Optimisation and comparison of generators with different magnet materials for a 6MW offshore direct drive wind turbine

Nurul Azim Bhuiyan, Alasdair McDonald

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

5 Citations (Scopus)
222 Downloads (Pure)

Abstract

In the past few years interest in the use of low speed permanent magnet generators for direct-drive wind turbine generator applications has increased significantly. The significant fluctuations in NdFeB magnet prices has encouraged designers to optimise magnet utilisation and to look at alternative magnet materials for wind turbine electrical generators. In this paper an analytical design model is developed for 6 MW offshore direct-drive wind turbine generators using different magnet materials (one with surface mounted NdFeB and another with flux concentrating ferrite magnet). Finite element method models are used to check key dependent variables calculated by the analytical models. The generator designs are optimised using a hybrid optimisation method incorporating a Genetic Algorithm and Pattern Search approaches. This is applied for four different objective functions, the first two which concentrate on maximising rated torque per unit magnet mass or unit of generator active material cost. They are simple and quick to execute but prioritise cost reduction and ignore lower efficiencies leading to lower turbine energy yields and hence poor cost of energy. A third objective function which seeks to minimise the sum of the generator active material cost and the costs of lost revenue over a finite number of operational years. This gives similar results to a fourth objective function which is an explicit turbine cost of energy calculation. The cost of NdFeB magnets affect the cost of energy of the surface mounted generator which tested with different cost €40/kg, €60/kg and €80/kg. The ferrite magnet generator being better when the NdFeB magnet price rises to €80/kg.
Original languageEnglish
Title of host publication8th IET International Conference on Power Electronics, Machines and Drives (PEMD 2016)
Number of pages6
DOIs
Publication statusPublished - 19 Apr 2016
Event8th IET International Conference on Power Electronics, Machines and Drives - The Hilton Hotel, Glasgow, United Kingdom
Duration: 19 Apr 201621 Apr 2016

Conference

Conference8th IET International Conference on Power Electronics, Machines and Drives
Abbreviated titlePEMD 2016
Country/TerritoryUnited Kingdom
CityGlasgow
Period19/04/1621/04/16

Keywords

  • optimisation
  • permanent magnet machine
  • wind turbine generator
  • tower and foundation cost
  • hybrid algorithms
  • pattern search algorithm
  • genetic algorithm
  • ferrite magnet machine

Fingerprint

Dive into the research topics of 'Optimisation and comparison of generators with different magnet materials for a 6MW offshore direct drive wind turbine'. Together they form a unique fingerprint.

Cite this