Recent advances in multilevel inverter topologies and their command techniques for photovoltaic applications: A review

Multilevel inverters (MLIs) have become an enabling technology for photovoltaic (PV) energy conversion because of their capability to produce high-quality output voltages with reduced harmonic distortion and improved overall efficiency. However, conventional MLI constructions, including cascaded H-bridge, neutral-point-clamped, and flying-capacitor inverters, are characterized by large number of components, complex requirements for voltage balancing, and limited suitability for compact PV systems. This review examines the latest advances of reduced-component MLI constructions and their associated modulation techniques for PV applications. The study systematically evaluates representative families of converters with a greater focus on the recently published topologies. Additionally, a comparative evaluation of recent designs based on a number of important parameters including component count, voltage gain, total standing voltage (TSV), total harmonic distortion (THD), modulation strategy, and voltage boosting capability. The analysis demonstrates that no single topology simultaneously optimizes all performance criteria and highlights the trade-offs between hardware complexity, voltage gain, harmonic performance, and efficiency. The analysis provides updated design insights and practical guidance for selecting suitable MLI topologies for PV systems while identifying future research directions toward compact, high-efficiency, and reliable power conversion systems.