Reflection-type single long-pulse solar simulator for high-efficiency crystalline silicon photovoltaic modules

Photovoltaic module measurements are predominantly taken by using pulsed solar simulators. However, significant errors can be generated when the existing simulators are applied to current high-efficiency crystalline silicon photovoltaic modules. This paper presents the design and implementation of a novel solar simulator featuring reflection-type light source and single long-pulse flash. The analysis and experimental study of the capacitance effect and the technical details of the simulator including reflection-type lamp house, xenon flash lamp power supply, and source-measure unit are introduced. The results show that the complete system achieves Class AAA performance in accordance with the international standard. The proposed simulator outperforms other similar products on the market and has been adopted by some well-known photovoltaic module manufacturers. The practical application demonstrates that this high-performance and cost-effective simulator is quite suitable for photovoltaic module production line.     

用于焊接驻极体麦克风的锡焊机器人系统

针对手机用驻极体麦克风与柔性印刷电路锡焊的特殊要求进行了分析.根据需求设计了专用的锡焊机器人;详细介绍了原型机的机械结构特点和基于PMAC的电机运动控制、焊接压力控制、PMAC设备驱动和上位机软件总体结构;经测试证明,该原型机在运动精度、压力控制效果及焊接产品质量等方面具有一定的优势.     

基于改进 EfficientNet 的红外图像光伏组件故障识别研究

光伏组件的故障会影响光伏阵列的输出性能,从而降低电站的发电效率,严重时甚至会危害电站的安全运行。 传统的 方法无法满足目前光伏组件故障检测快速性和正确率需求。 因此,本文提出了一种基于改进 EfficientNet 的光伏组件故障识别 方法。 首先,利用采集到的光伏组件红外图像建立故障数据集,并利用图像分割和数据增强对数据集进行预处理;其次,基于 EfficientNet 网络构建故障识别模型,同时在模型中引入双通道注意力模块(CBAM),该模块能够抑制不必要特征的识别,增强 模型对空间特征信息的提取能力,进而提高模型的识别准确率;最后,通过对比仿真实验证明模型的有效性和先进性。 实验结 果表明,该模型的故障识别准确率达到了 90. 83% ,相较于原始的 EfficientNet 模型提高了 2. 83% ,且模型大小仅为 20. 3 M,具有 良好的实用性,能够满足光伏电站实际应用的需求。     

砷化镓光伏电池的激光光照特性研究

激光无线能量传输技术具有广阔的应用前景,而光伏电池的激光辐照特性是设计激光无线能量传输系统的重要依据。针对该问题,研究了激光功率与温度对光伏电池的影响,搭建了光伏电池激光辐照特性的实验测试平台,测量并分析了光伏电池输出特性随激光强度和电池温度的变化规律。结果表明,激光辐照条件下,激光强度一定时,短路电流随温度升高而降低;温度一定时,转换效率与填充因子随激光强度的增大呈现先增大后减小的趋势。该研究可为激光无线能量传输条件下的系统设计仿真以及激光辐照下光电电池的输出特性研究提供参考。     

A silicon tracking detector module for the CLAS12 experiment

Results of testing the detecting module prototype for the barrel part of the tracking system of the CLAS12 experiment are presented. The module consists of four series-connected silicon microstrip sensors with a 30-cm total length and FSSR2 readout chip. The measurement results of the signal along the module and noise level for different lengths of strips in the module are given. It is possible to conclude from the obtained results that, at a strip length of <30 cm, the signal-to-noise ratio is 6: 1 or higher when minimum ionizing relativistic particles are detected.     

基于PLC的模块式自动化生产教学系统气动电控设计

本文介绍了模块式自动化生产教学系统的设计思路，并提出了这种教学系统基于PLC的结构设计和气动电控方案。     

一种适用于光伏发电系统的高增益Boost变换器

一般而言,光伏阵列电池的输出电压较低,必须经过升压才能满足后级逆变器的要求.在分析普通单相Boost变换器在高增益变换场合显现的不足的基础上,提出了串入等效电压源的概念,采用耦合电感实现了高增益变换.研究结果表明,其拓展了变换器的电压增益,减小了开关管的电压应力.漏感能量能够无损转移,提高了系统的效率.     

太阳能光伏阵列模拟器设计与实验研究

针对分布式发电系统的特点和太阳能电池阵列的输出特性,设计了光伏阵列模拟器和最大功率点追踪控制器,并进行了实验研究,实验结果表明所设计的光伏阵列模拟器能够对给定参数的光伏阵列进行模拟,并具有较高精度。     

基于FL-net网络的液晶面板模组生产线在线监控系统

针对液晶面板生产设备自动化程度高、工艺复杂的特点,提出了基于FL-net网络的液晶面板模组生产线在线监控系统,论述了监控系统的网络拓扑结构,硬件的选用以及网间通信协议的设置。     

Two-dimensional laser-induced periodic surface structures formed on crystalline silicon by GHz burst mode femtosecond laser pulses

Femtosecond laser pulses with GHz burst mode that consist of a series of trains of ultrashort laser pulses with a pulse interval of several hundred picoseconds offer distinct features in material processing that cannot be obtained by the conventional irradiation scheme of femtosecond laser pulses(single-pulse mode). However, most studies using the GHz burst mode femtosecond laser pulses focus on ablation of materials to achieve high-efficiency and high-quality material removal. In this study, we...     

