M. CHEBABHI Ali

In practical three-phase PWM rectifiers, external disturbances, such as changes in load and grid voltage, and internal disturbances, such as DC capacitor uncertainty, have caused major problems, including DC-link voltage fluctuations, harmonic distortion, and power factor degradation. They can also cause problems with power balance, stability, system dynamics, reduced efficiency, and increased stress. This paper proposes an enhanced linear state observer (ELSO) with a PLL-less voltage-oriented control (PLL-less VOC) method for a three-phase PWM rectifier in the synchronous coordinate frame (dq coordinate), aiming to simultaneously improve the DC-link voltage dynamics, disturbance rejection ability, and the grid current control loop’s transient response. The ELSO is suggested instead of the load current sensor not only to estimate the disturbance but also to estimate the overall switching losses of the PWM rectifier, resulting in good DC-link voltage disturbance rejection and transient fluctuation suppression, high robustness against DC capacitance change, low size and cost, and high reliability. Furthermore, contrary to the traditional VOC method, where the PLL and Park transforms are important parts for controlling the rectifier in the dq coordinate, the PLL-less VOC method can control the grid currents directly in the dq coordinate without needing PLL and Park transforms, which can offer a fast transient response and low computational burden. The frequency domain analysis of the ELSO is used to identify its gains and enhance its stability and disturbance rejection capability. Finally, hardware-in-the-loop (HIL) simulation using the OPAL-RT 4510 real-time simulator is also given to confirm the superiority and efficacy of the suggested control method.

Dans les systèmes triphasés autonomes déséquilibrés, où la circulation du courant homopolaire (séquence zéro) est nécessaire, les onduleurs à quatre bras fournissent une connexion neutre pour les charges monophasées ou autres charges déséquilibrées typiquement utilisées dans les systèmes de distribution triphasés. De plus, le contrôle de l'amplitude et de la phase de la tension et/ou du courant de séquence zéro est également réalisé à l'aide des onduleurs à quatre bras. En raison de ces avantages, les onduleurs à quatre bras sont largement utilisés dans de nombreuses applications d'alimentation autonome basées sur les ressources d'énergie renouvelable, notamment les systèmes d'alimentation autonomes (Stand-alone power-supply systems : SPSS), les configurations parallèles et les micro-réseaux isolés à quatre fils.

Voici les défis auxquels sont confrontés les SPSS basés sur des onduleurs à quatre bras, les configurations d'onduleurs à quatre bras parallèles et les micro-réseaux isolés à quatre fils basés sur des onduleurs à quatre bras :

(1) Déséquilibre et perturbations de la tension de charge, (2) Grandes erreurs statiques sous des charges monophasées et triphasées déséquilibrées, (3) Réponses dynamiques lors de la variation de la charge ou de la tension de référence de charge, (4) Grand courant de circulation pour les configurations d'onduleurs à quatre bras parallèles qui circule entre les bras de chaque phase de ces onduleurs lorsque les onduleurs fonctionnent avec un partage de courant déséquilibré ou des paramètres de filtre de sortie déséquilibrés, (5) Partage de puissance, gestion du courant homopolaire et du courant de circulation pour les micro-réseaux isolés à quatre fils lorsque les onduleurs fonctionnent avec des paramètres des files déséquilibrés, (6) Analyse et contrôle de la qualité de l'énergie pour les trois systèmes, (7) Complexité et charge de calcul pour les trois systèmes, (8) Nombre élevé de capteurs nécessaires pour les trois systèmes.

Les travaux futurs et les solutions pour chaque configuration seront détaillés dans chaque partie de cette présentation.

This paper proposes an inverse droop control strategy (IDCS) to ‎enhance the performance of voltage source inverter (VSI)-based distributed generation (DG) units in an ‎islanded microgrid (IMG) with mismatched line impedances. The method aims to improve power sharing, ‎energy management, decoupling, and oscillation reduction while eliminating circulating currents using a ‎decentralized approach. While the traditional droop control method (TDCM) performs well in ideal IMGs, its ‎effectiveness diminishes under line impedance mismatches. Our proposed IDCS addresses these ‎challenges for three VSI-based DG units in an IMG. MATLAB/Simulink simulations validate the ‎performance of the IDCS. Results demonstrate significant improvements in IMG control, including equal ‎active and reactive power sharing with minimal oscillations, elimination of reactive power errors among DG ‎units, mitigation of circulating currents. These outcomes showcase the proposed method's ability to enhance ‎overall IMG performance under line impedance mismatches.‎

The proposal combines optimal energy management for electric vehicles via slap swarm optimization and ‎differential flatness control. A battery-supercapacitor power system is utilized. A synchronous reluctance ‎motor (SynRM) drive gets power from DC-DC bidirectional converters that connect each source in parallel to ‎the DC bus. The suggested EMS basic forces utilize a combination of the complementing properties of two ‎methodologies: the Slap Swarm Optimization Algorithm and Differential Flatness (DF). The Slap Swarm ‎optimization algorithm employs a rapid optimization process to adapt the DF gains in real-time, hence ‎enhancing system performance. DF employs predetermined trajectories that adhere to the system's physical ‎properties, serving as an effective mechanism to ensure the dynamic restrictions of the sources while ‎achieving the necessary robust control characteristics. A lot of hardware-in-the-loop (HIL) real-time ‎simulations of the electric vehicle were run using the OPAL-RT OP4510 simulator to test the proposed EMS's ‎viability and performance. The main goal of the suggested EMS is to keep the DC-bus stable by reducing the ‎DC-bus voltage changes (Δv = 5 V) and voltage overshoots to 15 V (3.2%), while still meeting the SynRM ‎motor's power needs. Moreover, the technique reduces induced harmonics from the drive (10.49%), ‎decreasing the battery current ripple by 17.15A and thus improving the battery's lifespan.‎

