Influence of interval type-2 fuzzy control approach for a grid-interconnected doubly-fed induction generator driven by wind energy turbines in variable-speed system

Abstract

This paper suggests a developed control technique using an interval type-2 fuzzy logic control (FLC) tuned PI for optimum torque adjustment for wind turbines operated by doubly fed induction generator (DFIG). The suggested control regulates the error of the mechanical rotor speed to enhance the performance of the torque and the output power results in the study system's overall performance improving. The suggested control combines the advantages of the two techniques: fast response of conventional PI control and adaptively properties of interval type-2 FLC. The studied system is a wind farm of 9 MW composed of 6 wind turbines of 1.5 MW each. Wind speed functions of several types are studied such as step change, extreme change, and constant high speed. The results indicate how the power and optimal torque have fast response with interval type-2 FLC tuned PI compared to the type-1 fuzzy tuned PI and conventional PI control. The simulated results deduce that the suggested interval type-2 FLC can enhance the wind energy system's stability and reliability in a better manner compared to the type-1 FLC and conventional PI.