Blar i Institutt for marin teknikk på forfatter "Nejad, Amir Rasekhi"
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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 ... -
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 ... -
Digital Twins for Fault Prognosis in Offshore Wind Turbine Drivetrains
Mehlan, Felix Christian (Doctoral theses at NTNU;2024:178, Doctoral thesis, 2024)This thesis investigates the relatively novel concept of Digital Twin (DT) in the context of offshore wind turbine drivetrains. DT can be described as a virtual representation of a system or asset that calculates system ... -
Dynamic Analysis and Design of Gearboxes in Offshore Wind Turbines in a Structural Reliability Perspective
Nejad, Amir Rasekhi (Doctoral thesis at NTNU;2015:191, Doctoral thesis, 2015)The drivetrain is the heart of the wind turbine. In wind turbines, the wind's kinetic energy is converted to electrical power through the drivetrain which often consists of a gearbox and a generator. The drivetrain is ... -
Effectiveness of Offshore Maintenance Bases in Norwegian Offshore Wind
Jacobsen, Fredrik Stennes (Master thesis, 2023)Den norske regjeringen har ambisjoner for en storstilt utvikling av havvind. For å nå målet er det nødvendig å redusere kostnader, spesielt for flytende havvind. Det er forventet at kostnader tilknyttet havvind vil reduseres ... -
Main bearings in large offshore wind turbines: development trends, design and analysis requirements
Torsvik, Jone; Nejad, Amir Rasekhi; Pedersen, Eilif (Journal article; Peer reviewed, 2018)This paper discusses analysis requirements for design and operation of main bearings in modern multi-megawatt offshore wind turbines, motivated by the industry's search for reliable and cost effective main bearing solutions ... -
On Tower Top Axial Acceleration and Drivetrain Responses in a Spar-Type Floating Wind Turbine
Nejad, Amir Rasekhi; Bachynski, Erin Elizabeth; Moan, Torgeir (Chapter; Peer reviewed, 2017)Common industrial practice for designing floating wind turbines is to set an operational limit for the tower-top axial acceleration, normally in the range of 0.2–0.3g, which is typically understood to be related to the ... -
Proceedings of the 3rd Offshore Structural Reliability Conference (OSRC2016)
Moan, Torgeir; Nejad, Amir Rasekhi (Book, 2018)