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光伏电池组件非线性输出特性的物理建模及其优化参数的准确提取是光伏发电系统设计计算、性能评估及优化控制的重要前提.相对于传统的隐式单二极管模型,该文在光伏电池显式单二极管模型的基础上利用Lambert W函数推导了光伏组件的显式单二极管模型,提出一种基于重启边界约束Nelder-Mead单纯形算法的参数提取方法rbcNM,并利用两种典型光伏电池组件的实测数据对隐式、显式单二极管模型的准确性进行了对比测试和验证.结果表明:rbcNM算法可以快速准确的提取隐式、显式单二极管模型的优化参数,计算结果与实测数据具有很好的一致性,相对于已有文献在准确度上取得了大幅度的提升;显式单二极管模型的准确性显著高于隐式单二极管模型,对光伏电池组件的电流-电压和功率-电压特性曲线具有更高的拟合精度. 相似文献
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为提升近场热光伏发电系统的能源转换效率和发电功率,设计了Ⅲ-Ⅴ族半导体表面的矩形光栅结构,以实现从热发射器到热光伏电池的近场辐射热流选择性调制.使用在近红外波段具有表面等离子体激元特性的掺杂氧化锌作为热发射器,在GaSb热光伏电池表面添加亚微米二维光栅结构,在近场间距下形成与表面波耦合的陷光效应,由此有选择性地增强了电池能带内的光谱辐射热流.有别于以往类似研究中常用的等效近似方法,开展了时域有限差分方法模拟,能够严格考虑周期性结构细节,结合以涨落耗散理论为基础的Langevin方法,直接计算了复杂结构参与的近场辐射传热问题,以此揭示表面结构影响近场辐射传热的物理机理.结果显示使用带表面结构的薄膜GaSb电池,可使辐射热流的光谱峰值达到同温度远场黑体辐射源情况下的2.84倍,且热流增益区集中在波长略短于电池能带的窄波段区间,适应高效率、高功率热光伏系统对辐射传热设计的要求. 相似文献
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聚光内球面太阳能电池 总被引:1,自引:1,他引:0
为提高阳光利用率和光电转换率,研究了聚光内球面太阳能电池的主要性能,设计了聚光内球面太阳能电池的结构.通过菲涅耳聚光镜将太阳光聚光后射入内表面制备了多晶硅光伏电池的球腔内,在内球面上实现了聚光光伏效应.利用腔内光子气体模型分析计算了内球面上的光照强度,提出硅光电池上的最佳光强概念,计算了在内球面多晶硅电池半导体层厚10 μm时最佳聚光倍数为18、层厚5 μm时最佳聚光倍数为9.应用有限元分析法讨论了聚光内球面太阳能电池系统的温度,在AM1.5,8倍聚光条件下,光伏电池最高温度353.15 K,处于正常工作范围.采用主动风冷或水冷方法提高对流换热系数可大大降低光伏电池温度,稳定工作效率.通过分析硅光电池效率制约因素,设计了内球面光伏电池的优化结构,填充因子可达0.85,阳光辐射功率为800 mW/cm2时,聚光内球面太阳能电池效率将超过33%. 相似文献
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光伏发电是将“取之不尽、用之不竭”的清洁能源太阳能直接转化为电能的一种新能源技术。大力发展光伏技术并促进其大规模应用是推进能源结构转型的重要途径。光伏发电是通过太阳能电池实现的,经过60多年的发展,涌现了各类太阳能电池,其中硅太阳能电池一直占据主导地位,极大地推动了光伏产业的大规模应用。但硅太阳能电池进一步降低成本愈发困难,而新型薄膜太阳能电池拥有低成本、高效率,且适于多场景应用的优点,成为明日之星。铜锌锡硫硒太阳能电池作为一种新型薄膜太阳能电池,其吸光系数高、弱光响应好、稳定性高、环境友好、组成元素储量丰富且价格低廉,具有很大的发展潜力,近年来受到越来越多的关注。文章重点介绍铜锌锡硫硒太阳能电池的工作原理、关键材料与器件的研究进展以及未来的发展前景。 相似文献
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本文对太阳能聚光分频利用电热联产的机理进行了探讨,给出了太阳能光谱有效能函数以及太阳能聚光分频利用电热联产的设计方案,并对该系统进行了热力性能分析,发电投资和成本比较.结果表明,对30倍聚光分频的光伏/光热系统,光伏发电效率约0.095,250~280℃热量利用效率0.14,折算为电的总发电效率为0.139;与普通光伏发电系统相比,单位面积硅光电池发电功率提高约16倍,投资成本仅0.33倍,每千瓦时的发电上网成本可从3.52元降到0.84元,考虑税收后的上网成本将从5.1元降到1.18元. 相似文献
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光伏阵列的输出特性受光照强度影响很大,在弱光下光伏电池的最大功率点跟踪控制算法无法达到蓄电池的充电要求。为了最大限度利用光伏阵歹tl的输出功率,采用超级电容减小光照变化对蓄电池充电的影响。针对独立光伏发电系统的特点,设计了一种有源式混合储能方案,在保证光伏电池获得最大功率跟踪的同时,也能满足蓄电池的充电要求,建立的Simulink/MATLAB仿真模型验证了该设计方案的有效性。 相似文献
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光伏电池作为光伏发电系统的重要组成部分,研究其模型的准确性并对其最大功率点进行预测与跟踪,对于光伏发电效率的提高具有重大意义。本文首先根据光伏电池的内部结构和伏安特性建立其数学模型,并对所建立的模型进行参数辨识,进而得到模型输出与测量信息偏差最小的参数值,验证模型的准确和有效性。根据模型所反映的规律,将温度和光照强度作为输入变量,最大功率点对应的电压作为输出变量,构建了用于MPPT的神经网络模型。神经网络经训练后对最大功率点电压进行预测与跟踪,结果表明构建的神经网络具有良好的适应性。 相似文献
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《中国光学快报(英文版)》2017,(6)
Polymethyl methacrylate(PMMA) plate luminescent solar concentrators with a bottom-mounted(BM-LSCs)photovoltaic(PV) cell are fabricated by using a mixture of Lumogen Red 305 and Yellow 083 fluorescent dyes and a commercial monocrystalline silicon cell. The fabricated LSC with dye concentrations of 40 ppm has the highest power gain of 1.50, which is the highest value reported for the dye-doped PMMA plate LSCs. The power gain of the LSC comes from three parts: the waveguide light, the transmitted light, and the reflected light from a white reflector, and their contributions are analyzed quantitatively. The results suggest that the BM-LSCs have great potential for future low-cost PV devices in building integrated PV applications. 相似文献
