Robust Individual Blade Pitching Control of Wind Energy Conversion System in Wind Shear Field above Rated Wind Speed

Constant power control is needed to mitigate wind shear effects when wind energy conversion systems are subjected to wind shear above their rated wind speed tolerances; therefore, robust blade pitching controllers are essential. The issues of individual blade pitch control for wind energy conversion systems located in wind shear fields are discussed. Our proposed collective blade pitching controller uses an active disturbance rejection control method and three individual blade pitching controllers with disturbance compensation technology. In our design, the collective blade pitching controller compensates for the uncertainties produced by wind speed variation and wind turbine parameters variation, in addition to effectively restraining the electromagnetic torque ripples. The individual pitching controllers restrain the speed ripples and the flap-wise aerodynamic loads and are robust in withstanding changes to the frequency and amplitude of the collective pitching signal. The theoretical analysis and simulation results clearly demonstrate the success of the combined collective and individual blade pitching controllers.