A constrained wind farm controller providing secondary frequency regulation: An LES study

Active power control for wind farms is needed to provide ancillary services. One of these services is to track a power reference signal with a wind farm by dynamically de- and uprating the turbines. In this paper we present a closed-loop wind farm controller that evaluates 1) thrust coefficients on a seconds-scale that provide power tracking...

Distributed State Estimation for Medium-Fidelity Wind Farm Models in pursuit of Model-Based Closed-Loop Control

In research, the overall power production in a wind farm is typically increased by employing model-based wind farm control. A controller, in an open-loop setting, operates based on the velocity of the wind flow, predicted by a wind farm model. For a controller to achieve the desired level of power production, a wind farm model has to be accurate...

Dynamic Wind Farm Control using the WFSim flow model

Renewable energy is becoming more and more important in today's society. Wind energy plays an important role in the production of renewable energy. Due to economic advantages, wind turbines are often sited close together, creating wind farms. As a result, the wind turbines in the farm become interconnected due to the wakes of the turbines. In...

Robust lidar-based closed-loop wake redirection for wind farm control

Wind turbine wake redirection is a promising concept for wind farm control to increase the total power of a wind farm. Further, the concept aims to avoid partial wake overlap on a downwind wind turbine and hence aims to decrease structural loads. Controller for wake redirection need to account for model uncertainties due to the complexity of...

Active power control of waked wind farms

Active power control can be used to balance the total power generated by wind farms with the power consumed on the electricity grid. With the increasing penetration levels of wind energy, there is an increasing need for this ancillary service. In this paper, we show that the tracking of a certain power reference signal provided by the...

Adjoint-based model predictive control of wind farms: Beyond the quasi steady-state power maximization

In this paper, we extend our closed-loop optimal control framework for wind farms to minimize wake-induced power losses. We develop an adjoint-based model predictive controller which employs a medium-fidelity 2D dynamic wind farm model. The wind turbine axial induction factors are considered here as the control inputs to influence the overall...

Preconditioning Optimal Flow Control Problems Using Multilevel Sequentially Semiseparable Matrix Computations

Optimal flow control problems are important for applications in science and engineering. Solving such problems usually requires the solution of a large linear generalized saddle-point system. This linear system is sparse and highly indefinite. In order to solve such systems using Krylov subspace methods, efficient preconditioners are necessary...