This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW ph...This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW photovoltaic solar panels, a converter, and storage batteries as the proposed sources. The main objective of this study is to conduct a detailed analysis and optimization of a hybrid diesel and renewable energy system to meet the electricity demand of a remote area village of 800 to 1500 inhabitants located in the north of Ngazidja Island in Comoros. The study uses the Hybrid Optimization Model for Electric Renewable (HOMER) Pro to conduct simulations and optimize the analysis using meteorological data from Comoros. The results show that hybrid combination is more profitable in terms of margin on economic cost with a less expensive investment. With a diesel cost of $1/L, an average wind speed of 5.09 m/s and a solar irradiation value of 6.14 kWh/m<sup>2</sup>/day, the system works well with a proportion of renewable energy production of 99.44% with an emission quantity of 1311.407 kg/year. 99.2% of the production comes from renewable sources with an estimated energy surplus of 2,125,344 kWh/year with the cost of electricity (COE) estimated at $0.18/kWh, presenting a cost-effective alternative compared to current market rates. These results present better optimization of the used hybrid energy system, satisfying energy demand and reducing the environmental impact.展开更多
为实现双碳目标,构建新型低碳能源体系,针对华北地区某大型工业园区源网荷储一体化系统容量配置优化问题,采用二级优化策略,以新能源发电消纳率最大和系统平准化度电成本LCOE(levelized cost of energy)最小为优化目标进行配置。首先建...为实现双碳目标,构建新型低碳能源体系,针对华北地区某大型工业园区源网荷储一体化系统容量配置优化问题,采用二级优化策略,以新能源发电消纳率最大和系统平准化度电成本LCOE(levelized cost of energy)最小为优化目标进行配置。首先建立园区源网荷储一体化系统拓扑结构模型,一级优化以源-网-荷-储4个方面的约束为限制,以弃风弃光率小于5%为目标函数进行寻优,然后再将输出结果作为HOMER软件的初始值进行仿真,以平准化度电成本最小为目标函数在一级优化的解集内寻优。通过对二级优化结果进行系统评估,得到兼具经济性、环保性和可靠性的最优配置组合。优化结果证明了二级优化通过枚举法的优化额外考虑了实际工程中会受到土地面积、变压器容量等变量,相较于直接使用HOMER软件更具有合理性。对比不同方案下系统的配置结果,得出最优源网荷储系统配置,为大型工业园区的源网荷储系统的规划提供了参考。展开更多
Solar system design for green hydrogen production has become the most prominent renewable energy research area, and this has also actively fueled the desire to achieve net-zero emissions. Hydrogen is a promising energ...Solar system design for green hydrogen production has become the most prominent renewable energy research area, and this has also actively fueled the desire to achieve net-zero emissions. Hydrogen is a promising energy carrier because it possesses more energy capacity than fossil fuels and the abundant nature of renewable energy systems can be utilized for green hydrogen production. However, the design of an optimized electrical energy system required for hydrogen production is crucial. Solar energy is indeed beneficial for green hydrogen production and this research designed, discussed, and provided high-level research on HOMER design for green hydrogen production and deployed the energy requirement with ASPEN Plus to optimize the energy system, while also incorporating fuzzy logic and PID control approaches. In addition, a promising technology with a high potential for renewable hydrogen energy is the proton exchange membrane (PEM) electrolyzer. Since its cathode (hydrogen electrode) may be operated over a wide range of pressure, a control process must be added to the system in order for it to work dynamically efficiently. This system can be characterized as an analogous circuit that consists of a resistor, capacitor, and reversible voltage. As a result, this research work also explores the Fuzzy-PID control of the PEM electrolysis system. Both the PID and Fuzzy Logic control systems were simulated using the control simulation program Matlab R2018a, which makes use of Matlab script files and the Simulink environment. Based on the circuit diagram, a transfer function that represents the mathematical model of the plant was created, and the PEM electrolysis control system is determined to be highly significant and applicable to the two control systems. The PI controller, however, has a 30.8% overshoot deficit, but when the fuzzy control system is compared to the PID controller, it is found that the fuzzy control system achieves stability more quickly, demonstrating its benefit over PID.展开更多
为充分利用清洁能源、减少快充电站对电网的冲击,针对并网状态下的高速公路光伏充电站提出了一种容量分级优化策略。首先,分析了光伏充电站容量优化模型及充电需求模型,提出用基于时刻充电概率的蒙特卡洛法进行高速公路充电站的负荷预测...为充分利用清洁能源、减少快充电站对电网的冲击,针对并网状态下的高速公路光伏充电站提出了一种容量分级优化策略。首先,分析了光伏充电站容量优化模型及充电需求模型,提出用基于时刻充电概率的蒙特卡洛法进行高速公路充电站的负荷预测,得到充电需求曲线;在综合考虑生命周期内建设成本、运行成本、置换成本、环境成本等系统净现总成本TNPC(total net present cost)小和光伏供电比高的基础上,考虑混合储能,建立了高速公路光伏充电站容量分级优化配置模型,利用HOMER和禁忌算法相结合进行求解。最后,以周期25年使用寿命为例,对高速公路光伏充电站进行优化配置,从容量变化趋势及储能出力等方面进行分析,结果表明,当敏感变量售电量增大和最大容量缺额比减小时,系统配置容量将增大;混合储能比单一储能更加可靠和经济。展开更多
