Verification of Floating Offshore Wind Linearization Functionality in OpenFAST

Journal Article · 24 October 2019 · Journal of Physics. Conference Series

DOI: https://doi.org/10.1088/1742-6596/1356/1/012022 · OSTI ID:1578255

Johnson, Nicholas  ^[1]; Jonkman, Jason  ^[1]; Wright, Alan D. ^[1]; Hayman, Greg ^[1]; Robertson, Amy N.  ^[1]

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1. National Renewable Energy Lab. (NREL), Golden, CO (United States)

The wind engineering community relies on multiphysics engineering software to run nonlinear time-domain simulations, e.g., for design standards-based loads analysis. Although most physics involved in wind energy are nonlinear, linearization of the underlying nonlinear system equations is often advantageous to understand the system properties and exploit well-established methods and tools for analyzing linear systems. Previous work in this area has focused on the development of the new linearization functionality of the open-source engineering tool OpenFAST for floating offshore wind turbines, as well as the concepts and mathematical background needed to understand and apply it correctly. This paper focuses on the verification of this new linearization functionality, which is carried out by comparing results to previous stable versions of FAST. A nonlinear time-domain simulation for a floating offshore platform is also compared to the time-domain response of the linearized state-space model. The linearized results show good alignment between OpenFAST and previous versions of FAST, as well as with the time-domain simulations, thereby showing the accuracy of the new features in OpenFAST.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Wind and Water Technologies Office (EE-4W)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1578255
• Report Number(s): NREL/JA-5000-74210
• Journal Information: Journal of Physics. Conference Series, Vol. 1356, Issue 1; ISSN 1742-6588
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English