Controller design forfor a wind farm, Controller design a wind farm, considering bothpower power and load considering both and load aspects aspects Maryam Soleimanzadeh Maryam Soleimanzadeh Rafael Wisniewski Contents: • Introduction & Overview • Wind farm control • Control strategy • Load • Power • Results Introduction •Motivation: • A wind flow model in the form of •The wind farm controller should (based on the model): • Provide power reference for each WT • Minimize load Overview Overview Overview Wind Farm Control • The Wind Farm Controller block controls the power production of the wind farm by sending out reference signals to each individual wind turbine. • Wind turbine controller: responsible to execute the references sent from the wind farm controller Wind Farm Configuration Load Reduction Structural Loads (dynamic): • The tower fore-aft motion • The tower side-to-side The blade flap motion Blade edge & Drive train torsion Reducing the tower fluctuations (fore-aft and side-to-side), will significantly reduce fatigue loads Load Reduction Depending on wind turbines operating region Control Strateg y Wind Farm Control •Farm control Strategy : (Idea from WT control strategy, following figure) • Below rated wind speed •Farm windController turbines are to produce produces: as much power as possible • Rotor speed reference • the pitch angle is kept signals almost constant. • Above rated wind speed • wind turbines are to follow Farm Controller produces: the power reference signal • Power reference • thesignals rotor speed is kept almost constant. •Pitch angle reference Figure: Bianchi, F. et al. , Wind turbine control systems , 2006 Wind Farm Control • Below rated Wind speed: • pitch angle: constant, • Additional thrust by rotor speed variations: to increase damping Wind Farm Control • Below rated Wind speed: Wind Farm Control • Below rated Wind speed: Increasing tower fore-aft damping Maximize Power Minimize load • S.T. Minimize load Increasing tower side-to-side damping x = V (Wind Speed), u= Ct Wind Farm Control • Above rated Wind speed: • Rotor speed: constant, • Additional thrust by pitch angle variations: to increase damping Wind Farm Control • Above rated Wind speed: Power Reference Determination Minimize load • S.T. Increasing tower fore-aft damping Minimize load Increasing tower side-to-side damping x = V (Wind Speed), u= Ct Wind Farm Control Optimal control solution for below rated wind speed Comparison of total produced power by each WT in low wind speed, with and without wind farm controller Wind Farm Control Optimal control solution for above rated wind speed Total power reference for each wind turbine in high wind speed, with and without controller. Total demanded power from the wind farm for both cases are equal. Conclusion • It is founded on the dynamical model of the flow in wind farms. • The wind farm controller focuses on optimization of both power and load simultaneously. • Determines the reference signals for each individual wind turbine controller in two scenarios based on low and high wind speed. In low wind speed, the reference signals for rotor speed are adjusted. In high wind speed, the power and pitch reference signals are determined. But • It does not consider the interactions between wind turbine controllers and the farm controller. Thank you!