A Generalized Switched-Capacitor Multilevel Inverter Topology with Voltage Boosting Ability and Reduced Inrush Current

Abstract

This article presents a novel quadruple boost inverter (QBI) with an integrated boost stage that comprises an inductor, a capacitor, a switch, and an input source. The inductor on the input side limits the inrush current and also the capacitor charging current ripples. The QBI topology comprises a dc source, an input inductor, nine switches, three diodes, and capacitors. This produces a nine-level waveform, which reduces the need for additional filters such as inductors and capacitors. The proposed QBI is elementary, compact, and needs fewer components than existing nine levels inverter. Compared to the typical triangular carrier-based sinusoidal pulse width modulation, the newly developed parabolic level-shifted carrier has a much greater RMS value. Another advantage of the proposed topology is extension for generating higher voltage levels without increment in the blocking voltage across the switches. This makes the topology ideal for medium voltage high power applications. The output voltage has been determined in terms of selection, sizing, and expression. The proposed QBI is compared to existing similar nine-level inverters in order to assess its efficacy. The experiment is performed on a laboratory prototype to state the practical feasibility of QBI topology for the inductive load, variation in input, load, and modulation index.