Vienna-Rectifier-Based Direct Torque Control of PMSG for Wind Energy Application

Abstract

Vienna rectifier as generator-side converter of wind energy conversion system (WECS) using a permanent-magnet synchronous generator (PMSG) has several advantages compared to conventional back-to-back inverter, such as higher efficiency and improved total harmonic distortion. On the other hand, direct torque control (DTC) of the generator in WECS is of interest, particularly for low-power applications due to several merits, including fast torque response, insensitivity to PMSG model and associated parameters, elimination of rotor position sensor, and reduced computations. In this paper, the effects of Vienna rectifier voltage vectors on instantaneous PMSG torque and stator flux are derived, and DTC of PMSG by the Vienna rectifier is implemented, considering the constraints imposed by the Vienna rectifier. Experimental tests for a 1-kW prototype are presented, which confirm the simulations and theoretical results.