ABSTRACT
A Passive Teeter & Feather Brake Mechanism for reliable output control of the large-scale horizontal axis wind turbines above rated wind speed is developed. The control parameters and the aerodynamics of the imposed braking effect of this mechanism are investigated experimentally. In the previous papers in EUWEC96 and EWEC’97, this mechanism was discussed from a viewpoint of the output characteristics, the local flow field around the blade and oncoming velocity. In this paper the relationship between the ratio of teetering and feathering angles and the braking effect of wind turbine is investigated experimentally. Also, the relationship between power suppression and the flow patterns around wind turbine are investigated by the velocity distribution measurements and flow visualization methods.
