Individual Pitch Controller for Power Quality Improvement on Megawatt Direct-Drive Wind Turbines

The aim of the designed pitch control algorithm is to improve the power quality and to reduce voltage flicker for megawatt direct-drive wind turbines. The simulation model of individual pitch controller and permanent magnet direct-drive wind turbine were developed by using the simulation tool of MATLAB. The short term flicker severity without fictitious Grid model is calculated based on IEC61400-21 because of no disturbance from other turbines. The individual pitch control method and the collective pitch action are compared. The active power and short-term flicker with full wind speed range under two controllers are simulated. The result indicates that the megawatt direct-drive wind turbines equipped with individual pitch controller exhibits good behavior with respect to output power and produce lower voltage flicker, especially for 3P frequency reduction.