ABB RER615 - Page 501

Figure 250: Description of the equivalent load distance
The exact value for Equivalent load Dis can be calculated based on the load flow and
voltage drop calculations using data from DMS-system and the following equation.
Equivalent load Dis
U
U
d real
d tap d
=
=
( )
( , )1
(Equation 50)
U
d(real)
The actual maximum voltage drop of the feeder
U
d(tap,d=1)
The fictional voltage drop, if the entire load would be tapped at the end (d=1)
of the feeder (not drawn in Figure 250 ). The calculation of this value requires
data from the DMS system.
Alternatively, the setting Equivalent load Dis can be determined by conducting a
single-phase earth-fault test (R
fault
= 0 Ω) at that point of the feeder where the
maximum actual voltage drop takes place. This point is typically located at the end
1MRS758755 C
Protection related functions
REC615 & RER615
Technical Manual
501