This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing...This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing signal loss. The design incorporates a modified broadband dispersion compensating structure, optimized for operation across the E, S, C, and L communication bands within a wavelength range spanning 1360 nm to 1625 nm. Notably, the CT-PCF demonstrates a remarkable birefringence of 2.372 × 10<sup>-2</sup> at 1550 nm, surpassing traditional PCF structures. Single-mode performance is evaluated using the Higher Order Mode Extinction Ratio (HOMER) method, revealing a peak HOMER value of 10<sup>4</sup> at 1550 nm. Furthermore, at 1550 nm, the CT-PCF exhibits exceptional nonlinear characteristics, featuring a high nonlinearity of 50.74 W<sup>-1</sup>⋅Km<sup>-1</sup> for y polarization. In comparison to existing designs, the proposed CT-PCF exhibits superior performance metrics and optical characteristics. Additionally, the y polarization dispersion coefficient of the CT-PCF at 1550 nm is measured at -3534 ps/(nm⋅km). Overall, the CT-PCF represents a significant advancement, outperforming established systems in terms of performance metrics and optical properties.展开更多
Anterior cervical surgery is commonly used for cervical vertebral body lesions. However, the structure of blood vessels and nerve tissues along the route of anterior cervical surgery is complex. We aimed to measure th...Anterior cervical surgery is commonly used for cervical vertebral body lesions. However, the structure of blood vessels and nerve tissues along the route of anterior cervical surgery is complex. We aimed to measure the data of the longus colli, the sympathetic trunk and the cervical sympathetic trunk （CST） ganglia in Chinese cadaver speci- mens. A total of 32 adult cadavers were studied. We delineated the surgical anatomy of the CST. The superior and inferior/cervicothoracic ganglia of the sympathetic trunk consistently appeared. The middle ganglion was observed in 28.1% of the specimens and there were 2 cases of unilateral double middle cervical ganglia. The inferior ganglion was observed in 25.0% of the specimens and the cervicothoracic ganglion was observed in the remaining speci- mens. The distance between the CST gradually decreased from the top to the bottom, and the distance between the medial edges of the longus colli gradually broadened from the top down. The average angle between the bilat- eral CST and the midline of the vertebra was 11.2°± 1.8° on the left side and 10.3°± 1.4° on the right side. The average angle between the medial margins of longus colli of both sides was 11.1°± 1.9°. The CST is at high risk when LC muscle is cut transversely or is dragged heavily, especially at the levels of C6 and C7. Awareness of the regional anatomy of the CST could help surgeons to identify and preserve it during anterior cervical surgeries.展开更多
文摘This study aims to provide electricity to a remote village in the Union of Comoros that has been affected by energy problems for over 40 years. The study uses a 50 kW diesel generator, a 10 kW wind turbine, 1500 kW photovoltaic solar panels, a converter, and storage batteries as the proposed sources. The main objective of this study is to conduct a detailed analysis and optimization of a hybrid diesel and renewable energy system to meet the electricity demand of a remote area village of 800 to 1500 inhabitants located in the north of Ngazidja Island in Comoros. The study uses the Hybrid Optimization Model for Electric Renewable (HOMER) Pro to conduct simulations and optimize the analysis using meteorological data from Comoros. The results show that hybrid combination is more profitable in terms of margin on economic cost with a less expensive investment. With a diesel cost of $1/L, an average wind speed of 5.09 m/s and a solar irradiation value of 6.14 kWh/m<sup>2</sup>/day, the system works well with a proportion of renewable energy production of 99.44% with an emission quantity of 1311.407 kg/year. 99.2% of the production comes from renewable sources with an estimated energy surplus of 2,125,344 kWh/year with the cost of electricity (COE) estimated at $0.18/kWh, presenting a cost-effective alternative compared to current market rates. These results present better optimization of the used hybrid energy system, satisfying energy demand and reducing the environmental impact.
