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Global Energy Interconnection 2024年第1期7卷 106-116页

作者： Lingqing Pan Xizhou Du Xing Lei Ting Ye dawei xiang Hao Li College of Electrical Power Engineering Shanghai University of Electric PowerShanghai 200090P.R.China State Grid Shanghai Municipal Electric Power Company Shanghai 200122P.R.China College of Electronics and Information Engineering Tongji UniversityShanghai 201804P.R.China

Insulation failure significantly contributes to the unpredictable shutdown of power *** to the partial discharge and high-frequency(HF)injection methods,the HF common-mode(CM)leakage current method offers a non-intrusive and highly sensitive ***,the detection of HF CM currents is susceptible to interference from differential-mode(DM)currents,which exhibit high-amplitude and multifrequency components during normal *** address this challenge,this paper proposes a double-ring current sensor based on the principle of magnetic shielding for inverter-fed machine winding insulation *** inner ring harnesses the magnetic aggregation effect to isolate the DM current magnetic field,whereas the outer ring serves as the magnetic core of the Rogowski current sensor,enabling HF CM current ***,the magnetic field distributions of the CM and DM currents were ***,a correlation between the sensor parameters and signal-to-noise ratio of the target HF CM current was ***,an experimental study was conducted on a 3-kW PMSM for *** results indicate that the proposed double-ring HF CM sensor can effectively mitigate DM current *** to a single-ring sensor,a reduction of approximately 40%in the DM component was achieved,which significantly enhanced the precision of online insulation monitoring.

关键词： Magnetic shielding Double-ring Common-mode current Maxwell simulation

High-sensitive state perception method for inverter-fed machine turn insulation based on FrFT-Mel

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Global Energy Interconnection 2024年第2期7卷 155-165页

作者： Ruitian Fan Xing Lei Tao Jia Menglong Qin Hao Li dawei xiang College of Electrical Power Engineering Shanghai University of Electric PowerShanghai 200090P.R.China State Grid Shanghai Municipal Electric Power Company Shanghai 200437P.R.China State Grid Technology College Shandong 250002P.R.China College of Electronics and Information Engineering Tongji UniversityShanghai 201804P.R.China

Amidst the swift advancement of new power systems and electric vehicles,inverter-fed machines have progressively materialized as a pivotal apparatus for efficient energy *** winding turn insulation failure is the root cause of inverter-fed machine *** online monitoring of turn insulation health can detect potential safety risks promptly,but faces the challenge of weak characteristics of turn insulation *** study proposes an innovative method to evaluate the turn insulation state of inverter-fed machines by utilizing the fractional Fourier transform with a Mel filter(FrFT-Mel).First,the sensitivity of the high-frequency(HF)switching oscillation current to variations in turn insulation was analyzed within the fractional ***,an improved Mel filter is introduced,and its structure and parameters are specifically designed based on the features intrinsic to the common-mode impedance resonance point of the electrical ***,an evaluation index was proposed for the turn insulation state of inverter-fed *** results on a 3kW permanent magnet synchronous machine(PMSM)demonstrate that the proposed FrFT-Mel method significantly enhances the sensitivity of turn insulation state perception by approximately five times,compared to the traditional Fourier transform method.

关键词： State perception Turn insulation Switching oscillation Fractional Fourier transform Mel filter

Effects of traditional Chinese medicine on treatment outcomes in severe COVID-19 patients:a single-centre study

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Chinese Journal of Natural Medicines 2024年第1期22卷 89-96页

作者： XIAO Yongjiu LI Binbin LIU Chang HUANG Xiuyu MA Ling QIAN Zhirong ZHANG Xiaopeng ZHANG Qian LI Dunqing CAI Xiaoqing YAN xiangyong LUO Shuping xiang dawei XIAO Kun Emergency Department the 940th Hospital of Jiont Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Scientific Research Center the Seventh Affiliated HospitalSun Yat-sen UniversityShenzhen 518000China School of Medicine Nankai universityTianjin 300000China Department of Cardiology the 940th Hospital of Joint Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Department of Radiation Oncology Fujian Medical University Union HospitalFuzhou 350000China Department of Traditional Chinese Medicine the 940th Hospital of Joint Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Department of Geriatric Diseases the Seventh Medical Center of Chinese PLA General HospitalBeijing 100700China Health and Sport Administration Muskingum UniversityOhioanUSA Laboratory of Vaccine and Antibody Engineering Beijing Institute of BiotechnologyBeijing 100071China Department of Pulmonary and Critical Care Medicine the 940th Hospital of Joint Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Center of Pulmonary&Critical Care Medicine Chinese People’s Liberation Army(PLA)General HospitalBeijing 100853China

As the search for effective treatments for COVID-19 continues,the high mortality rate among critically ill patients in Intensive Care Units(ICU)presents a profound *** study explores the potential benefits of traditional Chinese medicine(TCM)as a supplementary treatment for severe COVID-19.A total of 110 critically ill COVID-19 patients at the Intensive Care Unit(ICU)of Vulcan Hill Hospital between Feb.,2020,and April,2020(Wuhan,China)participated in this observational *** patients received standard supportive care protocols,with a subset of 81 also receiving TCM as an adjunct *** characteristics during the treatment period and the clinical outcome of each patient were closely monitored and *** findings indicated that the TCM group exhibited a significantly lower mortality rate compared with the non-TCM group(16 of 81 vs 24 of 29;0.3 vs 2.3 person/month).In the adjusted Cox proportional hazards models,TCM treatment was associated with improved survival odds(P<0.001).Furthermore,the analysis also revealed that TCM treatment could partially mitigate inflammatory responses,as evidenced by the reduced levels of proinflammatory cytokines,and contribute to the recovery of multiple organic functions,thereby potentially increasing the survival rate of critically ill COVID-19 patients.

