Investigations on Multilevel inverter topologies for medium power applications

Abstract

The high-power conversion systems have drawbacks like Increased losses, necessitate greater thermal dissipation and cooling measures, resulting in increased costs, space requirements and weight. Therefore, various industries have transitioned from low voltage (690 V) to a medium voltage level (4160 V) using multilevel inverter topologies. This voltage increase reduces the current level by a factor of six (6x), leading to a significant reduction in conduction losses and harmonic distortion and hence improved efficiency and power quality in industrial power conversion system. Current multilevel inverter topologies suffer from drawbacks such as a high number of components (both active and passive) and a high blocking voltage across the switch, resulting in low efficiency and poor power quality. This research aims to address these issues by developing a multilevel inverter for industrial power conversion systems that offers high efficiency, good power quality, and low cost. The research proposes two innovative solutions_ Firstly, a novel Single-Source Switched-Capacitor Multi-Level Inverter (S3 CMLI) is introduced, which reduces the number of components required. Secondly, a low voltage stress multilevel inverter (LVS-MLI) with reduced components is proposed. The focus of this research is to enhance efficiency, improve power quality, and minimize costs in multilevel inverters used in industrial power conversion systems. This research presents a new design for a single-source switched-capacitor multilevel inverter (S3 CMLI) that incorporates horizontal and vertical extensions. The design aims to minimize component count while achieving nine levels in the output voltages and enabling dual boosting capabilities newline