ABB RELION 620 Series Technical Manual page 848

Section 5
Protection related functions
842
The "Load modelling" algorithm requires the Equivalent load Dis setting, that is, an
equivalent load distance, as an additional parameter. The derivation and meaning of
this parameter is illustrated in
distributed along the feeder, resulting in the actual voltage drop curve as seen in the
middle part of Figure 435.
In case of evenly distributed load, Equivalent load Dis ~ 0.5. When the load is tapped
at the end of the feeder, Equivalent load Dis = 1.0. If the load distribution is unknown,
a default value of 0.5 can be used for Equivalent load Dis.
The maximum value of the voltage drop, denoted as U
the feeder. The Equivalent load Dis parameter is the distance at which a single load tap
corresponding to the total load of the feeder would result in a voltage drop equal to
U (real). The dashed curve shows the voltage drop profile in this case.
drop
GUID-134928BF-ACE3-42C9-A70F-985A1913FB75 V3 EN
Figure 435: 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.
Figure 435, where the load is assumed to be evenly
drop
1MRS757644 F
(real), appears at the end of
620 series
Technical Manual