Tilt Angle Optimality Criteria for Stand Alone PV Systems

The conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy availability varies, this criterion may not be optimal. This study explores two alternative optimization criteria focused on maximizing baseload supply potential and minimizing required storage capacity to address seasonality in energy generation. The optimal tilt angles determined for these criteria differed significantly from the standard approach. This research highlights additional factors crucial for designing solar power systems beyond gross energy generation, essential for the global transition towards a fully renewable energy-based electric grid in the future.

Modified particle swarm optimization-based antenna tilt angle adjusting scheme for LTE coverage optimization

In order to solve the challenging coverage problem that the long term evolution（ LTE） networks are facing, a coverage optimization scheme by adjusting the antenna tilt angle（ ATA） of evolved Node B（ e NB） is proposed based on the modified particle swarm optimization（ MPSO） algorithm.The number of mobile stations（ MSs） served by e NBs, which is obtained based on the reference signal received power（RSRP） measured from the MS, is used as the metric for coverage optimization, and the coverage problem is optimized by maximizing the number of served MSs. In the MPSO algorithm, a swarm of particles known as the set of ATAs is available; the fitness function is defined as the total number of the served MSs; and the evolution velocity corresponds to the ATAs adjustment scale for each iteration cycle. Simulation results showthat compared with the fixed ATA, the number of served MSs by e NBs is significantly increased by 7. 2%, the quality of the received signal is considerably improved by 20 d Bm, and, particularly, the system throughput is also effectively increased by 55 Mbit / s.

Estimation of Solar Radiation on Horizontal and Tilted Surface over Bangladesh

To estimate the monthly averaged solar radiations (global, diffuse and direct solar radiation) on horizontal surface and tilted surface over 10 stations (districts) in Bangladesh, thirty years monthly averaged data of various meteorological parameters namely the monthly averaged value of maximum temperature, minimum temperature, humidity and sunshine hours were used in this study. Assessment of the solar resources for the solar based renewable energy technologies of Bangladesh may be based upon this kind of measured data analyzed study. This study tried to estimate the monthly averaged solar radiation by presenting data in table and graph and finally analyze through equations and descriptions. Correlation between the measurements of monthly averaged solar radiation and the meteorological parameters was given for the selected 10 stations in Bangladesh. In conclusion, we tried to make a comparison among solar radiation on horizontal surface, fixed 20.83 ° (degree) optimal tilt angle and variable optimal tilt surface at Dhaka station.

Coverage Optimization of LTE Networks Based on Antenna Tilt Adjusting Considering Network Load

In this paper,we investigate the coverage optimization for LTE networks considering the network load. The network coverage is defined as the number of served users of evolved Node B(eNB)which is determined by e NBs' antenna tilt angles(ATA). The coverage is optimized by optimizing the number of served users based on the Modified Particle Swarm Optimization(MPSO)algorithm. Simulation results show that both the number of served users by each e NB and the system throughput are significantly increased. As well,the average load and the bandwidth efficiency of the network are improved.

Optimization and Sizing of a Stand-Alone Photovoltaic System and Assessment of Random Load Fluctuation on Power Supply

This study presents an optimization technique and design for a stand-alone photovoltaic (PV) system to provide the required electricity for a single residential household in remote areas. From the basic solar components analysis, the irradiance on tilted surface is derived and compared to that on horizontal surface for Furu-Awa locality to infer the appropriate tilt angle (β) that maximizes the collection of solar energy. Seven optimum values of β applicable to the PV network were then derived depending of the period of the year and this simulation resulted that the panels are to be adjusted seven times a year. The optimization technique for load demand based on total apparent power of the household appliances produces an increase of 18% compared to the simple case of the PV components design using active power but leads to the optimum configuration that meets the real load demand of the household. Following the sizing of the station, reliability tests simulations were conducted for a one year corresponding period to infer the sensitivity of power supply to initial state of charge, to check the system autonomy and to evaluate the effect of random variation of the load on the smooth functioning of the PV system using a pseudo random number generator. This analysis shows that the minimum capacity of the battery for normal run of the Plan is 22.2% and that with random fluctuation of load, there will be periods of the year where the system experiences power failure depending on how important is the variation. The result of the study may imply a small increase in the cost of the entire plant but improves the stability and flexibility of such a station.

