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The low harmonic distortion and reduced switching losses are the advantages of using the multilevel inverter. For this purpose, the three-level inverter is used in this paper as a three-phase four-leg shunt active power filter (SAPF). The SAPF is used to eliminate the harmonic current to compensate the reactive power current, and to balance the load currents under an unbalanced non-linear load. A fuzzy logic controller and self-tuning filters (STF) are used to control the active power filter (APF) and generate the reference current. To demonstrate the validity of the proposed control strategy, we compared it with a conventional p − q theory, under distortion voltage conditions and unbalanced non-linear load. The Matlab-Simulink toolbox is used to implement the algorithm of Fuzzy logic control. The performance of the SAPF controller is found very effective and adequate as compared with the p − q theory.

This paper discusses neural network ANN controller applied for five phase shunt active power filter. Three-phase shunt active power filters are widely studied, however in this paper we investigate to extend their application to five phase embarked electrical network. Two-level five phase inverter is used as a shunt active power filter to reduce harmonics and compensate reactive power injected by a five-phase diode rectifier. An artificial neural network controller has been used to regulate the DC side of the inverter, thereby contributing to the calculation of the reference harmonic currents on the one side and controlling the injected harmonic currents on the other. Self-tuning filter (STF) is used to calculate the reference current. By using STF allow to extract the voltage and current fundamental components in the α-β-axis directly without the use of a phase-locked loop (PLL). Simulation results shows that the ANN controller presents appreciable performances in references tracking and the proposed five-phase shunt active power filter provides a sinusoidal supply current in phase with the line voltage with low harmonic distortion.

This paper presents an interleaved boost DC-DC converter taking advantages such as low ripple current delivered by the PEMFC (Proton Exchange Membrane Fuel Cells), and the reduction of the stresses on the semiconductors since each converter carries 1/N of the current delivered by the PEMFC. Undeniably, the fuel cells are very sensitive to the high undulation currents created by power electronic converters. To improve the lifespan of PEMFCs, an interleaved boost convert is proposed in this paper in order to reduce the current undulation. Also in this paper a detailed modelisation of the DC-DC boost converter has been presented. The output voltage of the interleaved boost converter is regulated using a simple PI controller.Simulation results shows that the proposed structure of the interleaved boost converter offers good performances in reduction of the undulation of the current delivered by the PEMFC. Also the simple PI controller show good performances versus reference voltage variation, and load variation.

Since the Z-Source Inverter (ZSI) was first proposed in 2003, impedance source inverters (ISI) have experienced a rapid progress. This evolution is not limited to developing network topologies, but also involves their modulation and control techniques to improve their performance and efficiency from different aspects. Accordingly, discontinuous PWM (DZPWM) techniques gained substantial attension in the last few years due to their advantages compared with continuous modulation schemes. The aim of this paper is to study, analyse, and compare three recent DZPWM methods for the Zsource/ quasi-Z-source inverter (qZSI). The operating principal of each DZPWM technique has been presented and analyzed. Moreover, a comparative investigation based on the inductor current ripple, voltage gain, power loss, and some other factors has been carried-out. Finally, computer simulations using MATLAB/Simulink and PLECS softwares have been performed to evaluate the presented DZPWM techniques. Such a comparative analysis helps researchers and designers to choose for their ISI modulation strategy for their application.

In recent years, the impedance source network has been studied by many researchers focusing on high conversion gain power electronics. Several number of topologies have been developed. The combination of the Switched inductor cells and Z-source networks has shown its capability of achieving high voltage gains and good power conversion at low shoot through duty cycle values as compared to traditional Z-source network. This paper contributes as an overview of different Switched inductors cells combined with Z-source or quasi Z-source network. General analytical classification, main characterestics, and comparison of different topologies and their modifications, are provided in this paper. This study should be of interest for engineers and researchers when selecting their high voltage gain impedance source converter.

This paper presents a robust control scheme for shunt active power filter based on predictive direct power control with space vector modulation. The proposed control strategy solves the problem of variable switching frequency of predictive control strategy, and it offers simple and robust hardware implementation. It uses a discrete model of the system based on time domain to generate the average voltage vector, at each sampling period, with the aim of canceling the errors between the estimated active and reactive power values and their references. Concerning the DC-side voltage of the inverter, anti-windup PI controller is tuned offline using particle swarm optimization algorithm to deliver an optimal performance in DC bus voltage regulation. The overall system has been designed, simulated and validated experimentally; the obtained results in different phases demonstrate the higher performance and the better efficiency of the proposed system in terms of power quality enhancement.

