Wattmetric-Based Earth-Fault Protection Wpwde; Identification; Function Block; Functionality - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.2.7
4.2.7.1
4.2.7.2
4.2.7.3
4.2.7.4
496

Wattmetric-based earth-fault protection WPWDE

Identification

Function description
Wattmetric-based earth-fault protection

Function block

GUID-9CB65CEF-77E3-4E86-B480-47C373CB6CF9 V1 EN
Figure 271: Function block

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.
WPWDE measures the earth-fault power 3UoIoCosφ and gives an operating signal
when the residual current Io, residual voltage Uo and the earth-fault power exceed the
set limits and the angle (φ) between the residual current and the residual voltage is
inside the set operating sector, that is, forward or backward sector. The operating time
characteristic can be selected to be either definite time (DT) or a special wattmetric-
type inverse definite minimum type (wattmetric type IDMT).
The wattmetric-based earth-fault protection is very sensitive to current transformer
errors and it is recommended that a core balance CT is used for measuring the residual
current.
WPWDE contains a blocking functionality. It is possible to block function outputs,
timers or the function itself.

Analog channel configuration

WPWDE has two analog group inputs which must be properly configured.
IEC 61850 IEC 60617
identification identification
WPWDE Po> ->
1MRS759142 C
ANSI/IEEE C37.2
device number
32N
REX640
Technical Manual