THD optimization in a 15-level asymmetric reduced switch count multilevel PV inverter using optimization algorithms

Abstract

Philosophers and industries have focused on designing multilevel inverters that use significantly fewer power switches and DC sources to achieve high power, low switching losses, and reduced harmonic output distortion for medium-voltage applications. Even so, these multilevel inverters have downsides, including the use of many electronic components, electromagnetic interference (EMI), complex driver circuits, long reverse recovery times, and voltage-balancing issues. This article introduces a modern asymmetrical multilevel inverter with fewer switches and drivers than the standard topology. The powerful analogy addresses traditional inverter topologies of a similar structure. The proposed MLI is relatively simple and easy to extend for many output levels. The proposed MLI design is implemented for 15level outputs, achieving a precise, high-quality near-sinusoidal waveform with seven switches, three DC sources, and three diodes; hence, the volume, cost, and driver circuit complexity are considerably reduced. The novelty of the proposed topology is the use of reduced ON-state semiconductor switching devices. The output of the MLI is evaluated with the parameter of total harmonic distortion (THD). To minimize the THD, optimization algorithms such as GA, PSO, WOA, and HHA were implemented at the fundamental switching PWM control method. The comparative analysis of these algorithms with respect to the proposed inverter performance is integral to this research. The efficacy of this topology enhances the integration of renewable energy sources.