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S. V. Yablonskii A. S. Mikhailov S. P. Palto S. G. Yudin S. V. Yakovlev G. Durand 《JETP Letters》1998,67(6):409-415
We have developed a new method for measuring tilt bias angles in spatially uniform and nonuniform thin films of nematic liquid
crystals. The method employs modulation ellipsometry, based on the use of an exponentially decaying light wave to probe the
boundary layer. Oscillations of the director of the liquid crystal, which are induced by the flexoelectric torque, are excited
with an external periodic field. A periodic variation of the ellipticity of the light wave reflected from the interface is
detected at both the first and second harmonics of the exciting electric field. When these two Fourier components of the electrooptic
response are known, it is possible to calculate both the tilt bias angle θ0 of the director and the dynamic deviation δ0 of the tilt bias angle. The angles θ0 and δ0 measured by this method on the surface of an electrode (ITO) and on the surface of a ferroelectric film (a copolymer of vinylidene
fluoride and trifluoroethylene), oriented in a corona discharge, were equal to θ 0=5.1°, δθ=0.5° and θ0=89°, δθ=0.06°, respectively.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 6, 387–392 (25 March 1998) 相似文献
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K. Sogut 《Physics of Particles and Nuclei Letters》2006,3(4):256-260
The tracking part of the CMS detector will be built with ∼16000 silicon detector modules, and kept at −10°C for the ten years
of the operation of the LHC. All the model materials need to be verified of having a good performance at this low temperature,
before their installation into the CMS Tracker. In order to track performance quality, assurance tests are done with two different
systems. Of the two setups used, the LT system module is the one that is used to identify whether the performance of readout
electronics and leakage current flowing on the silicon sensors is affected by low temperature. In this paper a detailed layout
of the CMS TOB modules and their front-end hybrids are presented. In addition, the LT testing results of the 190 TOB modules
that were produced and tested in 2004 by the FNAL-CMS group are given.
The text was submitted by the author in English. 相似文献
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Quasi-phase-matched frequency conversion in KNbO3 structures consisting of 90° ferroelectric domains
Periodic 90° domain structure with 18.6 μm periodicity was fabricated by applying a 200 V/mm electric field over (1̄01)-cut
KNbO3 plate. The blue light generation by quasi-phase-matched frequency doubling in this periodic 90° domain structure is demonstrated.
The 90° domain structure completely compensates for a Poynting vector walk-off of the second-harmonic beam. Moreover, these
structures exhibit amphoteric Poynting vector refraction properties, i.e., the refraction can be negative or positive depending
on the angle of incidence at the 90° domain boundary.
