The dynamics of an isolated self-excited induction generator driven by a wind turbine

This paper presents the effect of magnetizing inductance in self-excitation and also the minimum and maximum value of speeds necessary to initiate the self-excitation process in an isolated three-phase induction generator for a given capacitance value and load. Wind powered self-excited induction generators (SEIG) have an input which is not controllable, wind, but they can be set to operate within a given variation of speed. During self-excitation the variation in the value of magnetizing inductance, due to saturation, is the main factor that stabilizes the growing transient of generated voltage and then to continue to oscillate at a particular frequency and voltage in the steady state. Normally attention is given to the value of magnetizing inductance around the rated voltage for motoring application, but for SEIG the value of the magnetizing inductance varies, due to saturation, as the generated voltage grows. The variation of magnetizing inductance, increasing at lower voltage and then decreasing at higher voltage until it reaches the rated voltage, and its effect on self-excitation is discussed in this paper.