Direct torque and flux control of the converters for a permanent magnet wind power generation system

This paper presents a Space-Vector Modulated (SVM) Direct-Torque-Control (DTC) scheme for a direct-drive permanent magnet synchronous generator (PMSG) and a gird converter 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 the PMSG according to the generator speed. Fixed switching frequency and very low torque ripple are obtained with space vector modulation. SVM-DTC can also be implemented into the grid converter in which nearly sinusoidal input current and fast dc link voltage regulation can be achieved. Experimental results verify the effectiveness of the proposed control technique for the PMSG and grid converter other than the widely used field orientated control.