Abdelmajid Abouloifa - Academia.edu (original) (raw)

Papers by Abdelmajid Abouloifa

2018 Renewable Energies, Power Systems & Green Inclusive Economy (REPS-GIE), 2018

In this paper, the supplied energy by a fuel cell is managed using a double boost converter. The ... more In this paper, the supplied energy by a fuel cell is managed using a double boost converter. The study of the whole system begun by presenting the model of the fuel cell, followed by the system dynamics of the double boost converter described by the averaged 4th order nonlinear state space model, then a final model is derived using Euler-LaGrange (EL) system equations, based on such model, a robust non-linear controller is synthesized using the passivity-based control as a global defining and global stabilization control method. The simulation results have been performed through Matlab/SimPowerSystems environment and show that the designed controller meet its objectives.

2019 4th World Conference on Complex Systems (WCCS), 2019

In this work, the focus is put on the issue of controlling a single-phase single stage Boost Inve... more In this work, the focus is put on the issue of controlling a single-phase single stage Boost Inverter by an output feedback adaptive control. The main goal of this study is to provide a sinusoidal output voltage which follows tightly the desired reference. The considered control problem is permeated by many difficulties in terms of: (i) The nonlinearity of the studied circuit topology; (ii) The presence of the phenomenon of non-minimum phase makes the system difficult to control; (iii) Inaccessibility to measurements of all currents; (iiii) Unknown load. The issue is dealt using an indirect output voltage regulation: (i) An inner loop is designed using output feedback adaptive control based on the observer with a view to estimating the state variables (Currents); (ii) An outer loop regulates the output voltage to track its reference. The simulation outcomes have been corroborated within Matlab/Simulink/Simpowersystems, which demonstrate that the suggested controller achieves the desired aim.

- Dans ce travail, nous etudions la modelisation et la commande d’une chaine de conversion d’ener... more - Dans ce travail, nous etudions la modelisation et la commande d’une chaine de conversion d’energie eolienne a base d’une generatrice asynchrone a double alimentation. Tout d'abord, le modele mathematique de l'ensemble du systeme etudie est developpe dans les coordonnees du Parc d-q. Par la suite, la strategie de commande proposee est concue a partir d’une technique de commande de type Backstepping dont les objectifs : Extraire le maximum de puissance a partir des vitesses variables du vent (MPPT) ; Injecter le courant electrique dans le reseau tout en gardant un tres bon facteur de puissance (PFC). Finalement les resultats des differentes simulations de toute la chaine de conversion, realisees sous environnement MATLAB/Simulink

Recent Advances in Electrical and Information Technologies for Sustainable Development, 2019

This chapter considers the control of serial multicellular power converter feeding DC motor. For ... more This chapter considers the control of serial multicellular power converter feeding DC motor. For this purpose, a new control strategy based on flatness approach is developed. The main aim consists on regulating the DC motor velocity to a desired level, keeping in mind the necessity of ensuring an equitable distribution of the supply voltage on the power switches of serial multicellular power converter. To this end, the regulation of the voltage at the terminals of the flying capacitors is necessary. The synthetized controller was verified by computer simulation using Matlab/SimPowerSystems, and the obtained results prove the effectiveness of the designed controller and show that the entire objectives are achieved.

2015 3rd International Renewable and Sustainable Energy Conference (IRSEC), 2015

In this paper, we present a system used a Permanent Magnet Synchronous Generator (PMSG) applied t... more In this paper, we present a system used a Permanent Magnet Synchronous Generator (PMSG) applied to wind energy, to generate electricity and inject it into home network. The objective is to perform modeling and nonlinear control system, and then the objective of the control is: enforcing power factor correction (PFC) with respect to the power grid. First part, we present the mathematical model of the whole system under study. Thereafter we propose a nonlinear backstepping control, to ensure the shape of the current and thus harmonic distortion reduced relative to classical control. To demonstrate the performance of methods, some results of the overall system simulations are presented under MATLAB / Simulink software.

2019 4th World Conference on Complex Systems (WCCS), 2019

This paper presents the dynamics of interleaved Buck converter (IB) used as an active power filte... more This paper presents the dynamics of interleaved Buck converter (IB) used as an active power filter (APF) and proposes a control system that guarantees two objectives: i) compensation of the current harmonics and the reactive power absorbed by the nonlinear load; ii) tight regulation of the DC bus voltage. The proposed control system is based on two cascaded loops: An inner loop is designed to deal with the compensation issue using the half wave current controller. The outer-loop is designed to regulate the output converter voltage using a proportional-integral (PI) regulator. Finally, it is formally demonstrated, through simulation results in Matlab/SimPowerSystems environment that the control strategy achieves desired objectives and it validates the performance of IB-APF.

