Evaluation of PMSG‐based drivetrain technologies for 10‐MW floating offshore wind turbines: Pros and cons in a life cycle perspective

Abstract

This paper presents an in depth evaluation and comparison of three different drivetrain choices based on permanent-magnet synchronous generator (PMSG) technology for 10-MW offshore wind turbines. The life cycle approach is suggested to evaluate the performance of the different under consideration drivetrain topologies. Furthermore, the design of the drivetrain is studied through optimized designs for the generator and gearbox. The proposed drivetrain analytical optimization approach supported by numerical simulations shows that application of gearbox in 10-MW offshore wind turbines can help to reduce weight, raw material cost, and size and simultaneously improve the efficiency. The possibility of resonance with the first torsional natural frequency of drivetrain for the different designed drivetrain systems, the influence of gear ratio, and the feasibility of the application for a spar floating platform are also discussed.This study gives evidence on how gearbox can mitigate the torque oscillation consequences on the other components and how the latter can influence the reliability of drivetrain. KEYWORDSdrivetrain optimization, floating offshore wind turbine, life cycle assessment, permanent-magnet synchronous generator INTRODUCTIONThe capacity of offshore wind turbines and the distance from shores is rising rapidly, so that multigigawatt offshore wind farms based on multimegawatt floating turbines show potentials to be one of the dominant sources of power production in the future. The latter is due to availability of better wind resources, less turbulence, steadier winds, and less wind shear; easier transportation of larger turbines on the sea; technological developments in power electronic converters and direct current (DC) power transmission technologies; the establishments of required market infrastructures; and technological achievements in installation of turbines in deep waters, which lead to a considerable drop in the levelized cost of energy (LCOE) of offshore wind turbines. In spite of significant improvements, there are still no unanimous decision about the drivetrain system technology in offshore wind turbines. 1,2 Offshore wind reaches to 10-MW turbines or even higher, but there are still different interests between manufacturers in the selection of drivetrain technology. One reason is that the drivetrain in wind originally comes from available experiences in other industries, which has been modified over time. The latter has then been upscaled for higher powers with some modifications to reduce the production costs and improve the dynamic response. Because the wind turbines are developed for a wide range of power in various onshore/offshore, fixed/floating, two-/three-bladed rotors, upwind/downwind, high/medium/low wind, fix/variable speed, stall/active yaw, and stall/active pitch applications, a customized design of the drivetrain for the cost reduction and performance improvement is inevitable. Therefore, there is a need for a special drivetrain design for each power class for different applicati...

Drivetrains on floating offshore wind turbines: lessons learned over the last 10 years

“…In the Hywind Tampen project currently under construction, 8 MW direct drive turbines will be employed. Moghadam and Nejad [7] employed optimized analytical 10-MW drivetrain designs, representing the three most common, different drivetrain concepts, and compared the cost, efficiency, operation and dynamic behavior in a life-cycle perspective, using a systems engineering approach and considering both gearbox and generator effects. The results were in the favor of medium speed drivetrains indicating that utilization of gearbox can improve both the economics and operations of the wind turbine in 10-MW floating offshore wind turbines.…”

Wind turbine drivetrains: state-of-the-art technologies and future development trends

“…The reliability and availability of the wind generator system has a decisive impact on the cost of energy (COE), especially offshore (Carroll, 2016;Shipurkar et al, 2016). The generator design should consider the interactions with other components to improve the system reliability of the drivetrain (Moghadam and Nejad, 2020). In large wind turbines, multiphase windings with modular converters can be used to improve the generator system availability (Shipurkar et al, 2015;McDonald and Jimmy, 2016).…”

“…The two main drivetrain configurations and components that characterize them are depicted in Figure 1. A variety of wind turbine drivetrain technologies are available, with pros and cons for each in terms of cost, weight, size, manufacturing, materials, efficiency, reliability, and operation and maintenance (O&M) (Polinder et al, 2006;Arabian-Hoseynabadi et al, 2010;Moghadam and Nejad, 2020;Harzendorf, 2021;Harzendorf et al, 2021). With digitalization expanding in all industries, new opportunities have arisen in the operation phase, including digital O&M and digital twins.…”

An IoT-Based Life Cycle Assessment Platform of Wind Turbines

“…Jesuina et al [ 27 ] attempted to quantify the relative contribution of individual stages toward life cycle impacts by conducting a life cycle assessment with SimaPro and the IMPACT2002+ method. Moghadam et al [ 28 ] developed an in-depth LCA evaluation of three different drive train choices based on permanent-magnet synchronous generator technology for 10 MW offshore wind turbines. Mendecka et al [ 29 ] proposed simplified LCA models that predict the final results with acceptable uncertainty.…”