Section 8 Secondary System Supervision; Current Circuit Supervision Ccsspvc; Identification; Application - ABB REQ650 Applications Manual

1MRK 505 383-UEN A
Section 8
8.1
8.1.1
8.1.2
8.1.3
Breaker protection REQ650 2.2 IEC
Application manual
Secondary system supervision

Current circuit supervision CCSSPVC

Identification

Function description
Current circuit supervision

Application

Open or short circuited current transformer cores can cause unwanted operation of
many protection functions such as differential, earth-fault current and negative-
sequence current functions. When currents from two independent three-phase sets
of CTs, or CT cores, measuring the same primary currents are available, reliable
current circuit supervision can be arranged by comparing the currents from the two
sets. If an error in any CT circuit is detected, the protection functions concerned
can be blocked and an alarm given.
In case of large currents, unequal transient saturation of CT cores with different
remanence or different saturation factor may result in differences in the secondary
currents from the two CT sets. Unwanted blocking of protection functions during
the transient stage must then be avoided.
Current circuit supervision CCSSPVC must be sensitive and have short operate
time in order to prevent unwanted tripping from fast-acting, sensitive numerical
protections in case of faulty CT secondary circuits.
Open CT circuits creates extremely high voltages in the circuits
which is extremely dangerous for the personnel. It can also damage
the insulation and cause new problems. The application shall, thus,
be done with this in consideration, especially if the protection
functions are blocked.

Setting guidelines

GlobalBaseSel: Selects the global base value group used by the function to define
IBase, UBase and SBase as applicable.
Secondary system supervision
IEC 61850 IEC 60617
identification identification
CCSSPVC -
Section 8
IP14555-1 v5
M14870-1 v5
ANSI/IEEE C37.2
device number
87
M12395-13 v9
M12397-17 v8
127