基于光学三角形法的太阳帆板平面度测量系统

介绍了一种采用斜光学三角形测量结构和基于虚拟精密测量基准的太阳帆板平面度无接触测量系统及其误差补偿方法。提出的虚拟精密基准的建模与误差补偿技术 ,解决了在非精密基准上实现精密测量的问题 ,研制的系统利用现有平台可实现对太阳帆板平面度的高精度测量。测量结果表明 ,系统对面积为 2 5 81mm× 175 5mm太阳帆板的平面度测量精度达 0 .0 2mm(rms)。     

Modeling and Simulation of a Hybrid Photovoltaic Module Equipped With a Heat-Recovery System

This paper presents a multiphysics model of a hybrid solar panel equipped with a solar concentrator and a cooling interface with heat-recovery capability. It is shown how the temperature profile along the cells can be predicted as a function of the cooling strategy. From this information, the I-V electrical characteristic of the whole module can be derived. An original compact electrothermal macromodel of the photovoltaic module is employed which allows one to properly incorporate the effect of temperature gradients along the cells. By exploiting this macromodel, accurate and efficient electrothermal simulations of the solar system can be carried out with a conventional electrical simulator, like Spice.     

高精度太阳位置检测系统的设计

针对目前太阳位置检测系统精度不高的情况,设计了一种基于CMOS图像传感器和ARM11微控制器的高精度太阳位置检测系统。该系统可以实时采集太阳图像、定时保存图像并对保存的图像进行图像处理、计算太阳光斑圆心偏离图像中心的偏差角,计算所得的数据可以显示在系统界面上。将系统所得太阳偏差角传送到太阳能板转台控制器中,转台控制器调整太阳能板位置使太阳能板正对太阳,从而提高太阳能利用率。实验结果表明,该系统测量精度高、误差小。     

Application of short light pulses for measuring parameters of a solar cell

An optimum circuit for controlling bias voltages applied to a solar cell during the process of measuring its pulsed current-voltage characteristic (IVC) is suggested. It is shown that the use of an optimum law of control of bias voltage under conditions of a sufficiently short light pulse (6.5 ms) makes it possible to substantially reduce the deviation of dynamic IVC from the ideal static characteristic. This significantly increases the accuracy of the measuring system, which, in turn, leads to an increased accuracy of determining the internal parameters of a solar cell on the basis of the consideration of one or other electrical model.     

Characterization testing of Measat GaAs/Ge solar cell assemblies

The first commercial communications satellite with gallium arsenide on germanium (GaAs/Ge) solar arrays was launched in January 1996. The spacecraft, named Measat, was built by Hughes Space and Communications Company. The solar cell assemblies consisted of large-area GaAs/Ge cells supplied by Spectrolab Inc. with infrared reflecting (IRR) coverglass supplied by Pilkington Space Technology. A comprehensive characterization program was performed on the GaAs/Ge solar cell assemblies used on the Measat array. This program served two functions: first to establish the database needed to accurately predict on-orbit performance under a variety of conditions; and second, to demonstrate the ability of the solar cell assemblies to withstand all mission environments while still providing the required power at end-of-life. Characterization testing included: measurement of electrical performance parameters as a function of radiation exposure, temperature and angle of incident light; reverse bias stability; optical and thermal properties; mechanical strength tests, panel fabrication, humidity and thermal cycling environmental tests. The results provided a complete database enabling the design of the Measat solar array, and demonstrated that the GaAs/Ge cells meet the spacecraft requirements at end-of-life.     

Application of short light pulses for measuring parameters of solar cells

An optimum scheme is suggested for controlling bias voltages applied to a solar element in the process of measuring its pulsed current-voltage characteristic (IVC). It is shown that the use of an optimum law of control of the bias voltage under conditions of a sufficiently short light pulse (6.5 ms) makes it possible to substantially reduce the deviation of the dynamic IVC from the ideal static characteristic. This substantially increases the accuracy of the measuring system, which, in turn, leads to an improved accuracy of determining internal parameters of a solar cell proceeding from the consideration of this or that electrical model.     

