Fuzzy soliding mode control for maximum power point tracking of wind power generation system

To tackle maximum wind power tracking problems, a fuzzy sliding mode control strategy was developed in this paper. This method established sliding mode surface based on state variable of generator rotational speed and electromagnetic torque, and equivalent control law and switch control law were obtained. Meanwhile, fuzzy rule inference method was proposed based on state of sliding surface to flexible on-off component in order to weaken sliding mode control chattering, and then fuzzy sliding mode control law was gained. Furthermore, optimal operating region of wind turbine was introduced and maximum wind power capture control of a 1.5MW wind power generator unit was studied. The simulation results show that the improved fuzzy sliding mode control can adjust wind turbine rotational speed to follow wind speed accurately, and make wind turbine output power in optimal operating region, with maintaining optimal tip-speed ratio and maximum power coefficient, and reduce mechanical load of the unit under the capture of maximum wind energy.