International Journal of Electrical Power & Energy Systems, 2021

Abstract This paper addresses the problem of controlling a single phase shunt active power filter... more Abstract This paper addresses the problem of controlling a single phase shunt active power filter (SAPF) in presence of nonlinear loads. The considered SAPF is based on a Dual Buck Half Bridge converter (DBHB), which has the ability to eliminate the shoot-through problem arising in the conventional inverter circuit. The aim is to design a controller that is able to achieve the following three control objectives: (i) simple and indirect estimation of harmonic components, (ii) compensating for the harmonic and reactive currents generated by the nonlinear load for assuring a satisfactory power factor correction (PFC) in the grid side, (iii) regulating the DC capacitor voltage of the DBHB converter. In order to meet these control objectives, a new controller based on multi-loop structure is proposed. In the inner loop, a hybrid automaton representation of the DBHB-SAPF is used for the purpose of designing an appropriate control law so that to ensure a unity power factor. In the outer loop, a fuzzy logic controller is developed to guarantee a tight regulation of the converter DC voltage to a desired value. The effectiveness of the proposed controller is verified and validated by numerical simulation using MATLAB/Simulink environment. From the obtained results, the designed controller shows significant performance in terms of robustness and tracking compared to the standard strategy based on PI regulator.

2021 American Control Conference (ACC), 2021

In this letter, an advanced adaptive controller is designed for NNN -cascaded H-bridge multilevel... more In this letter, an advanced adaptive controller is designed for NNN -cascaded H-bridge multilevel inverters, each fed by a DC voltage source. The studied system provides an added-value to Uninterruptable Power Supply applications, and is able to generate a precise sinusoidal voltage using a low dimensional LC filter. The main objectives of this letter are: i. generating a low THD sinusoidal voltage, ii. developing adaptive control laws able to regulate the system even with the presence of parameters’ variations, and iii. proving the stability of the designed system using some tools from Lyapunov stability, Lasalle’s invariance principle and persistency of excitation. This latter proves that the closed-loop control system is uniformly exponentially stable. To achieve these objectives, the adaptive backstepping approach is used. The performance of the system is checked with the use of MATLAB/SIMULINK/ SimPowerSystems environment, where the synthesized regulator meets its objectives.

Journal of Control, Automation and Electrical Systems, 2021

We consider the problem of controlling wind energy conversion systems that are based on doubly fe... more We consider the problem of controlling wind energy conversion systems that are based on doubly fed induction generators. The aim is to design a nonlinear controller to fulfill the control goals considering the two sides, grid and rotor side. On the rotor side, the control objectives are twofold: (i) ensuring the maximum power point tracking requirement and (ii) maintaining the stator reactive power at a desired reference. On the grid side, we also seek the achievement of two control objectives: (i) regulating the DC-link voltage at a given reference value and (ii) ensuring a zero reactive power. Besides the multi-objective nature of this study, the difficulty of the control problem lies in the nonlinearity and uncertainty of the system dynamics and external disturbances. The control problem under consideration is dealt with by designing a model-based controller using the adaptive sliding mode technique. The stability and performances of the closed-loop control system are analyzed both theoretically and by numerical simulations. The latter are performed using 2MW grid-connected wind turbine system in MATLAB/SIMULINK/SimPowerSystems environment. The simulation results confirm that the suggested controller meets its objectives and features robustness properties.

2019 4th World Conference on Complex Systems (WCCS), 2019

This paper aims at highlighting on the importance of the cascaded H-bridge multilevel inverter in... more This paper aims at highlighting on the importance of the cascaded H-bridge multilevel inverter in overcoming the disadvantages of the conventional multilevel inverter by combining three H-bridge modules together so as to increase the power level. The three H-bridge modules, which are empowered fundamentally by an H-bridge module, generate seven voltage levels as output. This topology can be used for large-scale PV conversion systems (> 10MW), electric vehicles (EVs) or hybrid EVs through a hybrid control of cascaded H-bridge multilevel inverters, where each module of the inverter can be supplied using a DC source, found mainly in fuel cells, batteries, photovoltaic systems or ultra capacitors. Our main focus in this paper is to provide sinusoidal voltages with very low harmonic distortion to be used in an Uninterruptable Power Supply (UPS) system. The three-cell H-bridge inverter is commanded by PWM generators and controlled by two types of regulators. The first one is the nonlinear backstepping approach and the second one is the adaptive backstepping approach. The structure under investigation is analyzed using MATLAB/SIMULINK environment.

