Journal of Renewable Energies

Design of a test bench for a small wind turbine emulator

Tarek Zine-eddine Benhacine — 2024-06-30

In this work, the authors present a small-scale wind turbine emulator that reproduces the steady-state performances of a wind turbine at various wind conditions. The proposed emulator is based on a three-phase induction machine powered by a variable-speed drive. The model of the emulated wind turbine comes from the PropID program, which permits an accurate modeling of its aerodynamic characteristics. In this study, the model of the Whisper100 wind turbine from Southwest Windpower is chosen for the test validation. The performances of the emulated Whisper100 wind turbine are examined by an experimental test bench under variable operating conditions. The theoretical results are compared with those obtained experimentally.

An efficient, intelligent PSO-P&O-PI MPPT mechanism for Photovoltaic Systems under variable climatic conditions

Layachi Zaghba — 2024-06-30

In recent years, there has been a global challenge in developing MPPT algorithms that provide maximum power efficiency. This paper deals with a novel P&O-PI MPPT mechanism where the soft computing technique called particle swarm optimization (PSO) is used to tune the PI parameters. The proposed approach was designed to improve the tracking response time of MPP with high efficiency. This MPPT is applied to two types of PV systems: tracking systems and fixed systems. The energy gain of a dual-axis tracker was compared to that of a fixed system. Simulation results were carried out in Matlab and Simulink environments to demonstrate the effectiveness of the suggested control strategy in terms of productivity, efficiency, and oscillations under different fast environmental conditions. We can see that the recommended technique shows excellent performance in terms of power overshoot, low oscillation, and response time. The PSO-P&O-PI-algorithm offers a considerable improvement in tracking efficiency of 99.90% and a time response of 0.023 s. We have demonstrated the significance of involving the sun-tracker PV system regarding produced power (acquired power) with around 25% energy gain, particularly during the less sunny hours.

Burkholderia Fungorum, A promoter biological tool for heavy metals bioresorption

Insaf Tou — 2024-06-30

In this work, we studied the effect of Burkholderia fungorum strain Bf01 bacterium on three heavy metals bioresorption: cadmium, copper and zinc. The heavy metals bacterium resistance was studied in liquid minimum standard medium, added with increasing metals concentrations. Furthermore, the Burkholderia fungorum strain Bf01 was monitored during its growth for its capacity to reduce high metals. The strain Bf01 showed high Minimal Inhibitory Concentrations about (1500 mg/L, 400 mg/L and 50 mg/L) for Cadmium, Zinc and Copper, respectively. Therefore, it was assumed that Burkholderia fungorum strain Bf01 had a high metals resistance degree especially for cadmium and it exhibited a high adsorption affinity and removal metals from bacterial suspensions. As a result, Burkholderia fungorum strain Bf01 presents an excellent biological tool for heavy metals bioresorption for its efficiency, reliability and low cost.

Performance, combustion, and emission features of a diesel engine powered by biodiesel mixture and butanol blends

Shumani Ramuhaheli — 2024-06-30

The search for permanent fossil fuel substitutes has become critical due to the declining supply of fossil fuels and the toxic pollution emitted by diesel engines. In this study, diesel engine characteristics have been investigated numerically and experimentally using diesel, biodiesel mixture from waste vegetable oil and soybean oil (BM100) and butanol blends (5%, 10%, and 15%). The experimental work was conducted on the single-cylinder diesel engine generator at different speeds (1000, 1500, 2000, and 2500 rpm) and full load conditions. A commercial Diesel-RK software was used to perform the numerical aspects of the diesel engine. The different percentages of butanol blends were added to biodiesel mixture to form biodiesel mixture-butanol blends. It was discovered that there was good agreement between the experimental and numerical results. The cylinder pressure, heat release rate, brake power, brake-specific fuel consumption, brake thermal efficiency, nitrogen oxide, carbon dioxide, and particulate matter (PM) emissions were all predicted using the numerical technique. Results showed a decrease in carbon dioxide, particulate matter, and brake power. When compared to regular diesel fuel, at maximum speed, there was a decrease in brake-specific fuel consumption and an increase in nitrogen oxide emissions.

