Investigation of Various Levels of Cascade Multi-Level Inverter DVR for Improve Power Quality of Induction Motor Drive

This paper presents a direct torque control (DTC) of induction motor drive (IMD) using Different levels of Cascade Multilevel DVR. The DTC is one of the most excellent strategies of flux ripples control and torque of IMD. The main drawback of the DTC of IMD using conventional PI controller based SR is high torque, stator flux ripples and speed of IMD is decreasing under transient and steady state operating conditions. This drawback was eliminated using In front of DTC IM drive connected Different levels of Cascade Multilevel DVR. The main objective of this paper is to present an approach capable of performing fast torque response and harmonics reduction in DTC drive. Because of that, an efficient control strategy is applied, is needed to reduce the voltage fluctuations like sag and swell conditions and also to reduce current and voltage harmonics in the DTC drive system. In this paper, the work proposed is aimed at obtaining results exhibiting improved THD contents of 5, 7 and 9 level cascade multilevel inverters at the ac mains and reduced the Torque ripples of the DTC IMD Drive.