A Five-level Inverter Scheme Using Single Dc Link With Reduced Number Of Floating Capacitors And Switches Or Open-end Im Drives

A Five-Level Inverter Scheme Using Single DC Link with Reduced Number of Floating Capacitors and Switches for Open-End IM Drives

Abstract—

            This paper presents a 5-Level inverter topology for Open-End Induction Motor drives (OEIM) by using a single DC source. The open stator windings of the drive are supplied with a 3-Level Flying Capacitor inverter (FC) from one end and capacitor fed 2-Level inverter from another end. The voltage ratio of the DC link to the capacitor in 2-Level inverter is maintained at 4:1 ratio to generate five level voltage output. The capacitor in 2-Level inverter is balanced by the switching redundant vector combinations from both the inverters while the floating capacitors in the 3-Level inverter are balanced by using redundant switching states. The proposed topology gives 5-level operation with less numbers of floating capacitors and power semiconductor switches compared to other existing topologies. Also, the balancing of the capacitors is independent of load power factor and modulation index. Further, the generalization Of the proposed dual inverter scheme for any n-level inverter is also included in this paper.