Blar i NTNU Open på forfatter "Moan, Torgeir"
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Conceptual study of a gearbox fault detection method applied on a 5‐MW spar‐type floating wind turbine
Nejad, Amir Rasekhi; Odgaard, Peter Fogh; Moan, Torgeir (Journal article; Peer reviewed, 2018)In this paper, a model‐based fault detection method for fault detection of gearboxes in offshore wind turbines is presented. The main aim of this paper is to support conceptual studies with more emphasis on early fault ... -
Condition monitoring of spar‐type floating wind turbine drivetrain using statistical fault diagnosis
Ghane, Mahdi; Nejad, Amir Rasekhi; Blanke, Mogens; Gao, Zhen; Moan, Torgeir (Journal article, 2018)Operation and maintenance costs are significant for large‐scale wind turbines and particularly so for offshore. A well‐organized operation and maintenance strategy is vital to ensure the reliability, availability, and ... -
Correlation between Acceleration and Drivetrain Load Effects for Monopile Offshore Wind Turbines
Rasekhi Nejad, Amir; Bachynski, Erin Elizabeth; Li, Lin; Moan, Torgeir (Journal article; Peer reviewed, 2016)This paper investigates the correlation between the tower-top axial acceleration and the load effects in drivetrain components in a monopile (bottom-fixed) offshore wind turbine. In designing offshore wind turbines, it is ... -
Coupled Analysis of a Spar Floating Wind Turbine considering both Ice and Aerodynamic Loads
Saccoman, Marine Yvette Josette (Master thesis, 2015)In this thesis a model is proposed for establishing the coupled analysis of a spar floating wind turbine considering both ice and aerodynamic loads. This topic is important within the field of renewable energies research ... -
Damage Identification of an Offshore Wind Turbine Jacket Support Structure
Brauer, Simon Adrian (Master thesis, 2014)Due to the variable and stochastic offshore environment, offshore wind turbines are prone to fatigue. Fatigue damage usually occurs as cracks and is an important indicator of the structure's condition and the remaining ... -
Design and analysis for a steel braceless semi-submersible hull for supporting a 5-MW horizontal axis wind turbine
Luan, Chenyu (Doctoral theses at NTNU, 2018:194, Doctoral thesis, 2018)This thesis deals with design and analysis of steel semisubmersible hulls for supporting MW-level horizontal axis wind turbines. The thesis address the following four topics: 1) conceptual design methods, 2) conceptual ... -
Design and Analysis of a Braceless Steel 5-MW Semi-Submersible Wind Turbine
Luan, Chenyu; Gao, Zhen; Moan, Torgeir (Chapter; Peer reviewed, 2016)This paper introduces the design data and numerical analysis of a braceless steel semi-submersible wind turbine. The hull of the semi-submersible wind turbine is designed to support a reference 5-MW horizontal axis wind ... -
Design and analysis of a large wind floater - A reinforced concrete pontoon-type semi-submersible supporting the DTU 10MW reference turbine
Deac, Marius (Master thesis, 2014)In the project work, the candidate has made a preliminary design of a concrete semi-submersible floater for supporting the DTU 10MW wind turbine. In particular, the focus was the design of pontoons and columns of this ... -
Design and Analysis of Mooring System for Semi-submersible Floating Wind Turbine in Shallow Water
Xu, Kun (Doctoral thesis, 2020)Floating wind turbines are necessary to produce power from wind in deeper water where bottom-fixed wind turbines are not economically competitive. However, it is still not clear to which water depth a floating wind turbine ... -
Design and Analysis of Mooring System for Semi-submersible Floating Wind Turbines in Shallow Water
Xu, Kun (Master thesis, 2015)There has been a remarkable development in offshore wind energy. From the view of cost efficiency, floating wind turbine becomes more competitive than bottom fixed wind turbine when the water depth comes above 50 m. ... -
Design and Analysis of Semi-submersible Floating Wind Turbines with focus on Structural Response Reduction
Vittori, Felipe Eduardo (Master thesis, 2015)Floating structures as spar, semi-submersibles and TLP have been proposed for offshore wind turbines for deep waters (>60m) according to the report of Arapogianni, Moccia, Williams, & Phillips (2011), where bottom fixed ... -
Design and comparative analysis of alternative mooring systems for floating wind turbines in shallow water with emphasis on ultimate limit state design
Xu, Kun; Larsen, Kjell; Shao, Yanlin; Zhang, Min; Gao, Zhen; Moan, Torgeir (Journal article; Peer reviewed, 2021)Floating wind turbines represent a cost-efficient energy solution in deep water where bottom-fixed wind turbine becomes excessively expensive. However, mooring design is quite challenging for all shallow water depths ... -
Design and Dynamic Analysis of a 10-MV Medium-Speed Drivetrain in Offshore Wind Turbines
Wang, Shuaishuai (Doctoral theses at NTNU;2021:124, Doctoral thesis, 2021)This thesis deals with design and dynamic analysis of 10-MW medium-speed drivetrains for large-scale offshore wind turbines. Many issues related to two main topics, drivetrain design and dynamic analysis, have been ... -
Design and Dynamic Analysis of a Compact 10 MW Medium Speed Gearbox for Offshore Wind Turbines.