In recent years, grid-connected multifunctional photovoltaic (PV) systems have proven to be highly efficient. This system integrates PV panels with a DC–DC boost converter (DC–DC–BC) and the electrical distribution grid (DEG). Linking the PV to the AC-DEG is accomplished through a three-level multifunctional voltage source inverter (MVSI). The DC–DC–BC component in this study is engineered to perform maximum power point tracking (MPPT) irrespective of normal or abnormal conditions. The conventional MPPT technique poses several challenges and constraints on system usage. Hence, the suggestion is to adopt synergetic control (SC) and sliding mode control (SMC) to enhance the MPPT technique's performance within the proposed system framework. Moreover, predictive direct power control is applied to the MVSI-based shunt active power filter, utilizing a phase-locked loop technique to achieve multiple objectives: minimizing energy fluctuations, injecting active power, correcting power factors, compensating reactive power, and mitigating harmonic currents. To implement the proposed system, the MATLAB is used for this purpose, with several tests used to study the behavior of the controls proposed in this work. Numerical results indicate significant reductions in active and reactive power fluctuations, with estimated rates of 38.46% and 15.30%, respectively, compared to traditional strategies. Moreover, the total harmonic distortion (THD) of the source current after filtering is reduced by 31.88% under solar irradiation of G = 1000 Wm2. Before filtering, the THD of current experiences a reduction estimated at 97.65%. These findings underscore the superior performance of the proposed control technique across all evaluated aspects.

This research focuses on the analysis of power quality and its improvement in three-phase, four-wire Photovoltaic grid-connected inverters using a three-phase, two-level inverter with four legs that performs as an active power filter connected in parallel with the perturbing load. This powerful electronic circuit is designed to attenuate harmonic currents from unbalanced non-linear loads. This research paper compares the efficiencies of the synchronous reference method (SRF) with both low pass filters and high pass filters inside the control by the park’s transformation this control based on hysteresis modulation used to generate harmonic currents on hysteresis regeneration. For the three-phase, four-leg, two-level shunt active power filter (SAPF) to improve the power quality of four-wire grid-connected photovoltaic systems and on the opposite side a non-linear load designed, using MATLAB/Simulink, the performance analysis of the two techniques is based on response time and harmonic distortion ratio (THD). The results show that the SRF theory is significantly more accurate and dynamic with the use of high pass filters than the low pass filter adapted in our studied system it means the choice of pass filters in the SRF control should be taken in consideration to have better results of power quality. Simulation results in MATLAB Simulink demonstrate the effectiveness of our choice of high pass filter in improving power quality of the system using SRF theory.

This paper aims to improve the control performance of VSI-based distributed generation (DG) units in an islanded microgrid (IMG) under line impedance mismatches, focusing on power sharing, power decoupling, power oscillation reduction, and circulating current eliminations, all while utilizing a decentralized method. The traditional droop control method (TDCM), with well-established inner voltage and current controllers, can work effectively under ideal IMG. However, the existence of mismatches in line impedances tends to worsen its performance. In this context, a virtual complex impedance-based droop control method is proposed in this paper for three VSI-based DG units in an IMG. To examine and validate the performance of the proposed virtual complex impedance (VCI)based droop control method (DCM) used for controlling the three VSI-based DG units of the IMG, simulations using MATLAB/Simulink are performed. The results demonstrate that the proposed method can significantly enhance the control performance of the IMG. The system shares the active and reactive powers equally, with few oscillations. It also gets rid of the three DG units’ reactive power errors and mitigates the circulating currents.

Due to its good reliability, high modularity, zero-sequence current (ZSC) path, and lower size and cost, the parallel four-leg source voltage inverter’s topology is a perfect choice for many power
applications, including renewable power generation-based stand-alone power-supply systems (SAPSSs). However, the major concern associated with this topology is the presence of a zero-sequence circulating
current (ZSCC) that circulates between the phase legs of these inverters when the inverters operate under unbalanced current sharing or unbalanced output-filter parameters, which leads to multiple consequences,
including output current distortion, power losses, and system stability degradation, as well as impacting the efficiency, reliability, and operational lifespan of the system. The ZSCC model demonstrates that the
ZSCC amplitude is linked to the filter inductance and difference between zero-sequence duty ratios or zero-sequence voltages (ZSVs). Considering these facts, we propose a new modified three-dimensional
space vector pulse width modulation (3DSVPWM) methodology to suppress ZSCC and its effects on the current quality, efficiency, reliability, and operational lifespan of the parallel system. The suggested strategy
aims to eliminate the difference between ZSVs by adjusting the zero-vector duty ratios in each switching period. This adjustment keeps the ZSCC constant at zero with minimal oscillations and switching losses,
thereby improving the output current quality, particularly in mitigating the 3rd harmonic and its multiples, and enhancing the system’s efficiency, reliability, and operational lifespan. The proposed method offers the
advantages of being suitable for suppressing both the ZSCC and ZSC and not impacting the control purposes or the system’s output quality. The efficiency and performance of the designed method are validated through various Hardware-in-the-loop (HIL) tests under different conditions using the OPAL-RT-OP5700 real-time simulator.

Generally, wind farms are built in areas far away from demand centres and utility grids. Due to its benefits, the doubly-fed induction generator (DFIG) is currently the most widely used topology in wind energy conversion systems. Therefore, long transmission lines connect wind farms with the power grid, exposing DFIGs to severe grid faults. For these reasons, this work presents an efficient control method that uses the nonlinear integral backstepping control (IBC) technique of the DFIG to stabilize and improve the transfer power capacity of the system during several faults. Hence, the grid's voltage and current, rotor side converter (RSC) and grid side converter (GSC) currents controllers, dc-link voltage, and active and reactive powers are presented through Matlab/Simulink environment to prove the effectiveness of the suggested integral backstepping technique compared to the Proportional-Integral controller, specifically in terms of disturbance rejection, steady-state performance and dynamic response, stability and robustness against parametric variations.

