Advertisement
GRD140
1.3s
Non-directional
GRD140
1.3s
Non-directional
Figure 2.1.10
Power Systems with Sources at both Line Terminals
In power systems with sources at both line terminals as shown in Figure 2.1.11, the fault current
flows in from both terminals.
G1
c
F2
Figure 2.1.11
Protection of a power system with sources at both line terminals
The protection is performed by setting the directional element at points 1, 2 and 3 which operates
only when the fault current (F1: solid lines) flows in from source G1 and at points a, b and c which
operates only when the fault current (F2: dotted lines) flows in from source G2, with grading provided
by time delays .
0.1s
0.1s
A
Protection of a Ring Main Circuit
1
b
⎯
⎯
18
1.0s
0.4s
F
1.0s
0.4s
B
a
3
2
6 F 2 S 0 7 5 8
0.7s
0.7s
G2
F1
Advertisement