Wang, Shuaishuai; Nejad, Amir R.; Moan, Torgeir (Peer reviewed; Journal article, 2021)This paper deals with the design of a compact gearbox for the DTU 10 MW reference offshore wind turbine. An innovative gearbox concept consisting of a fixed planetary stage and a differential compound epicyclic stage is ... -
Design and Dynamic Analysis of a Steel Pontoon-type Semi-submersible Floater Supporting the DTU 10MW Reference Turbine
Wang, Qiang (Master thesis, 2014)In recent years, oshore wind energy has experienced a huge development. Floating wind turbines may become competitive for water depth larger than 50m. However, high cost is still the main challenge for the oshore wind ... -
Development and verification of a time-domain approach for determining forces and moments in structural components of floaters with an application to floating wind turbines
Luan, Chenyu; Gao, Zhen; Moan, Torgeir (Journal article; Peer reviewed, 2017)Structural design of the floater is an important aspect in developing cost efficient and reliable floating wind turbines. It is difficult to well account for the effect of strong non-linear dynamic characteristics and ... -
Development of a 5 MW reference gearbox for offshore wind turbines
Rasekhi Nejad, Amir; Guo, Yi; Gao, Zhen; Moan, Torgeir (Journal article, 2016)This paper presents detailed descriptions, modeling parameters and technical data of a 5MW high-speed gearbox developed for the National Renewable Energy Laboratory offshore 5MW baseline wind turbine. The main aim of this ... -
Diagnostic monitoring of drivetrain in a 5 MW spar-type floating wind turbine using Hilbert spectral analysis
Ghane, Mahdi; Nejad, Amir Rasekhi; Blanke, Mogens; Gao, Zhen; Moan, Torgeir (Journal article; Peer reviewed, 2017)The objective of this paper is to investigate the frequency-based fault detection of a 5MW spar-type floating wind turbine (WT) gearbox using measurements of the global responses. It is extremely costly to seed managed ... -
Drivetrain load effects in a 5-MW bottom-fixed wind turbine under blade-pitch fault condition and emergency shutdown
Rasekhi Nejad, Amir; Jiang, Zhiyu; Gao, Zhen; Moan, Torgeir (Journal article; Peer reviewed, 2016)In this paper, the effect of the blade-pitch fault and emergency shutdown on drivetrain responses in a 5-MW bottom-fixed wind turbine are investigated. A 5-MW reference gearbox with 4-point support is employed and the ... -
Dynamic analysis of a floating vertical axis wind turbine under emergency shutdown using hydrodynamic brake
Wang, Kai; Hansen, Martin Otto Laver; Moan, Torgeir (Journal article; Peer reviewed, 2014)Emergency shutdown is always a challenge for an operating vertical axis wind turbine. A 5-MW vertical axis wind turbine with a Darrieus rotor mounted on a semi-submersible support structure was examined in this study. ...