A new symmetric modular eleven‐level inverter using single and double source unit for low voltage applications with reduced number of switches

Abstract

AbstractThis study proposes a modular multilevel inverter for low‐voltage applications, including ac‐coupled renewables and energy storage systems. These inverters require many switches and gate drivers in their structures, which complicates the control system, reduces efficiency, and increases costs. This study introduces a new modular multilevel inverter that can produce five levels of positive voltage using only six power switches and five DC voltage sources. The basic unit is composed of a single‐ and double‐source (SDS) unit. SDS reduces the number of power electronic components, such as the insulated gate bipolar transistors, freewheeling diodes, gate driver circuits, dc voltage sources, and blocking voltage by switches. The proposed topology can boost the number of output voltage levels and decrease the number of switching devices and voltage stress using some combinations of basic submodules. The performance of the proposed 11‐level single‐phase inverter is compared with that of the conventional structures and recent symmetric topologies considering the number of switches, cost, and efficiency. The waveform quality and both the voltage and current harmonic characteristics were determined in accordance with IEEE 519–2014. Finally, an 11‐level prototype was constructed to validate the theoretical analysis, feasibility, and effectiveness of the proposed inverter.