Energy consumption has drastically increased to meet the growing demand of domestic and industrial usage needs. This has led to a significant rise in the contribution of renewable energy sources, owing to their eco-friendly nature. Solar photovoltaic (PV)-based power generation plays an important role and is growing rapidly. However, it faces challenges due to its inherently low output voltage and non-linear characteristics, which limit its efficiency and performance. These limitations necessitate the use of DC–DC converters to optimize voltage levels and ensure efficient energy transfer, making them a crucial component in PV systems. Among them, non-isolated converters were preferred due to their compact size and their ability to effectively control the output of solar PV. This article critically reviews various non-isolated DC–DC converters, such as conventional, hybrid, and high-gain converters, and analyzes their performance for optimal selection. A thorough study, including mathematical modeling and performance validation through simulation, is presented in detail. The critical discussion and comparison of the various converters will significantly help design engineers and researchers in selecting the appropriate converter for solar PV applications.

This work presents an improved structure of a single-phase muti-input multilevel inverter (MIMLI) for distributed energy resources, which is capable of producing a nine-level output in symmetric mode and 21 levels in asymmetrical mode. The topology uses four DC sources and ten switches, with four switches being bidirectional and the remaining unidirectional. The operation of the circuit is analyzed in an asymmetrical mode, and switching signals are accomplished using the Nearest Level Control (NLC) PWM technique. Depending on the value of the DC sources used, the number of levels can vary. In this work, different DC source algorithms were also proposed, and the analysis of the inverter has been carried out considering the algorithms producing the maximum number of levels. The inverter was simulated in MATLAB/Simulink under steady state and dynamic conditions, achieving a 3.89% THD in output. The thermal analysis was conducted using PLECS software 4.1.2 to assess losses and efficiency. A laboratory prototype of the proposed topology was developed and tested, confirming its performance through simulation results and proving it economically viable for medium- and high-power applications.

This paper presents an improved structure of an asymmetrical single-phase multilevel inverter topology with reduced device count. The proposed topology achieves 19 voltage levels at the output using only 12 power switches and 3 DC sources. The topology can be easily extended, resulting in a modular topology with more voltage levels at higher voltages. Moreover, the reliability analysis of the proposed converter results in a higher mean time to fault. The simulation is performed in MATLAB/Simulink, and a hardware prototype is developed to validate the circuit’s performance. A low-frequency Nearest Level Control PWM technique is implemented to generate switching signals and achieves 4.30% THD in output voltage. The PLECS software is used for power loss and efficiency analysis, resulting in a maximum efficiency of 99.08%. The proposed converter has been compared with other MLI topologies to demonstrate its superiority. The results indicate that the proposed topology has proven superior and outperformed other topologies in various parameters, making it suitable for renewable energy applications.

Multilevel inverters (MLIs) are a key solution for converting DC to AC power. In this article, an improved single-source SC-MLI topology is developed for solar PV applications. It consists of 12 unidirectional switches, 3 capacitors, and 3 diodes to provide sextuple voltage boosting with a lower cost function. Since the capacitor's voltage is self-balanced, there is no need for an additional circuit or sensors, bringing down the circuit's complexity. A simple and fundamental frequency-based control strategy, nearest-level pulse width modulation, is applied to assess the viability of the proposed topology. As a result, the proposed topology has an efficiency of over 97%, and it can generate 13 levels with a total harmonic distortion (THD) of 6.51%. Comparative analysis is performed to show the feasibility of the proposed topology which outperformed other 13-level similar topologies in terms of component count, cost factor, and boosting factor. The proposed topology's performance is evaluated under static and dynamic loads. Furthermore, the thermal analysis is performed using PLECS software to determine the efficiency of the circuit topology. Finally, the feasibility of the proposed circuit is verified for solar PV application.