Parameters extraction of single diode model of photovoltaic cell using improved firefly algorithm

Models of photovoltaic (PV) are significant in the design, study and control of renewable energy system. In these models, equivalent diode circuit model is widely researched and used because of its high precision. In diode circuit model, usually there are several parameters to be determined. To improve the performance of PV models, it is important to extract their unknown parameters exactly and quickly. However, because of the nonlinear of the V-I characteristic output of PV, it is difficult to obtain the parameters accurately. In this paper, a self-adaptive firefly algorithm is proposed to extract the parameters of single diode circuit model. Through introducing an adaptive mutation factor into the evolution process of a firefly algorithm, it improves the precision and stability of the solution. The proposed adaptive firefly algorithm is used to extract the parameters of single diode model which have 5 unknown parameters. By using measure output voltage and current data of PV, the proposed algorithm can extract parameters exactly and quickly. The proposed algorithm is compared with classic firefly algorithms and other algorithms in the paper. The results show that the effectiveness of the proposed algorithm

An economically viable PV hybrid micro-grid model for remote villages in developing countries

Africa contains a significant portion of the world’s population who are in energy poverty. The Sub-Saharan region, in particular, is laden with low electrification rates and high energy prices. This restricts affordable and reliable energy access, specifically in urban slums and rural communities. Decreasing component costs, such as photovoltaic (PV) modules have allowed for renewable energy systems to compete with fossil fuels and in some cases, can also gain an economic as well as environmental advantage. This study looks at the feasibility of incorporating PV into the many existing diesel-fueled mini-grids in Tanzania, offering a hybrid renewables-based system using HOMER software. Using the net present cost (NPC) and levelised cost of electricity (COE) designs were optimised to provide cleaner and cheaper electricity, when compared to the existing diesel counterparts. A hybrid PV-diesel system with battery storage proved the most economical with a COE of $0.29/kWh compared to the diesel-fueled COE of$0.35, a 16% decrease. The NPC for the hybrid model was $1,726,922 compared to$2,056,400 for the diesel model, proving the potential financial benefits of converting mini-grids across Tanzania to renewable energy

An economically viable PV hybrid micro-grid model for remote villages in developing countries

Africa contains a significant portion of the world’s population who are in energy poverty. The Sub-Saharan region, in particular, is laden with low electrification rates and high energy prices. This restricts affordable and reliable energy access, specifically in urban slums and rural communities. Decreasing component costs, such as photovoltaic (PV) modules have allowed for renewable energy systems to compete with fossil fuels and in some cases, can also gain an economic as well as environmental advantage. This study looks at the feasibility of incorporating PV into the many existing diesel-fueled mini-grids in Tanzania, offering a hybrid renewables-based system using HOMER software. Using the net present cost (NPC) and levelised cost of electricity (COE) designs were optimised to provide cleaner and cheaper electricity, when compared to the existing diesel counterparts. A hybrid PV-diesel system with battery storage proved the most economical with a COE of $0.29/kWh compared to the diesel-fueled COE of$0.35, a 16% decrease. The NPC for the hybrid model was $1,726,922 compared to$2,056,400 for the diesel model, proving the potential financial benefits of converting mini-grids across Tanzania to renewable energy

PtI₄-Catlyzed C–H Bond Functionalization in Alkynyl Ether: Density Functional Theory Survey

In this article, the PtI4-catalyzed reaction mechanism for C–H bond functionalization in alkynyl ether is investigated using DFT methods. Two possible reaction pathways are explored in this reaction. Path 1 is associated with the direct [1,5]-hydride transfer, followed by the C–C bond formation, leading to cycloisomerization; path 2 corresponds to the [1,6]-hydride transfer after the formation of a Pt-vinylidene intermediate. Our results reveal that in both paths 1 and 2 the rate-determining processes are associated with the combination of C–C bond formation and [1,2]-hydrogen transfer toward the final product. We have also found that the existence of zwitterionic intermediates in solvent is very important. Due to the high irreversibility of zwitterionic intermediates, the selectivity of the reaction pathways should be controlled by the competition between [1,5]- and [1,6]-hydride transfer. Accordingly, it is found that path 1 is more favorable than path 2. Additionally, the acetonitrile solvent has a strong effect on the structures and energies during the reaction

The effect of RSV on I/R-caused uterine damage by H&E staining.

(A) The control group. (B) I/R group. (C) I/R+RSV/20 group. (D) I/R+RSV/40 group. Arrows: inflammatory cell infiltration. Triangles: stromal cell degeneration. Asterisks: congested vessels. Scar bars = 150 μm. Images are under 100 x magnification.</p

The effect of RSV on the inflammatory response induced by uterine I/R in rat serum.

The concentrations of IL-6 (A), TNF-α (B), IL-10 (C) and IL-37 (D) in rat serum in control, I/R, I/R+RSV/20, and I/R+RSV/40 groups were examined by ELISA. Bars represent means ± SD, n = 3. *Pvs. I/R group.</p

The effect of RSV on the oxidative stress induced by uterine I/R in rat uterus.

(A) The content of MDA in rat uterus in control, I/R, I/R+RSV/20, and I/R+RSV/40 groups. (B-D) The activities of MPO (B), CAT (C) and SOD (D) in rat uterus in each group. Bars represent means ± SD, n = 3. *Pvs. I/R group.</p

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The effect of RSV on the inflammatory response induced by uterine I/R in rat uterus.

The concentrations of IL-6 (A), TNF-α (B), IL-10 (C) and IL-37 (D) in rat uterus in control, I/R, I/R+RSV/20, and I/R+RSV/40 groups were examined by ELISA. Bars represent means ± SD, n = 3. *Pvs. I/R group.</p

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