In this paper, a proton exchange membrane PEM fuel cell power plant is used to improve the filtering performance of the conventional active power filter, as well as simultaneously contribute with the electric grid to supply the power to the load. The five-level inverter is used as a shunt active power filter, taking advantages of the multilevel inverter such as low harmonic distortion and reduced switching losses. It is capable of compensating power factor, current harmonics and can also make the interface between renewable energy sources and the electric grid, injecting the energy generated by PEM fuel cell to the load. The active power filter control strategy is based on the use of self tuning filters for reference current generation and a fuzzy logic current controller. The MATLAB Fuzzy Logic Toolbox is used for implementing the fuzzy logic control algorithm. The obtained results show that the PEM fuel cell contributes successfully to supply simultaneously the load with the electric grid and produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

This paper proposes a high performance control scheme for a double function grid-tied double-stage PV system. It is based on model predictive power control with space vector modulation. This strategy uses a discrete model of the system based on the time domain to generate the average voltage vector at each sampling period, with the aim of canceling the errors between the estimated active and reactive power values and their references. Also, it imposes a sinusoidal waveform of the current at the grid side, which allows active power filtering without a harmonic currents identification phase. The latter attempts to reduce the size and cost of the system as well as providing better performance. In addition, it can be implemented in a low-cost control platform due to its simplicity. A double-stage PV system is selected due to its flexibility in control, unlike single-stage strategies. Sliding mode control-based particle swarm optimization (PSO) is used to track the maximum power of the PV system. It offers high accuracy and good robustness. Concerning DC bus voltage of the inverter, the anti-windup PI controller is tuned offline using the particle swarm optimization algorithm to deliver optimal performance in DC bus voltage regulation. The overall system has been designed and validated in an experimental prototype; the obtained results in different phases demonstrate the higher performance and the better efficiency of the proposed system in terms of power quality enhancement and PV power injection.

This paper presents five-level inverter as a shunt active power filter (SAPF) to compensate reactive power and suppresses harmonics drawn from a diode rectifier supplying RL load under distorted voltage conditions. The harmonic current extraction is based on the use of self tuning filter (STF) and fuzzy logic controller employed to control harmonic current and inverter DC voltage. The aim of the present work is to obtain a perfect compensation by extracting accurate harmonic currents to improve the performances of the five-levels active power filters. The proposed scheme is validated by computer simulation using MATLAB Fuzzy Logic Toolbox in order to show the effectiveness and ability of this method. The results have demonstrated that the proposed shunt active power filter with STF and Fuzzy Logic Controller (FLC) have produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

This paper presents a control strategy applied to three-phase uninterruptible power supplies with a low switching frequency (1500 Hz). In The controller design, the gains are determined by minimizing a cost function, which reduces the tracking error and smoothes the control signal. A recursive least square estimator identifies the parameters model at different load conditions. Then the linear quadratic controller gains are adapted periodically. The output voltage is the only state variable measured. The other state variables are obtained by estimation process. Simulation results show that the proposed control strategy offers good performances for either linear and non-linear loads with low total harmonic distortions (THD) even at low frequencies making it very useful for high power applications.

This paper presents the simulation study of three phase shunt active filter connected to photovoltaic array that based on DPC approach. The proposed system has the ability to inject active power into the grid, however it improves the quality of energy by correcting the power factor and reducing harmonic currents in distribution network. This work interests in improving the control of DC side where it is proposed to use fuzzy logic controller in DC bus voltage regulation loop, this later have been developed to provide better performance compared to conventional PI controller. Otherwise, to extract the maximum power of PV system it is proposed to associate the PV panels by a DC–DC boost converter. Therefore, the control of the boost is based on sliding mode that has good accuracy on following the maximum power point. The results of simulation obviously demonstrate that the designed fuzzy logic controller can be used for improving DC bus voltage under external parameter variation.

