COMPONENTS AND OPERATION
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Table of contents page 4
BONUS
ENERGY A/S
¨
THE WIND TURBINE
BONUS
INFO
T H E N E V E R E N D I N G S T O R Y
Autumn 1999
THE WIND TURBINE
COMPONENTS AND OPERATION
Special Issue
BONUS-INFO is a newsletter for
customers and business associates of
the Bonus Energy A/S. This news-
letter is published once or twice a
year.
The first number came out in 1998,
and the newsletter has now been
published in four issues.
Each number has included an
article on the components and opera-
tion of the wind turbine. We have
received many suggestions and
requests that these articles should be
reprinted and published as a special
single issue.
Bonus is pleased to have hereby
fulfilled this request with the
publication of this special issue.
Author:
Henrik Stiesdal
Responsible under the press law
Lay-out/ Production:
Claus Nybroe
Translation:
John Furze, Hugh Piggott
Autumn 1999
BONUS ENERGY A/S
Fabriksvej 4, Box 170
7330 Brande
Tel.: 97 18 11 22
Fax: 97 18 30 86
E-mail: bonus@bonus.dk
Web: www.bonus.dk
4
THE WIND TURBINE
COMPONENTS AND OPERATION
The Aerodynamics of the Wind Turbine 5
Basic Theory ¥ The aerodynamic profile ¥ The aerodynamics
of a man on a bicycle ¥ Wind turbine blades behave in the
same way ¥ Lift ¥ The change of forces along the blade ¥
What happens when the wind speed changes ¥ The stall
phenomena ¥ Summary
The Transmission System 11
The hub ¥ Main shaft ¥ Main Bearings ¥ The clamping unit ¥
The gearbox ¥ The coupling
The Generator 15
Direct current (DC) ¥ Alternating current (AC) ¥ Three
phase alternating current ¥ Induction and electromagnetism ¥
The wind turbine generator as a motor ¥ Generator operation
¥ Cut-in ¥ Closing remarks
Con