M. O. Mahmoudi

Sensorless direct torque control of five-phase induction motor drives

This paper presents a simple and novel sensorless scheme for five-phase induction motor control. The power measurement is used for speed computation. The drive is controlled using direct torque control (DTC). Speed sensorless control scheme is tested under speed variation and load changes. The control method is simulated and implemented in real time on the DS1103 board.

A new 3D-SVPWM algorithm for four-leg inverters

A new algorithm of tetrahedron determination applied to the SVPWM control of four leg inverters is presented in this work. Indeed during the last years two main families of works were existing under this subject, the first one used the αβγ frame , while, the second one used the abc frame. In this algorithm, it is proposed a new method for the determination of the reference vector location in the space of a three phase system, even though; it presents unbalance, harmonics or both of them. The calculation of the duty times is done simply using the values of 0 or 1 representing the status of the switching patterns. The use of this algorithm with the active filtering gives good operation performances, chiefly when the algorithm used for the calculation of the voltages or currents references is based on the αβγ frame. This algorithm can minimize extremely the time and the complexity of calculation since the proposed new process is simpler and faster and can be implemented easily.

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 .

Particle Swarm Optimization applied for the improvement of the PWM AC/AC choppers voltage

The main aim of this paper si the improvement of the output voltage quality of the AC/AC choppers to minimize the harmonics continents and to increase the power factor of the voltage source. Several works were done in this field using classical algorithms to fulfill the objective mentioned. In the present paper the Particle Swarm Optimization (PSO) algorithm is used to achieve the minimization of the harmonic continents of the delivered 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.

Shunt Active Power filter apparent power for design process

The main purpose of this paper is the study of the shunt active power filter (APF) compensations capability for different perturbations in three wire AC power system such as current unbalance, phase shift current and undesired harmonics generated by non linear load under balanced power system voltages. Indeed Shunt APF has been proved to be an effective solution to compensate for such disturbances. The capability of the shunt APF is determined by the maximum rate of the apparent power that can be delivered to achieve this compensation under such conditions. This study is based on the definition of the effective apparent power as defined in IEEE 1459-2000 which was proved to be suitable amount to be concerned in the design process of different devices which allows a good estimation of the shunt APF dimensions with low economic burden. The ratio of the compensation apparent power is presented to clarify the capability of the shunt APF.

The use of the Particle Swarm Optimization for the improvement of the AC/AC choppers output voltage

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.

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.

Application of SHE-PWM for seven-level inverter output voltage enhancement based on Particle Swarm Optimization

In the present work, the Selective Harmonic Elimination Pulse width Modulation SHE-PWM is used to improve the output voltage quality of the AC/AC choppers. To achieve the requirement of the SHE-PWM such as a desired fundamental magnitude and the elimination of the low order harmonics contained in the output voltage, two heuristic and evolutionary algorithms were used. The problem of the SHEPWM is presented by a constrained nonlinear objective function which has to be minimized. The main aim is the calculation of the switching angles vector solution presenting the best minimal value for the objective function. The results obtained with the present application show the effectiveness of the use of the Particle Swarm Optimization. On the other side, the application of the PSO with SHE-PWM is a promising solution which can make a great improvement with different power electronics converters.

Comparative study of the SVPWM 3-D algorithms used for fourinverters

This paper deals with the comparative study of two families of algorithms used in the SVPWM 3-D control of the four leg inverters. The aim of these algorithms is the improvement of the quality of the output voltage and the absorbed load current. On the other side, the control of the fourth leg current which presents the neutral current. This is important mainly when the load is unbalanced and is generating an important amount of harmonics components that can affect the neutral of the power source. The comparison is based on the time execution, complexity and simplicity of application and measurements.