Implementation and Comparison of Symmetric and Asymmetric Multilevel Inverters for Dynamic Loads

This paper implements and compares a symmetric hybridized cascaded multilevel inverter and an asymmetric multilevel inverter utilizing a switched capacitor unit for 17 level inverters. The symmetric hybridized multilevel inverter topology consists of a modified H-bridge inverter, which results in an increase in the output voltage to five level from the three level by using a bi-directional switch at the midpoint of a dual-input dc source. In the proposed asymmetric multilevel inverter, dc sources are replaced with the switched capacitor unit, which in turn boosts the output voltage and produces twice the voltage levels at the loads. The proposed topology with the staircase modulation technique has been verified using MATLAB–SIMULINK, and the results are experimentally executed with prototype models, which are interfaced with dSPACE RTI 1104. The results of the proposed topologies are experimentally obtained for steady state, and the performance of the same is tested under different resistive and inductive load disturbance conditions. The results substantiate that these multilevel inverter topologies are better stabilized during load disturbance conditions with low total harmonic distortion, a lesser number of switches, and increased output voltage levels, and these topologies well suit for renewable energy applications.