Energy conversion materials for the space solar power station

Since it was first proposed,the space solar power station(SSPS)has attracted great attention all over the world;it is a huge space system and provides energy for Earth.Although several schemes and abundant studies on the SSPS have been proposed and conducted,it is still not realized.The reason why SSPS is still an idea is not only because it is a giant and complex project,but also due to the requirement for various excellent space materials.Among the diverse required materials,we believe energy materials are the most important.Herein,we review the space energy conversion materials for the SSPS.

Multi-Layer and Multi-Objective Optimization Design of Supporting Structure of Large-Scale Spherical Solar Concentrator for the Space Solar Power Station

Space solar power station is a novel renewable energy equipment in space to provide the earth with abundant and continuous power.The Orb-shaped Membrane Energy Gathering Array,one of the alternative construction schemes in China,is promising for collecting space sunlight with a large-scale spherical concentrator.Both the structural and optical performances such as root mean square deformation,natural frequency,system mass,and sunlight blocking rate have significant influences on the system property of the concentrator.Considering the comprehensive performance of structure and optic,this paper proposes a novel mesh grid based on normal polyhedron projection and spherical arc bisection for the supporting structure to deal with the challenge of the large-scale structural modular design.For both achieving low system mass and high surface precision,a multilayer and multi-objective optimization model is proposed by classifying the supporting structure into different categories and optimizing their internal and external diameters.The Particle Swarm Optimization algorithm is adopted to find optimal sectional dimensions of the different kinds of supporting structure.The infinite model is also established and structural analysis is carried out,which are expected to provide a certain reference for the subsequent detailed structural design.The numerical results indicate that the spherical concentrator designed by the novel mesh grid would obtain as high as 94.37%sunlight collection efficiency.The supporting structure constructed with the multiple layers would reduce the system quality by 6.92%,sunlight blocking rate by 28.54%,maximum deformation by 41.50%,and root mean square by 9.48%to the traditional single layer,respectively.

Distributed power conditioning unit of large-scale space solar power station

In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple independent PV arrays.In each PV array,there are multiple independent PV subarrays.In this paper,a V-P droop control method with adaptive droop coefficient is proposed,which modifies the droop intercept based on the bus voltage deviation and the power per unit value of the PV array.This method ensures the accuracy of bus voltage and achieves proportional distribution of power between PV arrays based on the proposed topology structure in this paper.When the load changes or the output power of the PV array fluctuates,this method can ensure that power is distributed proportionally.The principle and control method of the proposed droop control method is analyzed in this paper.The effectiveness of the method is verified through MATLAB/Simulink simulation and experiment.Simulation and experimental results show that the proposed method can achieve power distributed proportionally when load changes and PV output power fluctuates,reduce bus voltage error caused by line impedance and differences in rated power of different PV arrays,and improve the performance of PV power generation system applied to space.

Technical challenges of space solar power stations:Ultra-large-scale space solar array systems and space environmental effects

Space solar power station(SSPS)are important space infrastructure for humans to efficiently utilize solar energy and can effectively reduce the pollution of fossil fuels to the earth’s natural environment.As the energy conversion system of SSPS,solar array is an important unit for the successful service of SSPS.Today,solar arrays represent the standard technology for providing energy for spacecraft,thanks to their high conversion efficiency and reliability/stability in orbit.With the development of solar arrays,many new materials,new photovoltaic devices and new control systems have emerged.Solar arrays are directly exposed to the space environment,and harsh environmental factors can degrade the performance.To ensure the long-term safe inorbit service of SSPS as well as its ultra-large solar array,these new materials,devices,and control systems must operate certification and evaluation that can be used in space applications.In this review,the development history and research progress of SSPS and the corresponding space solar arrays are summarized and discussed,and the space environmental effects of solar arrays are analyzed at multiple levels(materials,devices,and systems).Finally,in response to the current space environmental effects of the ultra-large solar array used in the SSPS,future development trends and challenges are proposed.

