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 494

produced power. Next to these disadvantages, power electronics are one of the main
sources of failure in wind turbines. They account for about 25 % of turbine failures
and, unlike mechanical failures, they are not predictable and therefore in-crease
maintenance costs. Additionally, when looking at the North American market, GE
owns a patent on variable speed wind turbines incorporating power electronics.
This increases the interest for variable speed systems using a different technology.
At the moment, a number of wind turbines using a different technology to obtain the
variable speed are available on the market. These technologies incorporate some
kind of variable transmission in the drive train to control the rotor speed. For
example, Wikov Wind in cooperation with ORBITAL2 Ltd. has launched a 2 MW
wind turbine equipped with a variable transmission.
Because of this growth Wind Turbine simulation became admired to verify the
particular performance. For researchers modeling and simulation is bene

cial with
the purpose of diminish expenses for expansion of components, controller design
and the whole system of a Wind Turbine.
For testing and estimation parameter of the control, e.g. for the functionality
during voltage dip (LVRT), simulations are very useful to reduce cost and time. The
test of the Wind Turbine carried out via serious check tools creates capacity con-
sistent with an examination sketch. This test plan includes requirements of the
international technical guideline, the IEC 61400-21, limit values and further
requirements from grid codes. The next step of this development is the recreation of
these examinations, as distinct in the examination sketch. The comparison of the
measurement and simulation results and the validation according to de ned

validation routines are necessary for the assessment and results in any case in a
Validation Report. If the validation criteria are ful lled the Wind Turbine Model is

validated, if the differences are bigger than acceptable according to the validation
criteria the Wind Turbine Model has to be remodeled (Martin, Hamburg, Germany).
In any action, control has two major objective protection and optimization of
operation additionally, when relate to WECS, control turn more important in all
particular, as the central qua lit of WECS, is that they have to look with the
particularly variable, random and unpredictable nature of the wind, all WECS have
some variety of power control. Fixed speed WECS, with either acquiescent or
occupied or occupied stall, dominated the wind power energy for long time. Their
major catch is their in

fixed generator speed does not provide any
control suppleness. This pass form sight with the use of fall deposit power converts
WECS. Variable-speed performance become possible by include power electronics
transform (Brice et al. 2009 ).
Variable-speed WECS control organization generally comprises three main
control subsystems: One is aerodynamic power control, through pitch control.
Thirds Variable-speed action and energy apparel end maximization by utilizing
generator control. And

fl exible, as the

finally Grid power shift control, throughout the power
electronics convertor. One of the research area improvements can be reached
professional control, so wind power production the evolvement of ef cient manu-

facture tools has been increased. In addition the research works presented in this