Designing of Fuzzy Controller to Stabilize Voltage and Frequency Amplitude in a Wind Turbine Equipped with Induction Generator

Abstract

The use of wind turbines based on induction generator is very popular to generate electrical power and it has been noted by researchers because of its many advantages compared to conventional methods of electrical energy generation. Factors of uncertainty in the nature of the wind cause variable voltage in amplitude and frequency on the induction generator. It is not appropriate to apply such voltage to the load. So a controller must be designed to be kept constant voltage and frequency. In this paper, a fuzzy controller is used as state feedback to stabilize the voltage, frequency and voltage amplitude. The variable AC voltage generated by generator is converted by rectifier to a variable DC voltage. The variable DC voltage causes a change in the output voltage of the inverter. The PWM switching property is used to stabilize frequency and state feedback is used to stabilize the output voltage amplitude. The obtained error signal with its derivative is applied to the fuzzy controller as input to generate the considered control signal by controller to generate appropriate firing pulses to apply to PWM inverter. Therefore, frequency and amplitude of the output voltage is kept constant with switching control and so maximum power of wind is resulted. Simulation results show that by design the appropriate controller for the considered system output voltage can be stabilized in constant amplitude and frequency.