A 21-Level Bipolar Single-Phase Modular Multilevel Inverter

This paper presents a module for single-phase multilevel inverter topology. The proposed module generates maximum 21-level bipolar output voltage with asymmetric sources without H-bridge. This results in reduction in filter cost and size. The module can be cascaded for high voltage applications. The same arrangement of voltage source magnitudes in first module is maintained in the remaining cascaded modules. The proposed topology is suitable for the applications like electric vehicle and emergency services like residences and hospitality industries, etc. A set of comparisons between the proposed and recently published topologies are provided to differentiate between them. The topology is simulated and verified in MATLAB/SIMULINK. A hardware prototype is developed in the laboratory for experimental confirmation with various conditions.