A Seven-Level Single-Phase Shared Leg Toroidal Transformer Based Inverter For Grid-Connected Applications

The present paper introduces a 7-level single-phase shared leg toroidal transformer-based inverter for grid-connected applications. It uses optimal device count compared to conventional topologies such as a single DC source, eight semiconductor switches, and three toroidal transformers to get a seven-level symmetrical output voltage. Besides, the selective harmonic elimination (SHE) technique demands solving the transcendental equations, hence it becomes difficult for real-time closed-loop operation when connected to the grid. However, these transcendental equations are converted to a closed-loop control system with reduced memory size and get switching angles to achieve precise control to eliminate the required harmonics. The proposed configuration is verified using MATLAB/SIMULINK software and validated through a real-time simulator (OPAL-RT).