倾角传感器在太阳能跟踪系统中的应用研究

太阳能以其普遍性、永久性、无污染、分布广、利用方便等优点成为各国竞相研究和开发的热点。对太阳能跟踪控制系统中的倾角传感器应用进行了研究,以检测太阳能电池板的倾角,使得太阳能电池板在俯仰方向上与太阳的高度保持一致。设计了倾角传感器检测电路,通过对倾角传感器输出数据的采集和滤波处理,滤除了太阳能电池板在转动过程中因抖动而产生的随机误差信号,实现了在俯仰方向上的精确测量。     

基于历史信息的雷达测量精度等效评估方法

飞行器发射试验前需要评估测量设备的精度。针对无校飞实验条件下的雷达测量精度评估问题,提出了一种等效精度评估方法,利用历次试验的测量数据和试验前的测试数据评估参试雷达的测量精度。分析了雷达的测量信号流程,建立了检测信息、测试信息到测量精度映射的因子合成回归模型,给出了历次测试信息一致性的秩和非参数检验方法,在测试信息一致的前提下等效评估当前的测量精度。经飞行试验测量数据验证,所提方法对雷达的测量精度评估结果与实际精度的符合性较好,可用于无校飞试验条件下技术状态稳定的雷达精度评估。     

比色测温中外界环境误差的减小方法研究

基于比色测温原理,论述了对比色测温测量精度影响较大的外界环境因素。通过理论研究,提出从比色测温双波段采集到的信息中除掉外界环境干扰因素的思路,并通过对大量实验数据的处理分析,得出最佳的校正模型,提高了比色测温的测量精度。     

A Numerical Methodology for the Prediction of the Near-Field Parasitic Electromagnetic Emissions of Solar Panels

This paper presents a methodology that is developed to assess the parasitic electromagnetic (EM) emissions of a satellite solar panel from a quasi-static to several tens of megahertz bandwidth. In the method, the solar panel is first modeled as an equivalent electric circuit, which allows the computation of the current distribution in all the elements using Spice-like software. The model is then converted into a network of electric dipoles, which permits to calculate the total EM emissions of the solar panel at a given point by the vectorial summation of the EM emissions due to each electric dipole. Thus, only the dipolar moment and the position and the orientation of each electric dipole are required. Encouraging experimental validations performed on a prototype solar panel are presented to illustrate the efficiency and the accuracy of the method. The method described in this paper is considered as a first step required in order to prepare wider applications on real satellites in the near future.      

Electro‐optical study of a ×1024 concentrator photovoltaic system

Concentrator photovoltaic (CPV) systems are one of the most promising technologies for future energy supply. Several studies reported the interest of using a Fresnel lens coupled with a secondary optical element in such a system. For high concentration factor, the optimization of the optical configuration plays a key role regarding electrical performances. On the other hand, the thermal management of the solar cell is also critical to ensure a better module efficiency. This paper presents a study of a ×1024 CPV system performances and a methodology for estimating the optical chain efficiency, the cell temperature impact and the alignment requirements. Module efficiencies were then measured as a function of the cell temperature and correlated to optical performances through current‐tension characterizations under real solar illumination conditions and the estimation of the power density received by the solar cell. The system yield was up to 27% for a cell temperature around 30 °C, confirming that high concentration ratio should be of great interest in the near future. A 1D model was also developed in order to quantify the possible improvements of this CPV system. Using a solar cell with an efficiency of 36.7% at ×600, we then demonstrated that the ×1024 CPV system could reach up to 30% in standard test conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

Theoretical and Experimental Analysis of a Waveguide Mounting Structure

The induced EMF method has been extended and applied to derive the driving-point impedance of a common waveguide structure used for mounting small microwave devices. An equivalent circuit is developed and discussed in detail. Theoretical impedance curves are presented demonstrating the circuit characteristics for various configurations of the mount. The driving-point impedance of this mount has also been considered experimentally. A novel measurement technique is used based upon the use of subminiature coaxial line to gain electrical access to the terminal pair located inside the waveguide. A model of the measurement circuit, which enhances the accuracy of the results, providing excellent agreement between the theoretical and measured values, is developed. The multilateral nature of the circuit allows consideration of the mount in the waveguide as an obstacle to any incident propagating mode. Some related measurements have been made using standard techniques for the H/sub 10/ mode. It is anticipated that this formulation will permit accurate design of many components which previously required empirical methods based on limited experimental data.     

Toward accurate and efficient available bandwidth measurement

The packet-pair technique is the most popular end-based approach for bandwidth measurement. Most packet-pair based proposals use the fluid cross-traffic model to justify the design of their estimation techniques. However, real traffic is certainly not fluid. The consistency of the statistical packet-pair dispersion model in general bursty cross-traffic conditions has still not been fully justified in published research. Furthermore, we note that existing measurement techniques do not take account of the actual measurement variance, which means that they are often subject to significant fluctuations in accuracy. To achieve high accuracy and efficiency in available bandwidth measurement, we contribute analytical insights into packet-pair dispersion techniques by developing a queuing model to describe the impact of the cross-traffic on the packet-pair dispersion under bursty cross-traffic conditions. Based on this model, the consistency of statistical packet-pair dispersion measurement in general cross-traffic conditions is demonstrated and new approaches that help to detect and eliminate the elastic bias caused by measurement variance are presented. We show that the algorithm we developed works correctly on the Internet and offers more dependable measurement results than existing tools.     

