Design and simulation of high-performance multilevelinverters for renewable energy systems

his study presents the development of single and three phase Sinusoidal Pulse Width Modulation (SPWM) inverter circuits for the control of solar panels, wind turbines, and fuel cells, employing maximum power point tracking (MPPT) for efficient energy conversion in DC-DC boost converters. The renewable sources generated outputs of 310V photovoltaic (PV), 60V wind turbine, 215V fuel celland 25.9V batteries. Proportional-integral (PI) controllers ensured high-quality sinusoidal waveforms with minimal total harmonic distortion (THD). ForRload, the single-phase THD=0.65419%, with a load voltage of 217.3617V and a load current of 3.1052A. For three-phase R loads, the THD=1.5146%, with a voltage of 218.4261V and a current of 2.1843A. Under RL load conditions, THDvo=1.5969%, THDio=1.2905%, the load voltage was 214.201V, and the load current was 2.0916A. Simulation results demonstrate the effective integration of renewable energy sources to meet energy demands and ensure a stable power supply under varying load conditions.The study further explores the design and performance of an asymmetrical 49-level cascaded inverter tailored for renewable energy applications. The inverter was tested under three configurations: per-unit voltage ratios (1:2:7:14), actual voltage ratios (40:80:280:560 V), and PVmodules. Simulation results reveal high-quality sinusoidal waveforms with minimal harmonic distortion. In the per-unit configuration, the inverter achieved VoRMS=16.9719 V, IoRMS=1.0569 A, THDvo=0.71216% and THDio=0.093319%. For actual voltage levels, VoRMS=679.0492 V, IoRMS=4.265 A, THDvo=0.71227% and THDio=0.16719%. with PV modules, VoRMS=692.7293 V, IoRMS=43.1367 A, THDvo=1.2926% and THDio=0.33963%. These findings underscore the inverter's efficiency and versatility in producing high-quality power output, making it a valuable solution for renewable energy systems and industrial applications.Finally, the study examines a design and performance aspects of a 343-level asymmetrical cascaded inverter system specially designed for renewable energy systems are presented. The inverter's operation is analyzed under three distinct configurations. The system is built based on unequal DC source (Vdc) values using the structure (1:2:7:14:49:98) to get 343-level on the output. The Vdc is set in the first case equal to 1V as a per unit, and equal to 40V as an actual voltage value (40:80:280:560:1960:3920). In the third case the DC sources are replaced with PV modules. The simulations reveal that the inverter provides improved performance in producing high quality sinusoidal output voltage and current waveforms with minimal harmonics. With the per-unit voltage case, the inverter achievesVoRMS=120.9316V, IoRMS=3.7178A, THDvo=0.32422% andTHDio=0.22506 %. While with actual voltage values, the results set an output of VoRMS=4838.7577V and IoRMS=6.7445A with THDvo=0.32414% and THDio=0.25682%. For the PV modules configuration, the inverter records VoRMS =4827.9768V and IoRMS =148.4073A with THDvo=0.90328% and THDio=0.54142%. These results show the flexibility of the inverter to deliver an enhanced power output with low harmonic distortion and the suggested inverter has significant potential for use in modern renewable energy systems and industrial applications.