This article presents a wave energy converter consisting of a point absorber in heave with a directly coupled induction machine as power take off system. The induction machine is controlled by a Voltage Source Converter. A hydrodynamic model combined with a full model of an electrical generator and power electronic converter has been developed in order to investigate the technical challenges posed by the operation in wave energy conversion. Simulations have been carried out in the time domain. Results from the simulations include: varying voltage, peak power losses, field weakening, instability issues, sensor less control, and proposal of active front end converter as grid converter. Results show that the choice of point absorber, control strategies and generator control by the power electronics will directly affect the torque demands on the wave energy converter. The rating of the induction generator and the converter will be determined by the torque demands, in other words by the choice of control strategy and the incident wave.
