This paper presents the steady state analysis and
characteristics of a doubly-fed induction generator (DFIG)
employed in stand-alone wind energy conversion system
(WECSs) in a similar way as the synchronous generator. The
DFIG is excited through the rotor terminals by a slip-frequency
voltage and current injected to the rotor from a battery via rotor
side converter. A simplified mathematical model required for
evaluation of the steady state analysis and characteristics of the DFIG is presented. The effect of load variation on the rotor
voltage, active and reactive power when the generator operated
at constant speed is studied. Also, the effect of the generator
speed variation when operated at constant load on the rotor
voltage, active and reactive power is illustrated. The results
show that the parameters affected on the steady state analysis
and characteristics of the DFIG by using this method is more
clearly and simply. |