International Journal of Electrical Power & Energy Systems, 2021

Abstract This paper investigates the problem of controlling a single phase shunt active power fil... more Abstract This paper investigates the problem of controlling a single phase shunt active power filter (SAPF) connected to two photovoltaic arrays through a half bridge inverter involving two DC link capacitors. The control aims are threefold: ensuring a satisfactory power factor correction (PFC) at the grid-power filter connection point by compensating the harmonic and reactive currents produced by the nonlinear loads; extracting a maximum active power in the output photovoltaic arrays by applying the maximum power point tracking (MPPT) block and balancing the power exchange between the photovoltaic source and the AC power grid by regulating the DC link capacitors voltages. The problem is dealt with using a cascade nonlinear adaptive controller. The inner loop is designed using sliding mode and Lyapunov stability techniques so that to ensure a unity power factor. It also includes an adaptive observer that performs online estimation of the grid state variables which are not accessible to measurements. The outer loop is mainly constituted of filtered proportional-integral (PI) regulator, that ensures a tight regulation of the photovoltaic voltage, and the incremental conductance (IC) algorithm to meet MPPT. The resulting controller performances are formally analyzed making use of averaging theory. The theoritical analysis results are confirmed by numerical simulation within MATLAB/SimPowerSystems environment.

International Journal of Power Electronics and Drive Systems (IJPEDS), 2018

This article presents nonlinear control of wind conversion chain connected to the grid based on a... more This article presents nonlinear control of wind conversion chain connected to the grid based on a permanent magnet synchronous generator. The control objectives are threefold; i) forcing the generator speed to track a varying reference signal in order to extract the maximum power at different wind speed (MPPT); ii) regulating the rectifier output capacitor voltage; iii) reducing the harmonic and reactive currents injected in the grid. This means that the inverter output current must be sinusoidal and in phase with the AC supply voltage (PFC). To this end, a nonlinear state-feedback control is developed, based on the average nonlinear model of the whole controlled system. This control strategy involves backstepping approach, Lyapunov stability and other tools from theory of linear systems. The proposed state-feedback control strategy is tested by numerical simulation which shows that the developed controller reaches its objectives

Vibration Analysis and Control in Mechanical Structures and Wind Energy Conversion Systems, 2018

IFAC-PapersOnLine, 2016

In this paper, the problem of controlling three-phase boost power converter is considered for cha... more In this paper, the problem of controlling three-phase boost power converter is considered for charging the battery in uninterruptible power supply (UPS) systems. The control objective is twofold: (i) ensuring a satisfactory power factor correction (PFC) at the grid-UPS connection; (ii) guaranteeing a tight regulation of the DC output voltage despite of load uncertain. The considered control problem entails several difficulties including: (i) the numerous state variables that are inaccessible to measurements; (ii) the uncertainty that prevails on some system parameters. The problem is dealt with using a cascade nonlinear adaptive controller that is developed making use of the Lyapunov control design technique. The inner-loop ensures the PFC objective and involves an adaptive observer estimating the grid phase currents, the magnitude of the parameters grid phase voltages and the load resistance. The estimation is only based on the online measurements of DC output voltage. The outer-loop regulates the DC output voltage up to small size ripples.

International Journal of Electrical Power & Energy Systems, 2020

Abstract This work presents the control development of a single stage grid-connected photovoltaic... more Abstract This work presents the control development of a single stage grid-connected photovoltaic (PV) system. The topology used by the PV system consists of two PV panels, a single-phase half-bridge inverter using two DC link capacitors, and an LCL filter in the grid side. The aim is to design a nonlinear controller to ensure simultaneously the following three objectives: (i) PV panels to provide their maximum power, (ii) balanced power exchange by regulating the DC link voltage, and (iii) power factor correction, i.e. grid current in phase with grid voltage. In order to fulfill these objectives, a multi-loop controller is designed by using back-stepping and Lyapunov approaches for the power factor correction objective and a filtered PI regulator to ensure the power balance between the grid and the PV panels. The controller performances are formally analyzed using an average large signal model. The performance of the proposed controller is shown by means of simulation results in MATLAB/SimPowerSystems environment.

