“光储直柔”系统在既有建筑节能改造中的应用

文章以某高校“光储直柔”建筑示范项目为案例,分析了“光储直柔”技术在既有建筑节能改造设计方案和“光储直柔”系统中的关键技术,并对其经济效益和社会效益进行了评估,以期为相关研究者在进行类似建筑节能改造设计时提供参考,同时为中国实现“双碳”目标提供可行性技术支持。

光伏储能一体化道路研究

传统的地面光伏电站建设需要占用大片的土地,大规模开发太阳能资源使本来就日趋紧张的生存空间变得更加狭小。本文提出将道路作为建设光伏电站的载体。首先,提出光伏储能一体化道路系统;其次,研究本系统中核心部件—新型光伏路面发电组件结构形式;最后,从施工角度出发研究一种预制式光伏道路形式。同时,从维护角度提出一种冬季光伏道路维护方案。综合实用性和经济性,光伏路面发电技术在未来十年内有向社会大规模应用推广的前景和潜力。

基于APSO算法的公路光伏声屏障储充系统优化

为实现公路光伏声屏障发电系统的能源自洽,基于自适应粒子群算法提出了一套从光伏出力、蓄电池储能到充电桩用电的“光储充”容量配置方案。根据项目所在地的温度、辐射强度及光伏组件性能衰减规律建立光伏出力模型,结合公路光伏声屏障吸声降噪效果,计算光伏组件最佳倾角并获取该倾角下的光伏资源禀赋。基于光伏出力与负荷需求,获取蓄电池逐时荷电状态,利用雨流计数法和等效循环寿命法计算蓄电池的预估使用寿命,建立了涵盖初始投资、运行维护和设备更换3部分费用的成本模型,相较于传统固定寿命的成本模型更加具有实际意义。然后,以最小化总成本为优化目标,考虑系统的最小功率、占地面积、蓄电池荷电状态、系统负荷缺电率和系统弃能率5个约束条件,建立了公路“光储充”系统容量配置协调优化模型。采用自适应的粒子群算法,通过改进惯性权重提高了粒子的全局和局部搜索能力,得到了给定光伏板数量下蓄电池及充电桩的最优容量配置方案。结果表明:提出的公路“光储充”模型的能源自洽率达95%以上,对加快公路交通能源融合具有重要意义。针对蓄电池荷电状态,设定荷电状态全年处于0.2~0.8之间,防止了蓄电池的过充过放,显著提高了蓄电池的使用寿命;针对粒子寻优能力,采用自适应粒子群算法使得粒子寻优速度提升将近90%;最终优化结果同时满足5%的负荷缺电率及10%的系统弃能率,保证了系统可靠性。

A novel coordinated control strategy considering power smoothing for a hybrid photovoltaic/battery energy storage system

This work presents a novel coordinated control strategy of a hybrid photovoltaic/battery energy storage(PV/BES) system. Different controller operation modes are simulated considering normal, high fluctuation and emergency conditions. When the system is grid-connected, BES regulates the fluctuated power output which ensures smooth net injected power from the PV/BES system. In islanded operation, BES system is transferred to single master operation during which the frequency and voltage of the islanded microgrid are regulated at the desired level. PSCAD/EMTDC simulation validates the proposed method and obtained favorable results on power set-point tracking strategies with very small deviations of net output power compared to the power set-point. The state-of-charge regulation scheme also very effective with SOC has been regulated between 32% and 79% range.

Modeling and Controlling of an Active Power Filter Using Photovoltaic System with Reduced Energy Storage Capacitor

A novel three-phase active power filter （APF） circuit with photovoltaic （PV） system to improve the quality of service and to reduce the capacity of energy storage capacitor is presented. The energy balance concept and sampling technique were used to simplify the calculation algorithm for the required utility source current and to control the voltage of the energy storage capacitor. The feasibility was verified by using the Pspice simulations and experiments. When the APF mode was used during non-operational period, not only the utilization rate, power factor and power quality could be improved, but also the capacity of energy storage capacitor could sparing. As the results, the advantages of the APF circuit are simplicity of control circuits, low cost, and good transient response.

Energy Storage System for Solar Thermal Air Conditioning Combined with Ejector Cooling System

A system of energy storage for solar thermal air conditioning combined with ejector cooling system for residential is determined in this paper. The purpose of this study is to design the energy storage system for heating the water in a storage tank to reach the required temperature for exchanging heat with the refrigerant of cooling system. The design from calculation of thermal energy storage system that proper with the solar flat plate collector area results are 70 m2, and the hot water temperature is over than 80 ℃. A cooling system is selected for refrigerant of R141b from the solar air conditioning system of 10.5 kW, and the energy source is solar thermal energy from the collector that there is an efficiency of 0.46 approximately. This storage system for the electric solar cooling system can be reduced the problem of the intermittent of energy source with the constant generating temperature to run the cooling system continuously.

Segmented cylindrical vector beams for massively-encoded optical data storage

The possibility to achieve unprecedented multiplexing of light-matter interaction in nanoscale is of virtue importance from both fundamental science and practical application points of view. Cylindrical vector beams(CVBs) manifested as polarization vortices represent a robust and emerging degree of freedom for information multiplexing with increased capacities. Here, we propose and demonstrate massivelyencoded optical data storage(ODS) by harnessing spatially variant electric fields mediated by segmented CVBs. By tight focusing polychromatic segmented CVBs to plasmonic nanoparticle aggregates, recordhigh multiplexing channels of ODS through different combinations of polarization states and wavelengths have been experimentally demonstrated with a low error rate. Our result not only casts new perceptions for tailoring light-matter interactions utilizing structured light but also enables a new prospective for ultra-high capacity optical memory with minimalist system complexity by combining CVB’s compatibility with fiber optics.

Sodium iron hexacyanoferrate with high Na content as a Na-rich cathode material for Na-ion batteries

Owing to the worldwide abundance and low-cost of Na, room-temperature Na-ion batteries are emerging as attractive energy storage systems for large- scale grids. Increasing the Na content in cathode materials is one of the effective ways to achieve high energy density. Prussian blue and its analogues （PBAs） are promising Na-rich cathode materials since they can theoretically store two Na＋ ions per formula unit. However, increasing the Na content in PBAs cathode materials remains a major challenge. Here we show that sodium iron hexacyanoferrate with high Na content can be obtained by simply controlling the reducing agent and reaction atmosphere during synthesis. The Na content can reach as high as 1.63 per formula, which is the highest value for sodium iron hexacyanoferrate. This Na-rich sodium iron hexacyanoferrate demonstrates a high specific capacity of 150 mAh·g^-1 and remarkable cycling performance with 90% capacity retention after 200 cycles. Furthermore, the Na intercalation/ de-intercalation mechanism has been systematically studied by in situ Raman spectroscopy, X-ray diffraction and X-ray absorption spectroscopy analysis for the first time. The Na-rich sodium iron hexacyanoferrate can function as a plenteous Na reservoir and has great potential as a cathode material for practical Na-ion batteries.