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In this paper, a large-signal modeling technique has been developed for a three-phase, three-level Vienna rectifier operating in continuous conduction mode. The considered circuit is a fifth-order system with time-varying variables on the ac side. This model is first established in the direct abc reference frame using the state space averaging technique, then modified through an abc/dqo transform and adequate duty cycle alteration to avoid time-dependency. The system stability in a closed loop, using a multiloop PI-based control scheme, is proved by the convergence of the phase plane trajectories to the nominal point for any initial condition. These curves are drawn as ac line peak currents as a function of total output dc voltage. The different relationships governing the system inputs/outputs are verified not only for the nominal operating point, but also for a wide operation range. The accuracy of the proposed model is verified on a 1.5-kW experimental prototype controlled by the DS-1104 board of dSPACE. The converter large signal behavior is experimentally analyzed using output time domain responses toward different input variations. Significantly high accordance between the experimental results and the theoretical model, implemented with SIMULINK/Matlab, is verified.

La pollution du reseau de distribution de l'energie electrique constitue actuellement un probleme majeur en industrie. Sa presence entraine une mauvaise exploitation de l'energie electrique et risque d'endommager les appareils electriques connectes au reseau. Les convertisseurs statiques, qui sont de nature non lineaire, representent la principale source d'harmoniques. Au fil des annees, des changements ont ete apportes au niveau de leur structure et leur systeme de commande afin de reduire ces harmoniques. Le present article se propose d'etudier deux techniques de reglage lineaire par une seule boucle qui s'appliquent a un redresseur triphase a injection de courant. Ce convertisseur est caracterise par sa simplicite, son efficacite et surtout, le facteur de puissance pratiquement unitaire qu 'il presente vis-a-vis du reseau d'alimentation. Un modele dynamique du convertisseur, utilise dans la conception du systeme de reglage, est propose. Les resultats obtenus par simulation permettent de valider l'approche theorique utilisee.

In this paper, a component efficient multilevel rectifier is modeled and controlled using Model Predictive Control (MPC) technique. The recently introduced Capacitor Tied Switches (CTS) converter structure features two distinct dc-load terminals which can operate at different voltage levels while experiencing high voltage levels at the ac-side terminals. The CTS converter structure inherits attractive features from the efficiency and power quality perspectives, with excellent topology performance which was validated through different simulation scenarios.

Packed U-Cell (PUC) converter has been introduced as a 7-level converter in early 2008. Since then, different analysis and projects have been performed on, including various applications such as inverter and rectifier, linear and nonlinear voltage controllers. In this paper, authors try to do a detail review on this topology covering all aspects like topology design in single and three-phase, operation concepts, switching sequences for different multilevel voltage waveform generation, modelling and etc. It is shown that this topology can be comparable to popular multilevel converters (CHB and NPC) in terms of device counts and applications. Moreover, some performed and published works about the PUC are mentioned to show its different industrial applications and some other converter topologies derived based on the PUC. Experimental results are provided to show the good performance of PUC converter in several applications.

The non-supervised insertion of renewable energy sources into electric power networks causes fluctuations that may lead to voltage instability. The simple and coordinated secondary voltage control systems are used to avoid this instability. To obtain maximum regulation performance with optimized number of controllers, an appropriate selection of pilot buses is suggested. In this paper new algorithm is proposed to select optimal pilot buses. This method is based on the singular decomposition of the reduced Jacobian matrix with the voltage security margin index. To evaluate the efficiency of this algorithm, a comparison with the Bifurcation, Clustering with Node-Partitioning Around Medoids and the Hybrid algorithms is proposed. The simulation results show that the proposed algorithm gives optimal pilot buses according to the selection criteria (explained later in the paper).