Asian Journal of Control, 2017

The problem of controlling reduced-part three-phase shunt active power filters is addressed in th... more The problem of controlling reduced-part three-phase shunt active power filters is addressed in the presence of nonlinear loads. The control objective is twofold: (i) compensation of the current harmonics and the reactive power absorbed by the nonlinear load in order to ensure a satisfactory power factor correction (PFC) at the grid-filter connection point; (2) regulation of the DC bus voltage at the inverter input. The considered control problem entails several difficulties including: (1) the high dimension and strong nonlinearity of the system; (ii) the numerous state variables that are inaccessible to measurements; (iii) the system parameter uncertainty. The problem is dealt with by designing a nonlinear adaptive controller with cascade structure including two control loops. The inner-loop regulator is designed using the Lyapunov technique to ensure the PFC objective, while the outer-loop involves a linear PI type control law for DC bus voltage regulation. The controller also includes an adaptive observer estimating the grid voltages and impedances parameters. The resulting control performances are formally analyzed using the averaging theory. Simulation results are presented illustrating the performances and the strong robustness of the proposed control strategy.

Journal of Solar Energy, 2018

This paper addresses the problem of controlling the single-phase grid connected to the photovolta... more This paper addresses the problem of controlling the single-phase grid connected to the photovoltaic system through a full bridge inverter with LCL-filter. The control aims are threefold: (i) imposing the voltage in the output of PV panel to track a reference provided by the MPPT block; (ii) regulating the DC-link voltage to guarantee the power exchange between the source and AC grid; (iii) ensuring a satisfactory power factor correction (PFC). The problem is dealt with using a cascade nonlinear adaptive controller that is developed making use of sliding-mode technique and observers in order to estimate the state variables and grid parameters, by measuring only the grid current, PV voltage, and the DC bus voltage. The control problem addressed by this work involves several difficulties, including the uncertainty of some parameters of the system and the numerous state variables are inaccessible to measurements. The results are confirmed by simulation under MATLAB∖Simulink∖SimPowerSyst...

2018 Renewable Energies, Power Systems & Green Inclusive Economy (REPS-GIE), 2018

In this paper, the supplied energy by a fuel cell is managed using a double boost converter. The ... more In this paper, the supplied energy by a fuel cell is managed using a double boost converter. The study of the whole system begun by presenting the model of the fuel cell, followed by the system dynamics of the double boost converter described by the averaged 4th order nonlinear state space model, then a final model is derived using Euler-LaGrange (EL) system equations, based on such model, a robust non-linear controller is synthesized using the passivity-based control as a global defining and global stabilization control method. The simulation results have been performed through Matlab/SimPowerSystems environment and show that the designed controller meet its objectives.

2019 4th World Conference on Complex Systems (WCCS), 2019

In this work, the focus is put on the issue of controlling a single-phase single stage Boost Inve... more In this work, the focus is put on the issue of controlling a single-phase single stage Boost Inverter by an output feedback adaptive control. The main goal of this study is to provide a sinusoidal output voltage which follows tightly the desired reference. The considered control problem is permeated by many difficulties in terms of: (i) The nonlinearity of the studied circuit topology; (ii) The presence of the phenomenon of non-minimum phase makes the system difficult to control; (iii) Inaccessibility to measurements of all currents; (iiii) Unknown load. The issue is dealt using an indirect output voltage regulation: (i) An inner loop is designed using output feedback adaptive control based on the observer with a view to estimating the state variables (Currents); (ii) An outer loop regulates the output voltage to track its reference. The simulation outcomes have been corroborated within Matlab/Simulink/Simpowersystems, which demonstrate that the suggested controller achieves the desired aim.

