Design of an Improved MPPT Control of DFIG Wind Turbine under Unbalanced Grid Voltage using a Flux Sliding Mode Observer

Abstract

This study presents a control scheme of the electronic interface of a grid connected Variable Speed Wind Energy Generation System (VS-WEGS) based on a Doubly Fed Induction Generator (DFIG). The efficiency of the wind energy is represented to according to the control strategy applied. Thus, in the case of unbalanced grid voltage, the negative sequence voltage causes additional strong oscillation at twice the grid frequency in the stator instantaneous active and reactive powers. The objective of this work is to present an enhanced MPPT controller uses backstepping approach implemented in both dq + and dq − reference frames rotating to keep a safe operation of DFIG during unbalanced grid voltage associated with regulating rotor flux, in order to estimate rotor flux, a nonlinear observer based on sliding mode is proposed in this work. Note that the conventional controllers (PI, PI-R …) are not provided satisfactory performance during unbalanced voltage dips. The validation of results has been performed through simulation studies on a 4 kW DFIG using Matlab/Simulink

Torque estimator using MPPT method for wind turbines

“…This is the problem addressed by designers who aim to develop 1209 robust and reliable MPPT algorithms for maximum power point monitoring in order to optimize energy efficiency. The wind turbine is composed of a turbine with its own parameters defining its potential to capture the energy of the moving air mass [6][7][8]. A judicious choice of the control strategies of the conversion chain makes it possible to obtain a system with a minimum cost and energy efficient enough, regardless of the intermittence of the wind and the variation of the load.We opted first for a model of the mechanical part (turbine and speed multiplier), and this for the 1.5 MW wind turbine, commonly used in current wind systems.…”

High-performance MPPT control of DFIG with optimized flux reference in presence of nonlinear magnetic characteristic

“…So, the iron resistance is a variable parameter which was identified experimentally on a 4 kW DFIG driven by a DC motor. The procedure described in [19] was used to determine the values of the iron loss resistance as well as the magnetizing reactance [22]. The iron resistance characteristic is shown in Figure 2.…”

Integral Backstepping Based Nonlinear Control for Maximum Power Point Tracking and Unity Power Factor of a Grid Connected Hybrid Wind-Photovoltaic System

“…Most of the control strategies proposed in the literature for grid-connected PV systems have covered power factor control [25,26]. Concerning Doubly Fed Induction Generators (DFIG)based wind energy systems, except some research works that have considered power factor control of the DFIG rotor circuit [12,27,28], the vast majority has focused only on stator power control [29][30][31].…”