Abstract

This paper introduces a novel 49 Level (49-L) inverter topology designed to overcome the limitations of traditional inverters in photovoltaic (PV) renewable energy systems. This design focuses on minimizing component count and total standing voltage (TSV) at high output levels, making it versatile for various applications. The proposed inverter incorporates a modified packed H-Bridge unit and basic units to optimize component usage and reduce switch voltage stress. Mathematical formulations for calculating switching angles are provided, simplifying switching signal generation and reducing processing requirements. The 49-level inverter undergoes rigorous testing under different load conditions, with analysis emphasizing key performance metrics such as total harmonic distortion (THD), switch voltage stress, TSV, and efficiency. Its suitability for PV system integration - particularly in standalone systems - is demonstrated, highlighting its potential for renewable energy applications. The obtained results unveil that the proposed inverter achieves low THD for voltage and current, meeting IEEE 519 standards. The voltage THD is found to be at the value of 1.66% under all loads. The current THD is found to be at 1.66% under resistive load and ranges from 0.11% to 0.14% under RL loads. Moreover, the inverter's efficiency - depending on load conditions - is found to range from 96% to 98%. Additionally, the proposed inverter performs well under dynamic conditions, with smooth transitions during changes in irradiation levels and load types. Furthermore, this topology is the most cost-effective compared to other recent multilevel inverter (MLI) designs. Finally, the proposed 49-level inverter offers a promising solution for PV renewable energy systems, delivering high power quality, efficiency, and flexibility.

Key words: Multilevel inverter; PV system; Asymmetrical sources; Total harmonic distortion; Total standing voltage.