4.2.5.1 Identification
Description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Harmonics-based earth-fault pro-
tection
HAEFPTOC Io>HA 51NHA
4.2.5.2 Function block
OPERATE
START
Io
HAEFPTOC
I_REF_RES
BLOCK
Figure 182: Function block
4.2.5.3 Functionality
The harmonics-based earth-fault protection function HAEFPTOC is used instead
of a traditional earth-fault protection in networks where a fundamental frequency
component of the earth-fault current is low due to compensation.
By default, HAEFPTOC is used as a standalone mode. Substation-wide application
can be achieved using horizontal communication where the detection of a faulty
feeder is done by comparing the harmonics earth-fault current measurements.
The function starts when the harmonics content of the earth-fault current exceeds
the set limit. The operation time characteristic is either definite time (DT) or inverse
definite minimum time (IDMT). If the horizontal communication is used for the
exchange of current values between the protection relays, the function operates
according to the DT characteristic.
The function contains a blocking functionality. It is possible to block function
outputs, timer or the function itself, if desired.
4.2.5.4 Operation principle
The function can be enabled and disabled with the
Operation
setting. The
corresponding parameter values are "On" and "Off".
The operation of HAEFPTOC can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
Protection functions
1MRS758755 C
368 REC615 & RER615
Technical Manual
To Next Page
Loading...
