2. The cross-section the power supply line must laid out accordingly.5. For exam-
ple, industrial grids that are very symmetrical but show significant load fluctuations. Note that the calculation time
can take anywhere from seconds minutes.
General
0 not necessary, but possible, inject current and move the P-coil the same
time (the resonance curve calculated and not determined moving the P-coil).
Current injection features:
0 Two frequencies are used calculate the grid parameters
0 Switches off reduces the current injection, when the coil moves
0 Fast calculation; takes place within filter cycle (240 ms)
0 Works very symmetrical grids
0 Calculation results immune unbalance and crosstalk from the positive
sequence system the zero sequence system
0 Cyclical current injection for the constant monitoring changes the grid
13.Page 184 Commissioning current injection
We take care it.
13.
0 Currents can occur the secondary side for 500 power auxiliary wind-
ing. Commissioning current injection
Once the REG-DP/ REG-DPA has been commissioned, additional steps must taken to
commission CI. Two frequencies that
are unequal are injected into the zero sequence system estimate the grid pa-
rameters.1 The basics current injection
All the known processes are based the fact that zero sequence voltage created ei-
ther the natural unbalance the grid injecting current. The general
assumption that the grid situation the crosstalk behaviour the load the zero se-
quence voltage will not change during the calculation time.
The CIF algorithm (Control Injecting Frequencies) suppresses the component that
is caused the crosstalk from the load the zero sequence voltage.
0 The process used calculate the grid parameters described Chapter 2.
There are situations, however, which this simplification longer allowed.
YU
BC
UNE
BL
YW
IU
ICI f1,f2 U1N_50 Hz
Figure 116: Simplified equivalent circuit for current injection
. The easiest way commission current injection work through the
steps the sequence the chapters they are discussed in