This research introduces a new integral robust nonlinear backstepping command (IRNBC) approach for man-
aging a photovoltaic (PV) system connected to a distributed power resource (PV-DPR) grid. The control method
employs a direct power command (DPC) with space vector pulse width modulation (SVPWM) to command the
multifunctional voltage source inverter (MVSI), which links the PV-DPR to the grid. The DPC-IRNBC technique
was used to reduce overshoot and enhance performance across all control loops of the PV-DPR grid connection.
Both the DC-DC boost converter-based PV-DPR and the MVSI controllers are utilized to simultaneously regulate
the maximum power point (MPP) of the PV-DPR and ensure grid energy quality. Initially, the proposed approach
focuses on the MPPT, current, and DC voltage command loops of the PV-DPR to maintain a consistent DC voltage
at the desired level. This control aids in generating a reference current that facilitates efficient extraction and
continuous utilization of MPP from the PV-DPR. Subsequently, the strategy is extended to manage the energies
exchanged with the grid, along with the control of MVSI capacitor voltage. This comprehensive approach gua-
rantees precise power management and utilization, even for nonlinear loads, while maintaining high grid quality
in terms of harmonics, energy factor, overshoot, robustness, and response time. To validate the efficiency of the
designed IRNBC-based PV-DPR grid connection, extensive simulation tests were conducted using Matlab with
Sim Power Systems and S-Function. These tests involved a careful comparison with classical controllers, eval-
uating aspects such as success, performance, robustness, effectiveness, and the controller’s ability to respond
under varying irradiation conditions and nonlinear load imbalances.

This paper proposes a low computational complexity enhanced voltage-oriented control strategy (EVOC) based on robust backstepping controllers (BSC) in the synchronous rotating frame (dq0 frame) for a PWM four-leg voltage-source-rectifier (FLVSR). Unlike traditional VOC strategies, the suggested EVOC approach does not need any synchronization method and Park transformations, and it has the similar architecture and same features as the traditional VOC when it’s synchronization loop for grid voltage phase angle detection is properly operated. In addition to controlling the FLVSR, the suggested EVOC strategy is also used to develop the model of the three phase FLVSR in the dq0 frame using the concepts of direct instantaneous power control (DPC) theory, which combine the benefits of traditional DPC and traditional VOC with less computational complexity. The robust BSC is adopted for accurate regulation of FLVSR input currents and dc bus voltage simultaneously while taking into account the FLVSR parameter uncertainties. It produces sinusoidal currents with lower ripples and has high robustness against parametric variations. It is also simple to implement and has a relatively high grid voltage disturbance rejection ability. Finally, comparisons with both the traditional VOC strategy using PI controllers (VOC-PIC) and the EVOC strategy using PI controllers (EVOC-PIC) under various conditions demonstrate the superiority and benefits of the proposed EVOC-BSC strategy.

The energy provided by the PV system is strongly influenced by climatic conditions such as solar radiation and cell temperature. A suitable DC/DC converter and robust control strategy associated with the maximum power point tracking (MPPT) algorithm are required to harvest the panel's maximum power. In this paper, four legs interleaved boost converter (FLIBC) is proposed as an interface to the MPPT algorithm and controlled using super-twisting integral sliding mode control (ST-ISMC). The FLIBC has been used to overcome the drawbacks of the conventional boost converter (CBC). The ST-ISMC is proposed to maintain the PV voltage track the reference provided by the MPPT algorithm and ensure the equal sharing of input current between legs. The controller gains have been calculated using the grey wolf optimization algorithm for better performance. The simulation results prove the excellent performance of the proposed controller over the conventional PI controller.

Voltage Source Converters-based High Voltage Direct Current (VSC-HVDC) systems are generally implemented to transmit power across long distances due to their low cost and flexibility. This paper will discuss a new simple and low-computational-burden phase-locked loop less voltage-oriented control strategy (PLL-less-VOC strategy) for controlling and synchronizing a VSC-HVDC system in a synchronous rotating frame (dq frame). The proposed method is used not only to control the VSC-HVDC but also to obtain the mathematical model of both VSCs-based HVDC systems in the dq frame using the basics of the direct instantaneous power control theory (DPC) without using PLL and Parks transformations. The proposed PLL-less-VOC strategy is equivalent to the conventional VOC strategy for steady-state stability, but it has the benefit of both conventional VOC and DPC with a low computational burden in the implementation. Furthermore, better transient stability performance is presented when no PLL and Park’s transformation exists. To derive the findings and evaluate the validity and effectiveness of the proposed new control strategy for the VSC-HVDC system under various grid states and fault scenarios to ensure its dynamic stability, experimental tests were carried out using the STM32F407 microcontroller, which demonstrated that the experimental results closely matched the theoretical predictions.

This study proposes an intelligent robust controller to improve the performance of the multifunctional grid-connected photovoltaic (PV) system using the phase-locked loop (PLL). The novelty of this research is the use of a new strategy, called super-twisting algorithm (STA) based on genetic algorithm (GA) to improve the performance of the direct power control (DPC) with PLL technique and maximum power point tracking (MPPT), where DPC-STA-GA is used to control the active power filter. This proposed nonlinear technique is used to increase the power quality of the PV system under different conditions (variation of the nonlinear load, random nature of the irradiance solar and temperature,…etc). On the other hand, the STA-GA controller is successfully applied to control the DC link voltage of the multi-functional voltage source inverter. Durability and ease of implementation are among the most prominent features of the DPC-STA-GA with PLL technique to reduce the reactive and active power ripples compared to the DPC technique. The suggested intelligent nonlinear control ensures the harmonic current compensation and the transmission of PV energy to the electric grid and or the nonlinear load with high quality. To implement and verify the proposed controls with the PLL technique, Matlab software is used for this purpose, with the study of the behavior of the proposed controls based on STA-GA controllers with the PLL compared with the DPC in different conditions. The simulation results demonstrated the contribution of the DPC-STA-GA with the PLL in improving the performance, efficiency, effectiveness, and durability of the system under normal and abnormal conditions, where the proposed control reduced overshoot value in DC bus voltage by 100% compared to proportional-integral controller. In addition to reducing the value of THD of current compared to DPC and DPC-STA by 18.82% and 43.33%, respectively, in the case of solar radiation equal 1000 W/m2.

