A new multistep voltage generator using quartet of isolated DC sources with diminished power components

Multilevel inverters find a significant role over two-level inverters in Adjustable Speed Traction Drives (ASTD) and Renewable Energy Sources (RES) applications, due to their inherent uniqueness in producing high-quality output voltage with considerable reduction in harmonic distortion, reduced Electromagnetic Interference (EMI), and lower Total Standing Voltage (TSV) of the switching devices. Despite their benefits, classical topologies require an increased number of switching components, gate drivers, and isolated DC sources proportional to an increase in voltage levels, which makes the system more complex and increases implementation cost. To overcome the above drawbacks, a new solution is proposed in the form of a novel MLI structure that arranges a set of four isolated DC sources in an “S” shape to minimize total power components and switches in the conduction path. The proposed configuration has been modelled in MATLAB/Simulink and realized using an experimental prototype. Simulation and experimental studies on 9-, 15-, and 31-level output configurations demonstrate that the proposed topologies achieve peak efficiencies of 96.8%, 97.6%, and 99.3%, respectively, under a fixed RL load with a power factor of 0.954. These results confirm the energy-efficient performance of the system under realistic conditions. The proposed structure demonstrates substantial improvements in output performance over traditional MLIs, bringing a new avenue in MLI topology.