Multilevel Converter and Fuzzy Logic Solutions for Improving Direct Control Accuracy of DFIG-based Wind Energy System

Abstract

The purpose of this study is to enhance the accuracy of direct power/torque control (DPC/DTC) applied to back-to-back converters supplying a doubly fed induction generator (DFIG) based wind power system. Two solutions are proposed. The first one is to increase the degree of freedom of the DTC and DPC control by implementing three-level back-to-back converters. Fuzzy logic control is the second solution to enhance the performances of both conventional direct power/torque control, leading in a decrease of the DFIG's torque/flux ripples and the active/reactive powers ripples supplied by the grid side converter, consequently, reduce the grid currents' total harmonic distortion (THD). The MATLAB/Simulink environment is used to evaluate the wind power generation system performances. The collected findings show that the fuzzy direct control (FDC) technique outperforms conventional direct control (CDC) when used for two-level back-to-back converters.