Evaluation of Performance on 81-Level Switch-Ladder Inverter Using Minimum Components

An inverter is modeled to generate 81-level output voltage using a two-stage switch-ladder circuit. To design the source value of DC in the inverter, two different methods are identified and compared in terms of yielding more output levels with less number of circuit components. Detailed working of the inverter is studied with the switching sequence to obtain 81-level output. Comparative analysis is made with the classical inverter and some recently developed inverters. MATLAB simulation is carried out for the design, and the performance of 81-level inverter with RL load is analyzed in terms of THD. Simulation results of 81-level inverter are compared for both the algorithms, and presence of harmonic in the output voltage is found to be within the limits of IEEE standards.