Wind Mill with Variable Blades(VIT)-APSSDC

Modern large Wind Mills are variable-speed machines. When the wind speed is below rated, generator torque is used to control the rotor speed in order to capture as much power as possible. The most power is captured when the tip speed ratio is held constant at its optimum value. This means that as wind speed increases, rotor speed should increase proportionally. The difference between the aerodynamic torque captured by the blades and the applied generator torque controls the rotor speed. A variable-speed wind turbine allows the generator/rotor speed to vary proportional to wind speed between cut-in and rated speed, thus maintaining a constant TSR and optimal aerodynamic performance. Above rated speed, the generator/rotor speed is then held constant. The torque must be actively controlled.