Stress Analysis of the Blades and Long-Term Performance Assessment of the System for a Small Horizontal Axis Wind Turbine Equipped with an Automatic Pitch-Angle Control Mechanism

This study is to conduct a long-term performance assessment and an improvement for the small horizontal axis wind turbines (SHAWT) system that has a newly developed automatic variable pitch-angle control (AVPAC) mechanism. The function of the AVPAC mechanism is as follows: at low wind speed, the pitch-angle of the blades (BPA) is large so that the runner can be activated easily; at normal wind speed, the BPA is small so that the large angle of attack can give a large lift force to the blade and gain a good efficiency; at large wind speed, the BPA becomes so small or even negative that the blades become stalled and cannot exceed an angular speed limit. This protects the blade from breaking down through the reducing of the normal thrust. This project is proposed to be executed in a three year period. In the first year, we will establish an experimental system for the long-term performance assessment. The BE EN 61400-2:2006 standard is adopted as a protocol to guide the design and testing works so that the SHAWT system may be reliable to the customers. In the second year, we will evaluate the possibility of the mass production of the blade with injection molding through the use of commercial analysis software. The deformation of the injected blades will be referred to refine the blade design until the performance of the injected blades is not affected. Additionally, we will do the stress analysis for the injected blades to ensure the robustness of the blade. In the third year, we will use the data collected from the long-term testing of the SHAWT system to analyze the effects of the skew wake due to yaw variation and dynamic stall due to strong gusts. At the same time, we will evaluate the steadiness of the AVPAC mechanism for improving the reliability of the mechanism. Finally, we will design an innovative circuit to reduce the effects on the overall performance from the unsteady winds and the variations of the battery content.

Project ID:PB10007-2281
External Project ID:NSC100-2221-E182-063