Available online at www.sciencedirect.com ScienceDirect Mathematics and Computers in Simulation 167 (2020) 308–324 www.elsevier.com/locate/matcom Original articles Direct torque control improvement of a variable speed DFIG based on a fuzzy inference system W. Ayrir a , ∗ , M. Ourahou a , B. El Hassouni a , A. Haddi b a Laboratory of Innovative Technologies (LTI), University of ABDELMALEK ESSAÄDI, (ENSA) Tangier, Morocco b Advanced Sciences and Technologies team, University of ABDELMALEK ESSAÄDI, (ENSATe) Tetouan, Morocco Received 29 August 2017; received in revised form 10 May 2018; accepted 16 May 2018 Available online 30 May 2018 Abstract In this paper, a fuzzy direct torque control (DTC) for a variable speed doubly fed induction generator (DFIG) based wind turbine is investigated. The DTC has been widely applied to doubly fed induction machines in recent years due to the high performances that it provides in comparison with the classical field oriented control. Meanwhile, it has a major drawback that is the significant torque and flux undulations generated by the hysteresis band controllers. To overcome this problem, the improvement of this technique by removing these controllers is proposed in this paper. The proposed control technique is based on replacing the hysteresis controllers by a fuzzy inference system which will have the same inputs as these controllers plus the sector angle determination so that the look-up table can be replaced by a fuzzy rule-base matrix. The simulation was performed in MATLAB/SIMULINK, and the results obtained make it possible to evaluate the performance of the proposed technique over the classical one. c ⃝ 2018 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved. Keywords: MPPT; DFIG; Direct torque control; Fuzzy logic 1. Introduction Wind energy represents a significant promising source of renewable energy. It has undoubtedly been the most growing source in terms of installed capacity [27]. According to a report published by the Global Wind Energy Council (GWEC) in 25 April 2017 [13], the cumulative wind energy installed capacity reached 486.8 GW in the end of 2016, and it is expected to reach 800 GW by 2021. Despite this growth, its share in the total world electricity production remains limited, about 4% at the end of 2016 [23], but it is expected to reach 8% by 2018, 12% by 2020 and 20% by 2030 [27,4,16]. ∗ Corresponding author. E-mail address: ayrir-ouiam@hotmail.com (W. Ayrir). https://doi.org/10.1016/j.matcom.2018.05.014 0378-4754/ c ⃝ 2018 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved.