In this article, a new single-phase multilevel inverter is introduced with a reduced number of power switches and reduced voltage stress on power switches. The proposed topology consists of four input dc sources and nine semiconductor switches (eight unidirectional and one bidirectional switch). The topology can be used for asymmetrical voltage source configuration to generate seventeen voltage levels. The extended topology is constructed by a series connection of the topology circuit to produce higher voltage levels with less voltage stress on the switches without modifying the existing structure. Comparison is made with traditional and recently introduced topologies based on the number of power switches, dc sources, total blocking voltage of switches, and gate driver circuits, to prove the proposed topology's superiority. A simple nearest level modulation has been deployed as the switching scheme. Validation on the viability of the proposed topology has been carried out through simulation and hardware experimental setup.

Voltage source Multilevel Inverters (MLIs) are vital components for medium voltage and high-power applications due to their advantages like modularity and better power quality. However, the number of components used is significant. In this paper, an improved asymmetrical multilevel inverter topology is proposed producing 17-levels output voltage utilizing two dc sources. The circuit is developed to reduce the number of isolated dc-sources used without reducing output levels. The circuit utilizes six two-quadrant switches, three four-quadrant switches and four capacitors. The capacitors are self-balancing and do not require extra attention, i.e. the control system is simple for the proposed MLI. Detailed analysis of the topology under linear and non-linear loading conditions is carried out. Comparison with other similar topologies shows that the proposed topology is superior in device count, power quality, Total Standing Voltage (TSV), and cost factor. The performance of the topology is validated for different load conditions through MATLAB/Simulink environment and the prototype developed in the laboratory. Furthermore, thermal analysis of the circuit is done, and the losses are calculated via PLECS software. The topology offers a total harmonic distortion (THD) of 4.79% in the output voltage, with all the lower order harmonics being less than 5% complying with the IEEE standards.

Voltage source multilevel inverters (MLI) is widely utilized in medium and high‐power applications due to their advantages. Here, an 11‐level, asymmetrical multilevel inverter topology is proposed. The topology utilizes four unidirectional switches, three bidirectional switches along with two dc sources. The proposed configuration of switches and the concept of the dc‐link capacitor is utilized to generate eleven level output voltage. The reduced number of components such as power switches and DC sources, lower control complexity due to capacitors' self‐balancing nature, and low total standing voltage (TSV) are the critical features of the proposed topology. Moreover, a reliability assessment of the topology shows that the topology has a high mean time to fault (MTTF), which makes it robust and reliable. Matlab/Simulink environment is used to develop a simulation model of the proposed topology, while PLECS is used for the thermal modelling and analysis of the converter. A prototype is developed and tested in the laboratory to validate the performance for different loading conditions. The proposed topology can be cascaded to produce the ‘ n ’ number of levels. The critical comparison of the proposed topology shows that the proposed circuit has advantages over other compared topologies.

This paper analyses the technical and economic feasibility of using a hybrid renewable energy source for a typical telecom load in the state of Qatar. The hybrid system considered in this work consists of a solar photovoltaic with storage battery and diesel generator set. For this particular hybrid system, the meteorological data of solar irradiance in Doha city (latitude 25.15 ° North and longitude 51.33 ° East) are taken from NASA surface meteorology and solar energy websites. The solar irradiance in Doha is 5.33 kWh/m²/day on an annual average scale. The data are also taken through the study of load consumption of Qatar telecommunication hybrid power system. The system is designed and its techno-economic analysis is carried out using the Hybrid Optimization Model for Electrical Renewable software. The results show both technical and economic viability of replacing the conventional DG sets with the proposed renewable energy source.

With the increased power demand, the effort on the efficiency improvement of the existing renewable systems is also increased. One of the available options is the Solar PV-T cogeneration system. Such systems provide an alternative to utilize the extracted heat from the panel. As the electrical efficiency of the PV system mainly depends on the panel used and the power electronics converter efficiency. The panel efficiency increases with the reduction in panel temperature for particular isolation. And the reduction in power losses in the inverter can be achieved by reducing the number of device count of the inverter topology. For this, an efficient multilevel inverter (MLI) topology and nanofluid-based solar PV panel is proposed. The proposed panel uses TiO₂ Nano-fluid as the cooling agent. The prototype of the developed panel is tested in the laboratory in which a decrease in panel temperature of 18.7 °C is achieved. Performance of the panel is compared with other experimental studies available as well as with water and airflow fluid in the same environmental condition. Results show that the proposed panel can absorb 27% more heat than airflow panel, and the improvement of about 1.17% in the efficiency of the panel is achieved. An efficient and reliable inverter topology focusing on utilizing a single source is proposed. The developed circuit structure is compared with other existing seven-level topologies, and it is found that the proposed topology utilizes only one dc source with the lowest device count, thus have lower losses. Performance of the system incorporating the developed PV panel and the proposed inverter is verified through required simulation analysis. Results obtained shows that the integrated system works properly with lower converter losses and panel efficiency of 16.38%. Therefore the proposed system is efficient and very much suitable for solar PVT applications.