ABB RELION REX640 - 4.2.7 Wattmetric-based earth-fault protection WPWDE (ANSI 32 N); 4.2.7.1 Identification; 4.2.7.2 Function block; 4.2.7.3 Functionality

4.2.6.10 Technical data
Table 592: HAEFPTOC Technical data
Characteristic Value
Operation accuracy Depending on the frequency of the measured current: f
n
±2 Hz
±5% of the set value or ±0.004 × I
n
Start time , Typically 77 ms
Reset time Typically 40 ms
Reset ratio Typically 0.96
Operate time accuracy in definite time mode
3
±1.0% of the set value or ±20 ms
Operate time accuracy in IDMT mode ±5.0% of the set value or ±20 ms
Suppression of harmonics -50 dB at f = f
n
-3 dB at f = 13 × f
n
4.2.7 Wattmetric-based earth-fault protection WPWDE (ANSI
32N)
4.2.7.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Wattmetric-based earth-fault pro-
tection
WPWDE Po> -> 32N
4.2.7.2 Function block
Figure 304: Function block
4.2.7.3 Functionality
The wattmetric-based earth-fault protection function WPWDE can be used to detect
earth faults in unearthed networks, compensated networks (Petersen coil-earthed
networks) or networks with a high-impedance earthing. It can be used as an
alternative solution to the traditional residual current-based earth-fault protection
functions, for example, the IoCos mode in the directional earth-fault protection
function DEFxPDEF.
1
Fundamental frequency current = 1.0 × I
n
, harmonics current before fault = 0.0 × I
n
, harmonics
fault current 2.0 × Start value , results based on statistical distribution of 1000 measurements.
2
Includes the delay of the signal output contact.
3
Start time of the function also included.
4
Maximum Start value = 2.5 × I
n
, Start value multiples in range of 2...20.
1MRS759142 F Protection functions
REX640
Technical Manual
529