文摘为实现双碳目标,构建新型低碳能源体系,针对华北地区某大型工业园区源网荷储一体化系统容量配置优化问题,采用二级优化策略,以新能源发电消纳率最大和系统平准化度电成本LCOE(levelized cost of energy)最小为优化目标进行配置。首先建立园区源网荷储一体化系统拓扑结构模型,一级优化以源-网-荷-储4个方面的约束为限制,以弃风弃光率小于5%为目标函数进行寻优,然后再将输出结果作为HOMER软件的初始值进行仿真,以平准化度电成本最小为目标函数在一级优化的解集内寻优。通过对二级优化结果进行系统评估,得到兼具经济性、环保性和可靠性的最优配置组合。优化结果证明了二级优化通过枚举法的优化额外考虑了实际工程中会受到土地面积、变压器容量等变量,相较于直接使用HOMER软件更具有合理性。对比不同方案下系统的配置结果,得出最优源网荷储系统配置,为大型工业园区的源网荷储系统的规划提供了参考。
文摘Solar system design for green hydrogen production has become the most prominent renewable energy research area, and this has also actively fueled the desire to achieve net-zero emissions. Hydrogen is a promising energy carrier because it possesses more energy capacity than fossil fuels and the abundant nature of renewable energy systems can be utilized for green hydrogen production. However, the design of an optimized electrical energy system required for hydrogen production is crucial. Solar energy is indeed beneficial for green hydrogen production and this research designed, discussed, and provided high-level research on HOMER design for green hydrogen production and deployed the energy requirement with ASPEN Plus to optimize the energy system, while also incorporating fuzzy logic and PID control approaches. In addition, a promising technology with a high potential for renewable hydrogen energy is the proton exchange membrane (PEM) electrolyzer. Since its cathode (hydrogen electrode) may be operated over a wide range of pressure, a control process must be added to the system in order for it to work dynamically efficiently. This system can be characterized as an analogous circuit that consists of a resistor, capacitor, and reversible voltage. As a result, this research work also explores the Fuzzy-PID control of the PEM electrolysis system. Both the PID and Fuzzy Logic control systems were simulated using the control simulation program Matlab R2018a, which makes use of Matlab script files and the Simulink environment. Based on the circuit diagram, a transfer function that represents the mathematical model of the plant was created, and the PEM electrolysis control system is determined to be highly significant and applicable to the two control systems. The PI controller, however, has a 30.8% overshoot deficit, but when the fuzzy control system is compared to the PID controller, it is found that the fuzzy control system achieves stability more quickly, demonstrating its benefit over PID.
文摘为充分利用清洁能源、减少快充电站对电网的冲击,针对并网状态下的高速公路光伏充电站提出了一种容量分级优化策略。首先,分析了光伏充电站容量优化模型及充电需求模型,提出用基于时刻充电概率的蒙特卡洛法进行高速公路充电站的负荷预测,得到充电需求曲线;在综合考虑生命周期内建设成本、运行成本、置换成本、环境成本等系统净现总成本TNPC(total net present cost)小和光伏供电比高的基础上,考虑混合储能,建立了高速公路光伏充电站容量分级优化配置模型,利用HOMER和禁忌算法相结合进行求解。最后,以周期25年使用寿命为例,对高速公路光伏充电站进行优化配置,从容量变化趋势及储能出力等方面进行分析,结果表明,当敏感变量售电量增大和最大容量缺额比减小时,系统配置容量将增大;混合储能比单一储能更加可靠和经济。
文摘This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing signal loss. The design incorporates a modified broadband dispersion compensating structure, optimized for operation across the E, S, C, and L communication bands within a wavelength range spanning 1360 nm to 1625 nm. Notably, the CT-PCF demonstrates a remarkable birefringence of 2.372 × 10<sup>-2</sup> at 1550 nm, surpassing traditional PCF structures. Single-mode performance is evaluated using the Higher Order Mode Extinction Ratio (HOMER) method, revealing a peak HOMER value of 10<sup>4</sup> at 1550 nm. Furthermore, at 1550 nm, the CT-PCF exhibits exceptional nonlinear characteristics, featuring a high nonlinearity of 50.74 W<sup>-1</sup>⋅Km<sup>-1</sup> for y polarization. In comparison to existing designs, the proposed CT-PCF exhibits superior performance metrics and optical characteristics. Additionally, the y polarization dispersion coefficient of the CT-PCF at 1550 nm is measured at -3534 ps/(nm⋅km). Overall, the CT-PCF represents a significant advancement, outperforming established systems in terms of performance metrics and optical properties.
基金supported by National Natural Science Foundation of China(Grant 81171694, 81371968,81401791)a project funded by the Priority Academic Program Development of Jiangsu Higher Education institution
文摘Anterior cervical surgery is commonly used for cervical vertebral body lesions. However, the structure of blood vessels and nerve tissues along the route of anterior cervical surgery is complex. We aimed to measure the data of the longus colli, the sympathetic trunk and the cervical sympathetic trunk （CST） ganglia in Chinese cadaver speci- mens. A total of 32 adult cadavers were studied. We delineated the surgical anatomy of the CST. The superior and inferior/cervicothoracic ganglia of the sympathetic trunk consistently appeared. The middle ganglion was observed in 28.1% of the specimens and there were 2 cases of unilateral double middle cervical ganglia. The inferior ganglion was observed in 25.0% of the specimens and the cervicothoracic ganglion was observed in the remaining speci- mens. The distance between the CST gradually decreased from the top to the bottom, and the distance between the medial edges of the longus colli gradually broadened from the top down. The average angle between the bilat- eral CST and the midline of the vertebra was 11.2°± 1.8° on the left side and 10.3°± 1.4° on the right side. The average angle between the medial margins of longus colli of both sides was 11.1°± 1.9°. The CST is at high risk when LC muscle is cut transversely or is dragged heavily, especially at the levels of C6 and C7. Awareness of the regional anatomy of the CST could help surgeons to identify and preserve it during anterior cervical surgeries.
