Direct scalar torque control for wind turbine with permanent magnet synchronous generator

This paper proposes a PWM rectifier and torque controller for wind turbine (WT) with permanent magnet synchronous generator (PMSG). The considered rectifier does not need boost inductor whose current is usually controlled to impose the desired torque. To deal with this issue, in this paper initially the PMSG model is developed then a sliding mode observer is described in details aiming to obtain the estimation of the generator speed and torque. Whenever the wind speed is below the nominal value, the estimated turbine rotational speed is used to obtain the optimum torque to maximize the aerodynamics efficiency. Then, by controlling of boost converter it is possible to impose the desired torque. Simulation results demonstrated that the proposed technique can accurately estimate the rotational speed and torque to implemented the MPPT for the wind turbine as well as to limited the power whenever is required.