Fuzzy and DTC Control Methods of Doubly Fed Induction Generator

In this paper, we study the direct torque control method for controlling a double-fed induction generator. In direct torque control method, high ripples are produced in torque and flux linkage, due to the use of hysteresis controller and improper position of switching voltage source inverter space vector. To solve this problem, fuzzy controllers are used to select the most suitable switching voltage space vector for minimizing the torque ripples and flux linkage. However, fuzzy controllers resist against sudden load changes. Also, due to the capability of fuzzy logic in solving complex and inaccurate problems and in order to improve the speed control of the double-fed induction generator, fuzzy logic are used to design the speed controller. In this paper, both control methods, the direct torque control and improved direct torque control with fuzzy logics, are implemented based on stator flux oriented control requirements. Nevertheless the simulation is developed in Matlab/Simulink using accurate generator parameters.

DFIG; Doubly-fed induction generator; Back to back converter; Direct Torque Control; Fuzzy control.