Recently, sparse matrix converters are gaining the researchers' attention as an improved alternative to traditional matrix converters thanks to the advantages they offer by reducing their number of semi-conductor switches. Three major solutions are found in the scientific literature to increase the voltage transfer ratio limited so far to 0.86; the reverse operation of the matrix converter, the over-modulation of the matrix converter and the introduction of a Z-source network in the dc stage of the converter. In this paper, the Very Sparse Matrix Converter (VSMC) is adopted since it presents the smaller number of switches in the family of bidirectional matrix converters. It is simulated in three configurations designated to increase the voltage transfer ratio while improving the overall performances of the converter in order to facilitate its implementation in the wind conversion systems. First, the VSMC is simulated in normal operation, then in reverse operation. Second, it is simulated with the cascaded Z-source network and finally with the series Z-source network. All four configurations are compared in terms of voltage transfer ratio improvement and output voltages and currents waveforms. Then, further analysis is carried out for the cascaded and series Z-source configurations in order to compare both arrangements. The series Z-source VSMC presents better performances in terms of output current THD and Z-source components reduced constraints.

In this paper a new single-phase five-level buck-boost active rectifier is introduced called capacitor tied switches (CTS). The proposed rectifier has two independent DC outputs that can be connected to two different loads. Different switching states and the average mode of the proposed topology are analyzed to design the associated controller aims at regulating the two output DC voltages, generating five-level voltage at the input of the rectifier and finally draw unity power factor and sinusoidal current from AC grid. From AC grid view, the rectifier works in boost mode however the generated DC voltage can be split into two separate outputs which may be less than the AC peak voltage or even more leads to work in both buck and boost operation mode. Full simulation results are shown and analyzed to validate the effective operation and good dynamic performance of the proposed five-level buck-boost rectifier.

In this paper, a new cell based Modular Multilevel Converter (MMC) for AC-AC and AC-DC applications is presented. The new topology makes use of an efficient Packed U-Cells (PUC) structure to form the Multi-Cells Modular Multilevel Converters (M3C). It is a member of MMC root family, with extended operational capability covering therefore AC-AC and AC-DC modes of operation. A dynamic model of the PUC and the single phase M3C will be used along with predictive control method to validate the effectiveness of different operation modes of the converter.

The aim of this paper is to compare the performance of the single-phase shunt active power filter (SPSAPF) and the single-phase shunt hybrid power filter (SPSHPF) that adopt both an indirect current control scheme with a unipolar pulse width modulation (U-PWM) strategy. The SPSHPF topology includes, in addition to the components of the SPSAPF, a power factor correction capacitor connected in series with a transformer. The primary winding of the transformer is connected to the single-phase voltage-source inverter, which is the main part of the filter. The indirect current control technique that is implemented for both filters is based on extracting the source current reference from the distorted waveform of the load current. The U-PWM control technique is based on comparing simultaneously a triangular high frequency carrier signal with a slow-varying regulation signal and its opposite. The double comparison process results in the gate signals for the semiconductors. A laboratory prototype for each filter is built. It is demonstrated that the rating of the inverter used in the SPSHPF is three to four times lower than the one corresponding to the SPSAPF. In addition, the performance of the SPSHPF is found to be much better than that of the SPSAPF as far as the line current distortion is concerned.

This paper presents a performance evaluation of three-phase, three-switch, three-level, fixed-frequency pulse-width-modulated (PWM) rectifier, when an inductive connection is added between the DC-side capacitive mid-point and the AC-side source neutral. A new continuous-mode model that takes into account the presence of the added zero-sequence inductor is developed using the state-state averaging technique in the synchronous frame. The stability and the performance of the converter in terms of input current Total Harmonic Distortion (THD), power factor and DC voltage regulation are investigated, even for operation under unbalanced DC loads. The converter characteristics are evaluated for different values of the zero-sequence inductor in an attempt to derive useful optimized criteria for the design of the converter. The proposed study is supported by numerical simulations that are carried out a switching-functions-based model of the converter.

This paper studies the application of fuzzy logic control on a five degrees of freedom (DOF) robot arm, the Maker 100 of U.S. Robots. The elaboration of the fuzzy control laws is based on two structures of coupled rules fuzzy PID controllers. The fuzzy PID controllers are numerically simulated and the simulation results confirm the success of the fuzzy PID control in trajectory tracking problems. Seeking a performance optimization, a systematic study of the choice of tuning parameters of the controllers is done. The success of the proposed fuzzy control law is again affirmed by a comparative evaluation with respect to the computed torque control method and the direct adaptive control method, the last two controls being also numerically implemented using the same dynamic model of the robot arm.

