Instantaneous torque control of a permanent magnet wind power generator without a position sensor

The paper presents a direct-torque-control scheme for a direct drive variable-speed permanent magnet synchronous generator (PMSG) for wind energy without any position sensor. Direct control of the rotating velocity and amplitude of the stator flux vector allows very fast torque response of PMSG according to the generator speed. Fixed switching frequency and very low torque ripple are obtained with space vector modulation. Experimental results verify the effectiveness of the proposed control technique for PMSG other than the widely used field orientated control.