Stall Effect Applied to Blade of Design and Experiment on Small Horizontal Axis Wind Turbine

This paper focuses on the small horizontal axis wind turbine (HAWT) system. When the wind speed exceeds the rated speed, the internal temperature of the generator rises, and the torque will be reduced. At this time, the torque generated by the blades will make the generator unable to control and raise the speed of the blades, thus stalling on airfoil. To avoid the safety problem of the system at high wind speed, the design process of blade element momentum theory (BEMT) is adjusted in this paper, so that the designed blade tip section will face stall early at high wind speed. Although this design lowers the maximum power point of the system, the inertia of the system and the flow field characteristics of the wind are considered in this paper. Moreover, the performance of the designed blade stall is verified in the wind tunnel. Without affecting the component cost of the small wind turbine, the total power generation can meet the overall operation goal, and it is possible to improve the safety of the system operating at above rated wind speed.