STUDY ON AERODYMICS CHARACTERISTICS OF INDIVIDUAL PITCH CONTROL FOR REDUCTION OF DYNAMIC LOAD ON BLADE

Abstract

Recently, wind turbine is designed to make greater in size for economic efficiency. More dynamic loads, however, are produced due to increase in wind variations on rotor plane by larger turbine size. There are various factors inducing wind variations such as wind shear, tower shadow, wind misalignment, turbulence and etc. Fatigues, one of the major problems induced by the dynamic loads, not only shorten the system lifetime but also raise cost of production. Therefore, optimal design for minimizing dynamic loads is required. In this study, individual pitch control based on azimuth angle is adopted for reduction of dynamic load. Firstly, an analysis of performance and load using the numerical method based on Blade Element Momentum Theory (BEM) is carried out. And how the wind shear and tower shadow affect aerodynamic loads of turbine is investigated and optimal pitch angle to azimuth for reduction of the aerodynamic load fluctuation is presented. Finally, the effects on individual pitch control will be discussed through the simulation under the actual wind data for 5 minutes.