| Abstract |
The paper deals with a variable-speed induction generator, aimed at supplying an autonomous dc
power system with constant dc voltage. Reactive power requirements of the induction generator are
met by voltage source converter, operated in current controlled mode. Control of the compensator is
achieved using rotor flux oriented control principles. As operation in both base speed region and
field-weakening region is anticipated, the generator is represented with a suitable saturated machine
model. Estimation of instantaneous rotor flux space vector is performed using a recently introduced
estimator that fully accounts for main flux saturation. Description of the system is provided and an
extensive simulation study is performed. Self-excitation under no-load conditions, step application
and variation of a dc load, and variable speed operation in both base speed and field weakening
regions are examined by simulation. It is shown that the proposed control system is capable of
maintaining constant dc voltage under all operating conditions. Excellent tracking of rotor flux
reference is achieved, indicating that proper rotor flux orientation is maintained at all times. |