空间站电动工具开关按钮性能退化特性加速寿命试验与可靠性评估

面向中国空间站在轨寿命评估与延寿需求,以舱外电动工具开关按钮为对象,开展综合考虑在轨长期贮存与短期作业交替影响的加速寿命试验,设置多温度水平,研究开关按钮性能退化特性和失效机理,并采用基于伪寿命分布的可靠性评估方法开展评估工作。加速寿命试验结果显示:开关按钮在50℃和80℃温度下出现按压力松弛现象,按压力退化与时间呈线性关系;在110℃和140℃温度下出现卡滞、卡死和润滑脂溢出现象,且按压力迟滞量在贮存后期显著增大。可靠性评估结果显示:开关按钮满足10年寿命末期可靠度0.9954的指标要求。文章所述研究方法可为空间站内其他长期贮存单机的可靠性评估提供借鉴。

空间斯特林热电转换技术在轨试验

为提高空间同位素电源的效率和功率,满足深空探测、载人登月和火星登陆等航天任务对航天器能源的需求,梳理了空间自由活塞斯特林热电转换涉及的关键技术,设计了天宫空间站空间自由活塞斯特林热电转换装置的在轨试验方案,在轨开展了斯特林热电转换试验,验证了空间微重力环境下双活塞自由运动的间隙密封、双活塞相位保持等关键技术,获取了空间环境下双自由活塞精确的运动相位保持及漂移特性、动力学与热力学强耦合特性等关键参数。在轨试验结果表明,试验装置在轨运行性能良好,热电转换效率达到24.72%,为未来空间高效同位素电源等不依赖太阳能的能源技术应用奠定了基础。

Effect of operational condition of rotational subsystem on attitude control for space solar power station

Space Solar Power Station(SSPS)is a giant spacecraft to collect space solar energy and transmit electric energy to the ground by using the wireless transmission technology.As a concentrated space solar power station,SSPS via the Orb-shape Membrane Energy Gathering Array(OMEGA)system is comprised of the concentrator subsystem,the photovoltaic array subsystem and the transmitting antenna subsystem.In this manuscript,the comprehensive study on the coordinate kinematic among subsystems is carried out.Firstly,kinematic analysis and dynamic analysis are conducted.Secondly,under the condition of ideal attitude,the influence of the moving condition of the Photovoltaic(PV)array on the overall system is studied.Finally,the control ability for the deviation attitude caused by the acceleration process of the photovoltaic array is studied.The simulation results demonstrate the serious influence of the angular acceleration of the photovoltaic array on the system’s attitude and the validity of the designed attitude control system.

A review of dynamic analysis on space solar power station

The concept of a space solar power station(SSPS)was proposed in 1968 as a potential approach for solving the energy crisis.In the past 50 years,several structural concepts have been proposed,but none have been sent into orbit.One of the main challenges of the SSPS is dynamic behavior prediction,which can supply the necessary information for control strategy design.The ultra-large size of the SSPS causes difficulties in its dynamic analysis,such as the ultra-low vibration frequency and large fexibility.In this paper,four approaches for the numerical analysis of the dynamic problems associated with the SSPS are reviewed:the finite element,absolute nodal coordinate,foating frame formulation,and structure-preserving methods.Both the merits and shortcomings of the above four approaches are introduced when they are employed in dynamic problems associated with the SSPS.Synthesizing the merits of the aforementioned four approaches,we believe that embedding the structure-preserving method into finite element software may be an effective way to perform a numerical analysis of the dynamic problems associated with the SSPS.

