Set-up of a mechatronic test bench for Hardware-In-the-Loop simulation of floating offshore wind turbine

The ongoing global environmental crisis is thrusting both the research & development (R&D) and the industry to put an increasing committed effort into the implementation of the energetical transition, with the aim to cut the fossil-fuel related emissions of carbon dioxide within due time, hence avoiding the so-called “tipping points” to be reached. Floating offshore wind (FOW), among the sources of renewable energy, is the one whose development is proceeding with the highest rapidity. FOW, indeed, is characterized by an enormous potential (in terms of capacity factor and accessibility for new markets) which is in fact still far from being fully exploited - especially in the Mediterranean Sea, where not a single FOW turbine has been deployed and added to the grid yet. The purpose of this master thesis is to develop and set-up a mechatronic test bench (located in the Energy Center Lab of Politecnico di Torino) intended for the Hardware-In-the-Loop (HIL) simulation of a floating offshore wind turbine, with the eventual goal of an actual deployment in a suitable site near Pantelleria Island, in the southern-western Sicilian territorial waters. Concurrently, a Simulink model of the same system (developed in previous works) has been modified accordingly, in order to be compiled and imported in such test bench and therefore be validated in a HIL framework. The first two chapters of this dissertation contain, respectively, a deep introduction about the state of the art and the motivations behind this works, and a complete characterization of both the wind turbine system and its Simulink model. The third chapter discusses the test bench architecture, which is composed by a hardware plant reproducing in scale the turbine mechanics (asynchronous electrical motor, shaft, torque meter, synchronous generator), whose outputs are meant to represent in a faithful manner the actual output of the simulated device. On the other hand, the test bench is controlled via NI CompactRIO (cRIO-9040), which is programmed in NI VeriStand. The data transfer between the cRIO controller and the mechanical plant is implemented in a high-speed and deterministic fashion thanks to the use of the EtherCAT communication protocol. The fourth chapter deepens the whole programming procedure. As a result to this thesis work, the developed test rig proved to be a powerful tool to validate the control logic of the wind turbine in an effective way, providing a support for the engineers that will design the controller in the actual turbine; nevertheless, the research still has to be completed in future works. In particular, it will be necessary to carry out a proper simulation campaign to check the consistency of the test bench behaviour with respect to the Simulink model in a wide range of environmental and working conditions.