Toshiba GRL150-100 Series, Инструкция по эксплуатации

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6 F 2 S 0 8 2 8
2.8 Broken Conductor Protection
The unbalance condition caused by an open circuited conductor is detected by the broken
conductor protection. An unbalance threshold with programmable definite time delay is provided.
Figure 2.8.1.1 shows the sequence network connection diagram in the case of a single-phase series
fault assuming that the positive, negative and zero sequence impedance of the left and right side
system of the fault location is in the ratio of k
1
to (1 – k
1
), k
2
to (1 – k
2
) and k
0
to (1 – k
0
).
Figure 2.8.1.1 Equivalent Circuit for a Single-phase Series Fault
Positive phase sequence current I
1F
, negative phase sequence current I
2F
and zero phase sequence
current I
0F
at fault location in an single-phase series fault are given by:
Positive phase sequence
Single-phase series fault
Zero phase sequence
k
2
Z
2
(1-k
2
)Z
2
k
0
Z
0
(1-k
0
)Z
0
E
1A
E
1B
I
1F
I
1F
I
2F
I
2F
I
0F
I
0F
Negative phase sequence
(1-k
1
)Z
1
k
1
Z
1
E
1B
E
1A
k
1
1– k
1
E
1A
E
1B
I
1F
I
1F
(1-k
1
)Z
1
k
1
Z
1
k
2
Z
2
(1-k
2
)Z
2
K
0
Z
0
(1-k
0
)Z
0
E
1A
E
1B
I
1F
Z
1
Z
2
Z
0