Flux weakening control of PMSG based on direct wave energy converter systems

Thispaper deals with a Permanent Magnet Synchronous Generator (PMSG) driven by a Direct Wave Energy Converters (DWEC) through a PWM power converter and used for isolated sites. Control strategies for such train systems must be taken into account when the swell excitation forces exceed the rated value corresponding to the rated power of generator and converter. Over-rated swell effects occurs at large spring tides or under strong sea states; in these cases maximum power leveling strategies must be adopted to limit the generator power at rated value. In this work, power limitation strategy with flux-weakening control is investigated. This later is applied to extend the rotor speed operating range over the nominal speed during high speed swell effects. Robustness and performance of the considered system with flux weakening control of the PMSG are evaluated. Simulations are carried-out to highlight the proposed PMSG-based DWEC performance under flux weakening conditions.