课程文献中心 更多>>

关键词： 水肥一体机   数值分析   状态方程   灌施指令准确率   多维度融合  

摘要： 以进一步提升水肥一体机的智能性、数字性作业为目标,针对整机的灌施精准性要求展开设计。充分考虑水肥一体机的运用特点和结构组成,结合水肥的参数融合关系,建立用于水肥一体机准确控制作业的状态方程模型,设计以数值分析处理函数为核心的软件控制模块,搭建同步动作实施的硬件执行平台。展开多作物的灌施作业试验,结果表明:基于数值分析方法的水肥一体机系统架构设计合理,数值分析算法融入有效,整机试验的数值计算准确率可达98.00%以上;水肥混合均匀有度,整体管路灌施顺畅,灌施指令准确率可达99.00%以上,整机灌施效率较高,充分验证了数值分析方法应用的正确性与优越性,可以促进类似农机装备与高等数学多维度融合。

摘要： In line with Moore's Law and the International Roadmap for Devices and Systems (IDRS), shrinking MOSFET dimensions to the 3 nm technology node requires the introduction and thorough investigation of new device structures and advanced materials. The current study focuses on the implementation of Triple Metal (TM) and Quadruple Metal (QM) gate work function engineering techniques on both junctionless (JL) and inversion mode (IM) Double surrounding Gate (DSG) In 0.53 Ga 0.47 As nanotube (NT) MOSFET. The objective is to analyze the drain current (I D ) characteristics for a gate length of 3 nm using Silvaco ATLAS 3D TCAD. In order to make a fair comparison between JL and IM In 0.53 Ga 0.47 As NT, the doping concentration of TM and QM JL In 0.53 Ga 0.47 As NT is tuned to achieve two specific objectives. Firstly, the goal is to produce the same I ON as IM In 0.53 Ga 0.47 As NT. Secondly, the aim is to achieve the same threshold voltage (V TH ) as IM In 0.53 Ga 0.47 As NT. It was discovered that the I OFF for JL devices is approximately 2.93 times smaller compared to IM devices in the TM situation, while considering matching I ON and V TH . The JL devices have an I OFF that is 12.9 times smaller and an I OFF that is 10 2 times smaller compared to the IM device for the QM situation. This is achieved by matching the I ON and V TH values. It achieves a lesser drain-induced barrier lowering (DIBL) of approximately 28.10 mV/V, a virtually perfect subthreshold slope (SS) of roughly 60mV/dec, and a larger current ratio of I ON /I OFF , which is approximately 1.42 × 10 7 .

关键词： 串联谐振   等效阻抗   谐波抑制   无功功率  

摘要： 提出了一种带LC谐振单元的谐波抑制方法,将由电感和电容元件构成的串联谐振单元串接在系统进线端,与传统的无源电力滤波器配合使用.LC谐振单元对基波和谐波呈现不同等效电感值,对谐波呈现为大电感,增加系统谐波等效阻抗,迫使谐波流入无源电力滤波器;通过合适的参数设计,使LC谐振单元对基波也呈现为小电感,且该等效电感上消耗的无功功率等于或略大于无源电力滤波器提供的容性无功功率,从而实现在不补偿无功或消纳无功条件下抑制谐波.仿真验证了所提方法的有效性与正确性.

摘要： This paper investigates gate oxide degradation and its influence on Differential Mode(DM) EMI signals. The study reveals that changes in the parasitic capacitance within the chip, resulting from gate oxide degradation, can modify the amplitude-frequency characteristics of DM EMI signals, leading to unexpected transmission outcomes. This paper subjects SiC MOSFET modules to periodic high-temperature gate bias stress, extracts the spectrum characteristics of DM EMI, and assesses the impact of junction temperature. The analysis explores the impact of gate oxide degradation on low and high frequency DM EMI signals. Experimental results reveal distinct sensitivities of amplitude-frequency characteristics in the DM EMI signals to temperature variations and responses to gate oxide degradation at various frequency bands. The extrapolation of the correlation between the frequency-domain characteristics of the DM EMI signals and the degree of gate oxide degradation introduces a novel approach to evaluate the lifespan of power electronic devices.

摘要： —A novel power MOSFET structure with Drain-side N–Si/N-SiGe Heterojunctions (DH-MOS) is proposed by introducing a N SiGe region which is sandwiched between the N-drift region and N+ substrate on the drain side. The operation mechanism and simulation verification of DH-MOS are presented. Due to the difference in valence band of N Si/N SiGe heterojunction, holes can be more easily expelled from the N-drift region into N SiGe region during the reverse conduction of DH-MOS, resulting in a significant reduction in hole density inside the N-drift region, thus improving the reverse recovery performance. Simulation results show that the reverse recovery charge (Qrr) of DH-MOS is 2.08 μC/cm 2 , approximately 66.34 % lower than the 6.18 μC/cm 2 of conventional MOS. The introduction of new DH-MOS structure with N–Si/N-SiGe heterojunctions does not result in a significant increase in reverse conduction voltage (VF). In addition, it does not sacrifice any forward conduction and blocking characteristics. The proposed DH-MOS introduces changes on the drain side, unlike existing methods which focus on the source side or drift region. And it can be compatible with existing improving measures to further improve the reverse recovery performance.

关键词： 零功率反应堆   零功率实验   反应堆物理   研究堆  

摘要： 零功率反应堆是开展反应堆物理研究重要的基础性实验平台,其结构简单,灵活可变,堆芯活性区能够针对特定的研究对象进行调整,以验证核设计软件与核数据库的准确性,获得堆芯物理重要参数实验数据,检验反应堆测量控制设备的有效性。本文简要描述零功率反应堆的特征与用途,回顾国内外研发历程,并介绍当前研究进展以及对未来的展望。

关键词： 分布式光伏发电   功率因数变化   光伏并网点选择  

摘要： 低压并网工商业分布式光伏发电项目投资成本逐步降低,越来越多的企业开始投资光伏电站。分布式光伏并网后注入有功电流会导致原来电力系统的计量电能表的功率因数发生变化,许多企业在光伏发电高峰期间出现功率因数不合格情况。分析研究光伏低压并网对计量电能表功率因数变化及对电网的影响。

关键词： 核电厂   主变压器   负压   带压更换阀门  

摘要： 大型电力油浸变压器是核电站重要电气设备,随着运行时间的不断增加,由各种原因会导致其出现渗、漏油。当渗、漏较为严重时,不但降低使用寿命,还影响机组稳定运行。本文针对多种渗、漏油情况中阀门主密封、阀杆密封、阀门损坏等情况下,采用负压技术更换的方法进行研究和应用。通过研究和摸索,现已成熟掌握此项技术,同时进行适应性的改进,适用于多种油枕结构的大型电力油浸变压器,减少整体排油次数、降低受潮、节约成本、异物掉落等风险,同时更加适用于核电站紧急抢修的一种新型的检修工艺。

关键词： 电力设备   变压器   检修维护  

摘要： 电力变压器是电力系统中至关重要的组件,其性能直接影响电力供应的稳定性与安全性。本文深入探讨了变压器的运行检修与维护策略,阐述了定期检修的重要性,并详细讨论了检修流程、关键环节及其对变压器性能的影响,进一步分析了变压器的日常维护措施,指出通过系统性的监测和预防性维护可以有效预测和规避潜在故障,强调了综合检修与维护策略对于提升变压器运行效率、延长设备寿命以及保障电网稳定运行的重要作用。通过本文的研究,旨在为电力行业提供一套更为科学、高效的变压器管理方法。