Direct torque control of a wind energy conversion system with permanent magnet synchronous generator and Matrix Converter

This paper proposes a direct-torque control (DTC) scheme in a variable-speed direct-drive wind power generation system including a permanent-magnet synchronous generator (PMSG) and matrix converter (MC). Optimal torque control in the proposed DTC strategy is directly obtained from estimated rotor speed and is applied to the system as reference torque. Controlling generator torque at its optimal value makes maximum power point tracking (MPPT) possible under various wind speed and without the need of wind speed or rotor position sensors. The primary merits of the proposed technique are accurate and rapid response to variation of the wind speed, straightforward implementation and robustness to parameter uncertainties and variations of the PMSG. Moreover, DTC based Matrix Converter technique has lower flux and torque ripples and switching frequency as this converter is characterized with higher voltage vectors than conventional Back to Back converters. The effectiveness of the proposed DTC-MC scheme is verified by simulation studies on a 10kW PMSG wind turbine.