基于虚拟储能的微网风光储容量优化配置方法研究

风光储互补发电系统能够提高微网系统的稳定性。为了提升微网储能资源的合理配置,文章基于虚拟储能和电力弹簧概念,提出了计及主配储能协同的微网风光储容量双层优化配置方法,并利用改进的粒子群算法对风光储容量双层优化配置方法求解。最后,通过算例分析表明,文章配置方法提高了微网系统调节能力,降低了电压偏移率。     

风光储联合发电技术及其工程应用

阐述了风光储联合发电的发展背景和基本特点,分析了风光储联合发电技术发展过程中所面临的容量配比、储能装置功率和容量选择、风光储系统调度策略、智能控制调度系统、无功补偿配置方案等关键技术,介绍了风光储联合发电系统的工程应用情况,并对其未来的应用前景进行了分析和展望。     

含旋转备用的独立风光储系统控制与仿真

鉴于独立风光储系统配备一定容量的旋转备用的必要性,利用小型柴油发电机作为独立风光储系统的旋转备用,在PSCAD平台上建立了独立风光储系统的仿真模型,并提出将风力发电和光伏发电系统均采用恒功率(PQ)控制、蓄电池和超级电容器的混合储能系统作为主控制器采用恒压恒频(V/f)控制的控制策略,EMTDC仿真结果验证了将旋转备用控制引入独立风光储系统的正确性和有效性。     

Control strategies for a photovoltaic--Energy storage hybrid system

受光照,温度等自然条件影响,光伏电源输出有功功率具有较大的波动性.因此,本身既非恒压源又非恒流源的光伏电源并网运行时会产生一系列问题,如对电网冲击性大,需增加旋转备用容量,难以参与电网调度等.利用电池储能系统来控制有功功率输出,可以使平滑光伏电源功率波动成为可能.研究了光储联合发电系统的运行模式,提出了适用于光储联合发电系统的拓扑结构和控制策略,并对储能用功率转换系统(PCS)进行了分析和设计,最后基于某光伏电站的实际历史运行数据,对所提出的方案进行仿真研究,仿真结果验证了光储联合发电系统控制策略的有效性和可行性,为光储联合运行示范工程提供了一定的理论依据和有力借鉴.     

基于混合储能的风光储联合发电系统优化研究

风光储发电系统与混合储能系统的结合能够进一步提高系统的综合效率.为此,本文提出一种结合混合储能技术(锂电池和超级电容)、可再生能源综合利用技术(太阳能和风能利用)的风光储联合发电系统.针对性提出超级电容荷电状态二次反馈的混合储能控制策略.以系统年综合成本最小为优化目标,以本文新提出的结合人工鱼群算法的模拟退火算法为优化...     

光储联合电站建模与仿真

为解决光伏电站发电的波动性与不稳定性,介绍了光伏电站与全钒液流电池储能电站联合运行的系统结构,基于PSCAD/EMTDC仿真平台,建立了光伏电池、光伏控制系统、全钒液流电池及其控制系统的电气模型,对并网及故障模式下光储联合电站系统的运行情况进行了仿真研究。结果表明,光储联合电站运行时储能系统能很好地平抑光伏电站的输出功率波动,故障模式下能维持光伏电站的稳定运行。全钒液流电池储能电站可提高光伏电站运行的经济性与可靠性,同时增强了光伏电站输出的可预测性。     

基于序贯蒙特卡洛模拟的风光储发电系统可靠性评估

针对风、光资源的分布特点,结合发电系统设备的运行状态,建立含风力、光伏、储能的发电系统可靠性数学模型。定义风光储冗余容量比和出力偏移度两个指标来衡量含风光储发电系统的可靠性。采用序贯蒙特卡洛模拟法,构建含风光储发电系统的可靠性评估。利用可靠性测试系统(roy billinton test system,RBTS),分析不同协调运行方式、风光容量配置比和储能容量下含风光储的发电系统的可靠性指标。研究表明,合理的风光储配置能有效提高电能利用率,增强跟踪负荷能力,改善发电系统的可靠性。     

