Low Power Wind Generation System based on Variable Speed Permanent Magnet Synchronous Generators

This paper presents a Low Power Wind Generation System based on a permanent magnet synchronous generator and a High Power Factor rectifier. To achieve a high power factor in the generator side, it is proposed a power processing scheme that uses a passive rectifier and a DC-DC converter working in discontinuous conduction mode. This circuit is known as a boost rectifier. The proposed generator control structure is based on three cascaded control loops that regulate the generator current, the turbine speed and the amount of power that it is extracted from the wind, respectively, following the turbine aerodynamics and the actual wind speed. The analysis and design of both the current and the speed loop has been carried out, taking into consideration the electrical and mechanical characteristics, as well as the turbine aerodynamics, of the wind generation system. The power loop is not a linear one, but a Maximum Power Point Tracking algorithm, based on the Perturb and Observe technique, from which it is obtained the reference signal for the speed loop. Finally, to avoid the need of mechanical sensors, a linear Kalman Filter has been chosen to estimate the generator speed.