基于耦合辐射模型的太阳能集热器倾角优化研究

为了使太阳能集热器获得更多的太阳辐射量,须对集热器倾角进行优化。文章在建立倾斜面太阳辐射计算模型的基础上,分别优化直接辐射、散射辐射的计算过程。以太阳能集热器运行期间倾斜面接收最大辐射量为求解目标,借助MATLAB对集热器倾角进行优化分析,得到月度最佳倾角和年度最佳倾角。其中天津地区的太阳能集热器年度最佳倾角为36.3°,比当地纬度略小;月度最佳倾角为10~64°,表现为夏季小冬季大的特点。相较于水平放置,在年度最佳倾角和月度最佳倾角下,太阳能集热器接收的年太阳辐射量可分别增加12.4%,17.3%;相较当地纬度作为倾角时,以月度最佳倾角值逐月调整接收的太阳辐射量可增加5.0%。分别以广州、拉萨、济南和长春为例,计算得到上述地区的年、月最佳倾角。对不同地区进行对比分析发现,直接辐射占比较高的地区逐月改变最佳倾角可获得更高的能量增益。

倾转旋翼飞机倾转机构设计及优化

倾转机构在倾转旋翼机过渡飞行阶段起着重要作用。文中以某倾转旋翼机倾转机构为研究对象,建立计算数学模型,研究传动角随作动器固定点变化规律,并以整个倾转过程中传动角算术平均值最大为优化目标,得到作动器固定位置最优点,并以该点为研究目标,当作动器匀速运动时,研究倾转角度及角速度随时间变化规律,为倾转机构控制提供参考。研究结果表明:固定点位置横向距离为4r、纵向距离为0.7r时,倾转过程平均传动角最大为67.369°;当作动器匀速运动时,倾转机构角度接近线性增加,角速度先降低,后提高,呈类抛物线规律。

基于IDBO-PID的联合收获机割台控制系统

该研究专注于提升无人农场联合收获机在复杂地形作业时,割台高度控制的精确性与响应速度。首先,提出了一种基于双倾角传感器的高度检测补偿方法,通过最小二乘法拟合建立割台倾角与高度的相关模型,相关系数0.9958,显著提高测量准确性。随后,引入群智能算法优化的PID控制策略,利用Bernoulli混沌映射、粒子群算法(PSO)、t分布扰动改进蜣螂优化算法,解决了传统PID控制的精度低和响应慢等问题。基于这些优化,IDBO-PID控制器在仿真对比中相较于DBO-PID和传统PID,具有更优的响应速度和稳定性。试验验证表明,改进的控制策略使割台的上升速度达到0.44m/s、下降速度达到0.32m/s,并且高度误差控制在0.02m内,满足作业需求。

圆锥形固体粉料料斗下料不畅问题解决探析

某工厂现有圆锥形固体粉料料斗在出料过程中出现下料不畅问题,采用加装自动振动器进行间歇性循环锤击的初步解决方法,但效果不佳。通过分析料斗结构、料斗流型及固体粉料特性等影响料斗下料的因素,认为引起料斗下料不畅的主要原因是料斗倾斜角过小,造成了物料的偏流和沉积。运用改流体概念,提出在料斗内加装整块贯穿式倾斜挡板,加大料斗倾斜角的优化改进方案。改进后彻底解决了料斗下料不畅问题,生产效率大幅提高,现场应用效果良好。

基于交互式多目标决策方法的固定式光伏阵列最佳倾角优化

在确定固定式并网光伏阵列最佳倾角时,设计人员要兼顾考虑年发电量和光照辐射均匀性两方面的因素。建立了以倾斜表面年辐照量最大和辐射累积偏差最小的多目标光伏阵列最佳倾角模型。运用基于目标满意度和整体协调度的交互式多目标决策方法对所建模型进行了求解,实时将决策者的主观意愿与系统进行交互,计算效率高。算例证明了所建模型的合理性和交互式多目标决策方法的可靠性。

稀土电解槽电解效率优化数值模拟

建立了考虑阳极表面气体存在的稀土电解槽流场—电场双向耦合模型,根据阳极气体作用下的电场分布情况来调节阳极下半部倾角,从而使电场分布相对平衡。结果表明,电场受阳极气体影响呈斜型分布,调节阳极下半部倾角为3°~6°,阳极下端电压降主要区域向坩埚一侧偏移,当倾角达到5°时,槽体内部电场分布相对均匀,有效改善了电解效率。

太阳电池板安装倾角间歇性优化调节的研究

提出一种间歇性优化调节的固定式太阳电池板最佳安装倾角的计算方法。在研究直接太阳辐射、散射辐射和地面反射辐射量的变化情况和太阳电池板光电转换关系的基础上，导出固定式安装的太阳电池板聚光能量瞬时值的计算模型。通过对倾斜面上瞬时辐射量在调整周期内的连续积分，获得在年能量收益最大化下的按月、季、半年进行调整以及全年固定式太阳电池板的最佳安装倾角。仿真计算表明，与水平安装的太阳电池板电池板相比，在不同地区按冬、夏半年期进行最佳倾角调整的太阳电池板聚光能量可增加23．8％～29．6％，有较好的综合效益。

一种固定式光伏电池板最佳安装倾角优化算法

针对安装固定式的光伏电池板建立瞬时辐射量模型,并给出固定安装时的年最佳设计倾角计算方法。以步长为0.01°逐一计算不同安装倾角下的年辐射量,利用设定角度范围进行循环穷举法寻优的方式计算安装固定式的光伏太阳电池板的最佳倾角。以部分城市为例计算固定安装时的年最佳设计倾角,另外给出了以北京为例一个城市的每月最佳倾角及平均日光辐射总量。结果分析表明,本算法具有一定的实用参考价值。

