Environmental Engineering Reference
In-Depth Information
v
1
(
s
)
K
TV
+
n
μ
32
s
(
)
Ω
r_
ref
β
d
(
s
)
β
(
s
)
+
Ω
r
(
s
)
A
β
(
s
)
K
G
(
s
)
+
+
1
T
β
+
-
d
tf
(
s
)
T
g
(
s
)
n
μ
33
s
(
)
A
T
(
s
)
T
gd
(
s
)
K
Ω
T
Fig. 14.13 Block diagram for rotor speed control system [
2
]
d
tf
ð
s
Þ¼
d
l32
ð
s
Þ
n
l32
ð
s
Þ
K
TX
¼
I
r
I
w
I
g
s
5
þ½ð
I
r
I
g
B
l
þ
B
h
I
r
I
w
þ
I
r
I
g
B
h
R
T
þ
B
l
I
w
I
g
Þð
I
g
I
w
Þ
K
TX
s
4
...
þ½ð
K
l
I
w
I
g
þ
B
h
I
r
B
l
þ
B
l
I
g
B
h
r
t
þ
K
h
I
r
I
w
þ
I
r
I
g
K
l
þ
B
l
B
h
I
w
þ
I
r
I
g
K
h
R
t
Þ
ð
B
h
I
w
þ
I
g
B
l
þ
I
g
B
h
R
t
Þ
K
TX
s
3
...
þ½ð
B
l
K
h
I
w
þ
K
l
I
g
B
h
R
t
þ
K
h
I
r
B
l
þ
B
h
I
r
K
l
þ
K
l
B
h
I
w
þ
I
g
B
l
K
h
R
t
Þ
ð
B
h
B
l
þ
I
g
K
l
þ
I
g
K
h
R
t
þ
K
h
I
w
Þ
K
TX
s
2
...
þ½ð
I
g
K
l
K
h
R
t
þ
K
h
I
r
K
l
þ
K
l
K
h
I
w
Þð
K
h
B
l
þ
B
h
K
l
Þ
K
TX
s
ð
K
h
B
l
þ
B
h
K
l
Þ
K
TX
ð
14
:
33
Þ
14.4 System Identification
Figure
14.14
shows the control system block diagram of the wind turbine. G
p
(s),
G
t
(s), c
1
and c
2
are part of the control algorithm, which works in the metric system.
G
p
(s) is the rotor speed pitch controller, G
t
(s) the torque controller, and c
1
and c
2
the coefficients needed to operate with the NXT motor and the Glide-Wheel sensor
(see Sect.
14.2
), which work in degrees and rpm respectively: c
1
= 180/p deg/rad
and c
2
= p/30 rad/s/rpm.
The blocks F
1
(s), F
2
(s) and F
3
(s) in Fig.
14.14
correspond to the Eqs. (
14.28
)-
(
14.30
) developed in Sect.
14.3.3
, all in the metric system. They represent
respectively the transfer functions from the wind speed, pitch angle and electrical
torque to the rotor speed. The following sections identify experimentally the
parameters of the dominant dynamics of these transfer functions.
14.4.1 Rotor-Speed Versus Pitch-Angle Transfer Function
F
2
(S)
The dominant dynamics of the rotor-speed versus pitch-angle transfer function
X
rs
(s)/b(s) = P
1
(s), and the transfer function of the pitch-angle versus actuator-input
