Function Block - ABB REC650 Technical Manual

Section 12
Monitoring
12.14.3
12.14.4
472
The accurate fault locator is an essential component to minimize the outages after a
persistent fault and/or to pin-point a weak spot on the line.
The fault locator is an impedance measuring function giving the distance to the fault
km or miles. The main advantage is the high accuracy achieved by compensating for
load current and for the mutual zero-sequence effect on double circuit lines.
The compensation includes setting of the remote and local sources and calculation of
the distribution of fault currents from each side. This distribution of fault current,
together with recorded load (pre-fault) currents, is used to exactly calculate the fault
position. The fault can be recalculated with new source data at the actual fault to
further increase the accuracy.
Especially on heavily loaded long lines, where the source voltage angles can be up to
35-40 degrees apart, the accuracy can be still maintained with the advanced
compensation included in fault locator.

Function block

LMBRFLO
PHSELL1* CALCMADE
PHSELL2* FLTDISTX
PHSELL3* BCD_80
CALCDIST* BCD_40
BCD_20
BCD_10
BCD_8
BCD_4
BCD_2
BCD_1
IEC09000621-2-en.vsd
IEC09000621 V2 EN
Figure 223: LMBRFLO function block
Signals
Table 406: LMBRFLO Input signals
Name Type
PHSELL1 BOOLEAN
PHSELL2 BOOLEAN
PHSELL3 BOOLEAN
CALCDIST BOOLEAN
Default Description
0 Phase selecton L1
0 Phase selecton L2
0 Phase selecton L3
0 Do calculate fault distance (release)
1MRK 511 287-UEN A
Technical manual