Environmental Engineering Reference
In-Depth Information
Time (sec)
Fig. 2.20
Grid voltage
Time (sec)
Fig. 2.21 Torque tracking performance during unbalanced voltage sags: Reference (blue) and
real (green)
connected to the grid in the presence of grid voltage sags. The HOSM control
performances are, therefore, assessed against this grid fault. In this context, when
unbalanced sags occur (Fig.
2.20
), very high current, torque, and power oscilla-
tions appear at double the electrical frequency, forcing a disconnection.
The LVRT performances are illustrated by Fig.
2.21
where an almost constant
torque is achieved. Good tracking performances are also achieved in terms of
DFIG rotor current (Fig.
2.22
). Fault-tolerance performances are also confirmed
by the quadratic error shown by Fig.
2.23
.
Time (sec)
Fig. 2.22 Current I
rd
tracking performance during unbalanced voltage sags: Reference (blue)
and real (green)