Improving efficiency through the optimization of energy losses in an induction machine for electric vehicle propulsion

Farid Tazerart — 2024-06-30

Research into industrial electricity consumption reveals that electric motors are the main actuators accounting for overall consumption expenditure. This underlines the importance of minimizing and optimizing the consumption of these electric motors, to the benefit of industry and, above all, contributing to environmental preservation. We present a strategy for improving efficiency by optimizing energy losses in an induction machine for electric vehicle propulsion. This involves incorporating a speed controller and a flux reference trajectory generator. The proposed control strategy dynamically adjusts the flux reference in real time, with the aim of minimizing the currents consumed by the machine and subsequently reducing losses, such as Joule losses due to currents and iron losses due to flux. The performance of the proposed control strategy is explicitly analyzed, as is its superiority to other strategies with fixed flow references. The effectiveness of the proposed controls has been verified by simulations and experimentally on a three-phase asynchronous motor. As an application, the optimal control of an asynchronous motor, fed by an inverter, is proposed for the propulsion of electric vehicles. The reduction in current demand on the machine controlled by optimal control means lower current consumption by the vehicle's batteries.

Design and sizing of a solar thermal power plant with parabolic trough collectors

Sylvain Niyonsaba — 2024-06-30

The aim of this project is to build a solar thermal power plant to supply the MUTSAMA center. The lack of electricity and the need to increase the efficiency of the MUTSAMA center are the main reasons why we decided to carry out this work. To achieve this, we adopted a strategy of studying the selection of the site and the solar resource, calculating and adapting the parameters of the solar thermal power plant and choosing the equipment for our production source. To meet the objective, we carried out a modelling and simulation study of the solar thermal power plant using the SAM tool, and designed a system for orienting the collectors to the path of the sun using an Arduino Uno R3 board and TinkerCad software. The plant's collectors are parabolic troughs made by Solagenix (SGX-1). The plant is built with two collectors, each formed by twelve modules, and produces a power of 0.5 MW with 12 hours of operation in the absence of sunlight. The results show that the plant can produce a power of 517.17KW, an energy evaluated at 325939KWh for one year with a capacity factor of 8.3% and gives a maximum power for a period of 10 hours to 16 hours during the day.

English An Assessment of the impacts of selected Meteorological and Land Use Land Cover Datasets on the accuracy of wind speeds downscaled with the Weather Research and Forecasting Model for coastal areas in Ghana

Denis Edem K Dzebre — 2024-06-30

Downscaling of wind speeds with the Weather Research and Forecasting model (WRF) model requires inputs from datasets such as Meteorological and Land Use and Land Cover (LULC) datasets. The accuracy of these datasets is among the factors that significantly impact the accuracy of the wind speeds that are generated by the model. In this study, we assess the accuracy of wind speeds data that are downscaled for an area in coastal Ghana using six meteorological, and two global Land use and Land Cover (LULC) datasets as inputs to the WRF model. In contrast to the LULC datasets tested, model wind speeds for the area were more significantly impacted by the different meteorological datasets. Meteorological datasets that were produced with higher resolution forecasts combined with more advanced data assimilation techniques produced better estimates of wind speed, and vice versa. The JMA JRA55 Reanalysis, NCEP GFS Analysis data, and ECWMF ERA5 gave the relatively best combinations of wind speed error metrics and are therefore recommended for consideration for downscaling of wind speeds for wind resources assessment in the coastal regions of Ghana. However, the ECWMF ERA5 is preferred as its mean error margins are fairly constant and so should be easier to correct.

Hydrogen fuel cell electric vehicles controlled by direct torque control (DTC) during low-speed operation

Farid Tazerart — 2024-06-30

Controlling the speed and torque of electric vehicles (EVs) under various road conditions poses a significant challenge with conventional control methods. This paper introduces a novel approach to direct torque control (DTC) by incorporating a self-tuning fuzzy speed controller specifically designed for EV applications. The self-tuning fuzzy proportional-integral-derivative (PID) controller is devised to continually update its output scaling factor. DTC, which directly links torque and speed control to the electromagnetic state of the motor, eliminates the need for a modulator. It performs effectively at high speeds and operates without a speed sensor. However, DTC is typically employed in the medium and low-speed range of electric vehicle propulsion. This paper aims to develop a DTC structure utilizing a self-tuning fuzzy speed controller for driving a fuel cell electric vehicle in low-speed urban scenarios. Simulation results demonstrate that the adaptive fuzzy PI control ensures better efficiency compared to the conventional PI controller, affirming its superior control performance.