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摘要： 在2020年款的比亚迪“汉”“唐”纯电动汽车，以及蔚来ET7和特斯拉ModelY、Model3等多款高端车上，SiCMOSFET(碳化硅-场效应管)功率模块已在变频系统中使用。驱动系统变频器是电动汽车最重要的功率转换部件，过去使用最多的是由IGBT半导体器件构成的变频器，IGBT是由BJT双极型三极管和MOS绝缘栅型场效应管，共同组成的复合全控型电压驱动的功率器件，兼有高输入阻抗和低导通压降的优点。而SiCMOSFET是比硅基IGBT半导体更优秀的功率器件，MOSFET是金属氧化物半导体场效应晶体管，也称绝缘栅场效应管。耐压更高、逆变电流更大，目前已有1 200V/840A甚至超1 000A的三相全桥SiC功率模块。

关键词： 问题导向   模型建构   高阶水平   变压器  

摘要： 模型建构能力是解决物理问题的关键学科能力。很多中学生仅能选择和使用常见模型，其解决实际问题的高阶建模能力尚有所欠缺。针对这一现状，从常见的教学过程中寻找问题根源，提出了“问题导向”的高阶建模能力培养流程。以《变压器》教学中建构理想变压器模型的教学片段为例，对该流程的实施进行具体阐述，并给出有效的教学策略。

摘要： IGBT（绝缘栅双极型晶体管）是由BJT（双极结型晶体三极管）和MOSFET（绝缘栅型场效应管）组成的复合全控型-电压驱动式-功率半导体器件，其具有自关断的特征。功率模块是实现绿色能源转换的重要部件，IGBT是一种综合性能优异的全控型电力电子器件，IGBT融合了BJT和MOSFET的两种器件的优点，既具有MOS管的易于驱动、控制简单、开关频率高的优点，还兼备了功率晶体管导通电压低、通态电流大和损耗小的优点，是电力电子器件中的主流产品，已广泛应用于工业、航空航天、国防军工等传统产业领域，以及轨道交通、新能源、智能电网、新能源汽车等战略性新兴产业领域，在市场应用中占主导地位。但IGBT作为使用频率最高的电源转换芯片，出现故障的频率也一直很高。本文就IGBT故障失效损坏的机理进行分析研究。

关键词： Substrates   Switches   Cryogenics   Transistors   Current measurement   Quantum computing   MOSFET   Velocity measurement   Probes   Memory management   Impact ionization   cryogenic memory   switching time   memory endurance   memory retention  

摘要： This paper presents a high-endurance capacitorless one-transistor (1T) cryogenic memory, fabricated in a 180 nm bulk CMOS technology, with a high memory window of (10(7) I-1/I-0 sense current ratio) and prolonged retention. The memory is enabled by the bistable I-D - V-G transistor characteristics due to impact ionization (II) at cryogenic temperatures (T < 30 K). Focusing on critical memory reliability parameters-switching time, endurance, and retention characteristics-we present write/erase speeds down to approximate to 45 ns at T < 10 K and cycling endurance surpassing 10(9) cycles while maintaining the I1 / I0 memory window. Retention times of >10 s with a 30x memory window were observed in extensive high-speed measurements. The fast switching and retention characteristics combine to yield a low power ( mu W-range) candidate for local cache memory to support quantum sensing or quantum computing control circuitry. Additionally, our study outlines essential measurements crucial for exploring the viability of alternative memory solutions for low-temperature quantum sensing and computation applications.

关键词： Electrical stress annealing effect   nonequilibrium body potential   radiation dose detector   silicon-on-insulator (SOI)   transient test   Psi-MOSFET   Electrical stress annealing effect   nonequilibrium body potential   radiation dose detector   silicon-on-insulator (SOI)   transient test   Psi-MOSFET  

摘要： A new transient method has been adapted to detect the radiation dose of gamma-ray based on pseudo-MOSFETs. In addition, the electrical stress annealing effect is studied after irradiation experiments without biasing. In order to reduce the impact of annealing effect on the dose detection results, the transient nonequilibrium body potential was measured to extract the threshold and flat-band voltages using a new mathematical method. Based on these two voltages, the charge separate method is employed to determine the midband voltage. A lookup table and functional relationship are obtained with respect to the shift of the midband voltage and the total dose (TD). This mathematical method is verified through both simulations and experiments, which show similar dose detection range to commercial dosimeter. Compared with the conventional quasi-static method, the transient data processing method using nonequilibrium body potential exhibits well accuracy and weak electrical stress annealing effect, which brings great benefits for radiation dose metrology.

