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Axial-flux permanent-magnet air-cored generator for small-scale windturbines

Bumby, J.R.; Martin, R.


J.R. Bumby

R. Martin


The design and development of an axial-flux permanent-magnet air-cored generator for use as a direct drive generator with small-scale wind and water turbines is described. The generator is designed for simplicity and ease of manufacture and consists of two rotor discs each with permanent magnets located around its periphery. The stator is made of plastic and has a number of bobbin-wound armature coils located around its periphery. A three-phase prototype generator has been designed and built with 16 magnets per rotor disc, 12 armature coils (four per phase) and an overall diameter of 495 mm. The generator produces 1000 W at 300 rpm or 2000 W at 500 rpm with an electrical efficiency substantially greater than 90%. The generator performs as predicted by the design process.


Bumby, J., & Martin, R. (2005). Axial-flux permanent-magnet air-cored generator for small-scale windturbines. IEE proceedings. Electric power applications, 152(5), 1065-1075.

Journal Article Type Article
Publication Date 2005-09
Deposit Date Apr 23, 2008
Journal IEE proceedings. Electric power applications.
Print ISSN 1350-2352
Electronic ISSN 1359-7043
Publisher IET
Peer Reviewed Peer Reviewed
Volume 152
Issue 5
Pages 1065-1075
Keywords Permanent-magnet air-cored generator, Small-scale wind turbine, Direct drive generator, Water turbine, Rotor disc, Plastic stator, Bobbin-wound armature coil, Three-phase prototype generator, Electrical efficiency.