A. Kouzou

Model Predictive Control applied for Quasi-Z-source inverter

This paper presents a Model Predictive Control (MPC) algorithm applied to a Quasi-Z-source inverter (qZSI). This control is based mainly on the measurement of the qZSI capacitor voltage and the AC load currents. These measured values are used to predict the future values of the capacitor voltage and load current. This task is based on the determination of each possible voltage vector generated by the qZSI which can ensure the tracking of the capacitor voltage and the output current references. This control is implemented under MATLAB/SIMULINK program; the obtained results are validated with real time simulation using dSPACE 1103 ControlDesk. The real time simulation results have been provided for principle validation.

Voltage quality enhancement of PWM AC Voltage controller using Particle Swarm Optimization

This paper deals with the improvement of the voltage quality of the AC/AC choppers delivered to the loads in a way to minimize the harmonics continents and to increase the power factor of the voltage source. Indeed a lot of works were done in this field using several algorithms to fulfill the objective mentioned. In the present work the Swarm Particle Optimization (PSO) algorithm is used to achieve the minimization of the harmonic continents of the deliver voltage, to improve the power factor of the voltage source and finally to increase the control range of the outer voltage .

Four wire Shunt Active Power Filter based on four-leg inverter

This paper deals with the four-leg two-level inverter used as a Shunt Active Power Filter (SAPF) to compensate the harmonics current, unbalanced currents, reactive power and neutral current in four wires power system grid connection. The control of the SAPF is based on a three-dimensional space vector pulse width modulation SVPWM which was recently proposed. This algorithm is benefiting from the advantages of the two SVPWM algorithms used in αβγ and abc coordinates which were previously presented in other papers. The strategy adopted for identifying the reference currents of the SAPF is the pq theory based on a PLL circuit, due to its easy implementation in real time, where the drawbacks of unbalanced power source voltages and the generated hidden currents are taken into account. To prove the compensation capabilities of the SAPF in ensuring sinusoidal waveforms of the source line currents, a neglected neutral current and a neglected shift phase between the line source currents and its corresponding voltages, a real-time investigation was curried out. The results obtained demonstrate the effectiveness of the four-leg SAPF under the proposed control strategy to fulfill the compensation requirement in four wire power system network.

A new switched-inductor quasi-Z-source inverter topology

This paper presents the study of a new switched-inductor quasi-Z-source inverter topology (SL-QZSI) with high boost voltage. The proposed topology is derived from the old quasi-Z-source inverters by replacing of the input side inductor by two additional inductors and three diodes. This inverter has several advantages, such as, lower component ratings, a common ground with the dc source, reduced capacitors voltage stress, reduced inductors current stress, reduced diodes current stress and simplified control strategies. On the other side, the presented topology of the switched-inductor quasi-Z-source inverter allows to avoid the problem faced in the classical topology of quasi Z-source inverters caused by the inrush current at start-up, on the same time a wide range of voltage gain can be achieved to fulfil the applications which require a large gain range, especially for motor controllers and renewable energy systems. Theoretical analysis of the proposed topology voltage boost under the maximum constant boost control methods with third harmonics injection is investigated in this paper. Where, simulation results are presented to verify the proposed concept and the theoretical analysis.

Selective Harmonics Elimination for a three-level diode clamped five-phase inverter based on Particle Swarm Optimization

In this paper Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) based on Particle Swarm Optimization is proposed for the control of a five-phase three-level NPC inverter. The aim of using this method is the enhancement of the output voltage quality. To achieve this requirement such as a desired fundamental magnitude and the elimination of a defined number of low order harmonics, the SHE-PWM is presented by the minimization of a constrained nonlinear objective function. It is based on the calculation of the switching angles vector solution representing the best minimal value for the objective function. The results obtained prove the effectiveness of the proposed method due to its simplicity and rapid convergence.

Apparent power ratio of the Shunt Active Power Filter

The main purpose of this paper is the evaluation of the shunt active power filter apparent power ratio between the apparent power generated by the source power system to the load and the compensation apparent power produced by the shunt APF to force the currents circulating toward the source to be sinusoidal and balanced. This ratio allows defining the compensations capability for different perturbations in AC power system such as current unbalance, phase shift current and undesired harmonics generated by non linear load. This capability is determined by the maximum rate of the apparent power that can be delivered. In this paper a method of evaluation of this ratio is proposed, it is based on the definition of the effective apparent power as defined in IEEE 1459-2000 which was proved to be a suitable amount to be concerned in the design process of different devices.

Current/voltage ripple minimization of DC/DC interface system for renewable energies

The main aim of the proposed paper is a study of the DC/DC buck-boost converter for interfacing with Renewable Energy systems, while overcoming the problem of voltage/current ripples. This goal can be achieved by the reduction or the elimination of low order harmonics from the output voltage spectrum. To fulfill this requirement; the heuristic evolutionary algorithm of particle swarm optimization (PSO) is used, where the Selective Harmonics Elimination (SHE) method is applied based on the minimization of an objective function. This objective function is presenting the switching angles used for the DC-DC converter which lead to the elimination of output voltage ripple and keeping its average equal to the desired value. Simulation applications are used to study the capabilities of the optimization method and the objective function is used to achieve the main goal of the present work, which is minimization of voltage/current ripples.