Current Transformer Supervision For High-Impedance Protection Scheme Hzccxspvc - ABB RELION REX640 Technical Manual

1MRS759142 C
6.3
6.3.1
6.3.2
6.3.3
REX640
Technical Manual
Current transformer supervision for high-impedance
protection scheme HZCCxSPVC
Identification
Function description
Current transformer supervision for
high-impedance protection scheme for
phase A
Current transformer supervision for
high-impedance protection scheme for
phase B
Current transformer supervision for
high-impedance protection scheme for
phase C
Function block
GUID-22A01AC9-35CD-41D4-A40F-9A17547AA37A V1 EN
Figure 662: Function block
Functionality
The current transformer supervision for high-impedance protection scheme function
HZCCxSPVC is a dedicated phase-segregated supervision function to be used along
with the high-impedance differential protection for detecting the broken CT
secondary wires. The differential current is taken as an input for the protection relay.
During normal CT condition, the value of the differential current is zero. However,
when the CT is broken, the secondary differential current starts flowing and it is used
for generating alarms.
To avoid maloperation, HZCCxSPVC should have a sensitive setting, compared to
the high-impedance differential protection. The function is likely to start under
through-fault conditions. However, by incorporating a high time delay (3 s or more),
the downstream protection clears the fault before an alarm is generated.
HZCCxSPVC generates an alarm when the differential current exceeds the set limit.
The function operates within the DT characteristic.
HZCCxSPVC contains a blocking functionality. It is possible to block the function
output, Timer or the whole function.
Supervision functions
IEC 61850 IEC 60617
identification identification
HZCCASPVC MCS I_A
HZCCBSPVC MCS I_B
HZCCCSPVC MCS I_C
Section 6
ANSI/IEEE C37.2
device number
CCM_A
CCM_B
CCM_C
1215