This paper proposes an enhanced voltage-oriented control strategy (EVOC) based on super twisting sliding mode control (STSMC) for a grid-connected four-leg source voltage inverter (GC-FLVSI) in the synchronous rotating frame (dq0–frame) without using a phase-locked loop (PLL) and Park's transformation. The proposed strategy is used not only to control the dq0–axes FLVSI inject currents but also to derive the mathematical model of the GC-FLVSI in the dq0–frame based on the direct instantaneous power control theory (DPC) and to eliminate the impact of PLL and Park's transformation. The principle of the proposed EVOC strategy is analyzed in detail. The STSMC is used for accurate dq0–axes FLVSI inject current control, and it can result in sinusoidal currents with high quality, high robustness against parametric variations, and low chattering with easy implementation. Finally, the superiority of the proposed EVOC-STSMC strategy in terms of complexity, response, steady-state errors, robustness, total harmonic distortion (THDs) mitigation, neutral current reduction, and robustness against parameter variations is verified through comparative analysis with the EVOC strategy based on the PI controller (EVOC-PIC).

Due to high performance demands of grid-connected pulse-width modulation (PWM) converters in power applications, backstepping control (BSC) has drawn wide research interest for its advantages, including high
robustness against parametric variations and external disturbances. In order to guarantee these advantages while providing high static and dynamic responses, in this work, a robust BSC (RBSC) with consideration of
grid-connected PWM converter parameter uncertainties is proposed for three-phase grid-connected four-leg voltage source rectifiers (GC-FLVSR). The proposed RBSC for GC-FLVSR is composed of four independent
controllers based on the Lyabonov theory that control DC bus voltage and input currents simultaneously. As a result, unit power factor, stable DC-bus voltage, sinusoidal four-leg rectifier input currents with lower harmonics and zero-sequence (ZS), and natural currents can be accurately achieved. Furthermore, the stability and robustness against load, DC capacitor, and filter inductance variations can be tested. The effectiveness and superiority of the proposed RBSC compared to the PI control (PIC) have been validated by processor-inthe-loop (PIL) co-simulation using the STM32F407 discovery-development-board as an experimental study.

The synchronization method’s ability is one of the fundamental guarantees for the stability and accuracy of injected current control for grid-connected converter-based distribution resources. These synchronization methods, such as phase locked loop (PLL), are generally based on Park transformation and grid voltage regulation, which may affect an unstable phenomenon under distortion and unbalanced grid voltage conditions and result in more computational complexity. In this present paper, analogous to the traditional voltage-oriented control strategy (VOC) in the synchronous rotating frame (dq0-frame) based on PLL and Parks transformation, an improved voltage-oriented control strategy (IVOC) without synchronization methods and Parks transformation is proposed for grid-connected four-leg inverters (GC-FLVSI) to achieve accurate current control with high-quality performance in the dq0-frame. This proposed strategy is not only used for controlling the GC-FLVSI but also to provide the module of GC-FLVSI in the dq0-frame based on the instantaneous active and reactive powers theory (DPC). The proposed IVOC strategy has the same properties and identical performance as the traditional VOC when the grid phase angle is correctly detected by any synchronization method, with the advantages of both traditional DPC and VOC at the same time. In order to validate the superiority and excellent dynamic and steady-state performances of the proposed IVOC strategy in comparison with the traditional VOC strategy, some simulation scenarios using MATLAB/Simulink under different operations and grid conditions have been performed and presented.

Parallel three-phase pulse with modulation (PWM) rectifiers with common sc and ac buses are widely used in power systems due to their many advantages such as flexibility, sinusoidal grid currents, lower switching frequency, and good reliability. However, this topology suffers from zero-sequence circulating current (ZSCC) generated by numerous reasons including filters inductors unbalanced, unequal dead time, and losses of synchronism between the control of each rectifier, which will distort the ac-side currents and increase power losses. This paper proposes both an adjusted space vector pulse width modulated (ASVPWM) method and proportional integral quasi resonant controller (PIQRC) method not only to force the ZSCC to be zero but also to reduce its ripples, which results in low frequency harmonic components in the ac side currents. This twofold objective can be achieved by adjusting the zero-vector duty ratios of ASVPWM to suppress the ZSCC and by using PIQRC to mitigate its predominant harmonics. Finally, the superiority and efficiency of the proposed control method in terms of ZSCC suppression and current ripple reduction are verified through comparative analysis with the conventional ZSCC-PI controller.

The present paper proposes a combined voltage-oriented control and direct power control (VOC-DPC) method associated with the backstepping control technique for a three-phase four-wire grid-connected four-leg rectifier in the synchronous rotating frame without using phase locked loop (PLL) and Parks transformation under balanced and unbalanced load and grid conditions. This control method is proposed in order to remove the drawbacks of the conventional VOC based on the PLL technique .The proposed control method is able to enhance the control performance and dynamic responses of the system when considering slow dynamics and instability issues of the PLL in several cases and can decrease the computational burden due to the absence of PLL and Park transformation. In addition, the performance of the proposed VOC-DPC method is enhanced by using backstepping control (BSC) based on Lyabonov theory for both the input currents and DC-bus voltage loops. As a consequence, constant DC-bus voltage, unit power factor, sinusoidal input currents, and neutral current minimization can be accurately carried out under both DC-bus voltage and load variations. Furthermore, robustness against filter inductance variations can also be achieved. The effectiveness, superiority, and performance of the proposed control method for a four-leg rectifier based on BSC in the dq0-frame are validated by several processor-in-the-loop (PIL) co-simulation tests sing the STM32F407 discovery development board.

