Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Wind is the fastest growing renewable and sustainable energy in electricity generation around the world. One trend to improve the efficiency of wind turbines and wind farms is to move them into the deepwater sea where the wind is stronger and more consistent than the onshore wind and where we need to set the turbines afloat. Due to the unfixed foundation, floating wind turbines can take advantage of their relocation capability to alleviate the wake effect between turbines, to increase the total power of multiple turbines, and to reduce the fatigue load of the turbines in the wind farm. However, one of the challenges in the operation of floating offshore wind turbines is the wave disturbance which acts on the platforms in an unpredictable manner. To enhance wind power generation, the undesirable vibration motions of the platform and the turbine excited by the wave need to be suppressed, and consequently wind energy cost need to be minimized, by control engineering technologies.

The main goal of this program is to establish control techniques for a utility-scale floating offshore wind turbine on a semi-submersible platform, in order to maximize the wind power capture and minimize the structural loading, thereby reducing the wind energy cost. The approach to this goal is original and novel in four ways. Firstly, for controller design, we adopt control-oriented models that can involve explicitly dynamical wave effect to the platform’s 3-D motion. Secondly, we exploit our recently-developed linear parameter-varying control techniques to design feedforward and feedback control systems. Thirdly, to further suppress the wave-induced platform vibration, we employ real-time wave pressure measurement for feedforward and predictive control. Lastly, as a low-level control under the high-level real-time wind farm layout optimization, we account for position control of the platform by making use of only the aerodynamic force, without adding any extra actuator.

To achieve the main goal described above, technical tasks in this program include 1) extension of the control-oriented modelling technique with structural flexibilities and the aerodynamic force distributed to three blades, 2) model-based design of linear parameter-varying controllers of a semi-submersible wind turbine, 3) design of platform position controllers within the movable range of the semi-submersible platform, and 4) software development for control-oriented modelling and controller design devised in this program. Simulation studies will be conducted to validate the developed models and controllers.

The research outcome will have a great impact on the environment, society and economy in Canada and worldwide. It will increase employment in the wind energy sector, investments and profits to the community, in both the short and long term. It will provide a clean environment without visual and noise impact on the surrounding environment.