A Robust Interval Type-2 Fuzzy Logic Controller for Variable Speed Wind Turbines Based on a Doubly Fed Induction Generator

Ahmed Vall Hemeyine,Anass Bakouri,Mohcine Mokhlis,Ahmed Abbou,Sidi Mohamed Ould Mohamed El Moustapha

doi:10.3390/inventions6020021

Ahmed Vall Hemeyine, Anass Bakouri + Show 3 more

Open Access

https://doi.org/10.3390/inventions6020021

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Abstract

This paper presents an implementation of a new robust control strategy based on an interval type-2 fuzzy logic controller (IT2-FLC) applied to the wind energy conversion system (WECS). The wind generator used was a variable speed wind turbine based on a doubly fed induction generator (DFIG). Fuzzy logic concepts have been applied with great success in many applications worldwide. So far, the vast majority of systems have used type-1 fuzzy logic controllers. However, T1-FLC cannot handle the high level of uncertainty in systems (complex and non-linear systems). The amount of uncertainty in a system could be reduced by using type-2 fuzzy logic since it offers better capabilities to handle linguistic uncertainties by modeling vagueness and unreliability of information. A new concept based on an interval type-2 fuzzy logic controller (IT-2 FLC) was developed because of its uncertainty management capabilities. Both these control strategies were designed and their performances compared for the purpose of showing the control most efficient in terms of reference tracking and robustness. We made a comparison between the performance of the type-1 fuzzy logic controller (T1-FLC) and interval type-2 fuzzy logic controller (IT2-FLC). The simulation results clearly manifest the height robustness of the interval type-2 fuzzy logic controller in comparison to the T1-FLC in terms of rise time, settling time, and overshoot value. The simulations were realized by MATLAB/Simulink software.

Highlights

Renewable energies have experienced strong progress in their development thanks to their significant contribution to minimizing polluting CO2 emissions and avoiding the high cost of energy production induced by the conventional energy sources [1]
We propose to use an interval type-2 fuzzy logic controller (IT2-FLC) in order to overcome the limitations of fuzzy logic type 1 previously developed
The type-2 fuzzy logic controller (IT2-FLC) is very useful in circumstances where we need to take into consideration the different uncertainties as the real machine parameters change, and as the controller for a variable speed wind turbine-based on doubly fed induction generator (DFIG) is used mainly to regulate active and reactive power exchanged with an electrical network

Summary

Introduction

Renewable energies have experienced strong progress in their development thanks to their significant contribution to minimizing polluting CO2 emissions and avoiding the high cost of energy production induced by the conventional energy sources [1]. The maximal speed ratio is supposed equal to the optimal value Cpmax = 0.48 which, as discussed previously, is obtained considering λopt = 8.1 and assuming that β is equal to 0, which allows extracting the maximum of power. Under these conditions, the maximum mechanical power that can be extracted from the wind is expressed as described in the following form:. The electrical energy produced by the wind turbine can be kept constant and equal to the nominal value

Modeling of DFIG

Control of Doubly Fed Induction Generator Using IT2-FL

Reference Tracking

Conclusions