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Ma, Yu

Publications and source records attributed to Ma, Yu.

9 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

A Reduced-form Cost Model for Prefeasibility Analysis of Hydropower at Non-Powered Dams

This study presents a reduced-form model to support a better understanding of the capacity potential and drivers of costs for hydropower development at U.S. non-powered dams (NPD), which are existing dams that are not currently used for hydropower. With information on nineteen reference sites, a set of reduced-form design and cost equations were estimated to enable rapid assessments of aggregate costs and their components for a large number of NPD sites. The model was then applied to 36,000+ potential U.S. NPD sites using the limited data commonly available. Although the cost estimates span a wide range, there exists a significant amount of U.S. NPD hydropower capacity potential, which are considered cost-competitive in the current market using baseline technologies.

13 HYDRO ENERGY↗
DOE OSTI2018

Wave forecast and its application to the optimal control of offshore floating wind turbine for load mitigation

Control algorithms play an important role in energy capture and load mitigation for offshore floating wind turbines (OFWTs). One of the advanced and effective control techniques is the feedforward or model predictive control approach, which requires the forecast of incoming environment conditions. For OFWTs, wave loading is one of the dominant sources to excite structural responses. This study is thus motivated to develop forecasting algorithms for wave elevations and wave excitation forces with the purpose of applying feedforward controllers on OFWTs. Two forecasting algorithms, the approximate Prony Method based on ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) and SVM (Support Vector Machine) regression, are developed and validated using wave records from tank tests. Utilizing the forecasted wave elevations and wave excitation forces, a feedforward LQR controller is designed to mitigate structural loads of an OFWT system.

17 WIND ENERGY↗