This study focuses on a backstepping control (BSC) of a three-phase four-leg pulse width modulation (PWM) rectifier under balanced and unbalanced load and grid conditions. The proposed BSC for the three-phase four-leg PWM rectifier (3P-4LR) connected to the grid is build up using three independent backstepping controllers based on Lyabonov theory to control simultaneously DC voltage and input currents. As a result, unit power factor, stable DC-bus voltage, sinusoidal input 3P-4LR currents with a lower harmonic content and lower zero-sequence and natural currents can be accurately achieved. Not only that, robustness against voltage grid fluctuations, load and filter inductance variations can also be carried out. The effectiveness, superiority, good dynamic, and steady-state performances of the proposed BSC based 3P-4LR have been validated by numerical simulations compared to the conventional proportional-integral control under balanced and unbalanced load and grid conditions.

Photovoltaic systems are one of the most widely used technologies for sustainable energy production due to their
various advantages, such as being clean, free, and renewable energy sources. However, the power generated by
the PV systems is strongly dependent on the atmospheric conditions. In addition, a suitable DC/DC converter
must be used with a robust controller to facilitate system operation point changes associated with the changed
climate conditions. In this paper, to deal with this challenge, a photovoltaic system based on four leg interleaved
boost converter (FLIBC) has been proposed and studied. For robustness, the presented system is controlled using
nonlinear integral backstepping control (IBSC) to track the maximum power point (MPP) and ensure an equal
sharing current among the FLIBC legs. Moreover, the particle swarm optimization algorithm is used to find the
optimum gains of the proposed IBSC. The entire system is simulated and validated using MATLAB/ Simulink
environment. The simulation results demonstrate the efficiency of the proposed system based on the optimized
IBSC (OIBSC) controller in terms of MPP tracking speed, overshoot and undershoot reduction, power ripple, and
optimization of the performance term integral time square error (ITSE).

These days, the use of power electronics equipment to transfer high voltages has a major effect on power grid stability. This research looks at how dynamic stability may be enhanced by the control of voltage source converter-based high-voltage-direct-current systems (VSC-HVDC). To regulate active and reactive power separately, the system voltages and currents are given in the synchronous reference frame (dq-frame). This paper focuses on a backstepping control technique based on the Lyapunov theory of a three-phase PWM VSC station under fault and grid constraints to ensure the proposed system's dynamic stability. Therefore, stable DC-link voltage, stable point-of-common-coupling (PCC) voltages, and sinusoidal AC side currents can be accurately realized. In addition, stability under fault and grid constraints can also be guaranteed. Through numerical simulations and comparisons with conventional proportional-integral control (PIC), the effectiveness and steady-state stability of the PWM VSC station-based HVDC using the proposed backstepping control technique have been established.

The energy provided by PV system is strongly influenced by the climatic conditions such as solar radiation and cell temperature. In order to harvest panel maximum power, a suitable DC/DC converter and robust control strategy associated with maximum power point tracking (MPPT) algorithm is required. In this paper, four legs interleaved boost converter (FLIBC) proposed as an interface to the MPPT algorithm and controlled using super-twisting integral sliding mode control (ST-ISMC). The FLIBC has been used to overcame the drawbacks of the conventional boost converter (CBC) and the ST-ISMC is proposed to maintain the PV voltage track the reference provided by the MPPT algorithm and ensure the equal sharing of input current between legs. The controller gains have been calculated using particle swarm optimization algorithm for better performance. The simulation results prove the excellent performance of the proposed controller over the conventional PI controller. The simulation is carried out using MATLAB/Simulink environment.

For medium and high-power renewable energy applications, parallel four-leg inverters are highly recommended to increase the power capability, power rating, and the efficiency of the system. However, a zero-sequence circulating current (ZSCC) will be generated by the difference between the zero sequence voltages (ZSVs) due to unequal output currents and filters inductors, as well as other factors such as different switching frequencies and dead times when the inverters are connected in parallel via common DC and AC buses. The ZSCC will seriously distort the output currents and degrade the control performance and the dynamic response of the overall parallel system. This paper proposes a modified carrier-based SPWM to eliminate the ZSCC by eliminating the difference between ZSVs through the adjustment of modulation voltages of the modified carrier-based SPWM. The proposed ZSCC suppression method can successfully achieve the ZSCC suppression even when the parallel four-leg inverters system has unbalanced output current sharing and filters inductances. The simulation results based on the parallel four-leg inverters distinctly confirm the effectiveness of the proposed ZSCC suppression method.

In this paper, a proportional integral (PI) controller tuned with particle swarm optimization (PSO) is proposed for a four-leg interleaved boost converter (FLIBC) connected to photovoltaic panels (PV). A dual closed-loop control based on a PI controller has been designed to control the PV voltage and inductors currents of the FLIBC to ensure the maximum benefit from PV and an equal share of the current between the inductors. The controller gains have been optimized using the PSO algorithm to enhance the performance of the proposed converter. The proposed work is simulated using the Matlab/Simulink environment. The FLIBC based on the PI controller optimized using the PSO algorithm shows excellent performance, such as fast response, low overshoot, and low current and voltage ripple, which is better than the classic boost converter (CBC).