In this paper, a new control strategy based on the pulsewidth-modulation technique is proposed and applied to an active-current-injection-based unity-power-factor three-phase ac-dc converter. The control circuit of the converter consists of a multivariable inner current regulator and an outer voltage regulator. Based on linear control techniques, the control circuit has been designed. Averaging techniques are used to derive a linear small-signal model of the converter in the frequency domain. Numerical simulations using the Power System Blockset tool of Matlab/Simulink highlight the performance of the proposed control scheme. Experimental results obtained on a 2-kW prototype validate the theoretical approach described in the paper.

Mechanical vibrations become a serious concern in drive applications when they adversely affect the dynamic performances of these applications and may end with physical deterioration of their structures. In many process applications, such perturbations must be detected and assessed in order to take the appropriate action to preserve the reliability of the operation. This paper presents a method of detection of one of the major causes of mechanical vibrations in asynchronous motor drive applications. The study, which involves linearized dynamic modeling of the asynchronous motor associated with its multi-mass load, shows the dependence of the vibrations frequencies on both the electrical and mechanical system parameters. Numerical simulations using Matlab/Simulink are performed using the set of parameters of a prototype drive system. The simulation results confirm the validity of the proposed method of detection.

In this paper, a new control method for adjusting the zero-sequence current in a three-phase four-wire Voltage-Source Inverter (VSI), used as a Shunt Active Power Filter (SAPF), is presented. Combined with the known instantaneous reactive power theory, the proposed control strategy achieves perfect compensation for harmonics and reactive power when the load currents are non-sinusoidal and severely unbalanced.

This paper proposes a DC-AC conversion system adapted to an electric vehicle with fuel cell. This conversion chain consists of a fuel cell, a unidirectional converter, an isolated bidirectional converter, an inverter, and a second voltage source. Matlab-Simulink is used in order to verify the theoretical results.

Three-level neutral point clamped (NPC) inverter topologies are becoming more and more the interest of studies, especially in grid connected systems, due to their advantages compared to other multilevel inverters. Synchronization with an AC source remains a challenge ring current injection to the grid. In order to enhance the performance and the immunity of such grid connected inverters, a sliding mode current controller based on Gao's reaching law has been designed in this paper, and then applied to a three-wire three-level NPC inverter to have a unity power factor system. A PI regulator has been also employed to deal with the split DC-capacitors voltage unbalance problem. Robustness towards external disturbances was verified through simulations using MATLAB.

AC-AC power converters are becoming essential in most of modern power systems and industrial applications. This conversion is usually done using a traditional converter which consists of a rectifier and an inverter separated by a storage component. During the last two decades, matrix converters gained the researchers attention as an alternative to traditional converters thanks to the advantages they offer. In fact, the absence of the storage component makes the converter more compact and more reliable; two advantages highly required in renewable energy applications such as wind generating systems. Furthermore, the matrix converter provides sinusoidal input and output waveforms, with minimal higher order harmonics; it has inherent bi-directional energy flow capability and operates with unity power factor. In this paper, different modulation techniques of matrix converters are presented with a special interest in the Space Vector Pulse Width Modulation (SV-PWM) that is studied in detail and simulated using Matlab/Simulink. Three different switching sequences are simulated and results are compared in terms of number of commutation per modulation period and total harmonic distortion (TDH) improvements.

Penetration of electrical sources based on renewable energies is becoming more and more significant in power transportation and distribution. Changes caused by this integration have an important impact on the network stability. This instability is avoided through the three hierarchical voltage control levels. In this paper we focus on the selection of pilot buses for the secondary level voltage control. Pilot buses are those where regulators are installed and the objective is to find the most appropriate selection that minimizes their number and maximizes the stability performance. A comparison between all existing selection algorithms is performed then an improvement is made on the most performing one. Results are validated by doing simulations on the standard IEEE 118 bus.

A Shunt Active Power Filter (SAPF) based on the multilevel flying-capacitor topology is used for a three-phase four wire power distribution networks. The compensator consists of three active legs, each having three cells, and a neutral connection at the mid-point of a DC capacitor leg. A new control method for adjusting the current zero sequence is presented in this work. Combined with the known instantaneous reactive power theory, this proposed control strategy is applied to the active filter the inverter to achieve a perfect compensation for harmonics and reactive power when the load currents are non-sinusoidal and severely unbalanced.

