Control design of the highly flexible segmented ultralight morphing rotor and segmented outboard articulated rotor wind turbines near high-wind cut-out
|Johnson, Kathryn E.
|Includes bibliographical references.
|Wind is a clean, sustainable and domestic source of energy  that is rapidly becoming cost-competitive in a variety of markets. Advances in wind energy technology have lowered the cost of wind energy, that had led to significant growth in wind energy production in the past 30 years . In 2021, 9.2% of total U.S. utility-scale electricity generation came from wind turbines . Based on the report published in , the goal is to produce 20% of the U.S. electricity demand by 2030 by wind energy. Wind energy provides a cost-competitive source of electricity, but to maintain and improve competitiveness further improvements to the design of turbines is necessary to decrease the levelized cost of energy (LCOE). Within conventional turbines (three-bladed upwind), the size of turbines has been limited due to the huge mass required to ensure the blades are stiff enough to prevent tower strike, which raises costs, as well as infrastructure issues such as production, transportation, and installation. A novel downwind two-bladed or three-bladed design has the potential to greatly decrease the cost of wind energy for offshore-extreme-scale configurations, in part by reducing the necessary stiffness and mass . The multi-disciplinary design process of which this thesis details one contributor’s part results in a final ultra-scale turbine configuration that reduces LCOE relative to other existing offshore wind turbines. Our wind turbine designs need novel advanced control because of their unique design and large scale. In this thesis, the high-level design process, control methods for a Segmented Ultralight Morphing Rotor(SUMR) 50-MW wind turbine, SUMR-D (demonstrator), and 25 MW Segmented Outboard Articulating Rotor (SOAR) turbine is presented. The main focus of this thesis is shutdown and operating at high wind speed which is applied on SUMR and SOAR turbines. Soft shutdown controllers are designed to keep the turbine safe from abrupt shutdown procedures at high wind speeds. In addition, model predictive control (MPC) is designed to reduce the number of unnecessary shutdowns to keep the turbine safe from shutdowns and prevent the reduction in annual energy production (AEP) caused by shutdowns. Although linear MPC can reduce the number of shutdowns in the cut-out region, unfortunately, MPC comes with its shortcoming. The Linear MPC does not outperform the classic PI controller in other regions. The proper controller should be able to work across all regions. On the other hand, the very well-known issue of the MPC is its expensive computational cost. As a result, the final chapter introduces the switching PI-MPC. The PI-MPC controller is designed to operate in all regions of wind turbines; it is faster than stand-alone MPC and can reduce the LCOE by maintaining the operation in an extended cut-out region.
|Colorado School of Mines. Arthur Lakes Library
|2022 - Mines Theses & Dissertations
|Copyright of the original work is retained by the author.
|Control design of the highly flexible segmented ultralight morphing rotor and segmented outboard articulated rotor wind turbines near high-wind cut-out
|Newman, Alexandra M.
|Moore, Kevin L., 1960-
|Doctor of Philosophy (Ph.D.)
|Colorado School of Mines
|Embargo Expires: 10/22/2023