- Dans ce travail, nous etudions la modelisation et la commande d’une chaine de conversion d’ener... more - Dans ce travail, nous etudions la modelisation et la commande d’une chaine de conversion d’energie eolienne a base d’une generatrice asynchrone a double alimentation. Tout d'abord, le modele mathematique de l'ensemble du systeme etudie est developpe dans les coordonnees du Parc d-q. Par la suite, la strategie de commande proposee est concue a partir d’une technique de commande de type Backstepping dont les objectifs : Extraire le maximum de puissance a partir des vitesses variables du vent (MPPT) ; Injecter le courant electrique dans le reseau tout en gardant un tres bon facteur de puissance (PFC). Finalement les resultats des differentes simulations de toute la chaine de conversion, realisees sous environnement MATLAB/Simulink

Recent Advances in Electrical and Information Technologies for Sustainable Development, 2019

This chapter considers the control of serial multicellular power converter feeding DC motor. For ... more This chapter considers the control of serial multicellular power converter feeding DC motor. For this purpose, a new control strategy based on flatness approach is developed. The main aim consists on regulating the DC motor velocity to a desired level, keeping in mind the necessity of ensuring an equitable distribution of the supply voltage on the power switches of serial multicellular power converter. To this end, the regulation of the voltage at the terminals of the flying capacitors is necessary. The synthetized controller was verified by computer simulation using Matlab/SimPowerSystems, and the obtained results prove the effectiveness of the designed controller and show that the entire objectives are achieved.

2015 3rd International Renewable and Sustainable Energy Conference (IRSEC), 2015

In this paper, we present a system used a Permanent Magnet Synchronous Generator (PMSG) applied t... more In this paper, we present a system used a Permanent Magnet Synchronous Generator (PMSG) applied to wind energy, to generate electricity and inject it into home network. The objective is to perform modeling and nonlinear control system, and then the objective of the control is: enforcing power factor correction (PFC) with respect to the power grid. First part, we present the mathematical model of the whole system under study. Thereafter we propose a nonlinear backstepping control, to ensure the shape of the current and thus harmonic distortion reduced relative to classical control. To demonstrate the performance of methods, some results of the overall system simulations are presented under MATLAB / Simulink software.

2019 4th World Conference on Complex Systems (WCCS), 2019

This paper presents the dynamics of interleaved Buck converter (IB) used as an active power filte... more This paper presents the dynamics of interleaved Buck converter (IB) used as an active power filter (APF) and proposes a control system that guarantees two objectives: i) compensation of the current harmonics and the reactive power absorbed by the nonlinear load; ii) tight regulation of the DC bus voltage. The proposed control system is based on two cascaded loops: An inner loop is designed to deal with the compensation issue using the half wave current controller. The outer-loop is designed to regulate the output converter voltage using a proportional-integral (PI) regulator. Finally, it is formally demonstrated, through simulation results in Matlab/SimPowerSystems environment that the control strategy achieves desired objectives and it validates the performance of IB-APF.

International Journal of Electrical Power & Energy Systems, 2021

Abstract This paper addresses the problem of controlling a single phase shunt active power filter... more Abstract This paper addresses the problem of controlling a single phase shunt active power filter (SAPF) in presence of nonlinear loads. The considered SAPF is based on a Dual Buck Half Bridge converter (DBHB), which has the ability to eliminate the shoot-through problem arising in the conventional inverter circuit. The aim is to design a controller that is able to achieve the following three control objectives: (i) simple and indirect estimation of harmonic components, (ii) compensating for the harmonic and reactive currents generated by the nonlinear load for assuring a satisfactory power factor correction (PFC) in the grid side, (iii) regulating the DC capacitor voltage of the DBHB converter. In order to meet these control objectives, a new controller based on multi-loop structure is proposed. In the inner loop, a hybrid automaton representation of the DBHB-SAPF is used for the purpose of designing an appropriate control law so that to ensure a unity power factor. In the outer loop, a fuzzy logic controller is developed to guarantee a tight regulation of the converter DC voltage to a desired value. The effectiveness of the proposed controller is verified and validated by numerical simulation using MATLAB/Simulink environment. From the obtained results, the designed controller shows significant performance in terms of robustness and tracking compared to the standard strategy based on PI regulator.

2021 American Control Conference (ACC), 2021

In this letter, an advanced adaptive controller is designed for NNN -cascaded H-bridge multilevel... more In this letter, an advanced adaptive controller is designed for NNN -cascaded H-bridge multilevel inverters, each fed by a DC voltage source. The studied system provides an added-value to Uninterruptable Power Supply applications, and is able to generate a precise sinusoidal voltage using a low dimensional LC filter. The main objectives of this letter are: i. generating a low THD sinusoidal voltage, ii. developing adaptive control laws able to regulate the system even with the presence of parameters’ variations, and iii. proving the stability of the designed system using some tools from Lyapunov stability, Lasalle’s invariance principle and persistency of excitation. This latter proves that the closed-loop control system is uniformly exponentially stable. To achieve these objectives, the adaptive backstepping approach is used. The performance of the system is checked with the use of MATLAB/SIMULINK/ SimPowerSystems environment, where the synthesized regulator meets its objectives.

