The DLR EWITAC Library

DLR EWITAC Library

The DLR EWITAC Library for wind turbines gives you a jump-start for modeling Wind Turbines with Modelica®. It contains complete turbine models, including all relevant components such as flexible rotor blades, flexible tower structures, standard control blocks and power electronic models for net- integration. Models for the environment enable you to play through scenarios such as gust load alleviation or a low-voltage-ride-through for grid code compliance. The library is commercially available at LTX.   

Features of the Library:

Example Turbine model based on NREL 5MWRotoraerodynamics with Blade Element Momentum TheoryMultidomain interactionAdvanced Control for Wind Turbines
  • Rotor aerodynamics
  • Power electronics model
  • Example controlle

  • Special Blade Element Model for Rotor Aerodynamics
  • Can be combined with rigid or flexible blades
  • Robust implementation for a wide variety of wind conditions
  • Validated against FAST reference tool

  • Complete model from power electronics to rotor aerodynamics achievable
  • Study effects of low-voltage ride through and the similar scenarios.

  • Standard Example Controller
  • Innovative yaw controller based on economic principles
  • Develop your own controllers e.g. for gust load alleviation

Application Examples


While the nominal control of wind turbine is already well handled by the state of the art, there is still much potential in the field of load reduction. Other aspects are key-technologies such as LIDAR systems that enable better on-line wind measurement. Using the EWITAC library, a new controller has been design that is based on Nonlinear Dynamic Inversion control methods combined with Pseudo Control Hedging. The controller uses wind speed measurement information to adjust to wind gust load. The simulation results show a large reduction of the gust load on the wind turbine.