Download IEC Classification of Wind Turbines

Appendix II
IEC Classification
of Wind Turbines
Wind turbine class
Vave (m/s)
Vref (m/s)
I
10
50
II
8.5
42.5
III
7.5
37.5
S
V50,gust (m/s)
70
59.5
52.5
User defined
Iref
A
B
C
0.16
0.14
0.12
In the table (IEC61400-1: 2005):
1. Rayleigh distribution is assumed, i.e. k = 2.
2. Vave is the annual mean wind speed at hub height; Vref is the 50-year extreme wind speed
over 10 minutes; V50,gust is the 50-year extreme gust over 3 seconds; Iref is the mean turbulence intensity at 15 m/s.
3. A, B and C are the categories of higher, medium and lower turbulence intensity characteristics respectively.
Wind Resource Assessment and Micro-siting, Science and Engineering, First Edition. Matthew Huaiquan Zhang.
© 2015 China Machine Press. All rights reserved. Published 2015 by John Wiley & Sons Singapore Pte Ltd.