平抑风光互补系统短时复合功率波动的 储能容量配置研究

摘要： 针对风光互补系统日内局部功率波动平抑问题,提出了一种风光储共建系统的储能容量匹配方法。在分析影响配置储能容量的相关因素基础上,建立了反映风光储共建系统发电效益与相关约束的指标,并提出一种配置储能容量的计算方法。所提方法通过构建风光复合功率波动量的概率密度函数,设定储能设备额定充放电功率,进而得到储能系统的额定容量。以甘肃某风光互补电站为例,对风光储发电系统的相关指标进行计算分析,验证了所提方法的有效性。     

风光储互补微网系统集成技术的研究与设计

为提高微电网的运行效率,从系统层面统一协调控制各分布式电源及负荷,提出了基于风光储互补的微网系统的集成技术。介绍了基于风光储互补的微网系统方案,提出了微网运行模式和微网离网、并网以及离并网切换的协调控制策略,设计了基于DSP 28335芯片的能量协调控制器,实现了风光储微网系统控制管理功能的集成。工程实践验证了该设计方案的有效性。     

多种调度模式下的光储电站经济性最优储能容量配置分析

光储联合发电系统是促进大容量光伏电站集中并网的解决方案之一。因现阶段储能造价较高,所以合理配置储能容量是提高光储电站经济性的重要前提。该文对光储电站不同调度模式进行分析,从发电企业的角度出发以净收益最优为目标建立储能容量优化模型。模型中,结合电池循环寿命数据,建立电池损耗成本函数,定量计算储能实际运行成本,同时计及售电收益、考核费用,利用粒子群算法求解净收益最优时的储能容量,并通过多种方案对比,仿真验证模型有效性。最后对影响光储电站经济性的敏感因素进行分析,为光储电站在不同调度模式、不同市场环境下的储能容量选择提供参考信息。     

Optical properties and thermal stability of pulsed-sputter-deposited AlxOy/Al/AlxOy multilayer absorber coatings

Spectrally selective Al_xO_y/Al/Al_xO_y multilayer absorber coatings were deposited on copper (Cu) and molybdenum (Mo) substrates using a pulsed sputtering system. The Al targets were sputtered using asymmetric bipolar-pulsed DC generators in Ar+O₂ and Ar plasmas to deposit an Al_xO_y/Al/Al_xO_y coating. The compositions and thicknesses of the individual component layers were optimized to achieve high solar absorptance (α=0.950-0.970) and low thermal emittance (ε=0.05-0.08). The X-ray diffraction data in thin film mode showed an amorphous structure of the Al_xO_y/Al/Al_xO_y coating. The X-ray photoelectron spectroscopy data of the Al_xO_y/Al/Al_xO_y multilayer absorber indicated that the Al_xO_y layers present in the coating were non-stoichiometric. The optical constants (n and k) of the multilayer absorber were determined from the spectroscopic ellipsometric data. Drude's free-electron model was used for generating the theoretical dispersion of optical constants for Al films, while the Tauc-Lorentz model was used for modeling optical properties of the dielectric Al_xO_y layers. In order to study the thermal stability of the Al_xO_y/Al/Al_xO_y coatings, they were subjected to heat treatment (in air and vacuum) at different temperatures and durations. The multilayer absorber deposited on Cu substrates exhibited high solar selectivity (α/ε) of 0.901/0.06 even after heat-treatment in air up to 400 °C for 2 h. At 450 °C, the solar selectivity decreased significantly on Cu substrates (e.g., α/ε=0.790/0.07). The coatings deposited on Mo substrates were thermally stable up to 800 °C in vacuum with a solar selectivity of 0.934/0.05. The structural stability of the absorber coatings heat treated in air (up to 400 °C) and vacuum (up to 800 °C) was confirmed by micro-Raman spectroscopy measurements. Studies on the accelerated aging tests suggested that the absorber coatings on Cu were stable in air up to 75 h at 300 °C and the service lifetime of the multilayer absorber was predicted to be more than 25 years. Further, the activation energy for the degradation of the multilayer absorber heat treated for longer durations in air is of the order of 64 kJ/mol.     

