scholarly journals A Rare-Earth Free Magnetically Geared Generator for Direct-Drive Wind Turbines

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 447 ◽  
Author(s):  
Reza Zeinali ◽  
Ozan Keysan
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Outer Diameter ◽  
Direct Drive ◽  
Torque Density ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Pole Type ◽  
Structural Mass ◽  
Large Wind

A novel Vernier type magnetically geared direct-drive generator for large wind turbines is introduced in this paper. Conventional Vernier-type machines and most of the direct-drive wind turbine generators use excessive amount of permanent magnet, which increases the overall cost and makes the manufacturing process challenging. In this paper, an electrically excited (PM_less) claw-pole type Vernier machine is presented. This new topology has the potential of reducing mass and cost of the generator, and can make the construction easy in manufacturing and handling. Analytical designs are verified using 3D finite-element simulations and several designs are evaluated to find the optimum design for a 7.5 MW, 12 rpm wind turbine application. It is shown, that the required torque can be achieved with an outer diameter of 7.5 m, and with a mass of 172 t (including the structural mass). The proposed generator is compared with commercial direct-drive generators, and it is found that the proposed generator has the highest torque density with 34.7 kNm/t.

Coupled Electromagnetic and Lattice Structure Optimization for the Rotor and Stator of Large Electric Machines

2021 ◽  
Author(s):  
Austin C. Hayes ◽  
Gregory L. Whiting
Keyword(s):  
Wind Turbine ◽  
Lattice Structure ◽  
Electric Machines ◽  
Force Density ◽  
Direct Drive ◽  
Element Analysis ◽  
Electromagnetic Design ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Structural Mass

Abstract Permanent magnet direct drive (PMDD) electric machines are advantageous due to higher efficiencies and lower maintenance concerns. For wind turbine generators, especially offshore turbines, this is advantageous to geared machines and is currently implemented by manufacturers such as GE, Siemens and Enercon. By nature, a direct drive machine must be larger than its geared counterpart in order to output the same power. As a result, the structural mass is larger and makes the machine prohibitively large. However, the structural mass and electromagnetic design is coupled and the electromagnetic criteria are an important consideration in the structural design. In this analysis, the electromagnetic design of a 5 MW PMDD generator was coupled to a triply periodic minimal surface (TPMS) lattice generator through means of an evolutionary algorithm. Finite element analysis (FEA) was used to determine the radial, torsional, and axial deformations under simulated wind turbine generator loading conditions subject to critical deflection criteria. Lattice functional grading was completed with the FEA deflection data in order to further optimize the structural mass. For the 5 MW test case, functional graded TPMS support structures maintained stiffness for a generator with a 32% higher force density with inactive mass 4% lower than baseline. This study suggests functional grading of TPMS lattice structures for wind turbine generators has the potential at significant mass savings.

Bayesian Networks in Electric Reliability Assessment of Doubly-Fed Wind Turbine Generator

2014 ◽  
Vol 494-495 ◽  
pp. 1791-1794 ◽  
Author(s):  
Hai Ning Pan ◽  
Ming Qin ◽  
Jun Zhang ◽  
Chao Chang ◽  
Pan Lei
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Reliability Assessment ◽  
Turbine Generator ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Reliability Methods ◽  
Doubly Fed ◽  
Electrical Components ◽  
Large Wind

For the development of large wind turbines, the approach of trial and error is also not adequate for mass produced wind turbines, a reliability-concerned manufacturing must be involved for the future development. An approach which introduces probabilistic reliability assessment which incorporates reliability methods into wind turbine engineering is described. Fault Tree of wind turbine generators electrical components is firstly built. Then it is transformed to the Bayesian network and probabilistic distribution is preceded using Markov chain Monte Carlo inference. Finally a set of qualitative and quantitative reliability is given according to a specific probabilistic input.

Evaluation of Human Exposure to the Noise from Large Wind Turbine Generators

1983 ◽  
Vol 21 (1) ◽  
pp. 30 ◽  
Author(s):  
Kevin P. Shepherd ◽  
Ferdinand W. Grosveld ◽  
David G. Stephens
Keyword(s):  
Wind Turbine ◽  
Human Exposure ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Large Wind

Performance Study of Wind Turbine Generators

Solar Energy ◽  
2003 ◽  
Author(s):  
G. R. Bhagwatikar ◽  
W. Z. Gandhare
Keyword(s):  
Power Consumption ◽  
Wind Turbine ◽  
Wind Power ◽  
Wind Turbines ◽  
Reactive Power ◽  
Variable Speed ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Utility Grid ◽  
Operational Issues