This work treats an improved direct power control strategy based on space vector pulse width modulation (DPC- SVPWM) used to the three phase three-level shunt active power filter (SAPF), This is to ensure the following objectives: reduce the THD factor to a level in accordance with IEEE-519, eliminate harmonic currents created by non-linear loads, compensate the reactive power and improve performances such as robustness, stabilization, trajectory pursuit, and reduce time response and active and reactive power ripples maintaining a fixed switching frequency. Lastly, the model developed and the control strategy are validated under the environment (MATLAB/SIMULINK).

The main objective of this paper is a comparative analysis between three well-known control techniques applied to active power filters, namely backstepping, sliding mode, and PI controls. The minimization of the current harmonics caused by non-linear loads, the compensation of the reactive power, as well as, the improvement of the performances in both dynamic and steady-state are the main parameters of comparison. To determine the reference currents, a theory of instantaneous real and imaginary power was used in this study, where three techniques (backstepping, sliding mode, and PI control) were analyzed mathematically and then simulated to find the best control. By comparing the results, I have found that the backstepping control was more satisfactory.

This study proposes a robust control strategy based super twisting-sliding mode direct power control. This latter has been applied at the two-level voltage Source inverter associated with a parallel active power filter (SAPF) withe space vector pulse width modulation (DPC SVM). This strategy to ensure the following objectives: obtain low total harmonic current, robustness, stabilization, reduce response time, ripple, and maintain fixed switching frequency. Finally, a comparison between traditional PI control and ST-SMC. The performance of the proposed control, all the simulation tests are in addition carried out with conventional PI control. The obtained results have shown an evident superiority of the super-twisting controllers against the PI one, regarding the current and dc voltage tracking, during the transient and the steady-state regimes. The model has been developed and the control strategy is validated under the environment (MATLAB/SIMULINK).

This study presents a photovoltaic system consisting of a photovoltaic generator (PVG) connected to a DC-DC Boost converter, this last is coupled to a three-phase electrical network via a three-phase three-level shunt active power filter (SAPF), which is used to achieve these objectives: improve the power factor, reduce the THD factor, injecting the power supplied by the (PV) system into the non-linear load and compensating the reactive power. On the other hand, the direct power control strategy associated with the space vector modulation (DPC-SVM) applied to the three-level (NPC) shunt active power filter (SAPF), facilitates the control of the energy system supplied by the PV system and make it in synchronization with the electrical grid. Parameters of the SAPF controllers are determined by proportional-integral with anti-windup compensation of the dc-link voltage-loop and powers loop controller. The extraction of the maximum power of the PV generator is based on the super twisting second-order sliding mode controller (STC-SMC). The developed model and the control strategies are validated using Matlab/Simulink environment and the simulation results demonstrate the robustness and the feasibility of the proposed technique.

The main objective of this article is to contribute the automatic fault diagnosis of broken rotor bars in three-phase squirrel-cage induction motor using vibration analysis. In fact, two approaches are combined to do so, based on signal processing technique and artificial intelligence technique. The first technique is based on discrete wavelet transform (DWT) to detect the harmonics that characterize this fault, using the Daubechies wavelet vibration analysis according to three axes (X, Y, Z). This application permits having the approximation mode function and the details (recd). To exact choice of reconstruction details which contains the information of the broken rotor bars faults, two statistical studies based on the root mean square values (RMS) and Kurtosis shock factor calculation are carried out for each (recd). The choice of (recd) is conditioned by (RMS) and Kurtosis values as: RMSrecd1 < RMSrecd2 and Kurtosisrecd1 > Kurtosisrecd2. Experimental results showed that (recd1 and recd2) satisfied the condition set for (RMS) and Kurtosis values. At the end of first technique, a spectral envelop of recd1 is adopted to detect the broken rotor bars fault and the second technique based on artificial neural network (ANN) is used to identify the number of broken rotor bars. The characteristics of features used as input variables of ANN are the RMS of recd1 and recd2, and the Kurtosis shock factor of recd1 and recd2. The experimental results demonstrated the high efficiency of the proposed method with rotor broken bars fault classification rate of 98.66%.

Conventional direct torque control (DTC) is one of the excellent control strategies available to control the torque of
the induction machine (IM). However, the low switching frequency of the DTC causes high ripples in the flux and
torque that leads to an acoustic noise which degrades the control performances, especially at low speeds. Many
direct torque control techniques were appeared to remedy these problems by focusing specifically on the torque
and flux. In this paper, a state of the art review of various modern techniques for improving the performance of
DTC control is presented. The objective is to make a critical analysis of these methods in terms of ripples reduction,
tracking speed, switching loss, algorithm complexity and parameter sensitivity. Further, it is envisaged that the
information presented in this review paper will be a valuable gathering of information for academic and industrial
researchers.

This paper presents an improved Direct Torque Control (DTC) strategy for a Doubly Fed Induction Machine (DFIM) powered by two voltage source inverters (VSI) at two levels. This strategy is based on
the fuzzy logic controller. The main objective is to improve the performance of the system by reducing electromagnetic torque ripples and improving the currents shape by optimization of the total harmonic
distortion (THD). The hysteresis regulators and voltage vectors selection table of the conventional DTC are replaced by fuzzy logic blocks to realize fuzzy DTC control. The two control strategies are simulated
in the MATLAB/SIMULINK environment followed by a comparative analysis to validate the effectiveness of the proposed strategy. Many improvements in term of rise time, torque ripples, flux ripples and
current harmonics have been done, namely stator and rotor flux ripple and torque ripple have been reduced more than 50%, 69.2% and 47.7% respectively. The stator and rotor currents THD have been
reduced around 84.5% and 84.3% respectively

