A three phase induction motor can be made to work as a
SEIG when its rotor is driven at suitable speed by wave energy
and its excitation is provided by connecting a three phase
capacitor bank at the stator terminal in order to build-up
voltage and regulate at a terminal voltage nominal value. The
performance of this type of induction machines is very
undesirable for an induction generator [8]. When considering
the operation region as shown in Fig. 1 [8] which is the
relationship between the air-gap voltage and frequency ratio
and the magnetizing reactance, an induction motor operates in
an un-saturation (linear) region different from a SEIG
operating in two regions namely, both un-saturation (linear)
and saturation (nonlinear) regions. The higher degree of
saturation, the higher increase in the induced voltage occur
leading to the core loss increase and the voltage distortion.
Therefore, a suitable SEIG is needed to be carefully designed