Abstract:
Wind energy, is renewable energy source, which is widely studied nowadays. Among wind turbine
systems, variable wind turbine are the most preferred one, since it is most efficient and has more
capability of control over wide speed area. Wind behavior determine the energy conversion
process of wind turbine. Due to the randomness and intermittent nature of wind speed the energy
conversation process is varied. So, to maximize the extracted energy from wind, pitch angle
controller is investigated. Pitch angle control phenomena helps to run the system with higher
efficiency and reliability in turbulent weather conditions (stochastic nature) and to stabilize output
power at higher wind speed and optimize at lower wind speed. However, to maximize extracted
energy conversion, pitch angle will tune the attack angle of a wind turbine rotor blade into or out
of wind waves depending on wind speed. In this thesis fuzzy logic based adaptive controller is
used to control the pitch angle of wind turbine to reduce external disturbance, robustness and
uncertainty of parameters. The objective of the controller is defined as that of maintaining the rotor
speed and pitch angle at suitable values depending on operating regions of wind turbine. Finally,
a new method of fuzzy logic based adaptive controller is compared with conventional controller
(PID) and the simulation results were analyzed. The simulation results shows that the fuzzy logic
based adaptive controller can achieve better control performances than conventional pitch angle
control strategies, minimizing fatigue and preventing input mechanical power to exceed the design
limits.