In this paper a novel model of the packed U-cell (PUC) inverter is derived considering the concept of single-phase multilevel converters. Based on the proposed model, a voltage balancing controller is designed to apply on the 7-level PUC inverter. The applied controller is in charge of fixing the capacitor voltage in PUC structure at a desired value to have the seven levels of the voltages at the output. The 7-level pulse width modulation (PWM) technique is used to produce the associated pulses for firing the PUC switches. The performance of the introduced controller is investigated via simulations in various conditions including changes in the load and DC bus voltage variations. The results prove the ability of the good dynamic performance and fast response of the controller in stable and unstable conditions.

The fluctuations in the power delivered to the grid remain a problem in photovoltaic grid-connected systems. Energy storage systems are proposed as a solution in order to comply with these standard power quality requirements. Due to their distinctive properties, supercapacitors can be considered as the most efficient energy storage systems available in the market today. Thus, their capability of fast charging and discharging and their high capacitance (hundred of farads) compared to the traditional ones have been the main reason of their massive integration in PV systems. This paper presents a comparison between a conventional capacitor and a supercapacitor used as DC-link in a PV grid connected system. The superiority of the supercapacitor is demonstrated through a performance evaluation based on simulation results.

This paper presents a review of modulation and control strategies for matrix converters applied to permanent magnet synchronous generator (PMSG) in wind power generation systems. Modulation techniques already discussed in scientific literature for the command of matrix converters are mostly divided into three categories: the scalar modulations, the pulse width modulations and the predictive control modulations. These modulation methods are combined with maximum power point tracking (MPPT)-based control strategies to secure and improve the performance of the overall system. Control strategies are combinations of two elementary blocs: the MPPT algorithms and the regulation approach. MPPT algorithms are crucial for the improvement of wind harvest and regulation approaches are generally based on adaptive, non-linear or linear automatic methods that are responsible for current control or field oriented control or reactive power control.

This paper presents the design and simulation of AC and DC passive power filters for a three-phase thyristor-based rectifier. On the source side, the purpose is to achieve harmonic current suppression and reactive power compensation and on the load side, to eliminate the DC voltage ripple. After a brief review of most common filtering methods, the paper emphasizes on the necessity of passive techniques for high power applications. The AC filter consists of RLC branches tuned to harmonic frequencies, while the DC filter inserted at the rectifier output includes a series inductor and shunt connected resistor and capacitor. Matlab/Simulink is the software used for building and simulating the filter models, in the two cases of DC inductive and capacitive loads. The results obtained before and after filtering demonstrate its efficiency in improving the waveforms quality on both AC and DC sides, and therefore in the optimization of power consumption.

The modular multilevel converter (MMC) is becoming one of the most promising topology in multilevel converter series especially for high-voltage and high-power applications. This valuable features, nominates MMCs to interface high-voltage and high-power renewable energy resources into modern HVDC electric grids for more penetration of renewable energy. This paper investigates recent modelling, control, and dc-fault protection techniques that have been applied to MMCs.

Silicon Power MOSFETs, with more than fifty years of development, are widely accepted and applied in power converters. Gallium Nitride (GaN) power devices are commercially available in recent years, but the device performance and application have not been fully developed. These devices include Schottky Barrier Diode (SBD) and P-I-N rectifiers,?? High Electron Mobility Transistor (HEMT), heterojunction bipolar transistors (HBT). In this paper, these GaN devices are discussed and compared with Si devices and SiC devices, which were the candidates to replace Si devices for their capacity to support high power density and high temperature environments. SiC devices high cost reduced their usage which resulted in the growth of GaN-based power switches.

This chapter presents the detailed analysis of three boost‐type pre‐regulators commonly used for power factor correction in single‐phase rectifiers: the single‐switch basic boost, the two‐switch asymmetric half‐bridge boost and the interleaved dual‐boost topology. The mathematical modeling approach is also illustrated and applied to the first two topologies. It can be systematically extended to the third one. On the basis of the obtained models, control algorithms were then developed and implemented. The reported simulation or experimental results show the effectiveness of these converters associated to their respective control systems, and validate the theoretical issues made out through the chapter.

