Aerodynamic Rotor Control. Safety is the most important consideration when evaluating wind turbines. Experienced turbine designers and European turbine certification rules require that there be some means of limiting rotor speed by aerodynamic control. Mechanical, electrical or hydraulic brakes should never be depended upon as the sole means of stopping a rotor. Although Aerostar turbines do have fail safe stopping brakes, the rotors are designed with articulating blade tips (tip brakes) which automatically activate and slow the rotor if the RPM exceeds a certain value.
On Aerostar wind turbines, if the rotor were to go into overspeed, the blade tips turn and provide aerodynamic braking. By articulating the tips, the useful area of the rotor is also reduced, further limiting rotor energy. This is the same general type of system used on many large wind turbines installed all over the world. The system is completely automatic and not dependant on an external source of power, which could fail precisely at the time when it was needed. The Aerostar tip brake design is simple and robust and designed to minimize aerodynamic noise. The design contains a number of innovate features that are the subject of pending patents.