AC drives based on cascaded inverters regulated by algorithms of synchronous multi-zone PWM

Abstract

This manuscript presents short survey of specialized strategies, techniques, and algorithms of space-vector-based synchronous multi-zone pulsewidth modulation (MZ PWM), disseminated and investigated for synchronous regulation of cascaded inverters of three-phase and six-phase adjustable speed drives with open-end winding of induction motor, characterized by an increased power rating. It assures providing both synchronization and symmetry of the basic voltage waveforms in these cascaded configurations of drive systems on the base of both standard two-level voltage source inverters (VSI) and neutral-point-clamped (NPC) inverters. Examples of application of algorithms of multi-zone PWM for adjustment of two-inverter-based and four-inverter-based cascaded topologies of motor drives are presented. Modeling and simulations give a behavior of three-phase and six-phase drive installations on the base of cascaded inverters with synchronous MZ PWM.