A NEW TECHNIQUE APPLIED TO A FUZZY REGULATOR TO CONTROL THE SHUNT ACTIVE FILTER DC BUS VOLTAGE

Abstract

This paper presents a shunt active power filter to compensate reactive power and reduce the unwanted harmonics. A shunt active filter is realized employing three-phase voltage source inverter (VSI) bridge with common DC bus condenser. The shunt active filter acts as a current source, which is connected in parallel with a nonlinear load and controlled to generate the required compensation currents. To shorten the rise of the regulated condenser voltage, adjust the Fuzzy Logic Controller (FLC) coefficient. Regulation of condenser voltage based on Fuzzy Logic Regulator (FLC) constant coefficient may improve the transient response of voltage regulation but it has a bad impact on the THD of supply phases currents. In this paper, a method is proposed based on FLC with variable coefficient in the aim of shortening the rise time of the regulated condenser voltage and improvement the THD of supply currents. Simulation results are presented to confirm the validity of the proposed technique.