It is well known that the wind power has definitely certain impact on the grid power. Issues associated with the integration of wind power into the utility grid are interface issues, operational issues and planning issues. Interface issues include harmonics, reactive power consumption, voltage regulation and frequency control. Operational issues are intermittent power generation, operating reserve requirements, unit commitment and economic despatch. And planning issues are concerned with intermittent wind resources compared to conventional power resources. An important question, when connecting the wind turbine generators to the utility grid, is how much the power / voltage quality will be influenced, since the power production by wind turbines is intermittent, quantity wise as well as quality wise. This paper is focused on the on comparison between the constant speed wind turbines and variable speed wind turbines, reactive power consumption and harmonics generated by both wind turbines. Total harmonic distortion is calculated by the application of C++ software and a comparison is done between the generators with respect to the harmonics. It is observed that constant speed wind turbine generates low order harmonics and variable speed turbine generates high order harmonics. On the basis of results, some solutions are suggested to improve the wind power quality and to reduce reactive power consumption. It seems that variable speed wind turbines with electronic interface are better with respect to the utility grid point of view.

Powder-Binder Jetting Large-Scale, Metal Direct-Drive Generators: Selecting the Powder, Binder, and Process Parameters

2019 ◽  
Author(s):  
Austin C. Hayes ◽  
Gregory L. Whiting
Keyword(s):  
Additive Manufacturing ◽  
Wind Turbine ◽  
Large Scale ◽  
Material Selection ◽  
Direct Drive ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Complex Parts ◽  
Printing Parameters ◽  
Binder Jetting

Abstract Additive manufacturing enables the production of complex geometries extremely difficult to create with conventional subtractive methods. While good at producing complex parts, its limitations can be seen through its penetration into everyday manufacturing markets. Throughput limitations, poor surface roughness, limited material selection, and repeatability concerns hinder additive manufacturing from revolutionizing all but the low-volume, high-value markets. This work characterizes combining powder-binder jetting with traditional casting techniques to create large, complex metal parts. Specifically, we extend this technology to wind turbine generators and provide initial feasibility of producing complex direct-drive generator rotor and stator designs. In this process, thermal inkjet printer heads selectively deposit binder on hydroperm casting powder. This powder is selectively solidified and baked to remove moisture before being cast through traditional methods. This work identifies a scalable manufacturing process to print large-scale wind turbine direct drive generators. As direct-drive generators are substantially larger than their synchronous counterparts, a printing process must be able to be scaled for a 2–5 MW 2–6m machine. For this study, research on the powder, binder, and printing parameters is conducted and evaluated for scalability.

scholarly journals Wind shear climatology for large wind turbine generators

1982 ◽  
Author(s):  
D.L. Elliott ◽  
L.L. Wendell ◽  
S.K. Heflick
Keyword(s):  
Wind Turbine ◽  
Wind Shear ◽  
Turbine Generators ◽  
Wind Turbine Generators ◽  
Large Wind

Electromagnetomechanical Coupled Vibration Analysis of a Direct-Drive Off-Shore Wind Turbine Generator

2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Michael Kirschneck ◽  
Daniel J. Rixen ◽  
Henk Polinder ◽  
Ron A. J. van Ostayen
Keyword(s):  
Wind Turbine ◽  
Structural Dynamics ◽  
Large Diameter ◽  
Air Gap ◽  
Direct Drive ◽  
Turbine Generator ◽  
Wind Turbine Generator ◽  
Generator Rotor ◽  
Turbine Generators ◽  
Wind Turbine Generators

In large direct-drive off-shore wind turbine generators one challenge is to engineer the system to function securely with an air gap length of about a thousandth of the outer rotor diameter. Compared to the large diameter of the generator rotor, the rolling element bearings can only be constructed with a relatively limited size. This makes it challenging to design appropriate constructions able to transmit the large applied magnetic forces encountered in the air gap of direct drive wind turbine generators. Currently, this challenge is met by designing stiff heavy rotors that are able to withstand the forces in the air gap. Incorporating flexibility into the design of the rotor structure can lead to a lighter less expensive rotor. In order to be able to do this the magnetomechanical coupling in the air gap and its effect on the structural dynamics need to be taken into account when predicting the intended flexibility. This paper introduces an approach for a multiphysical modal analysis that makes it possible to predict the dynamics of the strongly coupled magnetomechanical system. The new method is validated using measurements of a simple lab setup. It is then applied to a single-bearing design direct-drive wind turbine generator rotor to calculate the changes of the structural dynamics caused by the electromagnetomechanical coupling.

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