Environmental Engineering Reference
In-Depth Information
Nomenclature
P
cap
;
P
wind
Aerodynamic, wind power
q
Air density
R
Rotor radius
C
p
;
C
q
Power, torque coefficients
b
;
b
r
Actual, reference blade pitch angle
k
;
k
opt
Actual, optimal tip-speed-ratio
v
;
v
min
;
v
max
Point, minimum, and maximum wind speed
x
r
;
x
min
;
x
max
;
x
ropt
Actual, minimum, maximum, and optimal rotor
speed
T
a
Aerodynamic torque
T
g
;
T
gr
;
T
gm
;
Actual, reference, measured generator torque
J
r
;
J
g
Rotor, generator inertia
B
r
;
B
g
Rotor, generator external damping
x
g
Generator speed
n
g
Gearbox ratio
K
dt
;
B
dt
Torsion stiffness, damping coefficients
h
D
Torsion angle
f
Damping factor
x
n
Natural frequency
s
g
Generator time constant
C
pmax
Upper bound of power coefficient
A
wind
;
A
;
A
2
Upstream, disc, downstream, areas
P
þ
;
P
Pressure before, after actuator disc
F
d
Thrust exerted on the actuator disc
a
Axial interference factor
t
b
,t
w
Blade, turbulence times
S
Length of the disturbed wind
n
Number of blades
f
s
Sensor fault signal
e
t
;
e
x
;
e
v
Tracking,
state
estimation,
wind
measurement
errors
K
ðÞ
;
L
a
ðÞ
Controller, observer gains
P
1
;
P
2
;
c
;
l
;
X
1
LMI variables
A
ðÞ
;
B
;
E
ðÞ
;
C
;
D
f
System matrices
A
ðÞ
;
B
;
E
ðÞ
;
R
;
C
;
D
f
System matrices augmented with tracking error
integral
A
a
ðÞ
;
B
a
;
E
a
ðÞ
;
R
a
;
G
;
C
a
Observer augmented matrices
