An Inductorless Triple Boost 13-Level Switched Capacitor Inverter with Reduced Ripple Current

Abstract

Switched capacitor (SC) multilevel inverter (SCMLI) is a promising alternative to traditional voltage source inverters for industrial and renewable energy applications. In SCMLI, capacitors are used in a specific sequence during charging and discharging either in parallel or series with the source for level generation. During the charging period of the capacitor, a large ripple current is generated. This ripple may cause an increase in the peak current and ripple voltage of the capacitors. The reliability and life expectancy of the inverter can be severely affected by this ripple current of the capacitor. This article proposes an inductorless self-balance single-phase 13-level inverter with triple boosting capability. It aims to reduce the ripple current in both the source and capacitors by arranging the switching sequence in a particular fashion to implement a partial charging technique in the capacitors. Furthermore, it results in better efficiency and reduced current stress without the need for any source inductance or a complicated control algorithm. The performance of the proposed inverter is verified through its laboratory prototype under dynamic load conditions and varying modulation indexes. © 1986-2012 IEEE.