13.5 Selecting the right measurement points for Uen when inject-
ing current
The algorithm uses the measurement the zero sequence voltage (Uen) and the injected
current Ici calculate the grid parameters.
In this case, Uns corresponds Une and also describes the zero sequence voltage.Page 194 Commissioning current injection
We take care it. not needed for standard applications. The zero
sequence voltage can tapped from the coil (Uns) 'behind' the transformer from the
busbar's open delta winding (specified here Uod) always corresponds the zero se-
quence voltage across the coil.
.
Measurement points for the different algorithms:
Measu-
rement
point
Algorithm
Uod,Ici
Algorithm
Uns,Ici
Algorithm Uns,
Uod, Ins, If
Comment
Usync Synchronization voltage
UNS (Une) Zero sequence voltage P-
coil
U0D Zero sequence voltage on
open delta winding (on bus-
bar)
ICI Injection current
I0_S Current through the P-coil
I0_fix Current through addition-
al fixed coil
Note:
The Uns, Uod, Ins, algorithm was initially developed for the ENEL feature together with an
EDC-Sys.
The small algorithm (Uns, Ici the parameterization) can used for most applications
