Toshiba GRL100-101A, Инструкция по эксплуатации

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339
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6 F 2 S 0 8 3 5
restraint current
：
X+2Y+Z
This point can be expressed in the Id-Ir plane as shown in Fig.K-3.2. It can be seen that the effect
of the outflow current is to increase the apparent restraint quantity Ir and thereby shift the point to
the right of where it would normally fall.
Ir
Id
X+2Y+Z
X+Z
Id = Ir - 2DIFI2
Id = 1/6Ir+5/6DIFI1
2DIFI2
Fig.K-3.2 Internal fault in Id-Ir plane including out-flow current
In order to ensure that the GRL100 relay will operate correctly in this case, the point shown on the
plot must fall within the operating zone.
According to this requirement, DIFI2 can be calculated as follows.
X +Z > X+2Y+Z
−
2DIFI2
DIFI2 > Y (K-3.1)
This means that DIFI2 must be larger than the amount of out-flowing current.
Therefore the condition shown in Table K-2.1 and Table K-2.2 should be replaced by that in Table
K-3.1 and Table K-3.2 respectively.
Table K-3.1 CT Requirement defined by V
k
Td [ms] Requirement 1 Requirement 2
35
V
k
≧
I
fmax
(R
ct
+ R
2
)
×
3 V
k
>
Max{I
LMAX
+ I
fmin
/2, I
fmaxout
}
×
(R
ct
+ R
2
)
×
14.4
50 V
k
≧
I
fmax
(R
ct
+ R
2
)
×
3 V
k
>
Max{I
LMAX
+ I
fmin
/2, I
fmaxout
} ×
(R
ct
+ R
2
)
×
20
75 V
k
≧
I
fmax
(R
ct
+ R
2
)
×
4 V
k
>
Max{I
LMAX
+ I
fmin
/2, I
fmaxout
} ×
(R
ct
+ R
2
)
×
28.8
100 V
k
≧
I
fmax
(R
ct
+ R
2
)
×
4 V
k
>
Max{I
LMAX
+ I
fmin
/2, I
fmaxout
} ×
(R
ct
+ R
2
)
×
36.8
150
V
k
≧
I
fmax
(R
ct
+ R
2
)
×
8 V
k
>
Max{I
LMAX
+ I
fmin
/2, I
fmaxout
}
×
(R
ct
+ R
2
)
×
50.4
Max {
I
LMAX
+ I
fmin
/2, I
fmaxout
} : The larger of (I
LMAX
+
I
fmin
/2)
and I
fmaxout
.
I
fmin
: Minimum fault current
I
fmaxout
: Maximum out-flowing fault current for the special condition.