Journal of Control, Automation and Electrical Systems, 2021

We consider the problem of controlling wind energy conversion systems that are based on doubly fe... more We consider the problem of controlling wind energy conversion systems that are based on doubly fed induction generators. The aim is to design a nonlinear controller to fulfill the control goals considering the two sides, grid and rotor side. On the rotor side, the control objectives are twofold: (i) ensuring the maximum power point tracking requirement and (ii) maintaining the stator reactive power at a desired reference. On the grid side, we also seek the achievement of two control objectives: (i) regulating the DC-link voltage at a given reference value and (ii) ensuring a zero reactive power. Besides the multi-objective nature of this study, the difficulty of the control problem lies in the nonlinearity and uncertainty of the system dynamics and external disturbances. The control problem under consideration is dealt with by designing a model-based controller using the adaptive sliding mode technique. The stability and performances of the closed-loop control system are analyzed both theoretically and by numerical simulations. The latter are performed using 2MW grid-connected wind turbine system in MATLAB/SIMULINK/SimPowerSystems environment. The simulation results confirm that the suggested controller meets its objectives and features robustness properties.

2019 4th World Conference on Complex Systems (WCCS), 2019

This paper aims at highlighting on the importance of the cascaded H-bridge multilevel inverter in... more This paper aims at highlighting on the importance of the cascaded H-bridge multilevel inverter in overcoming the disadvantages of the conventional multilevel inverter by combining three H-bridge modules together so as to increase the power level. The three H-bridge modules, which are empowered fundamentally by an H-bridge module, generate seven voltage levels as output. This topology can be used for large-scale PV conversion systems (> 10MW), electric vehicles (EVs) or hybrid EVs through a hybrid control of cascaded H-bridge multilevel inverters, where each module of the inverter can be supplied using a DC source, found mainly in fuel cells, batteries, photovoltaic systems or ultra capacitors. Our main focus in this paper is to provide sinusoidal voltages with very low harmonic distortion to be used in an Uninterruptable Power Supply (UPS) system. The three-cell H-bridge inverter is commanded by PWM generators and controlled by two types of regulators. The first one is the nonlinear backstepping approach and the second one is the adaptive backstepping approach. The structure under investigation is analyzed using MATLAB/SIMULINK environment.

International Journal of Electrical Power & Energy Systems, 2021

Abstract This paper investigates the problem of controlling a single phase shunt active power fil... more Abstract This paper investigates the problem of controlling a single phase shunt active power filter (SAPF) connected to two photovoltaic arrays through a half bridge inverter involving two DC link capacitors. The control aims are threefold: ensuring a satisfactory power factor correction (PFC) at the grid-power filter connection point by compensating the harmonic and reactive currents produced by the nonlinear loads; extracting a maximum active power in the output photovoltaic arrays by applying the maximum power point tracking (MPPT) block and balancing the power exchange between the photovoltaic source and the AC power grid by regulating the DC link capacitors voltages. The problem is dealt with using a cascade nonlinear adaptive controller. The inner loop is designed using sliding mode and Lyapunov stability techniques so that to ensure a unity power factor. It also includes an adaptive observer that performs online estimation of the grid state variables which are not accessible to measurements. The outer loop is mainly constituted of filtered proportional-integral (PI) regulator, that ensures a tight regulation of the photovoltaic voltage, and the incremental conductance (IC) algorithm to meet MPPT. The resulting controller performances are formally analyzed making use of averaging theory. The theoritical analysis results are confirmed by numerical simulation within MATLAB/SimPowerSystems environment.