Hydrogen storage properties of multi-principal-component CoFeMnTixVyZrz alloys

This study presents an innovative multi-principal-element CoFeMnTiVZr alloy system for the absorption and desorption of hydrogen. Pressure-composition-isotherms (PCIs) demonstrate that CoFeMnTi_xVZr, CoFeMnTiV_yZr, and CoFeMnTiVZr_z can absorb and desorb hydrogen for x, y, and z that satisfy 0.5 ≤ x ≤ 2.5, 0.4 ≤ y ≤ 3.0, and 0.4 ≤ z ≤ 3.0, respectively. X-ray diffraction (XRD) reveals that CoFeMnTi_xV_yZr_z alloys have a simple C14 Laves phase with a single set of lattice parameters before and after PCI tests. The distributions of each element in CoFeMnTi_xV_yZr_z alloys are roughly equal, as revealed by SEM/EDS mapping. The effects of values x, y, and z on the hydrogen storage properties are elucidated in terms of lattice constant, element segregation, hydride formation enthalpies of the alloy components and hydrogen, and the averaged formation enthalpy. The high-entropy effect promotes the formation of a single C14 Laves phase, and the maximum hydrogen storage capacity is strongly related to the hydride formation enthalpy of the alloy and hydrogen.     

Explosion behavior of CH4/O2/N2/CO2 and H2/O2/N2/CO2 mixtures

In this work, the explosion behavior of stoichiometric CH₄/O₂/N₂/CO₂ and H₂/O₂/N₂/CO₂ mixtures has been studied both experimentally and theoretically at different CO₂ contents and oxygen air enrichment factors. Peak pressure, maximum rate of pressure rise and laminar burning velocity were measured from pressure time records of explosions occurring in a closed cylindrical vessel. The laminar burning velocity was also computed through CHEMKIN–PREMIX simulations.     

C/H/O/N/S/Cl/K/Na元素的详细化学反应机理的简化与验证

基于Senkin模型,应用自编化学反应机理简化程序,结合Kinalc和Mechmod开源程序,发展了详细化学反应机理的简化与验证方法.以电站锅炉燃烧的计算流体力学(CFD)数值模拟为应用背景,建立了考虑C/H/O/N/S/Cl/K/Na元素的详细化学反应机理(115组分,1,342基元反应),并运用此方法得到简化反应机理(28组分,20反应).验证结果表明,该简化机理在锅炉运行的主要参数变化范围内(温度T=1,100～1,500,℃,过量空气系数λ=0.8～1.2)具有较好的准确性和较高的计算效率,可应用于锅炉燃烧的CFD计算.     

Structural and transport properties of LixNi1−y−zCoyMnzO2 cathode materials

In this work structural and transport properties of layered LiNi_1−y−zCo_yMn_zO₂ (y = 0.25, 0.35, 0.5 and z = 0.1) cathode materials are presented. In the considered group of oxides, LiNi_1−y−zCo_yMn_zO₂, there is no clear correlation between electrical conductivity and the a parameter (M-M distance in the octahedra layers). A non-monotonic modification of electrical properties of Li_xNi_0.65Co_0.25Mn_0.1O₂ cathode materials is observed upon lithium deintercalation.     

Metal/CdTe/CdS/Cd1−xZnxS/TCO/glass: A new CdTe thin film solar cell structure

The potential of CdTe/CdS/Cd_1−xZn_xS structure as an alternative to CdTe/CdS structure in photovoltaic application has been demonstrated. The unoptimized solar cell structure grown on transparent conducting oxide coated soda lime glass of 3 mm thickness with no antireflection coating yielded a 10% efficiency. This efficiency is the highest ever recorded in any Cd_1−xZn_xS film containing CdTe solar cells.     

