Harmonics-Based Earth-Fault Protection Haefptoc (Ansi 51Nh) - ABB RELION REX640 Technical Manual

1MRS759142 F
Name Type
4.2.5.10 Technical data
Table 582: MREFPTOC Technical data
Characteristic
Operation accuracy
1, 2
Start time I
value
Reset time
Reset ratio
Retardation time
Operate time accuracy
Suppression of harmonics
4.2.6 Harmonics-based earth-fault protection HAEFPTOC (ANSI
51NH)
4.2.6.1 Identification
Description
Harmonics-based earth-fault pro-
tection
4.2.6.2 Function block
Figure 300: Function block
4.2.6.3 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.
1
Current before fault = 0.0 × I
from random phase angle, results based on statistical distribution of 1000 measurements.
2
Includes the delay of the signal output contact.
REX640
Technical Manual
Values (Range)
3=test
4=test/blocked
5=off
Value
Depending on the frequency of the current measured: f
±1.5% of the set value or ±0.002 × I
= 1.2 × set Start Minimum
Fault
30 ms
<50 ms
Typically 0.96
<50 ms
±1.0% of the set value of ±20 ms
-50 dB at f = n × f
, f = 50 Hz, earth-fault current with nominal frequency injected
n n
Unit
n
Typical
34 ms
, where n = 2, 3, 4, 5,...
n
IEC 61850 IEC 60617
identification identification
HAEFPTOC Io>HA
Protection functions
Description
±2 Hz
n
Maximum
38 ms
ANSI/IEEE C37.2
device number
51NH
521