ℋ∞ controller design for closed-loop wake redirection

Abstract

The focus of control research in wind energy has shifted more and more from individual wind turbines to wind farms due to the potential efficiency improvement in the energy production. In this work, the wind farm control concept “wake redirection” is further investigated. More precisely, the concept of lidar-based closed-loop wake redirection is extended. A lidar-based wake center estimation is assumed and fed back to a controller, which steers the wake by employing the yaw actuator to a desired position. In this work, a ℋ∞ controller design approach for lidar-based closed-loop wake redirection is investigated. The controller is designed using models that are obtained from the wind farm simulation tool WFSim. First, a model identification procedure is applied to derive the controller design models. Then, a ℋ∞ controller design is conducted to obtain a controller for each identified model. The controllers are presented and the performances are analyzed. In a final step, a single controller is implemented in WFSim and closed-loop step simulations are conducted illustrating the desired behavior.