A Switched-Capacitor Multilevel Inverter Using Series-Parallel Conversion With Reduced Components

Abstract

The switched-capacitor multilevel inverters (SC-MLIs) are the popular type of multilevel inverter. This kind of inverter topology uses the on-off states of switches to control the charging and discharging of capacitors to achieve multilevel output. Most SCMLIs make use of an H-bridge structure to change the polarity of the output voltage, which cause the switches to withstand the peak of the output voltage. The H-bridge is replaced by two half-bridges on both sides of the proposed inverters, and the maximum voltage stress (MVS) on switches in half bridge is kept within 2Vdc, as well as in the extended structure. Therefore, the voltage stress of the switches is greatly reduced. In addition, the topology has a modular structure, which makes the expansion and modulation of the topology simple, while achieving a higher voltage gain. Moreover, with the growth of output levels, the MVS of the switches in the topology remains unchanged, which has good practical application scenarios. In this study, the correctness and feasibility of the topology have been verified by experiments.