Nowadays, the three-level neutral point clamped (3L-NPC) inverter has become more attractive among multilevel inverters topologies, especially in transformerless grid connected photovoltaic systems. Due to the unbalance between the two DC load-side capacitor voltages, the development and improvement of such topology were important topics in recent studies. New structures were derived focusing on better distribution of losses, increasing efficiency, decreasing the switching devices losses and the conduction losses. For this reason, seven derived topologies are discussed in this paper and compared among the conventional inverter. In addition, a part of this study focuses on modifying modulation techniques in order to comply with the neutral point fluctuation problem. Several carrier-based PWM and space vector modulation techniques are considered, discussed and compared.

This paper describes a Self-Organizing Map (SOM) algorithm and its use for electric network partitioning. A comparative study has shown in a previous work that the SOM algorithm gives the closest result to the ideal case. In this paper, this algorithm is improved due to the consideration of two inputs instead of one. Voltage and phase angle variations are applied as inputs. The proposed idea is tested on an IEEE 39-bus system and an IEEE 118-bus system. Simulation results show that this approach gives more coherent and tightened partitions.

The study and control of industrial electrical drive systems become a great challenge for scientists because of their complexity. In order to facilitate this task, the multi-mass model has been established recently. In fact, for certain industrial drive systems (rolling mills, compressors, etc.), it is necessary to take into consideration the non infinite rigidity of the mechanical link elements which causes mechanical vibrations. These vibrations are a major problem in industry because they harm the system dynamic performances and may end with the deterioration of the system structures. For this purpose, it is useful to dissociate the mechanical part into several masses in order to elaborate the correspondent multi-mass system. This paper presents a linearized model for complex mechanical load based on a two-mass system driven by a DC servomotor and connected together by an elastic link. The first step of the study consists of determining the appropriate transfer functions of the model. Then, linear regulation loops for velocity and load position control are elaborated using PI or PID regulators. As a final step, numerical simulations for different load torques are performed with Matlab/Simulink using the set of parameters of a drive system model. The simulation results show that the regulated system responds conveniently. Further more, these simulations are used to compare the dynamic performances of the different implemented control strategies.

This paper presents a review of the recent advances in matrix converter topologies used with the permanent magnet synchronous generator (PMSG) in wind power generation systems. Dedicated literatures introduce different topologies inspired by the conventional matrix converter. Two-stage matrix converters known as sparse matrix converters are compared to the conventional matrix converter in terms of implementation complexity, cost, power rating and voltage ratio. Single-phase matrix converters topologies are implemented in high power wind applications in two different modular concepts: the reduced matrix concept for offshore wind farms and the multi-modular high power matrix converter. On the other hand, several modulation techniques applied to the matrix converter-PMSG scheme are briefly presented.

This paper presents a practical design and implementation of a modified Sheppard-Taylor-based Power Factor Correction (PFC) circuit used for single-phase low-voltage high-current applications. The proposed converter operates in Continuous Inductor Current Mode and Discontinuous Capacitor Voltage Mode (CICM/DCVM). In this mode of operation, the PFC provides zero-voltage turn-off switching, as well as natural input power factor correction over a wide range of input voltage. Due to the simplified control circuit and reduced switch current stress that it yields, this mode of operation offers better efficiency and higher reliability than the CICM/CCVM previously reported in the literature. The performance of the proposed PFC is analyzed through experimental measurements carried out on a 500W laboratory prototype. It is shown that this rectifier exhibits high input power factor and low line current distortion at very low output voltage level.

This paper presents a classification for partitioning algorithms used in secondary voltage control of distribution power networks. Also it presents a comparative study on fifteen different algorithms based on structure dependence, initial conditions, input data types, zones isolation, repeatability, generators distribution, computation effort and fitness score. This wide comparative study has shown that Self Organizing Map algorithm is the closest to the ideal case.

