ABB REL650 - Section 23 Inverse Time Characteristics

Section 23 Inverse time characteristics
23.1 Application
M16686-3 v5
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.
xx05000129.vsd
I> I> I>
IEC05000129 V1 EN-US
Figure 427: Three overcurrent protections operating in series
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Time
Fault point
position
Stage 1
Stage 2
Stage 3
Stage 1
Stage 2
Stage 1
IEC05000130 V1 EN-US
Figure 428: Definite time overcurrent characteristics
1MRK 506 382-UEN A Section 23
Inverse time characteristics
Line distance protection REL650 2.2 IEC 889
Technical manual