Wideband estimation of the drive torque of a wind turbine using LiDAR measure-ments, blade element momentum theory and Kalman filtering

Abstract

In this paper a method to estimate the drive torquesfrom Light Detection  and  Ranging  (LiDAR)  measurements  is proposed. Knowledge of these values brings many advantages for turbine  control  and  especially  active  damping  of  mechanical  oscillations.

Primarly a simplified method to calculate the aerodynamic torquefrom  wind  speed  measurements  of  a  nacelle  based  LiDAR-system will be presented which bases on  blade element momen-tum  theory  (BEM). Comparisons  of  results  of  the  original  and  a simplified  computation  method  show  small  deviations  in  the  relevant working range of a wind turbine. Additionally a Kalman Filter is used to estimate the drive torques   of the wind turbine.  

The method is tested in simulation using a model of a doubly fed induction  generator  (DFIG)  wind  turbine  including  a  gearbox.  Simulation results show good performance of the estimation.