This report describes a three-bladed, upwind, variable-speed, variable blade-pitch-to-feather-controlled multimegawatt wind turbine model developed by NREL to support concept studies aimed at assessing offshore wind technology.

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Definition of a 5-MW Reference Wind Turbine for Offshore System Development

Simulation and the monte carlo method

FAST User's Guide

This paper presents a comprehensive study on the state-of-the-art and emerging wind energy technologies from the electrical engineering perspective. In an attempt to decrease cost of energy, increase the wind energy conversion efficiency, reliability, power density, and comply with the stringent grid codes, the electric generators and power electronic converters have emerged in a rigorous manner. From the market based survey, the most successful generator-converter configurations are addressed along with few promising topologies available in the literature. The back-to-back connected converters, passive generator-side converters, converters for multiphase generators, and converters without intermediate dc-link are investigated for high-power wind energy conversion systems (WECS), and presented in low and medium voltage category. The onshore and offshore wind farm configurations are analyzed with respect to the series/parallel connection of wind turbine ac/dc output terminals, and high voltage ac/dc transmission. The fault-ride through compliance methods used in the induction and synchronous generator based WECS are also discussed. The past, present and future trends in megawatt WECS are reviewed in terms of mechanical and electrical technologies, integration to power systems, and control theory. The important survey results, and technical merits and demerits of various WECS electrical systems are summarized by tables. The list of current and future wind turbines are also provided along with technical details.

High-Power Wind Energy Conversion Systems: State-of-the-Art and Emerging Technologies

This report describes the development, verification, and application of a comprehensive simulation tool for modeling coupled dynamic responses of offshore floating wind turbines.

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Dynamics Modeling and Loads Analysis of an Offshore Floating Wind Turbine

/pdf/specification-document-for-oc6-phase-ii-verification-of-an-1jcwjfe8gu.pdf

Specification Document for OC6 Phase II: Verification of an Advanced Soil-Structure Interaction Model for Offshore Wind Turbines

Development of a Control Co-Design Modeling Tool for Marine Hydrokinetic Turbines

In this article, we present a time-varying formulation of the curled wake model that we implemented in FAST.Farm. The curled wake model, originally developed for steady-state conditions, is used to produce realistic wake profiles behind a wind turbine in yawed (or skewed) conditions. We begin by introducing the key elements of the FAST.Farm framework. Then, after briefly summarizing the original wake dynamics formulation of FAST.Farm based on a polar wake profile, we present the new time-varying formulation of the curled wake model, compare the two, and highlight the differences with the original curled wake model. After discussing some implementation details, we present different applications with increasing levels of complexity: single turbine with uniform and turbulent inflow, fixed and transient yaw, and multiple turbines. We verify our results using the original FAST.Farm implementation and large-eddy simulations. The results with the new curled wake model are improved compared to the original implementation, as they include cross-flow velocities and wake asymmetry. Yet, large-eddy simulation results show a more pronounced lateral convection of the wake and a stronger concentration of vorticity at the top vortex. The new curled wake implementation in FAST.Farm should enable the calculation of not only generator power but also wind turbine structural loads for applications involving intentional or unintentional skewed flow and wind-farm control involving wake steering. 

A time‐varying formulation of the curled wake model within the FAST.Farm framework

This paper describes the use of MATLAB/Simulink to simulate the electrical and grid-related aspects of a WTG and the FAST aero-elastic wind turbine code to simulate the aerodynamic and mechanical aspects of the WTG. The combination of the two enables studies involving both electrical and mechanical aspects of the WTG.

Hybrid Electro-Mechanical Simulation Tool for Wind Turbine Generators: Preprint

This work presents two aerodynamic models that are used to perform modal and stability analyses of wind turbines. Including aerodynamic effects in stability analyses is important to capture aerodynamic inertia, stiffness, and damping. The two models consist of a dynamic inflow model based on Øye’s model and an unsteady aerodynamics model based on a simplified Beddoes-Leishman dynamic stall model. Both models are written in a continuous-time state-space form, which is the form needed to perform linearizations within OpenFAST. In this article, we present the new models, perform some simple verifications against HAWC2 results, and then perform stability analyses. We investigate the contribution of the aerodynamic effects on the turbine modes, particularly the flapwise modes, which are the most affected. Because of the development presented in this work, Campbell diagrams accounting for dynamic stall and dynamic wake effects were generated for the first time using OpenFAST.

Jason Jonkman

Papers

Specification Document for OC6 Phase II: Verification of an Advanced Soil-Structure Interaction Model for Offshore Wind Turbines

Development of a Control Co-Design Modeling Tool for Marine Hydrokinetic Turbines

A time‐varying formulation of the curled wake model within the FAST.Farm framework

Hybrid Electro-Mechanical Simulation Tool for Wind Turbine Generators: Preprint

Dynamic inflow and unsteady aerodynamics models for modal and stability analyses in OpenFAST