Wind Turbine of the Savonius-Magnus Type with Conical Blades: Dynamics and Control

We consider a mathematical model of a horizontal-axis wind-energy unit in which Savonius rotors are used instead of classical blades. The Magnus force formed due to the autorotation of Savonius rotors creates a momentum supporting the rotation of the central turbine shaft. The main difference of this study from earlier investigations in this area is as follows: we take into account the variation of the blade width along the radius. In our model, the conical Savonius rotor is replaced by a pair of cylindrical rotors with different diameters, which provides the possibility to use the experimental force-momentum characteristics, taking into account the substantial variations of the velocity field along the blade's radius. In the model, we consider the possibility to control the value of the external electric resistance in the local circuit of the unit generator. We describe the dependence of the mechanical power on the parameters of the model and construct a control strategy providing the possibility to maintain the power close to the maximum possible value under changes in the wind velocity.