నైరూప్య

SIMULATION AND COMPARISION OF SYMMETRICAL AND ASYMMETRICAL 3- PHASE H-BRIDGE MULTI LEVEL INVERTER FOR DTC INDUCTION MOTOR DRIVES

G.Pradeep Sagar, K.Roopa, M.Rajasheker Reddy

Now a days the use of multi level inverters are increasing day to day life and they playing a vital role in case of medium and high power applications due to having less harmonic content compared with classical inverters. In this paper a comparison study is made between symmetrical and asymmetrical cascaded H-bridge multi level direct torque (DTC) induction motor drive. In this case, symmetrical and asymmetrical arrangements of seven and nine-level H-bridge inverters are compared in order to find an optimum arrangement with lower switching losses and optimized output voltage quality. The simulation results shows that an asymmetrical configuration provides more voltage levels with very low distortion, using less switching devices. Moreover, torque ripples are greatly reduced.