Adjustable Speed Induction Motor Drive Fed by 13-Level Cascaded Inverter and 54-Pulse Converter

Abstract

In this article, a 13-level asymmetric configured cascaded H-bridge (CHB) inverter is used with a 54-pulse ac–dc converter to feed a medium voltage indication motor (IM). A thorough analysis is carried out to design an isolated multiwinding transformer (MWT) based 54-pulse converter. Accordingly, the main aim of this converter is to extract the power from the grid as per the power quality standard. Moreover, a higher number of voltage levels in CHB inverter are used to adhere the power quality due to asymmetric dc supplies, having a 1:2:3 voltage ratio. Hence, a 13-level CHB-MLI is implemented with nine dc voltage sources. The converters of this drive system ensure that the quality of the grid currents and drive currents are excellent and meet the IEEE 519 power quality successfully. A nearest-level control technique is implemented to generate the switching logic for a 13-level CHB- CHB inverter. Simulated results demonstrate the performance of a 298.4 kW induction motor drive in steady-state and dynamic state. A validation study is conducted on an experimental setup with a 7.5 kW IM at steady and dynamic states. Test results show a good agreement in terms of total harmonics distortions, power loss, and efficiency.