不同固体表面下激光多普勒测速的数值模拟

激光多普勒测速仪(LDV)的测量精度和应用受到光电探测器、环境状况、频谱加宽和信号处理等因素影响。本文根据条纹模型和散射机理建立了固体LDV的数学模型,并通过数值模拟详细分析了固体表面特性和测量精度之间的关系,实验结果和数值模拟结果符合得很好。LDV能够精确地测量出固体表面运动速度,但要求被测固体的表面粗糙度在一定范围内,而且这个范围由条纹间距和有效探测体宽度决定。     

非平稳机载全极化SAR定量化测量误差分析及处理方法

即使SAR系统内外定标非常准确,在不同飞行条件下,机载全极化SAR测量精度仍然存在一定的变化,特别在非平稳及高波段时,精度恶化较为严重。针对该问题,该文首先建立了非平稳环境下全极化SAR误差模型,然后分析了分时收发体制下通道间轨迹的微弱变化对极化相位不平衡度的影响,指出随着波段的提升,相同运动误差导致的相位不平衡度相应加重,据此给出了相应的处理方法。最后通过仿真及高分航空专项S波段SAR获取的数据对该方法进行了检验,开展的多次应用示范,也验证了方法的有效性和稳定性。     

High throughput testing platform for organic Solar Cells

In this paper we present a high throughput testing setup for organic solar cells that is necessary for an efficient analysis of their behaviour. The setup comprises process parameter logging, automated measurement data acquisition and subsequent data management and analysis. Utilising this setup the reproducibility of solar cells and the effect of production parameter variations has been tested with a set of 360 solar cells based on the poly‐3‐hexylthiophene:1‐(3‐methoxycarbonyl)‐propyl‐1‐1‐phenyl‐(6,6)C₆₁ bulk heterojunction. Variations in power conversion efficiency between 1 and 3% were observed on varying production parameters hardly mentioned in literature. The conditions during the vacuum deposition of the aluminium cathode turned out to have a significant effect. The key solar cell parameter affecting the performance was the fill factor (FF). As such the work exemplifies the necessity for a combined approach to analyse the complex behaviour of organic solar cells. The developed high throughput testing setup provides a basis for an efficient testing of production parameter variations and materials and additionally opens the door for statistical analysis. Copyright © 2008 John Wiley & Sons, Ltd.     

某火炮故障检测系统设计及精度问题研究

火炮故障检测系统检测范围有限和检测精度低是火炮故障诊断系统的两大缺陷,针对现有火炮检测系统检测精度低的问题,从电路设计、A/D采集电路设计以及液晶显示等方面分析了影响系统检测精度的主要因素,并提出了多种改善检测精度的方案。针对现有火炮检测系统检测范围有限的问题,提出了一个可对炮控箱、操纵台和瞄控箱、电源、开关以及电位旋钮等多位置发生的故障进行检测的火炮综合故障检测系统,并对该系统相关的硬件和软件进行了设计。测试实验表明,该系统功能完善,通用性好,改善系统检测精度的方案实用性强,对于提高我国的火炮故障检测水平具有积极的意义。     

用光谱辐射计测量大气光学厚度的研究

本文给出了用光谱辐射计VF921-256测量大气光学厚度的实验结果，并对其与太阳辐射计DTF-1的同步测量结果进行了比对。实验结果表明：在比较好的大气条件以及对VF921-256测量中所应用的参考板的非朗伯特性进行校正后，两种方法的测量结果符合得较好。因此，在一定的误差范围内，VF921-256可以用于辐射校正中对大气光学厚度的同步测量。最后，本文对上面两种方法各自的测量误差也进行了进一步的分析讨论。     

环境温度对红外测温精度的影响及补偿方法研究

针对在线式红外测温仪的测温精度易受环境温度影响,导致测温误差增大的问题,提出一种基于环境温度的红外测温补偿方法,以减少测温误差.首先根据红外测温原理,搭建了红外测温实验平台,获取了不同环境温度下的测温数据;然后利用最小二乘法原理对提取的测温误差均值进行误差-环境温度的曲线拟合,得到了红外测温补偿模型;最后对其进行了实验验证.实验结果表明,使用该补偿模型对红外测温数据进行补偿,得到的红外测温值与真实目标温度值的最大相对误差为0.29％,说明提出的补偿方法降低了环境温度对红外测温的影响,有效提高了红外测温精度.