Technical Data; High-Impedance Based Restricted Earth-Fault Protection Hrefpdif; Identification; Function Block - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.3.4.10
4.3.5
4.3.5.1
4.3.5.2
4.3.5.3
672

Technical data

Table 613: LREFPNDF Technical data
Characteristic
Operation accuracy
1)2)
Start time
I
Fault
Operate value
Reset time
Reset ratio
Retardation time
Operate time accuracy in definite time mode
Suppression of harmonics
1) Current before fault = 0.0, f
2) Includes the delay of the signal output contact
High-impedance based restricted earth-fault protection
HREFPDIF

Identification

Function description
High-impedance based restricted earth-
fault protection

Function block

GUID-A1F915EF-79DE-4DAE-917E-F04B9D439C80 V1 EN
Figure 372: Function block

Functionality

The high-impedance based restricted earth-fault protection function HREFPDIF is
used for the restricted earth-fault protection of generators and power transformers.
The function starts when the differential neutral current exceeds the set limit.
HREFPDIF operates with the DT characteristic.
Value
Depending on the frequency of the measured
current: f
±2.5% of the set value or ±0.002 x I
Minimum
= 2.0 × set
37 ms
Typically 40 ms
Typically 0.96
<35 ms
±1.0% of the set value or ±20 ms
DFT: -50 dB at f = n × f
= 50 Hz, results based on statistical distribution of 1000 measurements
n
IEC 61850
identification
HREFPDIF
1MRS759142 C
±2 Hz
n
n
Typical Maximum
41 ms 45 ms
, where n = 2, 3, 4, 5, ...
n
IEC 60617 ANSI/IEEE C37.2
identification device number
dIoHi> 87NHI
Technical Manual
REX640