Multi-rotor wind turbine control challenge - A benchmark for advanced control development

We consider the control of a multi-rotor wind turbine consisting of two or more nacelles, each with at least a rotor and a generator, fixed to the same load carrying structure. We present a set of control challenges and provide an easily accessible simulation model as a benchmark for development of new ideas and comparison of methods for multi-rotor control. The control objective for the multi-rotor is to minimize the fatigue in the structure supporting the nacelles, while maximizing generated power and observing constraints on, e.g., rotational speed, rotor thrust, etc. We describe a model including the basic dynamics for a four rotor turbine. For this model an open Simulink model is made available for download. Furthermore, we provide an animation tool for visualization of the movement of the support structure during simulations. As an example we design and test a controller using the simulator. The is test completed for normal turbulence conditions obtaining significant fatigue load reductions with a limited power loss.