Growing a vibrant clean energy industry will lead to major societal benefits by reducing pollution and creating a large number of jobs. In addition to well-established renewables like wind, solar and traditional hydropower, marine currents have the potential to diversify and significantly strengthen the global energy portfolio. This project will conduct basic research focused on extracting electrical power from marine currents using ocean current turbines. These turbines will operate near the sea surface in major offshore currents and will be interconnected in arrays. The project will address fundamental issues related to coordinated, safe, reliable, and robust operation of these turbines within the array for maximum energy production. Networked electrical interconnections between devices and energy storage will also be investigated, with a focus on efficiently feeding electrical power from an array of turbines to an onshore grid. A diverse population of Faculty and student researchers will contribute to this project, creating a heterogeneous network of scholars that will improve the infrastructure for research and education. Important findings from this project will be integrated with active education and outreach programs at Virginia Tech, the University of New Orleans, and Florida Atlantic University which regularly share research outcomes with the public through presentations, workshops, the web, conferences, and summer camp activities. Broader scientific and technological impacts are expected in the energy sector, ocean engineering and technology, marine vehicles and devices, as well as autonomy and control systems.
Ocean current turbines will be interconnected in arrays through a local feed-in which sends generated power to a grid. These devices will be affected by flow perturbations such as current shear, turbulence, marine waves, as well as the shear and turbulence generated by neighboring turbines. The overall project goal is to ensure autonomous, reliable and robust coordinated operation of these turbines for maximum energy production and proper power conditioning in the presence of realistic perturbations and sub-system failures. For this purpose fault tolerant flight control, supervisory switching control to manage sub-system failures, formation and network control for ocean current turbine farms with energy storage will be investigated. Novel control systems, which include active blade pitch angle control by leveraging helicopter flight control technology and modern multivariable constrained control techniques will be developed. Control algorithms will be created and evaluated using numerical representations of commercial devices to increase applicability and encourage transfer to the commercial sector. Power conditioning solutions that utilize energy storage will be developed and evaluated to collect power from multiple devices for transfer to shore and grid connection. The project will also investigate energy storage and regeneration through fuel cells or hydrogen internal combustion engines. Basic principles and experimental data series will be combined to create a comprehensive simulation for the entire storage system. The model will be able to provide steady-state performance data for system design and for operations scheduling and control. Modeling and numerical simulation advancements will enable development and testing of controllers on numerical representations with dynamics very similar to commercial marine turbines. These will provide solutions for testing and evaluating the developed controllers, as well as advancements to turbine performance prediction capabilities. Dynamometer and in-water testing data will help advance the developed technologies towards implementation. Methods and tools from diverse disciplines such as control systems theory and technology, hydrodynamics modeling, optimization, as well as numerical computation and analysis will be involved.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
