The multilevel inverters (MLIs) are capable of handling large quantities of power and generating high-quality output voltages. Consequently, the size of the filters is reduced, and the circuitry is simplified. As a result, they have a diverse range of uses in the industrial sector, especially in smart grids. The input voltage boosting feature is required to utilize the MLI with renewable energy. In addition, a large number of components are required to attain higher output voltage levels, which increases the cost of the circuit and weight. A variety of MLI topologies have been identified to reduce losses, device quantity, and device ratings. The selective harmonic elimination (SHE) approaches reduce distinct lower order harmonics by computing the ideal switching angles. This research presents a nine–level Packed E–Cell (PEC–9) inverter that uses selective harmonic elimination to eliminate total harmonic distortion. In order to calculate the best switching angle, the reptile search algorithm (RSA) is implemented in this paper, a nature–inspired metaheuristic algorithm inspired by the hunting behavior of the crocodile. The hunting behavior of crocodiles is implemented in two main steps: the first is encircling, which is accomplished by belly walking or high walking, and the second is hunting, which is accomplished by hunting cooperation or hunting coordination. In this technique, nonlinear transcendental equations have been solved. The simulation was run in the MATLAB R2021b software environment. The simulation results suggest that the RSA outperforms the other metaheuristic algorithms. Furthermore, the simulation result was validated on a hardware setup using DSP–TMS320F28379D in the laboratory.

https://www.mdpi.com/2227-9717/10/8/1615/pdf?version=1660632189

Reptile Search Algorithm (RSA)-Based Selective Harmonic Elimination Technique in Packed E-Cell (PEC-9) Inverter

In this article, a new 7-level boost Multilevel Inverter (MLI) is explained. It involves the use of self-balanced switched capacitors. Compared to other inverter topologies, it has less number of switching components. Moreover, the power switches have low stress which adds to the distinct features of the proposed MLI. The simulation analysis along with the experimental verification has been done in order to test the proposed circuit in different conditions. MATLAB software is used for doing simulation whereas the experimental results have been taken by using a laboratory prototype. Along with this, the loss analysis of the proposed MLI has been done, which comprises of the details of the losses occurring in the power electronic switches. The results of the loss analysis has been presented and explained in the paper. PLECS software is used for carrying out the power loss analysis. The high frequency level-shifted pulse width modulation (PWM) technique has been used for generating switching signals. A comparative study has been provided to understand the superiority of the MLI discussed in this paper. 

Self-Balanced Switched Capacitor Based 7-Level Multilevel Inverter with Triple Voltage Gain and Reduced Switching Components

In this article, a new 7-level boost Multilevel Inverter (MLI) is explained. It involves the use of self-balanced switched capacitors. Compared to other inverter topologies, it has less number of switching components. Moreover, the power switches have low stress which adds to the distinct features of the proposed MLI. The simulation analysis along with the experimental verification has been done in order to test the proposed circuit in different conditions. MATLAB software is used for doing simulation whereas the experimental results have been taken by using a laboratory prototype. Along with this, the loss analysis of the proposed MLI has been done, which comprises of the details of the losses occurring in the power electronic switches. The results of the loss analysis has been presented and explained in the paper. PLECS software is used for carrying out the power loss analysis. The high frequency level-shifted pulse width modulation (PWM) technique has been used for generating switching signals. A comparative study has been provided to understand the superiority of the MLI discussed in this paper.

This paper describes a new symmetrical five-level DC-AC multi-level inverter (MLI) with double boost capability and a single DC input source based on a switching capacitor. It can be employed in modern industrial applications with intermittent input sources like low voltage fuel cells, PV cells, etc. Two H-bridge inverters and an auxiliary bidirectional switch are used in the proposed multi-level output boost (MLBO) converter to provide symmetrical DC-link output voltage, which is then transformed into AC. The proposed topology's operation is demonstrated using a single five-level boost inverter, as well as the devised control method. The suggested MLBO is validated by simulating it in MATLAB/Simulink environment. The simulation results show the effectiveness of the proposed structure. 

Single Input Source-based Boost Type Multilevel Inverter Topology

Energy has become an integral part of our life. The fossil fuel present in the environment is very much limited. On the other hand, fossil fuel emits harmful gases such as carbon dioxide, Chlorofluorocarbon (CFC), carbon monoxide, and others which harmed flora and fauna. Therefore, the concern for renewable energy application has become more vital due to the depletion of fossil fuels, rising global warming, and increased consumption of energy. Renewable energy aims to reduce pollution levels, enhancing the local economy and community sustainability. Solar energy is the most promising alternative energy source since it has various advantages over other renewable energy sources. The sun is an unquenchable source of energy capable of addressing all energy requirements of humankind. The solar energy concept has been around for a long time, and technological advancements will make it endure for a longer period. The PV-Effect is a mechanism that can produce an electric current when sunlight strikes the limiting layer of semiconductor materials. A photovoltaic (PV) system is a semiconductor device that produces electricity when exposed to luminosity. A PV module is made up of several solar cells that are coupled in parallel and series. This paper provides an extensive study of advancements in energy extraction techniques from a solar panel, analysing solar PV systems under diverse circumstances. PV technology is hastily evolving compared to alternative renewables, consequently leading to the Building Integrated Photovoltaics (BIPV) systems playing a significant role in the generation of electrical energy. BIPV system is a preferred choice as a building integrated solar energy storage system. It has been categorised into three subparts: Grid-connected BIPV system, BIPV system with a solar battery, and PV-Trombe wall. The BIPV mechanism simultaneously acts as a material for the envelope of the building and power extraction from. 

Recent Technological Advances in Solar Photovoltaic System and Its Applications in Building Integrated Photovoltaic System

Multilevel inverters (MLIs) are extremely influential in renewable energy systems, are used to convert DC power into AC. MLIs are more beneficial in comparison to the two-level conventional inverter in terms of lower total harmonic distortion (THD), lesser electromagnetic interference (EMI), increases the capability of fault tolerance, and are more efficient. The major aspect of this review article is to analyze the recent (MLI) topologies into two categories which are symmetric and asymmetric configuration which contains the reduced number of switches $(\mathrm{N}_{\mathrm{S}\mathrm{W}})$. currently, Researchers have an eye on the using reduced number of components in MLI topologies for lesser voltage stress and high efficiency. Performance parameters such as total standing voltage (TSV), THD, and modulation techniques are briefly discussed in this article. furthermore, the general comparison of these topologies is depicted in tabular & graphical representation based on the required number of switches, number of the gate drivers $(\mathrm{N}_{\mathrm{G}\mathrm{D}})$, Number of dc voltage sources $(\mathrm{N}_{\mathrm{D}\mathrm{C}})$, THD, and the number of level $(\mathrm{N}_{\mathrm{L}})$ that are obtained through the multilevel inverter topologies.

Rashid Ahmed Khan

Papers

Symmetrical and Asymmetrical Multilevel Inverter Topologies With Reduced Device Count: A Review