH
ITR
ITL
ITR
ITL
ITR
ITL
RES
OP
ITR
ITL
RES
ITR
ITL
ITR
ITL
OP
ITL
ITR
≥
+
=
+
−
+
=
−
+
=
+
=
+
=
∠
≅
∠
3
.
0
7
.
0
7
.
0
Summary of Contents for REL 356
Page 23: ...ABB REL 356 Current Differential Protection 1 10 Product Overview and Specifications ...
Page 83: ...ABB REL 356 Current Differential Protection 3 36 Settings and Application ...
Page 127: ...ABB REL 356 Current Differential Protection 5 28 Testing ...
Page 186: ...LINE SECTIONALIZING USING A PLC AND ABB PROTECTIVE RELAY Page 49 of 53 ...
Page 187: ...LINE SECTIONALIZING USING A PLC AND ABB PROTECTIVE RELAY Page 50 of 53 ...
Page 188: ...LINE SECTIONALIZING USING A PLC AND ABB PROTECTIVE RELAY Page 51 of 53 ...
Page 189: ...LINE SECTIONALIZING USING A PLC AND ABB PROTECTIVE RELAY Page 52 of 53 ...