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.

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.

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.

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。

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。

空间太阳能热动力系统的全局优化研究

为了为今后空间太阳能热动力发电系统的设计提供热能有效利用方案,提出了空间太阳能热动力发电系统的评价准则,建立了系统质量计算的数学模型,利用复形法编制了太阳能热动力发电系统的优化程序,运用该程序对太阳能热动力发电系统进行了全局优化分析,得到了系统各参数的最佳值和最佳工况下的系统部件质量。研究结果表明,全局优化可使系统发射总质量下降11.1％;发射总重量的评价准则综合考虑了系统质量和阻力面积,能够全面反映系统的经济性能,可以得到很好的优化结果。

空间太阳能热动力系统的轻量化研究

为了降低系统的质量和阻力面积,运用系统分析的方法,建立了空间站太阳能热动力发电系统的物理和数学模型,提出了发射总重量的系统性能评价准则,并对不同条件下的系统部件质量进行了数值模拟,分析了不同操作参数对系统部件质量的影响规律。研究结果表明,操作参数对系统部件质量有正负两方面的影响,优化这些参数可以明显降低系统的发射总质量。

结构参数对空间太阳动力系统质量的影响

为了降低系统的质量和尺寸 ,运用系统分析的方法 ,建立了空间站太阳能热动力发电系统的物理和数学模型 ,编制了空间太阳能热动力发电系统的数值模拟程序 ,运用该程序对不同条件下的系统性能进行了数值模拟 ,分析了不同结构参数对系统性能的影响规律。研究结果表明 ,结构参数对系统性能有正负两方面的影响 。

国外空间太阳能热动力发电系统发展及建议

空间太阳能热动力发电系统作为一种新型的空间供电方式 ,在费用上和性能上已经显示出了很大的优势 ,有可能成为未来的空间供电方式。国外对于它的研究已经超过 4 0年。通过介绍空间太阳能热动力发电系统的工作原理和技术发展 ,并且与其它电源系统、主要是光伏系统进行技术比较 ,显示出这种供电方式的的较大优势。重点介绍了NASA 2kW空间太阳能热动力发电系统地面样机的部件、结构和试验。根据国外研究经验 ,提出了空间太阳能热动力发电系统研究的建议。

光压摄动对空间太阳能电站轨道的影响研究

针对以重力梯度稳定方式设计的3种典型空间太阳能电站轨道动力学问题,提出了考虑地影和有效截面积变化的太阳光压模型.首先,采用能量方法,通过Legendre变换,引入广义动量,建立了Hamilton体系下轨道的正则方程;其次,采用辛Runge-Kutta方法求解相应的正则方程;最后通过数值试验分析,验证了模型的有效性以及数值求解方法的稳定性.同时,说明了地影和有效截面积变化对空间太阳能电站轨道有显著的影响;给出了空间太阳能电站对其半长轴、离心率以及轨道倾角的轨迹曲线,为空间太阳能电站的设计提供一种理论参考.

基于粒子群算法的空间太阳能热动力系统优化设计

太阳能热动力系统是空间站的重要组成部分。为有效降低太阳能发电系统的发射质量,在分析空间太阳能热动力系统的工作原理、粒子群算法的原理及实现的基础上,采用粒子群算法对太阳能热动力系统的发射质量进行了优化仿真设计。在保证压缩机的进口压力、压缩机的进口温度、压缩机的压缩系数、换热管的数目、换热管的直径、回热器的回热度、循环工质流道高度、热管直径、热管长度及能量转换单元的转速等独立变量满足系统要求的前提下,使得发射质量最小,从而有效地节约发射、管理和后续支持费用。将粒子群算法的优化结果通过遗传变异修正后,其结果要好于基本粒子群算法和遗传算法结果。

太阳能热动力系统Brayton装置与Stirling装置分析与比较

空间太阳能热动力发电系统是非常有前景的未来空间能源供应系统,对适用于空间SD装置的Brayton循环和Stirling循环进行了详细的分析,并以7kW发电装置为对象,从质量、效率和对吸热器的要求等方面对2种循环进行了比较。结果表明,Brayton装置为目前太阳能热动力发电的首选方案,Stirling装置是未来最理想的空间发电系统。

我国载人航天电源系统的技术发展成就及趋势

载人航天电源系统是一个庞大的系统工程,状态复杂、可靠性要求高、技术难度大。本文在阐述我国载人航天电源系统组成和特点的基础上,从电源系统架构、太阳电池翼、储能电池组、并网控制以及在轨维修与更换等方面,详细论述了我国载人航天电源系统的各阶段技术突破和技术引领,并对后续载人月球探测提出展望,梳理了能源系统重点研究方向和关键技术,为未来载人月球探测任务顺利实施奠定技术基础。

基于状态空间模型的电站厂房结构系统辨识

针对机组及其支撑结构的振动问题,为研究厂房结构振动的主振源及传递路径,以李家峡水电站为例,结合厂房原型振动测试试验,基于系统辨识理论,将顶盖水压脉动和垂直振动、推力轴承垂直振动、尾水管水压脉动为动力系统输入信号,将下机架基础测点垂直振动为输出信号,构建了多输入单输出系统状态空间辨识模型。研究结果表明:该方法较好地反映了结构系统的动态特性。

空间站太阳能热动力发电系统吸热器研究

系统介绍了国际上对空间站太阳能热动力发电系统中吸热器的研究成果。详细地介绍了目前国际上研究设计的两种吸热器的结构、尺寸以及工作原理 ,对蓄热相变材料及其和吸热管材料间的腐蚀、相容性进行了讨论 ,分析了吸热器相变材料储罐壁面的热松脱问题及其对策。

空间对称聚光太阳能系统在地球轨道的运动姿态规划研究

以空间对称聚光发电系统为研究对象,为实现系统全天候对日定向聚光,对系统的在轨姿态进行规划研究。首先,从运动学角度研究系统定向参数和入射光方位间的变换关系,分析出各关节角随时间的变化规律,并通过系统跟踪光线得出定向参数与光线跟踪角之间的关系;其次,给出一种系统对日定向姿态调控策略和具体实现方法,验证了姿态规划在满足对日定向条件下的合理性和有效性。这种规划策略能保证系统的高效、连续聚光,显著提高整体系统的聚光比。

分布式空间太阳能电站与能量传输技术研究

随着日益紧迫的能源需求及人类征服太空能力的加强,如何构建空间太阳能电站(SSPS)备受关注。此处对SSPS的起源及最新发展进行了阐述,针对当前SSPS的系统模型及空间能量传输技术进行了概括和分析,并结合我国当前空间技术水平,提出一种分布式SSPS设想。该分布式结构有效降低了系统太空组装难度及发射难度,为我国发展SSPS提供补充和借鉴。