Adjustable Speed Medium Voltage Drive Fed by A 24-Pulse AC-DC Converter and 5-Level Multi-Level Inverter

Medium voltage induction motor drives (MVIMDs) are the vital constituents of industries. Here, a less complex, compact size drive system meeting the power quality standard is developed for crucial applications of industries. This paper presents a novel structure of the multi-winding transformer (MWT) and power converter for the drive system with a focus on achieving minimum total harmonics distortion (THD) and high efficiency. Hence, a unique configuration of a 5-level cascaded multilevel inverter and a 24-pulse rectification system is designed to improve the power quality at the supply and the motor terminals of MVIMD, respectively. The simplest star-delta configurations are utilized to design a 24-pulse converter. Apart from this, less complex conventional configured three level voltage sources inverters are cascaded in way so that five level phase voltage is obtained. A modified level-shifted pulse width modulation and indirect field-oriented control (IFOC) are utilized to demonstrate the flexibility of the drive system during the steady-state and dynamic conditions. The higher pulse rectification and high number of level systems are needed to be investigated, because they comply with the stringent power quality standard defined in the IEEE-519. A prototype of the drive is developed, and the obtained simulated results and experimental response ensure the practicality of presented configuration of drive system.