Siemens siprotec 7SA522 - Setting Notes

2 Functions
296
7SA522 Manual
C53000-G1176-C155-3
Figure 2-119 Fault currents and voltages on double–end fed lines
2.17.2 Setting Notes
General The fault location function is only in service if it was selected to (QDEOHG during the
configuration of the device functions (Section 2.1.1.2, address ).
If the fault location calculation is to be started by the trip command of the protection,
set address  67$57 = 75,3. In this case a fault location is only output if the
device has also issued a trip. The fault location calculation can however also be
started with each fault detection of the device (address  67$57 = 3LFNXS). In
this case the fault location is also calculated if for example a different protection device
cleared the fault. For a fault outside the protected line, the fault location information is
not always correct, as the measured values can be distorted by e.g. intermediate in-
feeds.
To calculate the distance to fault in kilometres or miles, the device requires the reac-
tance per unit length data in Ω/km or Ω/mile. For correct indication of the fault location
in % of line length, the correct line length has also to be entered. These setting param-
eters were already applied with the Power System Data 2 (Section 2.1.5.1 at “General
Line Data”.
A prerequisite for the correct indication of the fault location furthermore is that the other
parameters that influence the calculation of the distance to fault have also been set
correctly. This concerns the following addresses
 5(5/=,
 ;(;/=
or
 .=,
 $QJOH.=.