ALGERIAN JOURNAL OF SIGNALS AND SYSTEMS (AJSS) Vol. 8, Issue 1, June-2023| ISSN: 2543-3792- EISSN: 2676-1548 8 DFIG Wind Turbine Controlled by Sliding Mode and Fuzzy-Sliding Control Modes Zahira BOUGUERRA (1) , Arezki BENFDILA (2)* Micro and Nanoelectronics Research Group, Faculty of Electrical Engineering and Computer Sciences, University Mouloud Mammeri, Tizi-Ouzou, Algeria * arezki.benfdila@ummto.dz Abstract: Many non-linear controllers have been used to improve system performances and robustness of double fed induction machine (DFIG) based wind turbines like sliding mode control (SMC). However, this type of controller is less efficient due to a sign function that can lead to chattering phenomenon. To overcome this deficiency, the function is replaced by fuzzy logic control (FLC). This is what is proposed in this paper which deals with doubly fed induction generator (DFIG) based wind turbine conversion system (WECs) by sliding mode control and fuzzy sliding mode control (FSMC). The system control have been applied to the back to back converters that connect rotor windings to the grid, For the rotor side converter (RsC), we have presented sliding mode control, and fuzzy sliding mode control to monitor active and reactive powers independently, when the grid side converter (GsC) was set to keep a constant DC voltage with a desired power factor. The effectiveness of the proposed control systems is tested using Matlab/Simulink software under a wind speed fluctuation and parameters variation. The simulation results showed that the FSMC is more robust and has better dynamic performances than the SMC control. Keywords: WECs, DFIG, Sliding mode control, Fuzzy sliding mode control, RsC, GsC. 1. INTRODUCTION The environmental impacts and diminishing reserve of fossil fuel is forcing the power system planners across the word to an increase the use of renewable energies [1]. Renewable energy sources are considered as an alternative energy sources to satisfy energy demand. Wind energy is seen to be capable of supplying large amounts of power. In the modern wind energy conversion systems (WECS), doubly fed induction generators (DFIG) have a crucial role in variable speed technology. DFIG has been widely used for large-scale wind power generation systems due to its various advantages, such as variable speed operation, controllable power factor and improved system efficiency, flexibility and robustness [2, 3]. Wind power depends strongly on wind speed, seasons, geography and many other factors which prevent a continuous supply of power to fed loads. Power fluctuation can often cause voltage and frequency limits alteration in weak systems. This can be also a severe problem for the systems stability [4]. Hence, there is a need of power electronics in wind power systems control to reach high efficiency and better performances. Power electronic converters are used to match the characteristics of wind turbines with the requirements of grid connections, including frequency, voltage, control of active and reactive power, harmonics, etc [5]. The DFIG rotor is connected to the grid through a back-to-back converter directly from the stator side. The rotor side converter (RsC) control allows decoupling the active and reactive powers control. The grid side converter (GsC) control allows maintaining a constant DC voltage. The power electronic converter rating is 25–30% that of the generator capacity [6]. In fact, wind energy systems have high nonlinearity resulting from uncertainties, wind speed turbulence, and changes in wind system parameters [7]. To overcome these perturbations, nonlinear control systems have been designed to be less sensitive to operating conditions variations and system parameters, as fuzzy logic controller [8-11], sliding mode controller [12-16]. However, addition of a discontinuous control signal to the sliding surface will cause chattering phenomenon. Hence, to improve this control mode, this paper comes up with design of an FSMC controller based on the combination of sliding mode with fuzzy logic that replaces the discontinuous part in SMC.