光伏电站阵列最佳倾角和间距确定方法研究

在光伏电站建设中,光伏电站在安装地点确定之后,为了确定最优的光伏组件的安装倾角以及间距,在常规光伏组件安装倾角和间距计算结果的基础上,引入了等量微曾率的概念。以二连浩特地区为例,通过PVsyst软件进行仿真优化。结果表明,优化后当地光伏电站每1 MW容量年发电量可增加约9 300 kW·h。

光伏建筑的安装施工与屋顶优化

对光伏建筑中电池组件的安装施工方法以及屋顶最佳倾角的选择进行了研究。光伏组件的施工包括就位和安装两个步骤,安装方法可分为外置式、表皮式、建材式3种。针对光伏建筑中的平面坡屋顶的最佳倾角选择进行了分析,给出最佳倾角的计算方法。光伏建筑设计时可参考计算结果选择倾斜角,使光伏建筑效能最大化。

太阳总辐射最佳倾角的时空分布

本文根据倾斜面上太阳总辐射最佳倾角的解析表示式,利用平均太阳总辐射和直接辐射月总量以及实际地表面反射率,计算分析了我国各月最佳倾角和最佳总辐射比的时空变化特征。同时对用天空散射辐射各向同性模式计算倾斜面上总辐射日总量的适用性问题亦作了简要讨论。

优化水肥与传统水肥对冬小麦叶片生长、群体光分布及产量的影响

与传统水肥相比 ,优化水肥、秸秆还田优化水肥处理冬小麦主茎上第四叶叶面积和厚度略微减少 ,叶倾角、消光系数、各层透光率与传统水肥处理差异很小 ,株形尚好。优化水肥和秸秆还田优化水肥处理冬小麦籽粒产量略高于传统水肥处理。与优化水肥处理相比 ,秸秆还田优化水肥处理有利于增加光合面积 ,提高叶片质量 ,改善冠层结构和光分布状况 ,增加单位面积籽粒产量。

面向桂林气象特征的太阳能光伏电池板最佳部署角度

在WSN节点太阳能光伏自供电系统中,光伏电池板的部署角度是影响获取太阳辐射量的重要因素之一。阐述了光伏电池板固定过程中的倾斜角度和方位角度,给出了倾斜角和方位角的最佳角度部署策略。在此基础上,以桂林某大学(E110.3°,N25.07°)为部署实验地点,利用PVsyst 6软件对光伏电池板最佳倾斜角和方位角的部署策略进行了仿真实验。结果表明,在该实验地点,最佳倾斜角度为20°,最佳方位角度为偏正东方向-1°~偏正西方向4°。同时,通过Meteonorm软件,以NASA提供的桂林市太阳能光照辐射量数据为例,对最佳角度部署模式(倾斜角度取20°,方位角度取1°)和水平面部署模式进行了对比实验,结果表明,从年度光照总辐射量来看,相对于水平面部署模式,本文提出的最佳角度部署模式能获取更多的能量,稳定性更好,性能更优越。

云南南向平板太阳能热水系统水箱水量与集热面积配比特性研究

文章基于平板型集热器日均能量输出模型,建立了太阳能热水系统水箱水量与集热器面积的配比模型。以云南7城市的典型气象数据为例,利用所建模型对太阳能热水系统的水量配比进行了计算,给出了水箱终温为60℃时各城市各季节或全年使用太阳能热水系统的水量配比的取值范围。为便于工程应用,文中给出了水量配比与倾角间相关系数大于0.999的二次关系式。进一步讨论发现,云南7城市春季、夏季、秋季、冬季或全年使用的太阳能热水系统集热器的最佳倾角分别为10~15°,0~0°,32~38°,45~50°,24~30°;其对应的水量配比分别为50~60 kg/m2,44~51 kg/m2,43~56 kg/m2,44~58 kg/m2,46~52 kg/m2。针对不同的供热目的 ,可利用文中的关系式和各季节或全年的最佳倾角对太阳能热水系统进行优化设计。

不同水肥优化模式下冬小麦叶片生长及群体光分布研究

试验结果表明,与传统水肥相比较,传统灌溉-优化施肥冬小麦主茎上四叶叶片短小叶面积减少,叶片相对较厚,叶倾角大,株型紧凑,消光系数小,冠层各层透光率较高;优化灌溉-传统施肥冬小麦主茎上四叶叶片变长叶面积增加,叶片相对较薄,叶倾角小,株型较为披散,消光系数大,冠层各层透光率较低;优化水肥及秸秆还田优化水肥冬小麦主茎上四叶叶面积略微减少,叶片厚度、叶倾角、消光系数及各层透光率与传统水肥差异很小,株型较好;各处理间经济产量无显著性差异。