VAMP 259 - Page 140

2.24 Inverse time operation
2 Protection functions
Technical description
140
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VM259.EN007
Example for Delay type "Moderately inverse (MI)":
k = 0.50
I = 4 pu
I
pickup
= 2 pu
A = 0.1735
B = 0.6791
C = 0.8
D = -0.08
E = 0.127
38.0
8.0
2
4
127.0
8.0
2
4
08.0
8.0
2
4
6791.0
1735.05.0
32





































t
The operation time in this example will be 0.38 seconds. The
same result can be read from Figure 2.24.1-11.
Figure 2.24.1-11 IEEE2 moderately
inverse delay
Figure 2.24.1-12 IEEE2 normal
inverse delay