International Journal of Power Electronics and Drive Systems (IJPEDS), 2018

This article presents nonlinear control of wind conversion chain connected to the grid based on a... more This article presents nonlinear control of wind conversion chain connected to the grid based on a permanent magnet synchronous generator. The control objectives are threefold; i) forcing the generator speed to track a varying reference signal in order to extract the maximum power at different wind speed (MPPT); ii) regulating the rectifier output capacitor voltage; iii) reducing the harmonic and reactive currents injected in the grid. This means that the inverter output current must be sinusoidal and in phase with the AC supply voltage (PFC). To this end, a nonlinear state-feedback control is developed, based on the average nonlinear model of the whole controlled system. This control strategy involves backstepping approach, Lyapunov stability and other tools from theory of linear systems. The proposed state-feedback control strategy is tested by numerical simulation which shows that the developed controller reaches its objectives

Vibration Analysis and Control in Mechanical Structures and Wind Energy Conversion Systems, 2018

IFAC-PapersOnLine, 2016

In this paper, the problem of controlling three-phase boost power converter is considered for cha... more In this paper, the problem of controlling three-phase boost power converter is considered for charging the battery in uninterruptible power supply (UPS) systems. The control objective is twofold: (i) ensuring a satisfactory power factor correction (PFC) at the grid-UPS connection; (ii) guaranteeing a tight regulation of the DC output voltage despite of load uncertain. The considered control problem entails several difficulties including: (i) the numerous state variables that are inaccessible to measurements; (ii) the uncertainty that prevails on some system parameters. The problem is dealt with using a cascade nonlinear adaptive controller that is developed making use of the Lyapunov control design technique. The inner-loop ensures the PFC objective and involves an adaptive observer estimating the grid phase currents, the magnitude of the parameters grid phase voltages and the load resistance. The estimation is only based on the online measurements of DC output voltage. The outer-loop regulates the DC output voltage up to small size ripples.

International Journal of Electrical Power & Energy Systems, 2020

Abstract This work presents the control development of a single stage grid-connected photovoltaic... more Abstract This work presents the control development of a single stage grid-connected photovoltaic (PV) system. The topology used by the PV system consists of two PV panels, a single-phase half-bridge inverter using two DC link capacitors, and an LCL filter in the grid side. The aim is to design a nonlinear controller to ensure simultaneously the following three objectives: (i) PV panels to provide their maximum power, (ii) balanced power exchange by regulating the DC link voltage, and (iii) power factor correction, i.e. grid current in phase with grid voltage. In order to fulfill these objectives, a multi-loop controller is designed by using back-stepping and Lyapunov approaches for the power factor correction objective and a filtered PI regulator to ensure the power balance between the grid and the PV panels. The controller performances are formally analyzed using an average large signal model. The performance of the proposed controller is shown by means of simulation results in MATLAB/SimPowerSystems environment.

Asian Journal of Control, 2017

The problem of controlling reduced-part three-phase shunt active power filters is addressed in th... more The problem of controlling reduced-part three-phase shunt active power filters is addressed in the presence of nonlinear loads. The control objective is twofold: (i) compensation of the current harmonics and the reactive power absorbed by the nonlinear load in order to ensure a satisfactory power factor correction (PFC) at the grid-filter connection point; (2) regulation of the DC bus voltage at the inverter input. The considered control problem entails several difficulties including: (1) the high dimension and strong nonlinearity of the system; (ii) the numerous state variables that are inaccessible to measurements; (iii) the system parameter uncertainty. The problem is dealt with by designing a nonlinear adaptive controller with cascade structure including two control loops. The inner-loop regulator is designed using the Lyapunov technique to ensure the PFC objective, while the outer-loop involves a linear PI type control law for DC bus voltage regulation. The controller also includes an adaptive observer estimating the grid voltages and impedances parameters. The resulting control performances are formally analyzed using the averaging theory. Simulation results are presented illustrating the performances and the strong robustness of the proposed control strategy.

Journal of Solar Energy, 2018

This paper addresses the problem of controlling the single-phase grid connected to the photovolta... more This paper addresses the problem of controlling the single-phase grid connected to the photovoltaic system through a full bridge inverter with LCL-filter. The control aims are threefold: (i) imposing the voltage in the output of PV panel to track a reference provided by the MPPT block; (ii) regulating the DC-link voltage to guarantee the power exchange between the source and AC grid; (iii) ensuring a satisfactory power factor correction (PFC). The problem is dealt with using a cascade nonlinear adaptive controller that is developed making use of sliding-mode technique and observers in order to estimate the state variables and grid parameters, by measuring only the grid current, PV voltage, and the DC bus voltage. The control problem addressed by this work involves several difficulties, including the uncertainty of some parameters of the system and the numerous state variables are inaccessible to measurements. The results are confirmed by simulation under MATLAB∖Simulink∖SimPowerSyst...