This paper deals with the modeling, analysis, control and simulation of a doubly-fed induction generator (DFIG) driven by a wind turbine. This grid connected wind energy conversion system (WECS) is composed of DFIG and two back-to-back PWM voltage-source converters in the rotor circuit. A mathematical model of the machine, derived in an appropriate dq reference frame is established. The grid voltage oriented vector control is used for the grid side converter (GSC) in order to maintain a constant DC bus voltage and to compensate for reactive power at the power network. The stator voltage orientated vector control is adopted in the rotor side converter (RSC) control strategy, providing efficient handling of active and reactive power at the stator, as well as a maximum power point tracking (MPPT) method for the DFIG-based wind turbine. The proposed system is simulated for different operating conditions to illustrate the reliability of the control technique. Corresponding system simulation results under nonlinear load variations and wind speed transients are presented to demonstrate the significance of MPPT in WECS, and the effectiveness of adopted control technique.

A four leg static compensator for harmonic mitigation and reactive power compensation is proposed for an unbalanced load consisting of CFL and R-L linear loads. The converter is controlled in order to insure high power factor and neutral current compensation at the source level. In order to verify the performance of the power conversion system a digital model of the CFL is developed and implemented into the SimPower simulation platform. The obtained results show high quality performance of the converter in terms of total harmonic distortion, power factor and transient characteristics. In addition, the system response towards load variation and unbalance is tested and analyzed.

Over the last fifty years, silicon has been the predominant semiconductor in the world of power electronics. Recently a faster, tougher, and more efficient replacement of pure silicon has been introduced; it is the Silicon Carbide (SiC). Several SiC devices are being developed. These devices include Junction Barrier Schottky (JBS) and Schottky Barrier Diodes (SBD), Junction Field Effect Transistor (JFET) and Metal-Oxide-Semiconductor-Field-Effect-Transistor (MOSFET), Bipolar Junction Transistor (BJT). Each one of these devices has different characteristics, structure and properties which make them suitable for many power switching applications. Therefore, a new range of SiC-based power electronics was created.

A single-stage DC-AC Boost topology for the PV systems gives more attraction and potential on Renewable Energy Sources in the field of machine Drive. The proposed configuration not only intended to boost the usually low DC voltage of the PV source to an AC voltage source but have the ability for controlling a Permanent Magnet Synchronous Machine (PMSM). Furthermore, the proposed topology aims to reduce the power losses in system conversion, reduce its size and achieve a high energizing efficiency for the PV systems. The application of vector control to the PMSM and complete modeling, simulation and analysis of the drive system are given. The real-time models of the inverter switches and its control law are also examined.

The non-sinusoidal current absorbed by non-linear loads induces current harmonic distortion in the power grid and affect severely its power quality. More specifically, Compact Fluorescent Lamps (CFL) with no power factor correction cause low power factor and high harmonic distortion. In this paper, and after an experimental measurement, a mathematical model of a 23W compact fluorescent lamp is proposed. This model is established on the basis of experimental data and using a spectral decomposition up to 31st harmonic. After model verification through numerical simulations using Matlab, the effect of increasing the number of CFL lamps, mixed to a load consisting of televisions and refrigerators, on the power factor, total harmonic distortion, the active, reactive and distorting power is evaluated. It is demonstrated that, by increasing the nonlinear part of the load given by the CFLs, the power factor reaches its maximum for a specific combination of CFLs and the given load, and then decreases for an increasing number of CFLs, whereas the total current harmonic distortion always increases. On the contrary, by using incandescent lamps instead of CFLs, it is shown that the power factor grows continuously whereas the total harmonic distortion decreases for an increasing number of lamps.

In this paper, an overview of active power electronics devices, dedicated to the compensation of current harmonics that are generated by the proliferation of nonlinear connected to the distribution power grids, is presented. A special attention will be brought on the discussion of Power Factor Correction (PFC) circuits commonly used in single-phase applications, and single-stage active rectifiers dedicated to the three-phase case. Active and hybrid power filters will also be briefly presented. The study will focus more specifically on the current tracking ability of the considered topologies, DC voltage regulation, performance limitations, design considerations, modeling processes, control complexity, voltage stresses and power efficiency. Other derived structures for high current applications and high power efficiency will also be discussed.

In this paper, a study of a two-stage regenerative grid-connected AC-DC power module for load emulation is presented. It consists of an active rectifier connected with a dual active bridge. Both conversion stages are designed and controlled in order to ensure power factor correction at the AC side and a regulated voltage at the DC side. The development of the control system is based on the small-signal transfer functions of the converter, which are computed the average modeling technique. A 5 kW module is used as a base to design and simulate such system. The steady-state and dynamic behavior of the converter is tested under varying operating conditions, and the stability of the interconnection between the two conversion stages is discussed.