Preparation and electrochemical properties of layer-structured LiNi1/3Co1/3Mn1/3−yAlyO2

Layer-structured LiNi_1/3Co_1/3Mn_1/3−yAl_yO₂ has been synthesized via a sol–gel method. The lattice constants of LiNi_1/3Co_1/3Mn_1/3−yAl_yO₂ decrease with the concentration of aluminum ions. XANES analysis further confirms that the valence of cobalt ion is 3+, and that of Ni is between 2+ and 3+ in LiNi_1/3Co_1/3Mn_1/3−yAl_yO₂. With doping aluminum ions, the redox centers for the electrochemical reaction change from nickel ions alone to both nickel and cobalt ions. The amounts of de-intercalatable lithium ions are affected by the concentration of aluminum ions; however, the extracting efficiency of lithium ions is improved by doping aluminum ions. Among all the samples, LiNi_1/3Co_1/3Mn_0.23Al_0.1O₂ exhibits the best capacity retention and the least irreversible capacity.     

Experimental and modeling studies of C2H4/O2/Ar, C2H4/methylal/O2/Ar and C2H4/ethylal/O2/Ar rich flames and the effect of oxygenated additives

The addition of dimethoxymethane (DMM or methylal) and diethoxymethane (DEM or ethylal) to a rich ethylene/oxygen/argon flame has been investigated by measuring the depletion of soot precursors. Three rich premixed ethylene/oxygen/argon (with and without added methylal or ethylal) flat flames have been stabilized at low-pressure (50 mbar) on a Spalding–Botha type burner with the same equivalence ratio of 2.50. Identification and monitoring of signal intensity profiles of species within the flames have been carried out by using molecular beam mass spectrometry (M.B.M.S.). The replacement of some C₂H₄ by C₃H₈O₂ or C₅H₁₂O₂ is responsible for a decrease of the maximum mole fractions of the detected intermediate species. This phenomenon is noticeable for C₂–C₄ intermediates and becomes more effective for C₅–C₁₀ species, mainly when C₃H₈O₂ added.A new kinetic model has been elaborated and contains 546 reactions and 107 chemical species in order to simulate the three investigated flames: C₂H₄/O₂/Ar, C₂H₄/DMM/O₂/Ar and C₂H₄/DEM/O₂/Ar. The reaction mechanism well reproduces experimental mole fraction profiles of major and intermediate species, and underlines the effect of methylal and ethylal addition on species concentration profiles for these flames.     

Highly structured TiO2/In(OH)xSy/PbS/PEDOT:PSS for photovoltaic applications

A system of highly structured TiO₂/In(OH)_xS_y/PbS/PEDOT:PSS has been developed and investigated by photovoltage spectroscopy, X-ray photo- and Auger electron spectroscopies, electron microscopy, and photovoltaic response. TiO₂, In(OH)_xS_y, PbS, and PEDOT:PSS serve as electron conductor, buffer layer, absorber, and hole conductor, respectively. Both buffer and absorber layers were prepared by chemical bath deposition. The band gap of as-prepared In(OH)_xS_y varied between 2.4 and 3.5 eV depending on the pH-value of the solution. In addition, the band gap of the PbS could be widened to about 0.85 eV making the application as absorber for solar cells feasible. At present, corresponding solar cell devices reach short-circuit current densities of about 8 mA/cm² and open-circuit voltages of about 0.3 V.     

Burning velocities and kinetics of H2/NF3/N2, CH4/NF3/N2, and C3H8/NF3/N2 flames

The combustion characteristics and reaction mechanism of mixtures containing nitrogen trifluoride (NF₃) were investigated. Burning velocities for H₂/NF₃/N₂, CH₄/NF₃/N₂, and C₃H₈/NF₃/N₂ flames were determined for the first time at various equivalence ratios and N₂ mole fractions. The burning velocities of the latter two flames were similar and showed peaks at equivalence ratios of ∼1.0, while those of the H₂/NF₃/N₂ flames had the pronounced peak at low equivalence ratios where the formation of the wrinkled flames was observed. A detailed kinetic model was constructed to simulate the laminar burning velocities of H₂/NF₃/N₂ and CH₄/NF₃/N₂ flames. The model accurately reproduced the experimental results. Analyses of the reaction mechanism revealed the major reaction pathways that involve the decomposition of NF₃, the oxidation and chain-fluoridation of H₂ and CH₄, and the formation of N₂.