基于随机变量概率分析的铁路隧道紧急救援站间距计算方法

考虑着火列车位置和残余运行时间两个随机变量,构建基于列车残余运行的紧急救援站间距定量计算方法并进行验证,分析隧道纵坡、列车制动性能、列车动力损失对紧急救援站间距的影响,以及不同紧急救援站间距的适用条件。研究结果表明,列车动力损失增大、制动性能减弱、隧道纵坡增大均会导致紧急救援站间距减小,其重要性排序为列车动力损失>列车制动性能>隧道纵坡;紧急救援站间距15 km的适用条件为列车动力损失≤1/4;间距20 km的适用条件为列车动力损失≤1/4,且隧道坡度为30‰时,通行列车制动性能应与CRH5相当;间距30 km的适用条件为99.97%保证率的列车残余运行时间≥21.5 min。

太空电站充电时基于真实手臂模型的SAR分析

空间太阳能电站所提供的将是高功率的电磁能量,在执行无线供电的过程中,将会在被供电设备上再次激励起不同频率的电磁波,对人体健康产生一定的威胁。对于低频的电磁波可以将人体整体等效为一个简易模型,分析电磁波对人体健康的影响。但是,当频率逐渐升高,其波长将和人体的局部组织尺寸可比拟,此时必须采用真实的人体模型才能更精确地分析电磁波对人体的影响。为此,文章研究5.8GHz频率下,基于真实手臂模型的比吸收率。利用平面波照射真实手臂模型,分析手臂表面以及透射到各个关键局部区域体积内的SAR值,可为高频率情况下电磁波对人体健康的影响提供一定的参考。

无线电能传输技术在空间太阳能电站中的研究与应用现状分析

空间太阳能电站是高效利用太阳能以解决当下严峻的能源危机的有效途径,如何实现电能从空间太阳能电站到地球的空-地传输是关键。无线电能传输技术可实现电能的非接触传输,并且具有较高的安全性、可靠性和便捷性,是解决空-地电能传输问题的有效措施。对无线电能传输技术在空间太阳能电站中的研究与应用现状进行了分析,并据此阐述了亟待解决的瓶颈问题和待进一步发展的关键技术,旨在为后续相关科研工作者提供参考和指导。

基于变遗忘因子的空间太阳能电站时变频率辨识

考虑空间太阳能电站(SSPS)在轨运行时帆板旋转所导致的系统变构型特征,提出一种变遗忘因子广义子空间跟踪器(VFF-GYAST)递推辨识方法,在轨辨识该时变动力学系统的模态频率参数,以提高GYAST方法对于这类时变系统的跟踪能力。基于模态综合技术和子结构方法,建立多旋转关节构型SSPS(MJ-SSPS)的时变姿态-振动耦合动力学方程;根据投影子空间理论,通过计算系统均方差来确定递推过程中的时变遗忘因子,以提高GYAST方法的跟踪性能并辨识得到系统的时变伪模态频率参数。数值仿真结果表明:所提方法能够有效地识别该大型柔性系统的时变频率参数。与传统的递推子空间方法相比,所提方法具有较高的抗噪声干扰能力,在低量测信噪比时所提方法对于频率辨识结果的相对误差的平均值小于5%,且对时变系统的跟踪性能优于基于固定遗忘因子的原始方法。

面向5G-R的链路级传输速率仿真技术

为帮助基于5G技术的铁路新一代移动通信(5G-R)系统在复杂铁路环境中确定基站间距,提出一种链路级传输速率仿真技术。该技术依托多种经验传播模型,获取电磁波在铁路沿线不同场景中的路径损耗,进而评估无线链路的参考信号接收功率(RSRP)。基于得到的RSRP数据,通过蒙特卡罗仿真方法计算链路级传输速率。仿真结果表明,对于开阔场景,基站间距可设置在2 000~3 000 m之间;在城市和复杂地形中,间距应缩短以维持性能。该技术能够反映5G-R系统在不同场景中的信号传输特性,包括不同基站间距下传输速率和RSRP的变化,为后续5G-R系统的基站部署规划提供了科学依据。

激光无线能量传输远场大光斑测试技术

无线能量传输系统作为空间太阳能电站的一个关键部分,其性能直接决定了空间太阳能电站技术的可行性。特别对于激光无线能量传输系统,准确测量激光远场光斑分布是分析和评价激光无线能量传输系统性能的有效手段。针对太阳能发电卫星轨道高、激光传输距离远、接收激光光斑面积大,并且受大气影响,光斑抖动严重,光斑能量分布以及光斑形状测量困难的问题,文章提出了基于光能探测器阵列的大面积激光光斑测试方法,采用光斑分布式测量及能量分布重构方法,完成激光无线能量传输系统远场光斑的测试,具有分布式测量,可灵活布局的特点,通过反演算法能够实现光斑能量密度分布重构,接收激光功率积分求解,光束发散角计算等,功能多样,适应能力强,为激光无线能量传输系统载荷的参数修订,以及在轨飞行任务的评价提供有效依据。

