Signals - ABB RELION REX640 Technical Manual

1MRS759142 C
4.2.3.7
REX640
Technical Manual
Earth-fault transients
In general, earth faults generate transients in currents and voltages. There are several
factors that affect the magnitude and frequency of these transients, such as the fault
moment on the voltage wave, fault location, fault resistance and the parameters of the
feeders and the supplying transformers. In the fault initiation, the voltage of the faulty
phase decreases and the corresponding capacitance is discharged to earth (→
discharge transients). At the same time, the voltages of the healthy phases increase and
the related capacitances are charged (→ charge transient).
If the fault is permanent (non-transient) in nature, only the initial fault transient in
current and voltage can be measured, whereas the intermittent fault creates repetitive
transients.
GUID-ED689851-84F8-4E7A-A2A7-B4523377AE6F V1 EN
Figure 244: Example of earth-fault transients, including discharge and charge
transient components, when a permanent fault occurs in a 20 kV
network in phase C

Signals

Table 503: INTRPTEF Input signals
Name Type
IRES SIGNAL
URES SIGNAL
BLOCK BOOLEAN
Table 504: INTRPTEF Output signals
Name Type
OPERATE BOOLEAN
START BOOLEAN
BLK_EF BOOLEAN
Protection functions
Default Description
- Residual current
- Residual voltage
0=False Block signal for activating the blocking mode
Description
Operate
Start
Block signal for EF to indicate opposite direction
peaks
Section 4
451