ABB 615 Series ANSI, Техническое руководство

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1MAC050144-MB C
Section 6
Supervision functions
615 series ANSI 439
Technical Manual
6.2.8 Monitored data
Table 381: TCM Monitored data
6.3 Current circuit supervision CCM
6.3.1 Identification
6.3.2 Function block
Figure 232: Function block
6.3.3 Functionality
The current circuit supervision function CCM is used for monitoring current transformers.
CCM 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 IED.
CCM 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.
6.3.4 Operation principle
The function can be enabled and disabled with the Operation setting. The corresponding
parameter values are Enable and Disable.
Name Type Values (Range) Unit Description
TCM Enum 1=enabled
2=blocked
3=test
4=test/blocked
5=disabled
Status
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Current circuit supervision CCRDIF MCS 3I CCM