LAUSR

In this paper, a novel sensorless control scheme for SCIG-based wind turbine systems, which utilizes cascaded second-order generalized integrators (SOGIs), is proposed. The DC offset and harmonics in the estimated rotor flux can be significantly reduced since the cascaded SOGI behaves like an adaptive filter. The stator frequency, which is regarded as the tuning frequency of the SOGI, is estimated from the amplitude differences among the cascaded SOGI outputs by a PI controller. Simulation and experimental results have verified the validity of the proposed sensorless scheme under wind speed variations.