庆元抽水蓄能电站装机容量选择研究

为研究浙江省庆元抽水蓄能电站技术经济合理的装机容量指标,着重分析了浙江省抽水蓄能电站需求空间及本工程的建设条件等主要影响因素,拟定了3个装机容量方案,重点针对工程布置方案、电力系统作用及经济指标等方面开展技术经济综合比较,以技术经济优、电力系统贡献大为原则,提出了推荐方案。研究思路可为同类型抽水蓄能电站装机容量选择提供参考。

多旋转关节空间太阳能电站概念方案设计

对于国际上典型的空间太阳能电站概念方案进行了分析,在此基础上提出了一种新的概念方案——多旋转关节空间太阳能电站,并给出总体构型和主要分系统初步方案设计结果。该方案采用多个相互独立的太阳电池子阵代替了传统的整体式太阳电池阵,以多个中等功率的导电旋转关节替代传统的极高功率的旋转关节,不仅解决了传统空间太阳能电站方案中的极大功率导电旋转关节技术难题,还可以避免导电关节的单点失效问题,模块化的设计也使得系统的组装和构建更加可行。

大型空间电站在轨展开与组装动力学与控制

针对大型空间电站在轨展开与组装过程中复杂的动力学环境,将桁架类大型空间电站视为一个刚柔多体系统,采用自然坐标法对刚性构件建模,基于绝对节点坐标方法描述柔性桁架结构,编写了一套动力学仿真软件,实现了大型空间电站在轨展开与组装动力学的精确仿真。仿真结果表明,采用摆线运动插值函数作为控制方程有利于提高多级展开过程的稳定性;在结构组装过程中,减小组装速度,增大组装机构阻尼系数与劲度系数,有利于提高结构稳定性。最终集成了一套针对大型空间电站的动力学仿真平台搭建方法,为大型空间电站在轨展开与组装动力学预示提供了理论依据和方法指导。

国际空间太阳能电站发展现状

空间太阳能电站(Solar Power Satellite,SPS)概念受到了国际的广泛关注,美国和日本都已制定了争取在2030年左右实现商业化运行的发展路线图,并且在概念和技术层面开展了大量的研究工作。中国有必要尽快开展此方面的相关研究工作,为未来的长远发展奠定基础。

空间太阳能电站微波能量传输验证方案设计

微波能量传输技术作为空间太阳能电站(Space Solar Power Station,SSPS)的关键技术之一,目前的研究和验证工作均集中在各单项技术的突破和验证,缺乏针对SSPS系统特点的全面优化设计。文章根据SSPS的工作模式给出了全面验证空间太阳能电站微波能量传输的验证系统方案设计,对收发天线进行了一体化设计,利用了幅度近似高斯分布的发射阵列场分布设计和低反射的接收整流阵列设计,以高精度来波方向测量和高精度移相控制为波束指向控制的技术途径。对验证系统的波束收集效率进行了分析,收集效率可达94.2%,比传统均匀分布系统高出17.6%。验证系统可从系统规模缩比、波束扫描范围、发射天线口径场分布、整流天线处功率密度、反向波束控制方法等方面模拟SSPS微波能量传输工作模式,推动SSPS系统技术的发展。

SSPS太阳能收集系统研究现状及发展趋势

为研究太阳能收集系统在未来空间太阳能电站(SSPS)中的发展和应用,对比和分析国内外典型系统设计方案的结构特点、光收集特性及优、缺点,展望空间太阳能电站太阳能收集系统的发展趋势,并提出对新材料、新结构、新技术、新理论和新方法的发展和应用需求。