A Novel Asymmetric Cascaded H-Bridge Concept Using Switched Rectifier

Abstract

In this paper, a new concept is proposed for classical cascaded H-bridge (CHB) multilevel inverter (MLI) configurations. The proposed structure includes a DC-DC converter circuit (switching rectifier) that generates multiple asymmetric voltages at the input of the H-bridges. This SR circuit can generate different voltages (1V_DC and 2V_DC) at the same terminals, thus providing a compact solution to existing topologies. Multiple DC bus voltages are generated using HFL and SR, resulting in higher levels at the output compared to traditional asymmetric source configurations. Three H-bridge circuits that generate a 27-level in trinary configuration and a 15-level in binary configuration are combined with two SRs to produce a 35-level output. With an output efficiency of over 96%, the topology offers low power losses and sustainable performance, making it an energy-efficient and cost-effective alternative. The high output level and stable performance characteristics make this hybrid CHB structure suitable for renewable energy systems, electric vehicles, and general power electronics applications. A comprehensive comparison with other MLI designs in the literature is made, and the simulation results are validated with a low-power prototype.