抄録
A new system to passively control pitch-angle of rotor blades is proposed in order to prevent over-rotation of a small horizontal axis wind turbine in a strong-wind condition. The system consists of a mandrel bar and a fiber-reinforced rubber pipe in which the metal fiber is arranged with oblique angle. This is installed at the root of each blade respectively. When the rubber pipe is subjected to the centrifugal force due to the rotation of the blade, the fibers are forced to be straight in the loading direction. This yields the torsional deformation of the pipe, and achieves the change of the pitch-angle of the blade corresponding to the revolution of the turbine passively. The tensile tests are performed to examine the fundamental elastic behavior of the fiber-reinforced rubber pipe. To investigate the power performance of the wind turbine with the present passive pitch-angle control system, the wind tunnel tests are carried out. It is confirmed that the present system enables to avoid the over-rotation of wind turbine and realizes the stable power generation even in the strong-wind condition.
