Performance Analysis of the Multi-Level Boost Converter (MLBC) connected in a Photovoltaic System

The paper concentrates on a comparison between two DC/DC converters topologies, the conventional Boost and the Multi Level Boost Converter (MLBC), for connecting into PV systems. Several performance criteria are included as part of this comparison process for both converters under varying climatic conditions (irradiation and/or temperature). The DC/DC converters' function is to serve as an interface between PV generator and load. We apply MPPT (Maximum Power Point Tracking) control with duty cycle adjustment using PWM technique for extracting the highest achievable output power from PV generator. The multilevel boost converter (MLBC), which is capable of monitoring and maintaining an equal voltage on all N output levels, along with controlling the input current. MATLAB/Simulink simulation results highlight the performance of the Multi-Level Boost Converter (MLBC) converter topology, to match the GPV voltage to the load

Impact of DC filters energies on the commutation failure in HVDC CIGRE benchmark

The present work is devoted to study and simulate of the functioning of monopolar HVDC LCC system of 500 kV in the presence of an AC power grids voltage disturbance. The CIGRE HVDC LCC Benchmark was simulated using MATLAB/Simulink in presence of AC grids voltage variations: first an overvoltage in AC grid 1 and second voltage drop in AC grid 2 have been simulated. All of these simulations are done to evaluate the robustness of the CIGRE HVDC LCC benchmark against AC grids voltage variation, and to investigate the ability of HVDC link function after disappearing of the simulated variation. The results showed that the HVDC LCC system is sensitive to overvoltage higher than 15 % appearing at the rectifier level, and is sensible too to voltage drops with more than 10 % at the invert level. In these conditions, a commutation failure leading to short-circuit was observed, which interrupt the HVDC link operation, and doesn’t permit re-establishment of link function after fault disappearing. To find the reason of the commutation failure appearing, the magnetic and electrostatic energies stored in DC filter elements have been measured and analyzed. The analysis show that when the magnetic energy is greater than the electrostatic one, the commutation failure appears

On the performance of a 21-level asymmetrical multilevel voltage inverter

This paper deals with a 21-level asymmetrical voltage inverter with a reduced number of switching components and isolated DC sources. A brief description of the used multilevel inverter is provided, including the circuit configuration and control signals. A pre-calculated switching technique is implemented where the inverter performance is achieved throughout a parametric analysis (THD and fundamental component amplitude). Therewith, selected simulation results are shown to discuss the output voltage and current for different RL-loads and modulation index. The computed current and load voltage signals show a reduced THD that is varying in the permissible limits

On the contribution of A PV generation in Adrar's isolated power system

This paper aims to study and analyse a 220 kV isolated power plant of Adrar, Algeria. This power system is mainly composed of nine buses and seven PV power plants. Simulations are conducted using this power system where the irradiance, power demand and temperature variations are considered. Firstly, the effect of PV module temperature on the generated power is presented and discussed. Secondly, the load flow is analysed during 24 hours in order to evaluate the overall contribution of the PV generation, especially during rush hours. Finally, the transmitted power is also studied, showing the purpose of the related high voltage lines

Camel livestock in the Algerian Sahara under the context of climate change: Milk properties and livestock production practices

Camel livestock is an ancestral activity in Algeria; however, climate change has forced camel herders to modify their breeding practices to make them more sustainable. This study summarized livestock production practices, milk qualities, and the potential of camel livestock to preserve production ability under global warming. To collect data related to livestock farming practices, 10 camel herders were interviewed using a formal questionnaire. Then, 15 milk samples (9 samples of raw milk and 6 samples that had undergone heat treatment) were collected in the region of Oued Souf in southeastern Algeria to carry out the physicochemical and bacteriological analysis. From 1990 to 2021, results showed severe drought accompanied by a significant increase in the annual average maximum temperature with a temporal slope of 0.04 °C year−1 and a significant decline in annual precipitation with a temporal slope of −0.07 mm year−1. A socio-demographic survey revealed a low educational level for camel herders. They owned small herd of camels (6.84 ± 8.66 camels) in the transhumant and extensive system or > 150 heads in the nomadic and extensive system. The average daily milk production in the nomadic system was very low (<3 L/day); it was less important compared to that in the transhumant system (4–5 L/day), with an acceptable physicochemical quality but poor bacteriological quality.Given the susceptibility of the research area, we recorded that camel livestock and travel mobility were used as adaptation strategies to the effects of climate change. On the one hand, camel breed conservation programs can enhance biodiversity and a sustainable ecosystem. On the other side, a genetic improvement program that might boost productivity and profitability might be advantageous. Smallholders may benefit from this by receiving a fair and secure income and good working conditions, which could contribute significantly to social equity and local economies