Embed Size (px)
Citation preview
EWEC’06 Athens 27 February-2 March 2006 1/16
European Wind Energy Conference and Exhibition
2006Athens, Greece
Advanced Aeroelastic Modeling of Complete Wind Turbine Configuration in View of Assessing Stability
Characteristics
V.A.Riziotis and S.G.Voutsinas
National Technical University of Athens School of Mechanical Engineering
Fluids Section
NTUA
EWEC’06 Athens 27 February-2 March 2006 2/16
NTUAOverview of the Presentation
EWEC’06 Athens 27 February-2 March 2006 3/16
NTUA
EWEC’06 Athens 27 February-2 March 2006 4/16
NTUA
• wind turbine modes are excited,
– by individual blade pitch
(rotor modes and tower fore aft mode)
– by point force applied at tower top (tower modes)
• duration of excitation 15sec
• pitch amplitude 2o
• tower force amplitude 2.5 ton
• damping extracted from transient loads time-series
Non-linear damping identification
time (s)
tow
er
ba
selo
ng
.be
nd
ing
mo
me
nt
(Nm
)
10 20 30 40 50 60 70 80
-5E+06
0
5E+06
1E+07
1.5E+07
2E+07
2.5E+07
time (s)
bla
de
pitc
h(d
eg
)
10 20 30 40 50 60 70 80-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
15 s5 rev
Excitation Method
EWEC’06 Athens 27 February-2 March 2006 5/16
NTUA
frequency (Hz)
H(f
,t0
)
0 0.5 1 1.5 2 2.5 3
1E+09
2E+09
3E+09
4E+09
5E+09
6E+09
time (s)bla
de
roo
tle
ad
-la
gb
en
din
gm
om
en
t(N
m)
30 40 50 60 70 80 90-1E+07
-8E+06
-6E+06
-4E+06
-2E+06
0
2E+06
4E+06
6E+06
8E+06
1E+07 Δt Δt
t0
t0 (sec)
ln(m
ax
(H(f
,t0
)))
0 1 2 3
22.575
22.58
22.585
22.59
22.595
22.6
22.605
22.61
-ζ Ωn
moving block method
Damping Identification Methods
EWEC’06 Athens 27 February-2 March 2006 6/16
NTUA
Hilbert method
du)ut(π
)u(y)]t(y[H)t(y~
)t(θje)t(A)t(y~j)t(y)t(z
A(t): envelope signal
900 phase shift
Damping Identification Methods
EWEC’06 Athens 27 February-2 March 2006 7/16
NTUA
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 20-5
0
5
10
15
20
25
30
wind speed (m/s)
fre
qu
en
cy(H
z)
6 8 10 12 14 16 18 200.3
0.4
0.5
0.6
0.7
0.8
0.9 GAST+RAFT linGAST+RAFT nolin (tower excit.)GAST2+GENUVP (tower excit.)measurements (OMA)measurements (generator excit.)
1st tower lateral bending
Comparison with Measurements
EWEC’06 Athens 27 February-2 March 2006 8/16
NTUA
1st tower longitudinal bending
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 200
10
20
30
40
50
60
70
80
90
100
wind speed (m/s)
fre
qu
en
cy(H
z)
6 8 10 12 14 16 18 200.3
0.4
0.5
0.6
0.7
0.8
0.9 GAST+RAFT linGAST+RAFT nolin (pitch excit.)GAST+RAFT nolin (tower excit.)GAST2+GENUVP (pitch excit.)measurements (OMA)measurements (pitch excit.)
Comparison with Measurements
EWEC’06 Athens 27 February-2 March 2006 9/16
NTUA
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 200
10
20
30
40
50
60
70
80
90
100
reduction of damping beyond 16m/s is associated with the inability of the damping identification method to predict well the damping of spectrally close modes
frequency (Hz)FF
To
fto
we
rb
ott
om
lon
g.b
en
din
gm
om
en
t(N
m)
0.5 1 1.5 20
5E+08
1E+09
1.5E+09
2E+09
2.5E+09
3E+09
10m/s20m/s
Comparison with Measurements
EWEC’06 Athens 27 February-2 March 2006 10/16
NTUA
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 200
10
20
30
40
50
60
70
80
90
100
0
0.2
0.4
0.6
0.8
1
1.2
1.4
-5 0 5 10 15
CL
-lif
t c
oe
ffic
ien
t
angle of attack (deg)
unsteadysteady naca 63424steady naca63415
0
0.2
0.4
0.6
0.8
1
1.2
1.4
-5 0 5 10 15
CL
-lif
t c
oe
ffic
ien
t
angle of attack (deg)
unsteadysteady naca 63424steady naca63415
r/R = 0.40
r/R = 0.85
Comparison with Measurements
EWEC’06 Athens 27 February-2 March 2006 11/16
NTUA
1st regressive rotor lead-lag
wind speed (m/s)
fre
qu
en
cy(H
z)
6 8 10 12 14 16 18 201.4
1.5
1.6
1.7
1.8
1.9
2 GAST+RAFT linGAST+RAFT nolin (pitch excit.)GAST2+GENUVP (pitch excit.)measurements (OMA)
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 20-5
0
5
10
15
20
Comparison with Measurements
EWEC’06 Athens 27 February-2 March 2006 12/16
NTUA
1st progressive rotor lead-lag
wind speed (m/s)
fre
qu
en
cy(H
z)
6 8 10 12 14 16 18 20
2
2.1
2.2
2.3
2.4
2.5GAST+RAFT linGAST+RAFT nolin (pitch excit.)GAST2+GENUVP (pitch excit.)meas. (OMA)
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 20-5
0
5
10
15
20
Comparison with Measurements
EWEC’06 Athens 27 February-2 March 2006 13/16
NTUA
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 20
0
2
4
6
8
10GAST+RAFT linGAST+RAFT nolin (moving block)GAST+RAFT nolin (Hilbert)GAST2+GENUVP (moving block)GAST2+GENUVP (Hilbert)
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 2010
20
30
40
50
60
70
80
1st tower lateral bending 1st tower longitudinal bending
Comparison of damping Identification Methods
EWEC’06 Athens 27 February-2 March 2006 14/16
NTUA
16 m/s
wind speed (m/s)
da
mp
ing
inlo
gd
ecr
em
en
t(%
)
6 8 10 12 14 16 18 2010
20
30
40
50
60
70
80
GAST+RAFT linGAST+RAFT nolin (moving block)GAST+RAFT nolin (Hilbert)GAST2+GENUVP (moving block)GAST2+GENUVP (Hilbert)
12 m/s
Comparison of damping Identification Methods
EWEC’06 Athens 27 February-2 March 2006 15/16
NTUAConclusions
EWEC’06 Athens 27 February-2 March 2006 16/16
NTUAAcknowledgements
•European Commission for funding this work under contract NNK5-CT2002-00627 (STABCON project)
•STABCON project partners for publishing of the paper
