On the optimization of generators for offshore direct drive wind turbines

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The objective of this paper is to optimize direct drive permanent magnet synchronous generators for offshore direct drive wind turbines in order to reduce the cost of energy. A 6MW wind turbine design is assumed and parametric electromagnetic and structural generator models are introduced for a surface-mounted magnet generator topology (using magnets with high BHmax) and a flux-concentrating variant (using magnets with lower BHmax). These are optimized using a hybrid Genetic Algorithm and Pattern Search process and the results show that the surface-mounted permanent magnet generator produces the lower cost of energy. The choice of objective function is addressed and it is found that a simplified metric incorporating generator cost and losses proxy produces similar designs to a full cost of energy calculation. Further steps to improve the quality of the model include the effect of generator mass on the design and cost of the turbine tower and foundation, which can add €0.4m to the turbine cost. Further optimizations are carried out to show the impacts of magnetic material costs (doubling this leads to a €1.1/MWh increase in cost of energy) and generator diameter limits (increasing the upper limit from 6m to 8m leads to a 0.9% drop in cost of energy) have on the choice of optimum independent variables.
LanguageEnglish
Pages1-10
Number of pages10
JournalIEEE Transactions on Energy Conversion
DOIs
Publication statusPublished - 2 Nov 2016

Fingerprint

Wind turbines
Costs
Magnets
Permanent magnets
Turbines
Magnetic materials
Synchronous generators
Towers
Genetic algorithms
Topology
Fluxes

Keywords

  • cost of energy
  • direct drive wind turbine
  • optimization
  • permanent magnet generator
  • structural model
  • tower and foundation

Cite this

@article{80c2179587744a958cd9c54a4ab829bf,
title = "On the optimization of generators for offshore direct drive wind turbines",
abstract = "The objective of this paper is to optimize direct drive permanent magnet synchronous generators for offshore direct drive wind turbines in order to reduce the cost of energy. A 6MW wind turbine design is assumed and parametric electromagnetic and structural generator models are introduced for a surface-mounted magnet generator topology (using magnets with high BHmax) and a flux-concentrating variant (using magnets with lower BHmax). These are optimized using a hybrid Genetic Algorithm and Pattern Search process and the results show that the surface-mounted permanent magnet generator produces the lower cost of energy. The choice of objective function is addressed and it is found that a simplified metric incorporating generator cost and losses proxy produces similar designs to a full cost of energy calculation. Further steps to improve the quality of the model include the effect of generator mass on the design and cost of the turbine tower and foundation, which can add €0.4m to the turbine cost. Further optimizations are carried out to show the impacts of magnetic material costs (doubling this leads to a €1.1/MWh increase in cost of energy) and generator diameter limits (increasing the upper limit from 6m to 8m leads to a 0.9{\%} drop in cost of energy) have on the choice of optimum independent variables.",
keywords = "cost of energy, direct drive wind turbine, optimization, permanent magnet generator, structural model, tower and foundation",
author = "Alasdair McDonald and Bhuiyan, {Nurul Azim}",
note = "(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works",
year = "2016",
month = "11",
day = "2",
doi = "10.1109/TEC.2016.2624219",
language = "English",
pages = "1--10",
journal = "IEEE Transactions on Energy Conversion",
issn = "0885-8969",

}

TY - JOUR

T1 - On the optimization of generators for offshore direct drive wind turbines

AU - McDonald, Alasdair

AU - Bhuiyan, Nurul Azim

N1 - (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

PY - 2016/11/2

Y1 - 2016/11/2

N2 - The objective of this paper is to optimize direct drive permanent magnet synchronous generators for offshore direct drive wind turbines in order to reduce the cost of energy. A 6MW wind turbine design is assumed and parametric electromagnetic and structural generator models are introduced for a surface-mounted magnet generator topology (using magnets with high BHmax) and a flux-concentrating variant (using magnets with lower BHmax). These are optimized using a hybrid Genetic Algorithm and Pattern Search process and the results show that the surface-mounted permanent magnet generator produces the lower cost of energy. The choice of objective function is addressed and it is found that a simplified metric incorporating generator cost and losses proxy produces similar designs to a full cost of energy calculation. Further steps to improve the quality of the model include the effect of generator mass on the design and cost of the turbine tower and foundation, which can add €0.4m to the turbine cost. Further optimizations are carried out to show the impacts of magnetic material costs (doubling this leads to a €1.1/MWh increase in cost of energy) and generator diameter limits (increasing the upper limit from 6m to 8m leads to a 0.9% drop in cost of energy) have on the choice of optimum independent variables.

AB - The objective of this paper is to optimize direct drive permanent magnet synchronous generators for offshore direct drive wind turbines in order to reduce the cost of energy. A 6MW wind turbine design is assumed and parametric electromagnetic and structural generator models are introduced for a surface-mounted magnet generator topology (using magnets with high BHmax) and a flux-concentrating variant (using magnets with lower BHmax). These are optimized using a hybrid Genetic Algorithm and Pattern Search process and the results show that the surface-mounted permanent magnet generator produces the lower cost of energy. The choice of objective function is addressed and it is found that a simplified metric incorporating generator cost and losses proxy produces similar designs to a full cost of energy calculation. Further steps to improve the quality of the model include the effect of generator mass on the design and cost of the turbine tower and foundation, which can add €0.4m to the turbine cost. Further optimizations are carried out to show the impacts of magnetic material costs (doubling this leads to a €1.1/MWh increase in cost of energy) and generator diameter limits (increasing the upper limit from 6m to 8m leads to a 0.9% drop in cost of energy) have on the choice of optimum independent variables.

KW - cost of energy

KW - direct drive wind turbine

KW - optimization

KW - permanent magnet generator

KW - structural model

KW - tower and foundation

U2 - 10.1109/TEC.2016.2624219

DO - 10.1109/TEC.2016.2624219

M3 - Article

SP - 1

EP - 10

JO - IEEE Transactions on Energy Conversion

T2 - IEEE Transactions on Energy Conversion

JF - IEEE Transactions on Energy Conversion

SN - 0885-8969

ER -