Switched capacitor based multilevel inverter structures with minimum device count [articol]

Abstract

This research work presents two novel switched capacitor multilevel inverter (SCMLI) structures. Both the proposed structures possess self-voltage balance capability. Further, a general structure of proposed SCMLI has been developed. An extensive comparative study has been performed with recently developed multilevel inverters in different aspects. Proposed topologies require lesser components like switching devices, capacitors, diodes, power supplies as compared to recently developed multilevel inverter structures to generate specific output voltage levels. Half-height fundamental frequency switching scheme is employed for the investigation. Different losses and procedure for selecting the switched capacitor have been discussed. The effectiveness and merits of the proposed topologies have been verified by extensive simulation study in MATLAB/Simulink of a 17-level inverter structure with four basic switched capacitor units. Further, a laboratory prototype of the same has been developed and experimentally verified for R-L, L and sudden load change conditions.