PACS 42.65.ky; 42.70.Mp; 77.80.Dj 相似文献
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This paper reports a new technique proposal to improve the photovoltaic systems. It was made to design and implement an electronic
system that will detect, capture, and transfer the maximum power of the photovoltaic (PV) panel to optimize the supplied power
of a solar panel. The electronic system works on base technical proposal of electrical sweeping of electric characteristics
using capacitive impedance. The maximum power is transformed and the solar panel energy is sent to an automotive battery.
This electronic system reduces the energy lost originated when the solar radiation level decreases or the PV panel temperature
is increased. This electronic system tracks, captures, and stores the PV module’s maximum power into a capacitor. After, a
higher voltage level step-up circuit was designed to increase the voltage of the PV module’s maximum power and then its current
can be sent to a battery. The experimental results show that the developed electronic system has 95% efficiency. The measurement
was made to 50 W, the electronic system works rightly with solar radiation rate from 100 to 1,000 W m − 2 and the PV panel temperature rate changed from 1 to 75°C. The main advantage of this electronic system compared with conventional
methods is the elimination of microprocessors, computers, and sophisticated numerical approximations, and it does not need
any small electrical signals to track the maximum power. The proposed method is simple, fast, and it is also cheaper. 相似文献
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M. F. Galyautdinov B. F. Farrakhov Ya. V. Fattakhov M. V. Zakharov 《Optics and Spectroscopy》2009,107(4):640-644
A method for the fast measurement of the temperature of solids under the action of a high-power light pulse is proposed and
demonstrated. This method is based on the application of the Fraunhofer diffraction and is implemented for silicon samples
heated to melting temperatures T
melt = 1412°C by a high-power light pulse. The current silicon temperature was determined by measuring the varying diffraction
angle of the probing laser beam. The diffraction angle was varied over time because the period of the diffraction grating
increased as a result of the dynamic thermal expansion of the crystal. An initial grating was formed on the surface of the
silicon plate with a period of d = 4 μm. The radiation beam of a He-Ne laser with λ = 0.6328 μm was used as the probing beam; the measured signal was recorded
in the pair of symmetric fifth-order diffraction maxima. 相似文献
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对空间光混频器的90°相位差补偿的几种方法进行了比较分析,并在此基础之上提出了两种新方法.第一种方法采取旋转本振光支路的1/4波片来补偿相位差,旋转信号光支路的第一个1/2波片来调整I路与Q路分光比;第二种方法通过旋转本振光支路的1/2波片和1/4波片到计算出来的角度来实现预定的相位差和分光比.对两种方法进行仿真分析和系统实验.采用第一种方法时,1/4波片快轴与x轴的夹角在-10°~10°变化时,相位差补偿范围为-14°~29°,分光比在0.7~1.4范围内变化;当1/2波片的快轴与y轴的夹角在35°~55°变化时,分光比在0.47~2.1范围内变化.采用第二种方法求解出I/Q路相位差分别为80°、85°、90°、95°、100°,I/Q路分光比分别为0.5、0.75、1、1.5、2时,1/2波片的快轴和1/4波片的快轴的位置.采用这两种方法均可以简单而精确地实现设定的相位差和分光比,有利于光锁相环的相位锁定以及解调出的信号强度的提高. 相似文献
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A two-exposure nearly common-path point diffraction interferometric phase microscopy (IPM) is presented using polarization modulation and one-step grating shifting to implement quantitative phase imaging. The IPM is constructed by an improved Michelson configuration with a reflective grating, and its frequency spectrum generated by a circularly polarized object beam makes double copies through a beam splitter. One copy is low-pass filtered and reflected by a reflective pinhole mirror to create a reference beam, and the other copy is converted by a polarizer and then reflected by a reflective grating to achieve a 45° linearly polarized object beam. By the combination of a polarizing cube beam splitter with 45° tilted angle and a translation of the reflective grating with a π phase shift, four interferograms with π/2 phase shift can be obtained in two exposures. The standard four-step algorithm can then be used to reconstruct the phase of the specimen. The utility of the proposed method was demonstrated with measurements on a phase plate, cells and an oil drop. 相似文献
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Intra-cavity sum frequency generation (SFG) of c-cut Nd:YVO4 self-Raman laser was investigated for the first time. A 4 × 4 × 10 mm3 KTP crystal with a type-II phase-matching cutting angle (θ = 83.4°, φ = 0°) was used for SFG between the fundamental light
at 1066 nm and first-Stokes light at 1178 nm. The laser system with different curvature radii of output couplers and different
pulse repetition frequencies were investigated. At a pump power of 14 W and pulse repetition frequency of 20 kHz, the average
output power of yellow-green laser at 560 nm up to 840 mW was achieved, corresponding to a slope efficiency of 7.6% and a
conversion efficiency of 6% with respect to diode pump power. 相似文献