Section 25 Inverse Time Characteristics; Application - ABB RED650 Technical Manual

1MRK 505 394-UEN A
Section 25
25.1
Line differential protection RED650 2.2 IEC
Technical manual
Inverse time characteristics

Application

In order to assure time selectivity between different overcurrent protections at
different points in the network different time delays for the different protections are
normally used. The simplest way to do this is to use definite time-lag. In more
sophisticated applications current dependent time characteristics are used. Both
alternatives are shown in a simple application with three overcurrent protections
operating in series.
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Figure 407: Three overcurrent protections operating in series
Time
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IEC05000130 V1 EN-US
Figure 408: Definite time overcurrent characteristics
Inverse time characteristics
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Section 25
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