VAMP 52 - 2.6. Broken line protection I2;I1> (46 R)

2.6 Broken line protection I2/I1> (46R) 2 Protection functions Technical description
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Figure 2.5.1-1 Remote scaling example.
In the Figure 2.5.1-1 can be seen the affect of remote scaling.
After enabling group is changed from group one to group two
and all settings from group one are copied to group two. The
difference is that group two uses scaled pick-up settings.
NOTE! When remote scaling function is used it replaces all the
settings of group 2 so this function cannot be used simultane-
ously with normal group change.
2.6. Broken line protection I
2
/I
1
> (46R)
The purpose of the broken line protection is to detect
unbalanced load conditions, for example a broken wire of a
heavy loaded overhead line in case there is no earth fault.
The operation of the unbalanced load function is based on the
negative phase sequence component I
2
related to the positive
phase sequence component I
1
. This is calculated from the phase
currents using the method of symmetrical components. The
function requires that the measuring inputs are connected
correctly so that the rotation direction of the phase currents are
as in chapter 8.10. The unbalance protection has definite time
operation characteristic.
1
2
2
I
I
K 
, where