Hybrid Two-Stage Single PhaseTransformerless Multilevel Inverter for PV Application

This article proposes a two-stage single-phase transformer less asymmetrical multilevel inverter with a hybrid structure tailored for PV applications. The new inverter configuration improves power conversion efficiency and reduces total harmonic distortion (THD) without requiring transformers, which are bulky. The inverter produces a near-sinusoidal output by synthesizing an output waveform that resembles a staircase from multiple DC sources, with less filtering needed. The hybrid topology combines a boost converter in the first stage to boost the DC voltage of PV panels and a multilevel inverter in the second stage to produce high-quality AC output. Different pulse-width modulation (PWM) methods, such as Phase Disposition (PD), Phase Opposition Disposition (POD), and Alternate Phase Opposition Disposition (APOD), were compared in terms of THD performance. Simulation outcomes indicate that the advanced topology substantially boosts efficiency, lowers voltage stress to power switches, and increases system dependability overall.