*Article* **Implementation and Validation of an Advanced Wind Energy Controller in Aero-Servo-Elastic Simulations Using the Lifting Line Free Vortex Wake Model**

**Sebastian Perez-Becker \*, David Marten, Christian Navid Nayeri and Christian Oliver Paschereit**

Chair of Fluid Dynamics, Hermann Föttinger Institute, Technische Universität Berlin, Müller-Breslau-Str. 8, 10623 Berlin, Germany; david.marten@tu-berlin.de (D.M.); christian.nayeri@tu-berlin.de (C.N.N.); oliver.paschereit@tu-berlin.de (C.O.P.)

**\*** Correspondence: s.perez-becker@tu-berlin.de

**Abstract:** Accurate and reproducible aeroelastic load calculations are indispensable for designing modern multi-MW wind turbines. They are also essential for assessing the load reduction capabilities of advanced wind turbine control strategies. In this paper, we contribute to this topic by introducing the TUB Controller, an advanced open-source wind turbine controller capable of performing full load calculations. It is compatible with the aeroelastic software QBlade, which features a lifting line free vortex wake aerodynamic model. The paper describes in detail the controller and includes a validation study against an established open-source controller from the literature. Both controllers show comparable performance with our chosen metrics. Furthermore, we analyze the advanced load reduction capabilities of the individual pitch control strategy included in the TUB Controller. Turbulent wind simulations with the DTU 10MW Reference Wind Turbine featuring the individual pitch control strategy show a decrease in the out-of-plane and torsional blade root bending moment fatigue loads of 14% and 9.4% respectively compared to a baseline controller.

**Keywords:** wind energy; wind turbine control; load mitigation; individual pitch control; lifting line free vortex wake; vortex methods