This paper proposes a three-phase current controlled power inverter for both photovoltaic (PV) power grid injection and power quality improvement. The inverter operates as a shunt active power filter (APF) to compensate the unbalances, harmonics, reactive power and supply voltage fluctuations. It supplies simultaneously the power from the PV array to the load and the grid. The PV source is connected to the active power filter by an intermediate boost dc-dc converter which is controlled using the Maximum Power Point Tracking (MPPT) technique. The MPPT controller's output determines the DC-bus voltage of the inverter according to PV maximum power. A nonlinear control scheme is proposed for the inverter in order to compensate the source voltage unbalance, the source voltage fluctuations, the current harmonics, the reactive power and the load unbalance. It avoids the use of passive filters that could affect severely the performance of the compensation system and slow down the dynamic response of the system. A bidirectional buck/boost converter is used to control the battery charging and discharging, which is essential in hybrid electrical vehicles or grid back-up sources during peak demand of energy. A combination of linear inductive load with single-phase and three-phase diode bridge rectifiers connected to DC R-L loads is considered. Simulation results that demonstrate the viability and effectiveness of the proposed configuration are presented and discussed.

This paper proposes a grid-connected Permanent Magnet Synchronous Generator (PMSG) driven by the wind turbine with harmonics, reactive power and unbalances compensation capability. The proposed wind energy conversion system consists of a PMSG coupled to a diode-bridge rectifier, a DC-to-DC converter and a three-phase four-wire inverter. The diode-bridge rectifier is used as an AC-DC converter. The DC-DC converter is used to achieve maximum Power Point Tracking (MPPT) for the wind turbine. The grid-side converter is controlled to supply extracted power from wind energy to the grid and to the loads as well as to compensate the harmonics, the reactive power and unbalances, so that the supply currents will be sinusoidal, balanced, and in phase with the supply voltages. A nonlinear control technique is proposed for the inverter. The effectiveness of the proposed variable speed wind energy conversion system is proved by simulation.

Power Factor Correction (PFC) circuits are widely used in single-phase rectifiers in order to emulate a pure resistive behavior. Several PFC topologies were introduced in the last thirty years, depending on the required source-load characteristics and system performance. This paper is dedicated to the comparative study of the most popular PFC converters, with an emphasis on their major features, their benefits and limitations in terms of performance. More specifically, the averaged model of each topology is presented, on the basis of which steady-state characteristics, current tracking ability and design criteria are elaborated and analyzed.

Current-injection rectifiers have found great interest in the Power Electronics community. This is mainly due to their high efficiency related to the reduced number of hard-switching devices, and their reliability with respect to other commonly known rectifiers. This paper presents an experimental investigation of a totally passive three-phase current injection rectifier with an emphasis on the parameters selection, the steady-state performance under rated and varying load conditions, and the system efficiency over a wide power range.

In this paper, the averaged model and linear control of a 2D KY buck-boost converter are developed. Unlike the traditional buck-boost converters, the KY converter has fast transient response, similar to the behavior of the buck converter with synchronous rectification. In addition, it has a non-pulsating output current. The KY converter operates in the Continuous Current Mode (CCM) which, not only reduces the stress on the output capacitor, but also reduces the ripple of the output voltage. Simulation results are provided to demonstrate the effectiveness of the proposed control system.

This paper presents a fuzzy feedback control system for DC voltage regulation of a phase-controlled three-phase rectifier. The controller operating range covers both the continuous conduction mode and the discontinuous conduction mode. In the latter operating region, the converter characteristics are highly nonlinear and too difficult to be modeled mathematically. For this reason, a fuzzy control design based on a heuristic representation of the process is proposed. The digital model of the controller is, first, established using the Fuzzy toolbox of Matlab/Simulink, then compiled in the OPAL RT-Lab OP4100 special device that allows real-time control. For experimental validation, the designed fuzzy controller is applied to a 3kW laboratory prototype three-phase thyristor-bridge feeding an inductive load. The tracking and regulation performances of the control system are tested, and the corresponding data are plotted.