Summary
In this paper, an improved direct torque control (DTC) strategy based on a fuzzy inference system is proposed to control a doubly fed induction generator (DFIG)‐based wind energy conversion system (WECS). The proposed method is based on increasing the number of sectors to 12 instead of six in the classical DTC (C‐DTC), and the use of a fuzzy inference system to generate the optimal voltage vector to apply to the rotor side converter (RSC). The proposed method aims to reduce the flux and torque undulations which are considered the main disadvantage of the C‐DTC and to control the power factor at the stator terminals by generating the referential rotor flux from the referential reactive power.
The effectiveness of the proposed strategy is well tested by the simulation. Moreover, a total harmonic distortion (THD) analysis was performed for the rotor and stator currents waveforms. The results show a considerable reduction of the undulations for both flux and torque, and a significant reduction of the THD.