关键词： Resistance   MOSFET circuits   Logic gates   MOSFET   Semiconductor device modeling   Junctions   Electrical resistance measurement   Cryogenics   Conductivity   Systematics   Series resistance   R-SD   cryogenic   extraction   model  

摘要： MOSFET parasitic series resistance (R-SD) is an important parameter when channel length scales down. This paper presents a systematic study of R-SD extracted from the mobility constant method down to 4 K. For the first time, the anomalous behavior of R-SD with temperature lowering is interpreted and modeled by combined effects of dopant freeze-out and mobility. Excellent fit between the standard N/P-MOSFET measurement data and this model for 40 nm bulk device from leading foundry is shown from 300 K to 4 K. In addition, R-SD change with width scaling combined with temperature effects is also discussed.

关键词： 主变压器   选型   运输   水电站   抽蓄电站  

摘要： 大型水电站和抽水蓄能电站工程主变压器具有电压等级高、容量大、超重超限运输困难等特点。为了解决偏远地区大型水电工程主变压器的运输与选型问题，对典型水电工程重大件运输条件和运输方式，以及电站选择对单相式变压器、组合式三相变压器、现场组装式三相变压器的技术性能和经济性等进行了全面分析。结果表明：200～300 t重量级的主变压器可采用DK36型落下孔车辆运输的铁路干线运输方式、牵引车+多轴多轮液压悬挂挂车组合的高速公路运输方式来实现；对于偏远地区大型水电工程，自铁路站、高速公路至工地现场的地方公路限制车货总重一般小于200 t,三相一体主变压器整体运输往往受限，宜选择单相式变压器组。现场组装式三相变压器可显著降低单元运输重量，减小占地面积，可为交通运输特别受限地区大型水电工程主变型式的优选。

关键词： 掺铥光纤激光器   光束质量   主振荡功率放大器   高功率  

摘要： 针对高功率掺铥光纤激光器在不同总泵浦功率、前后向泵浦比例、有源光纤吸收系数、种子光功率等条件下的光束质量变化特性，开展了理论和实验研究。通过理论模拟，分析给出了激光器在不同条件下的激光功率输出特性、折射率变化特性、光束质量变化特性。采用芯包直径比为25/400μm、数值孔径为0.09、吸收系数为4.2 dB/m的含基座掺铥光纤，搭建了200 W级的高功率掺铥光纤激光器系统，实验揭示了光束质量随上述参数条件的变化规律。理论模拟和实验验证结果表明：激光器光束质量随着总泵浦功率的提升而劣化；前后向泵浦比例为1∶1的泵浦方式能更好地抑制激光器内部热效应，有利于获得高光束质量的激光输出；采用低吸收系数的有源光纤可以降低光纤内部的温度，提升输出激光的光束质量；随着种子光功率的增加，激光器光束质量会轻微劣化；与增加种子光功率相比，改变前后向泵浦比例对折射率及光束质量的影响更为明显。在光束质量变化规律方面，实验结果与理论预测结果吻合较好，偏差约为10%。基于上述理论模拟和实验研究结果，进一步开展了更高激光功率水平下的光束质量特性实验验证：选取15 W种子光并在放大级选用1∶1的前后向泵浦比例，在总泵浦功率增加至1131 W时获得了波长为1940 nm、平均功率为513 W、光束质量因子M2为3.04的激光输出；光束质量测量值3.04与理论预测值2.8的偏差约为8.6%。

关键词： 光伏发电   超短期预测   发电功率  

摘要： 针对光伏电站预测系统在晴空和多云交替工况下不能很好实现超短期预测的情况，研究了一种人工干预的超短期预测光伏功率方法，并对相应系数进行修正和调整以提高光伏发电功率，同时基于光伏电站的应用场景进行实时数据分析，有效验证了该方法的可靠性。

关键词： SiC MOSFET   threshold voltage shift   transient current method   trap characteristics  

摘要： The threshold voltage shift issue caused by traps in silicon carbide metal-oxide-semiconductor field-effect transistors (SiC MOSFETs) is studied based on transient current method. Experiment results show gate stress, drain stress, and temperature all contribute to threshold voltage shift, with the underlying cause of traps. To obtain physical characteristics of the traps, we test the drain current of the device after filling the traps and utilize a Bayesian iterative deconvolution algorithm to extract the time constants. To accurately explore the impact of traps on the current, we further process the time constant spectrum into a differential amplitude spectrum (DAS), which provides greater precision in addressing the issue of trap amplitudes. We also analyze the variation of trap time constants at different environmental temperatures, and extract the activation energies of the traps in conjunction with the Arrhenius equation. Ultimately, experiments discover two types of electron traps and hole traps. © 2001-2011 IEEE.