Ce document est un support de cours d'électronique de puissance avancée destiné aux étudiants de la 1ère année Master en Électromécanique de la Filière Électromécanique, qui désirent approfondir leurs connaissances dans la matière. Ce document vise particulièrement à accompagner le travail personnel de l’étudiant et de rendre le travail de l’enseignant plus efficient. Le but recherché derrière ce cours
est de simplifier les idées essentielles contenues dans ce cours et de les rendre didactique plus simples. En conséquence, l'accent sera mis sur les explications physiques, les démonstrations, et les exemples lorsqu'ils seront indispensables à la bonne compréhension des étudiants.
Dans le cadre de ce cours, nous nous intéressons principalement à la présentation du contenu de la matière d'électronique de puissance avancée en conformité avec le programme officiel. Le programme est structuré sous forme de cinq chapitres; ces chapitres permettent d'introduire de façon simple les principaux concepts de l'électronique de puissance avancés.
Le premier chapitre de ce cours sera consacré à l’étude des quatre types principaux des hacheurs, les hacheurs non réversibles série et parallèle, les hacheurs réversibles en courant, en tension, et en courant et en tension.
Le deuxième chapitre sera dédié à l’étude des techniques de génération des signaux de contrôle des convertisseurs statiques, la hystérésis, la pleine onde, la modulation de largeur d’impulsion calculée (MLI calculée), la modulation de largeur d’impulsion triangulo-sinusoïdale (MLI), et la modulation de largeur d’impulsion vectorielle (Space Vector Modulation: SVM).
Dans le troisième chapitre, nous présenterons la définition des perturbations dans le réseau électrique, les principales charges émettrices des courants harmoniques et leurs effets sur le réseau électrique, les normes concernant les perturbations harmoniques, ainsi que les solutions traditionnelles et modernes proposées pour la réduction de ces harmoniques.
Dans le quatrième chapitre, nous représenteront et étudierons les nouvelles topologies des convertisseurs statiques, les convertisseurs multiniveaux (convertisseur à diodes flottantes clampé par le neutre (NPC), convertisseurs multicellulaires série dit aussi convertisseur multiniveaux à capacités flottantes) et les convertisseurs matriciels.
Le cinquième chapitre sera consacré à l’utilisation des convertisseurs statiques dans les systèmes électriques comme les variateurs de vitesse d’un entraînement électrique, les la compensateurs de l’énergie réactive, et le filtrage actif des harmoniques des réseaux électriques.
A la fin de ce document, des références bibliographiques permettant un approfondissement général sur le thème de l’électronique de puissance avancée.

In this paper, we are interested in the study and improvement of the performances of a Doubly Fed Induction Machine (DFIM) functioning in motor mode using the strategy of Direct Control Torque (DTC) based on fuzzy logic. At first, we are focusing in the study of the functioning principle and the modeling of the DFIM. Secondly, we applied the fuzzy approach to the DTC control. Finally, the simulation results of the control are validated on the Matlab/Simulink environment followed by a detailed analysis.

Direct torque control (DTC) of Doubly Fed Induction Machine (DFIM) has large torque ripples and inconstant switching frequency, especially at low speed. This paper proposes an enhanced
DTC method based on fuzzy logic technique. In order to improve the drawbacks of this conventional DTC and overcome the robustness problems against parametric variations of the
DFIM, the switching tables and conventional PI regulator of speed are elaborated by the reasoning of fuzzy logic. A very detailed analysis of simulation results of the system in
Matlab/Simulink environment is performed to the regarding to speed variation, reference tracking and robustness against system parameters variations. These results show the efficiency
and robustness of this fuzzy logic controller for enhancing the performance of the DTC control of DFIM.

Shunt active power filters (SAPFs) are modern filtering technologies for source current harmonic elimination and source reactive power compensation of nonlinear loads. In the case of normally balanced source voltages, the SAPFs are controlled to eliminate a wide range of source current harmonics and compensate the source reactive power generated by non-linear loads to provide source current functions with maximum power factor. However, if source voltages are unbalanced and/or distorted, these control objectives cannot be achieved, which impacts the SAPFs performances. In the present paper, we propose a new modification to extend the stable dynamic range and to enhance the transient response of a classical phase locked loop (CPLL). An enhanced phase locked loop (EPLL) based on a self tuning filter (STF) and fuzzy logic control
(FLC) associated with SRF theory are used in four leg shunt active power filter control under unbalanced source voltages and nonlinear loads. The aim is to enable the SAPFs to reach a higher compensation level of reactive power and current harmonics for all cases of source voltages and nonlinear loads for the limits specified in IEEE Std. 519. The success, robustness, and effectiveness of proposed control circuits are demonstrated through simulation, using Sim Power Systems and S-Function of MATLAB/SIMULINK.

In this article, we are interested in the comparative study between two control techniques of the doubly fed induction machine (DFIM) functioning in motor mode, these two control approaches are: the field oriented control (FOC) and the direct torque control (DTC). At the beginning, we focused on the study of the principle of operation and the modeling of the DFIM. Secondly, we studied and realized the implementation of commands on the Matlab/Simulink environment. Finally, the simulation results of the studied controls are presented, analyzed and compared.

The present paper describes the direct torque sensor less speed control of induction motor fed by three-level voltage source inverter. Inverter switches control is based on fuzzy logic control. Compared to conventional direct torque control (DTC), hysteresis controllers, flux position and voltage vector selection table are replaced by fuzzy logic blocks to realize a DTC-fuzzy control. The obtained results have showed high speed performance, reduced torque and flux fluctuations when the proposed DTC-fuzzy strategy is used for the control of three-level voltage source inverter associated with induction machine.

