Technical Data; Admittance-Based Earth-Fault Protection Efpadm; Identification; Function Block - ABB RELION REX640 Technical Manual

1MRS759142 C
4.2.3.10
4.2.4
4.2.4.1
4.2.4.2
4.2.4.3
REX640
Technical Manual

Technical data

Table 509: INTRPTEF Technical data
Characteristic
Operation accuracy (Uo criteria with transient
protection)
Operate time accuracy
Suppression of harmonics

Admittance-based earth-fault protection EFPADM

Identification

Function description
Admittance-based earth-fault protection

Function block

GUID-6852EAF4-629A-43D9-8769-73245405843D V1 EN
Figure 245: Function block

Functionality

The admittance-based earth-fault protection function EFPADM provides a selective
earth-fault protection function for high-resistance earthed, unearthed and
compensated networks. It can be applied for the protection of overhead lines as well
as with underground cables. It can be used as an alternative solution to traditional
residual current-based earth-fault protection functions, such as the IoCos mode in
DEFxPDEF. Main advantages of EFPADM include a versatile applicability, good
sensitivity and easy setting principles.
EFPADM is based on evaluating the neutral admittance of the network, that is, the
quotient:
Io
Yo
=
Uo
−
GUID-A8D426FD-7F03-4BE2-AA40-A13D2A7F3183 V1 EN
Protection functions
Value
Depending on the frequency of the measured
current: f ±2 Hz
n
±1.5% of the set value or ±0.002 × Uo
±1.0% of the set value or ±20 ms
DFT: -50 dB at f = n × f
IEC 61850 IEC 60617
identification identification
EFPADM Yo> ->
Section 4
, where n = 2, 3, 4, 5
n
ANSI/IEEE C37.2
device number
21NY
(Equation 44)
453