Extendable Switched-Capacitor Multilevel Inverter With Reduced Number of Components and Self-Balancing Capacitors

Abstract

Multilevel inverters (MLIs) with self-balanced switched-capacitors (SC) have received wide recognition for increasing the reliability and efficiency of renewable energy and high-frequency power distribution systems. This article presents a new SC MLI structure using a reduced number of components. The proposed dual-source SC MLI can be extended in various ways to increase the voltage levels at the output. The SCs are self-balanced by using a suitable charging-discharging pattern, and thereby, voltage boosting is achieved. The operational analysis and features of the proposed 25-level MLI are delineated in detail. Comparative analysis with state-of-the-art MLIs in terms of the number of components, voltage stress, and cost factor demonstrate the merit of the proposed extendable SC MLIs. Extensive simulation of the proposed MLI structure is performed on the MATLAB/Simulink environment using both the low and high switching frequency control schemes. Furthermore, simulation results are validated experimentally by developing a prototype of the proposed MLI under load variations, frequency change condition, and variation in the modulation index.