In HVDC (High Voltage Direct Current) systems the converters produce current harmonics that inject into the DC transmission lines and the AC grid. Passive filters and Active filter have been used to reduce
the harmful effects of the harmonic currents. In this paper the current harmonics can be compensated by using the Hybrid Filter that consists of a shunt active power filter (SAPF) connected with passive filter. The control strategy adopted use synchronous reference frame (SRF) theory. The reference current can be calculated by dq transformation. An improved generalized integrator control was proposed to improve the performance of SAPF. These topologies are applied in 12-pulse HVDC Converter (345 kV) for reactive power compensation and harmonic currents suppression generated by nonlinear loads. The simulation model is developed and performed using MATLAB-Simulink and SimPowerSystem Toolbox.

The present paper is focused on Direct Torque Control (DTC) Speed Sensorless of a double stator asynchronous machine (DSAM) fed by three-level six-phase inverter. The inverter switches control is based on Space Vector Modulation technique optimized by Artificial Neuronal Network (SVM-ANN). Compared to the conventional DTC technique, voltage vectors selection table is replaced by space vector modulation technique to realize a DTC-SVM speed sensorless control. Moreover, to validate the proposed control technique several tests were conducted by computer simulations. The obtained results have showed high speed performances and a reduction in torque and flux fluctuations compared to other techniques (DTC and DTC-SVM) when the proposed DTC-SVM-ANN control technique is applied to control a double stator asynchronous machine fed by a three-level six-phase inverter.

This paper presents an analysis by which the dynamic performances of a permanent magnet brushless DC (PMBLDC) motor is controlled through a hysteresis current loop and an outer speed loop with different controllers. The dynamics of the photovoltaic pumping drive system with sliding mode speed controllers are presented. The proposed structure is comprised of a photovoltaic generator associated to a DC-DC converter controlled by fuzzy logic to ensure maximum power point tracking. The PWM signals are generated by the interaction of the motor speed closed-loop system and the current hysteresis. The motor reference current is compared with the motor speed feedback signal. The considered model has been implemented in the Matlab /Simpower environment. The results show the effectiveness of the proposed method in increasing the performance of the water pumping system.

This paper presents a Distribution Static Compensator based on Four Leg Voltage Source Inverter (4-leg VSIDSTATCOM) with controlling by Synchronous Reference Frame theory (SRF) in the dq0 frame with Enhanced Phase Locked Loop based on Self-Tuning Filter (EPLL-STF) used for compensating four-wire distribution systems. The proposed 4-leg VSI DSTATCOM is used for load balancing, source harmonics filtering, reactive power compensation and power factor correction, and source neutral wire current compensation at the point of common coupling (PCC) in the four-wire distribution network under unbalanced linear loads and nonlinear load variation with various source and PCC voltages conditions. The new SRF theory with EPLL based on STF is used for harmonics current extraction and good estimation of PCC voltages without harmonics under unbalanced PCC voltages and loads. Three dimensional space vector modulation (3D SVM) is used to generate the gate switching pulses for the 4-leg VSI and to circumvent the problems of the switching frequency variant, and for DC bus voltage capacitor and compensating 4-leg VSI DSTATCOM currents we are going to use the PI controller (Proportional-Integral).
The effectiveness of the proposed 4-leg DSTATCOM under unbalanced PCC voltages and loads with various control strategies are demonstrated through simulation using sim-power-system and S-Function integrated in Matlab/simulink.

In this paper is proposed a new balancing three-level three dimensional space vector modulation (B3L3DSVM) strategy which uses a redundant voltage vectors to realize precise control and high-performance
for a three phase three-level four-leg neutral point clamped (NPC) inverter based Shunt Active Power Filter (SAPF) for eliminate the source currents harmonics, reduce the magnitude of neutral wire current
(eliminate the zero-sequence current produced by single-phase nonlinear loads), and to compensate the reactive power in the three-phase four-wire electrical networks. This strategy is proposed in order to
gate switching pulses generation, dc bus voltage capacitors balancing (conserve equal voltage of the two dc bus capacitors), and to switching frequency reduced and fixed of inverter switches in same times. A
Nonlinear Back Stepping Controllers (NBSC) are used for regulated the dc bus voltage capacitors and the SAPF injected currents to robustness, stabilizing the system and to improve the response and to eliminate
the overshoot and undershoot of traditional PI (Proportional-Integral). Conventional three-level three dimensional space vector modulation (C3L-3DSVM) and B3L-3DSVM are calculated and compared in
terms of error between the two dc bus voltage capacitors, SAPF output voltages and THDv, THDi of source currents, magnitude of source neutral wire current, and the reactive power compensation under unbalanced single phase nonlinear loads. The success, robustness, and the effectiveness of the proposed control strategies are demonstrated through simulation using Sim Power Systems and S-Function of MATLAB/SIMULINK.

This paper presents a new Three level Three Dimensional Space Vector Modulation (Three level 3D-SVM) strategy for three level four leg Neutral Point Clamped (NPC) inverter controlling which is competent to operate in Shunt Active Power Filter (SAPF), in order to reducing the source harmonic currents and the inverter harmonic output voltages, eliminating the zero-sequence current caused by single-phase non-linear loads, reducing the switching frequency and voltage supported by the switches, and to compensate the reactive power. Simulation results of three level four leg Shunt Active Power Filter performances are presented to validate the proposed three level 3D-SVM strategy for switching signals generating

This paper presents the modelling and simulation of a three-phase four leg shunt active power filter (SAPF) using artificial neural network (ANN) based synchronous reference frame theory (SRF) in the dq0-axes for power quality improvement. It is used for harmonics and zero-sequence current elimination, and reactive power compensation under unbalanced nonlinear loads. Backstepping regulators are used to control the reference currents and the dc bus voltage of four leg inverter based SAPF to robustness, stabilizing the system and to improve the response and to reduce the overshoot and undershoot of traditional proportional-integral (PI). The success of the proposed control is demonstrated through simulation using MATLAB/SIMULINK.