Analysis and control of PMSG-based wind turbine with Vienna rectifier near current zero crossings

Permanent-magnet synchronous generators are used widely in wind turbine applications. Recently, the Vienna rectifier was proposed as the generator-side converter, due to its improved efficiency and reliability. However, since the voltage output in this topology is dependent on the polarity of the currents, erroneous voltage space vectors are generated when phase currents are in the vicinity of zero, which in turn creates an undesirable component of torque ripple on the machine. In this paper, the phenomenon is analyzed, and a control method that solves this issue is proposed. The obtained improvement in current and torque ripple decreases the fatigue of the turbine´s mechanical drivetrain. Simulation results verify the efficacy of the control.