输送硅粉用耐磨旋盘阀

介绍了输送硅粉用耐磨旋盘阀的技术性能、结构特点和加工工艺。     

SMT回流焊温度模糊控制系统的研究

回流焊温度控制是SMT中的重要技术.从回流焊工艺出发,提出了采用西门子PLC为控制核心,以模糊控制与PID控制相结合的控制方法实现回流焊的温度控制,利用MATLAB对系统进行了仿真结果表明,墓于模糊参数在线自整定的PID控制器系统超调量小,控制系统的动静态性能均得到改善,能够满足回流焊温度控制要求.     

一种多路数据采集系统通信模块设计

本设计主要讲述了PC机与AT89C51单片机之间的串口通信的设计。由单片机采集信号,将信号传送给PC机显示,PC机程序用VB编写,单片机程序用C语言编写,最后用Proteus软件进行仿真实现串口通信。根据串口通信原理建立的PC机与单片机间的通信协议,利用VB对采集到的信号进行接收和描述,并将其显示在可视的VB界面当中。该数据采集系统还具有存储并形成数据曲线的功能,以便对信号进行分析和处理。     

Numerical study on thermal stress cutting of silicon wafers using two-line laser beams

We propose a method of cleaving silicon wafers using two-line laser beams. The base principle is separating the silicon wafer using crack propagation caused by laser-induced thermal stress. Specifically, this method uses two-line laser beams parallel to the cutting line such that the movements of the laser beam along the cutting line can be omitted, which is necessary when using a point beam. To demonstrate the proposed method, 3D numerical analysis of a heat transfer and thermo-elasticity model was performed. Crack propagation was evaluated by comparing the stress intensity factor (SIF) at the crack tip with the fracture toughness of silicon, where crack propagation is assumed begin when the SIF exceeds the fracture toughness. The influences of laser power, line beam width, and distance between two laser beams were also investigated. The simulation results showed that the proposed method is appropriate for cleaving silicon wafers without any thermal damage.

     

Nonequilibrium heat transfer characteristics during ultrafast pulse laser heating of a silicon microstructure

This work provides the fundamental knowledge of energy transport characteristics during very short-pulse laser heating of semiconductors from a microscopic viewpoint. Based on the self-consistent hydrodynamic equations, in-situ interactions between carriers, optical phonons, and acoustic phonons are simulated to figure out energy transport mechanism during ultrafast pulse laser heating of a silicon substrate through the detailed information on the time and spatial evolutions of each temperature for carriers, longitudinal optical (LO) phonons, acoustic phonons. It is found that nonequilibrium between LO phonons and acoustic phonons should be considered for ultrafast pulse laser heating problem, two-peak structures become apparently present for the subpicosecond pulses because of the Auger heating. A substantial increase in carrier temperature isobserveds for lasers with a few picosecond pulse duration, whereas the temperature rise of acoustic and phonon temperatures is relatively small with decreasing laser pulse widths. A slight lagging behavior is observed due to the differences in relaxation times and heat capacities between two different phonons. Moreover, the laser fluence has a significant effect on the decaying rate of the Auger recombination.     

激光加工机微机控制系统的研究

根据激光加工机的结构特点,阐述了用于激光加工机的微机控制系统硬件和软件结构及系统特点.激光加工机微机控制系统经过中间试验、工业试验和现场使用,测试结果令人满意,证明了系统的设计是合理的.     

A system for controlling laser writing devices

Software and hardware for laser writing systems are presented. A method of multipage recording with allowance for object motion, aimed at dynamic formation of images on cylindrical surfaces, is proposed. Tools for creating protective laser marking with the use of the multilevel regime of laser writing are implemented.     

一种指纹模块在考勤终端中的应用与研究

针对学生代考现象难以准确及时地发现这一问题,介绍了一种利用人体指纹生物特征实现的个人身份认证装置,该装置基于C8051F020核心处理器,嵌入光学指纹识别模块,集成了以太网络接口及相应的外围设备,使其具备单机和联网的双重工作模式和较高的安全性与可靠性、较强的适应能力.在初期的实践应用中,结果表明其具有较高的身份识别率,有利于减少学生代考现象的发生.     

Investigation on thermal characteristics of heat sinks for power module using STM

The device that controls dynamic motions in a washing machine is called as MICOM. This device includes an IPM that controls the rotation of a tub. Also, the overheating of IPM gives cause for lowering the service life of an applied chip and is directly linked with its faults. A heat sink that is larger than the volume of the applied chip more than 50 times is installed to prevent such overheating. In the operation of the IPM, the temperature specification of the heat sink can be determined as 80°C under the air temperature of 25°C. However, the heat sink used at the present time cannot satisfy this condition, so it is necessary to redesign such a heat sink to satisfy this condition. This study proposes an STM that is able to precisely calculate the temperature applied to IPM in a system level prior to redesigning the heat sink. The STM can be considered as a model that complements a JEDEC analysis model. This model implements a parameter analysis to perform the optimization of a heat sink and verifies the priority of parameters to reduce material costs. Furthermore, it investigates a counterproposal that replaces the conventional cooling methods in which it seeks a counterproposal that performs heat dissipation in a device according to the SoC of chips and is able to suppress EMI. This paper was recommended for publication in revised form by Associate Editor Jae Dong Chung Chung-Hyo Jung acquired the doctoral degree in the Dept. of Science for Open and Enviromental Systems at Keio University in 2003. The specialty in the doctoral course was GSMAC-FEM and studied on MHD (magnetohydrodynamics). Dr. Jung joined Samsung Electronics Co., Ltd. as a CFD engineer in 2003. Also, he has worked at Samsung Advanced Institute of Technology and has charged in the thermal analysis of semi-conductors (system LSI). One of the Dr. Jung’s major concerning fields is the mechanical application of Lie-Groups.