This paper introduces a technique based on linear quadratic regulator (LQR) to control the output voltage at the load point versus load variation from a standalone proton exchange membrane (PEM) fuel cell power plant (FCPP) for a group housing use. The controller modifies the optimal gains ki by minimizing a cost function, and the phase angle of the AC output voltage to control the active and reactive power output from an FCPP to match the terminal load. The control actions are based on feedback signals from the terminal load, output voltage and fuel cell feedback current. The topology chosen for the simulation consists of a 45 kW proton exchange membrane fuel cell (PEMFC), boost type DC/DC converter, a three-phase DC/AC inverter followed by an LC filter. Simulation results show that the proposed control strategy operated at low commutation frequency (2 kHz) offers good performances versus load variations with low total harmonic distortions (THD), which is very useful for high power applications.

In this paper, a five-level inverter is used as a shunt active power filter (APF), taking advantages of the multilevel inverter such as low harmonic distortion and reduced switching losses. It is used to compensate reactive power and eliminate harmonics drawn from a thyristor rectifier feeding an inductive load (RL) under distorted voltage conditions. The APF control strategy is based on the use of self-tuning filters (STF) for reference current generation and a fuzzy logic current controller. The use of STF instead of classical extraction filters allows extracting directly the voltage and current fundamental components in the α-β axis without phase locked loop (PLL). The MATLAB fuzzy logic toolbox is used for implementing the fuzzy logic control algorithm. The obtained results show that the proposed shunt APF controller has produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

In the area of sustainable development, solar energy has shown significant potential as a renewable energy source and it considered the important one in electricity generation. This paper focuses on power quality improvement in the distribution network using three phases shunt active power filter supplied by photovoltaic system. A new control method used to eliminate harmonic currents caused by the nonlinear loads and compensate reactive power has been presented in this work. This control method has the greatest impact on the accuracy of the harmonic current and reactive power compensation it is based on direct control of power different from conventional ones (p-q theory) which are based on harmonic currents identification and current control loops. This work proposes to combine a photovoltaic generator in parallel with Boost converter via DC-link capacitor to meet better the system requirements and to inject the maximum of active power produced by photovoltaic generator to the grid. The proposed system is verified by using MATLAB/Simulink, simulation results demonstrate the effectiveness of the system where the THD of the source current is reduced from 23.15 % to 3.03% after filtering.

In this paper, a five-level inverter is used as a shunt active power filter (APF), taking advantages of the multilevel inverter such as low harmonic distortion and reduced switching losses. It is used to compensate reactive power and eliminate harmonics drawn from a diode rectifier feeding a RL load under distorted voltage conditions.

This paper deals with a robust H ∞ output feedback control strategy for a single phase Uninterruptible Power Supply (UPS). Design procedure of the control scheme is discussed. Indeed, the load is supposed unknown and the load current is considered as an external disturbance. By introducing a new error weighting filter, the proposed strategy offers good performances for both linear and nonlinear loads with low total harmonic distortions (THD), excellent voltage regulation and insensitivity to load variation. A comparison of the simulation results between the proposed strategy and a multiple feedback loop approach is presented to verify the effectiveness of our design. The results demonstrate that the proposed strategy has a significant improvement. They are proved by experiment.

This paper proposes a simplified predictive direct power control for the grid-tied quasi Z-source inverter. The proposed control implements a model predictive control structure to achieve the maximum obtainable power from the collected PV source. The power delivered to the grid is managed to compensate for the reactive power and, as needed, to ensure the grid’s stability. A predictive power model for a quasi Z-source inverter is developed in which the proposed control can operate with a fixed switching frequency without a weighting factor. The simplified space vector modulation uses the three appropriate switching vectors that are selected and applied using precalculated switching times during each switching period, in which the required switching vectors are determined only from one sector in the space vector diagram, taking all of the information of the other sectors, which leads to reducing the computational burden. Simulation results and comparative study are used to confirm the proposed control performance for the grid-tied quasi Z-source inverter capable of tracking and generating the maximum power from PV with fast-tracking dynamics, ensuring the ac voltage desired, and better tracking of the active and reactive power reference with the lowest power ripple. The grid current harmonics were tested and conformed to the IEEE-519 standard. Additionally, the proposed simplified PDPC is experimentally validated using the Hardware-in-the-Loop emulator and the C2000TM-microcontroller-LaunchPadXL TMS320F28379D kit, establishing the usability and good result of our proposed control approach in terms of requirements.