Identification; Function Block; Functionality; Operation Principle - ABB RELION SMU615 Technical Manual

1MRS758407 C
5.2.1

Identification

Function description IEC 61850
Current circuit super-
vision
5.2.2

Function block

Figure 94: Function block
5.2.3

Functionality

The current circuit supervision function CCSPVC is used for monitoring current
transformer secondary circuits.
CCSPVC calculates internally the sum of phase currents (I_A, I_B and I_C) and
compares the sum against the measured single reference current (I_REF). The
reference current must originate from other three-phase CT cores than the phase
currents (I_A, I_B and I_C) and it is to be externally summated, that is, outside the
merging unit.
CCSPVC detects a fault in the measurement circuit and issues an alarm or blocks the
protection functions to avoid unwanted tripping.
It must be remembered that the blocking of protection functions at an occurring
open CT circuit means that the situation remains unchanged and extremely high
voltages stress the secondary circuit.
5.2.4

Operation principle

The function can be enabled and disabled with the
corresponding parameter values are "On" and "Off".
The operation of CCSPVC can be described with a module diagram. All the modules
in the diagram are explained in the next sections.
Figure 95: Functional module diagram
SMU615
Technical Manual
IEC 60617
identification identification
CCSPVC MCS 3I
Supervision functions
ANSI/IEEE C37.2
device number
MCS 3I
Operation setting. The
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