Application of multirate sampling approach in pitch control of wind generator systems

Pitch control is very important for variable-speed variable-pitch wind generator systems (VSVP-WGSs) working in high wind speed region. Dynamic inversion control is an emerging method applied in this situation. As the dynamic inversion method is very sensitive to parameters accuracy, a dynamic inversion control strategy based on multirate sampling is proposed in this paper. Multirate sampling method can be applied in the control of VSVP-WGSs in high wind speed region and provide good system performance even with parameter uncertainty. This approach simplifies the wind generator to two-mass model. This model is closer to the real system than the first-order dynamic model. Compared with traditional dynamic inversion controllers, the proposed method can increase system margin and guarantee the system with a better performance when parameters or external conditions change. These capabilities of the controller have been verified by analysis and simulation.