Review and Improvement of Several Optimal Intelligent Pitch Controllers and Estimator of WECS via Artificial Intelligent Approaches - Complex System Modelling and Control Through Intelligent Soft Computations - page 500

17

16

15

14

13

12

11

10

0 10 20 30 40 50 60 70 80 90 100

time (s)

Fig. 2 Simulated wind speed

1
2 qp

R 2

3
w C p k; ðÞ

P a ¼ m ð 4 Þ

m w wind speed. The aerodynamic
performance is the ratio of turbine power to wind power and is known as the
turbine ' is power coefficient, C p . Power coefficient is related to turbine characteristic
among blade pitch angle

That q is the air density, R is rotor radius,

b and tip speed ratio (TSR) k . The relationship between

performance C p with k and b can be presented by Endusa and Aki ( 2009 ):

e 21 = k i

116
k i

C p k; ðÞ¼

: : b þ : k ð Þ

0 5176 0 4 5 0 0068 5

where k proportion between the blade tip speed and the wind speed and k i depends

on instantaneous k; fg , thus we have:

k ¼ x t R

1 0 : 035

m w ; k i ¼ b

ð 6 Þ

k þ 0 : 8

3

b þ

1

In a control model the controlled torque C c , which it has been used for the
variable speed turbines, is given by Camblong ( 2004 ):

1
2 q

AR 3 C pmax
k

2

C c ¼ x ð 7 Þ

3

R is the rotor radius, and k is the tip-speed ratio at which the maximum power

coef cient C pmax occurs.