Design and development of a novel control regime for microgenerating wind turbines

In the wake of recent trends toward the idea of smart grids, interest is growing in decentralized energy supply. An urban environment with expected low wind speeds is particularly well suited for small scale wind turbines; various experiments using sustainable micro-energy sources have proven to contribute to a leveling of fluctuation in the electric network. This work is concerned with optimizing the operation of a cross-flow vertical axis wind turbine (VAWT) using magnetic braking. A first design step involved the development of a test bench prototype with emphasis on validation of available eddy current brake models. Another design step was focused on deriving a wind turbine model, in this case also a grey box model, for simulation purposes. The model developed has been based on input-output data retrieved from a VAWT prototype in a wind tunnel. A last development step within this work involved calculation of a rough maximum braking torque for a requirement analysis, combination of the models developed previously and a concept for a two-mode control strategy governed by supervisory control.