Environmental Engineering Reference
In-Depth Information
Wind speed (*) ; Blade tip speed (o)
Lambda (tip-speed ratio)
7
1.6
6.5
1.4
6
5.5
1.2
5
4.5
1
4
0.8
3.5
3
0.6
2.5
2
0.4
0
10
20
30
40
50
60
70
80
0
10
20
30
40
50
60
70
80
Time (sec)
Time (sec)
Cp (aerodynamic power coeficient)
Cp / Lambda
0.25
0.25
0.2
0.2
0.15
0.15
0.1
0.1
0.05
0.05
0
0
0
10
20
30
40
50
60
70
80
0.4
0.6
0.8
1
1.2
1.4
1.6
Time (sec)
Lambda
Fig. 14.23 Rotor speed control experiment: a wind speed v
1
and blade tip speed X
r
r
b
; b tip-
speed ratio k; c aerodynamic power coefficient C
p
; d C
p
versus k
(a)
(b)
6-
blade WT. Experimental data (-), Tgd command (-.), and rotor speed estimation (-
-)
6-blade WT. Blade tip speed and Tip speed ratio
6
Tgd command
8.6
5.5
8.4
8.2
5
8
Measured Tg
7.8
4.5
7.6
7.4
4
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
Time (sec)
Time (sec)
(c)
(d)
640
1.85
620
1.8
Estimated Wr
1.75
600
Measured Wr
1.7
580
1.65
560
1.6
540
1.55
0
5
10
15
20
30
35
40
25
0
5
10
15
20
25
30
35
40
Time (sec)
Time (sec)
Fig. 14.24 Effect of electrical torque T
g
on rotor speed X
r
: a Experimental electrical torque T
g
—
in mNm; b Blade tip speed X
rs
-in rpm; c Experimental and estimated rotor speed—in m/s; d Tip
speed ratio k
