In this work we study the behaviour of the dielectric constant of BaTiO3 single crystals doped with Cu and Fe for different ion percentages, particularly, the influence of these hetemvalent substitutions on the ferroe...In this work we study the behaviour of the dielectric constant of BaTiO3 single crystals doped with Cu and Fe for different ion percentages, particularly, the influence of these hetemvalent substitutions on the ferroelectric-paraelectric phase transition whose temperature is found at Tc=120℃ for pure samples. The dielectric constant e in terms of temperature shows that the Curie temperature decreases when the quantity of impurities increases and presents a broadening and flattering of the maximum oft（T） within higher values, with the transition becoming more and more diffuse. It is interesting to have a material with very high permittivity （high-k） because of its capacity to store an important quantity of electric charges. The t anisotropy and the Curie-Weiss law are also verified with a good ratio between the slopes ofε^-l（T） from both sides of the transition, leading to a Curie constant： C= 13 × 10^4 K for BaTiO3：1.6%Fe in the polar phase. BaTiO3 is a displacive ferroelectric going through a first-order phase transition. The substitutions have an effect on the dynamics of the perovskite lattice. They induce charges transfer to Ti and a diminution of elastic forces in BaTiO3. Then we discuss the transition but on the nature of the material. fact that the maximum of permittivity does not depend on the phase展开更多
Photovoltaic solar energy is still in its infancy in Burkina Faso, despite the country’s high solar potential. The electricity grid is experiencing an increase in demand for energy, creating a shortfall in supply. Th...Photovoltaic solar energy is still in its infancy in Burkina Faso, despite the country’s high solar potential. The electricity grid is experiencing an increase in demand for energy, creating a shortfall in supply. The Zagtouli photovoltaic solar power plant in Burkina Faso is the first milestone in the development of renewable photovoltaic energy, with a rated output of 33.6 Megawatts peak, to strengthen the electricity grid by reducing hydrocarbon consumption. The aim of this work is to evaluate the performance of the plant by proposing a performance score for the Zagtouli plant, which should provide a basis for assessing the performance of a power plant. To meet the objectives, we collected data for three consecutive years of production, from 2019 to 2021. From this data, we used the method based on the calculation of the performance indicators specified by the International Energy Agency (IEA) and described in the standardised norms IEC (International Electrotechnical Commission) CEI61724, and we also carried out a performance classification using the K-Means method. It is clear that with the results obtained for the PR performance index (over 70%), the installation can be classified as one of the best-performing systems. It also emerges that various losses (temperatures on the panels, cabling, partial shading, spectral losses, dirt, and unexpected inverter failures) have a negative impact on the installation’s energy production.展开更多
The study focuses on estimating the input power of a power plant from available data, using the theoretical inverter efficiency as the key parameter. The paper addresses the problem of missing data in power generation...The study focuses on estimating the input power of a power plant from available data, using the theoretical inverter efficiency as the key parameter. The paper addresses the problem of missing data in power generation systems and proposes an approach based on the efficiency formula widely documented in the literature. In the absence of input data, this method makes it possible to estimate the plant’s input power using data extracted from the site, in particular that provided by the Ministry of the Environment. The importance of this study lies in the need to accurately determine the input power in order to assess the overall performance of the energy system.展开更多
In this paper, we present a study on the prediction of the power produced by the 33 MWp photovoltaic power plant at Zagtouli in Burkina-Faso, as a function of climatic factors. We identified models in the literature, ...In this paper, we present a study on the prediction of the power produced by the 33 MWp photovoltaic power plant at Zagtouli in Burkina-Faso, as a function of climatic factors. We identified models in the literature, namely the Benchmark, input/output, Marion, Cristo-fri, Kroposki, Jones-Underwood and Hatziargyriou prediction models, which depend exclusively on environmental parameters. We then compared our linear model with these seven mathematical models in order to determine the most optimal prediction model. Our results show that the Hatziargyriou model is better in terms of accuracy for power prediction.展开更多
文摘In this work we study the behaviour of the dielectric constant of BaTiO3 single crystals doped with Cu and Fe for different ion percentages, particularly, the influence of these hetemvalent substitutions on the ferroelectric-paraelectric phase transition whose temperature is found at Tc=120℃ for pure samples. The dielectric constant e in terms of temperature shows that the Curie temperature decreases when the quantity of impurities increases and presents a broadening and flattering of the maximum oft（T） within higher values, with the transition becoming more and more diffuse. It is interesting to have a material with very high permittivity （high-k） because of its capacity to store an important quantity of electric charges. The t anisotropy and the Curie-Weiss law are also verified with a good ratio between the slopes ofε^-l（T） from both sides of the transition, leading to a Curie constant： C= 13 × 10^4 K for BaTiO3：1.6%Fe in the polar phase. BaTiO3 is a displacive ferroelectric going through a first-order phase transition. The substitutions have an effect on the dynamics of the perovskite lattice. They induce charges transfer to Ti and a diminution of elastic forces in BaTiO3. Then we discuss the transition but on the nature of the material. fact that the maximum of permittivity does not depend on the phase
文摘Photovoltaic solar energy is still in its infancy in Burkina Faso, despite the country’s high solar potential. The electricity grid is experiencing an increase in demand for energy, creating a shortfall in supply. The Zagtouli photovoltaic solar power plant in Burkina Faso is the first milestone in the development of renewable photovoltaic energy, with a rated output of 33.6 Megawatts peak, to strengthen the electricity grid by reducing hydrocarbon consumption. The aim of this work is to evaluate the performance of the plant by proposing a performance score for the Zagtouli plant, which should provide a basis for assessing the performance of a power plant. To meet the objectives, we collected data for three consecutive years of production, from 2019 to 2021. From this data, we used the method based on the calculation of the performance indicators specified by the International Energy Agency (IEA) and described in the standardised norms IEC (International Electrotechnical Commission) CEI61724, and we also carried out a performance classification using the K-Means method. It is clear that with the results obtained for the PR performance index (over 70%), the installation can be classified as one of the best-performing systems. It also emerges that various losses (temperatures on the panels, cabling, partial shading, spectral losses, dirt, and unexpected inverter failures) have a negative impact on the installation’s energy production.
文摘The study focuses on estimating the input power of a power plant from available data, using the theoretical inverter efficiency as the key parameter. The paper addresses the problem of missing data in power generation systems and proposes an approach based on the efficiency formula widely documented in the literature. In the absence of input data, this method makes it possible to estimate the plant’s input power using data extracted from the site, in particular that provided by the Ministry of the Environment. The importance of this study lies in the need to accurately determine the input power in order to assess the overall performance of the energy system.
文摘In this paper, we present a study on the prediction of the power produced by the 33 MWp photovoltaic power plant at Zagtouli in Burkina-Faso, as a function of climatic factors. We identified models in the literature, namely the Benchmark, input/output, Marion, Cristo-fri, Kroposki, Jones-Underwood and Hatziargyriou prediction models, which depend exclusively on environmental parameters. We then compared our linear model with these seven mathematical models in order to determine the most optimal prediction model. Our results show that the Hatziargyriou model is better in terms of accuracy for power prediction.
