Abstract
AC Adjustable Speed Drives (ASD’s) are very widely used in industrial, commercial and some residential applications. They are highly sensitive to power quality issues particularly to voltage sags. A voltage Sag is defined as a momentary decrease in the rms voltage, with a duration ranging from 0.5 cycles to 0.8 cycles. The voltage sag causes frequent tripping of equipments which leads to loss of production and revenue. This paper proposes a voltage sag mitigation technique using SWISS rectifier combined with Z-source inverter. The SR is a PFC buck type AC to DC converter which provide more controlled voltage at the DC-link. This rectified DC output voltage is fed to the ZSI. The impedance network in this inverter is used to buck or boost the input voltage depending upon the boost factor. The proposed topology is simulated using MATLAB/Simulink and the simulation results are analyzed and is compared with the conventional methods.