Abstract:
This thesis presents the development and test of an approach for improving the output performance of wind energy conversion system by regulating the frequency and voltage of a wind power generation system that considers stand alone wind-turbines equipped with self excited squirrel cage induction generators and a controlled secondary load without the use of energy storage devices. Since operating conditions in wind energy conversion system are kept changing, it is a challenge to design a control for reliable operation of the overall system. This control strategy is based on a fuzzy controller using the frequency as the input variable for the closed loop control and the power of a resistive secondary load as' the controlled variable: The secondary load is a simple controllable load capable of absorbing real power from the wind energy conversion system. The purpose of this secondary load is to quickly absorb any. excess wind power, thus helping to control the system frequency. To consider variable operating conditions, Mamdani fuzzy operator is taken into account to represent time-varying system, partitioned by linguistic rules. For improving the voltage profile synchronous condenser is used.
The proposed system is simulated in MATLAB 7.5.0. In the simulation study, the frequency, voltage, generated and consumed power profiles during startup and production are discussed. The proposed controller is compared with a conventional proportional-integral derivative (PID) controller. Simulation results show that the proposed controller is more effective against disturbances caused by wind speed and load variation than the PID controller, and thus' it contributes to the better performance of wind energy conversion system.
