Modified PWM Technique for a Multi-Pulse Converter fed Multilevel Inverter Based IM Drive

This paper deals with a 36-pulse AC-DC converter fed 5-level cascaded H-bridge multilevel inverter (CHB-MLI) based induction motor drive (IMD). A new configuration of a multi winding transformer (MWT) is designed for a 36-pulse AC-DC converter at the utility end. The existing MWT for a 36-pulse AC-DC converter requires phase-shift in both primary and secondary windings. Whereas, this MWT does not require any phase-shift on the secondary side and it only requires phase-shift in primary windings. Therefore, this MWT needs less numbers of isolated winding than existing MWT. Because of it, the design and manufacturing of this MWT, are quite easy than the existing MWT. Apart from it, a modified PWM technique is used to operate a 5-level CHB-MLI in such a way that, this MLI has less power losses than the existing 5-level CHB-MLI. Therefore, this IMD has enhanced efficiency than an existing IMD. This system configuration performance is validated by simulating it in MATLAB/Simulink environment during various operating conditions of IMD.