Fuzzy Logic Controller of Five Levels Active Power Filter

AbstractThis 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

Etude de l’auto-adaptivité du filtre actif parallèle aux variations de la charge

Cet article s’intéresse à l’amélioration des performances du filtre actif parallèle pour s’adapter d’une manière automatique aux variations de la charge. Ce filtre est un onduleur de tension à MLI destiné à éliminer les harmoniques de courant générés par un pont redresseur triphasé non commandé (charge non linéaire). Pour assurer l’auto-additivité du filtre aux variations de la charge, deux schémas de régulation à base du régulateur P sont proposés, l’un pour la tension continue et l’autre pour le courant injecté. Les résultats obtenus par simulation ont montrés une amélioration des performances de ce filtre. Le taux de distorsion harmonique (THD) calculé après filtrage est inférieur à 5% et le filtre s’adapte parfaitement aux variations de la charge. Mots clés: filtre actif parallèle; harmoniques; onduleur à MLI; taux de distorsion d’harmonique; méthode p-q. The purpose of this work is to improve shunt active filter performances to cope automatically with load changes. This filter is a PWM inverter used to reduce harmonic currents generated by uncontrolled three phase bridge rectifier (non linear load). To ensure filter auto-adaptivity, two control schemes based on P controller are proposed; one for dc voltage control and the second for the injected current (active filter current) control. The obtained results by simulation have showed effectiveness and improvement in the performances of the filter. The calculated total harmonic distortion (THD) factor is less than 5% and the filter copes with load variations.Keywords: shunt active filter; harmonics; PWM inverter; total harmonic distortion; p-q theory

An Adaptive Linear Quadratic Regulator for Three-phase UPS System Powering Nonlinear Loads

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