关键词： COVID-19 Pneumonia Novel coronavirus Critically ill Traditional Chinese medicine Clinical outcome

栅氧老化下SiC MOSFET开通瞬态栅极振荡特性研究

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中国电机工程学报 2024年第9期44卷 3656-3664,I0027页

作者：李豪成芮俊杰向大为田鑫上海电力大学电气工程学院上海市杨浦区200090 同济大学电子与信息工程学院上海市嘉定区201804

栅氧老化问题已成为制约碳化硅(SiC)金属半导体氧化物场效应管(metal oxide semiconductor field effect transistor,MOSFET)可靠性的关键因素,该文尝试利用SiC MOSFET高速开关在变换器中引起的高频开关振荡获取栅氧状态信息,重点研究... 详细信息

栅氧老化问题已成为制约碳化硅(SiC)金属半导体氧化物场效应管(metal oxide semiconductor field effect transistor,MOSFET)可靠性的关键因素,该文尝试利用SiC MOSFET高速开关在变换器中引起的高频开关振荡获取栅氧状态信息,重点研究栅氧老化对开通瞬态栅极高频振荡特性的影响。首先,分析SiC MOSFET栅氧老化机理及其对器件开通时间的影响。然后,建立开通瞬态栅极回路分阶段高频等效电路模型,揭示SiC MOSFET栅极开通振荡电流的形成机理和影响因素。最后,通过33 V高压栅偏加速老化实验进行验证。研究结果表明,随着栅氧老化程度的加深,SiC MOSFET阈值电压会逐渐增加而开通速度变慢,导致栅极开通振荡电流显著减小(约28%)。该文的工作有望为SiC MOSFET栅氧老化在线监测提供一种新的思路。

关键词：碳化硅金属半导体氧化物场效应管(SiC MOSFET) 栅氧老化栅极振荡在线状态监测

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基于高频振荡的变流器杂散电感多参数提取方法

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高电压技术 2024年第2期50卷 775-783页

作者：肖云鹏向大为李豪郑燕赵宁同济大学电子与信息工程学院上海201804 上海电力大学电气工程学院上海200090

针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述... 详细信息

针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述了高频振荡法的基本原理,建立了不同谐振实验的等值电路模型。然后,以1700 V/450 A IGBT变流器系统为例,通过仿真与实验进行了可行性与有效性验证。最后,通过实验与传统双脉冲法进行了对比分析。研究表明:所提出的方法可有效提取变流器内不同位置的杂散电感参数,与双脉冲法提取开关杂散电感结果基本一致,精度可达纳亨级。

关键词：变流器杂散电感高频振荡 LC谐振电力电子开关暂态双脉冲法

基于差模开关振荡的变频电机绕组相端绝缘状态特征提取与解耦

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中国电机工程学报 2024年第4期44卷 1608-1617,I0030页

作者：李豪刘静宇向大为顾奕上海电力大学电气工程学院上海市杨浦区200090 同济大学电子与信息工程学院上海市嘉定区201804

变频电机相端绝缘受脉冲宽度调制高频开关暂态过电压冲击易发生劣化。利用开关振荡谐振效应可望灵敏感知相端绝缘状态的微弱变化,但绝缘状态特征存在多因素高频耦合的问题。为此,该文提出一种基于差模开关振荡的相端绝缘状态特征提取与... 详细信息

变频电机相端绝缘受脉冲宽度调制高频开关暂态过电压冲击易发生劣化。利用开关振荡谐振效应可望灵敏感知相端绝缘状态的微弱变化,但绝缘状态特征存在多因素高频耦合的问题。为此,该文提出一种基于差模开关振荡的相端绝缘状态特征提取与解耦方法。首先,通过分析变频电机系统开关振荡主导模态,选择高频差模开关振荡作为敏感模态,解耦逆变器功率器件分布电容的影响;然后,通过变分模态分解算法提取多模态开关振荡中的差模频率特征,解耦暂态运行工况下功率器件动态开关时间的影响。最后,利用逆变器侧和电机侧差模开关振荡电流幅值比特征,解耦电缆高频分布参数的影响。在380V/3kW永磁电机变频驱动系统中验证所提方法的有效性,结果表明,所提方法能够灵敏反映电机相端绝缘状态的微弱变化,可以有效解耦逆变器、电缆、运行工况等因素的影响。

关键词：变频电机绕组绝缘开关振荡特征提取解耦

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基于中性点对地电压高频开关振荡的变频电机绕组内部绝缘在线监测

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中国电机工程学报 2024年第2期44卷 817-826,I0032页

作者：李豪李耀向大为李宇昂上海电力大学电气工程学院上海市杨浦区200090 同济大学电子与信息工程学院上海市嘉定区201804

绝缘状态在线监测是提高变频电机可靠性的有效手段。在高速PWM开关暂态激励下,电机绕组漏感与内部分布电容发生谐振会产生几十至几百k Hz的电压振荡,威胁绕组内部绝缘安全可靠运行。该文利用逆变器自激高频开关振荡在线监测绕组内部绝... 详细信息

绝缘状态在线监测是提高变频电机可靠性的有效手段。在高速PWM开关暂态激励下,电机绕组漏感与内部分布电容发生谐振会产生几十至几百k Hz的电压振荡,威胁绕组内部绝缘安全可靠运行。该文利用逆变器自激高频开关振荡在线监测绕组内部绝缘状态。为避免开关振荡多模态混叠并提高状态监测灵敏度,提出一种基于中性点对地电压高频开关振荡的绝缘在线监测方法。首先,分析变频电机共模电压激励特性;然后,研究中性点对地电压高频开关振荡的形成机理与特性,从理论上推导出振荡频率与绕组内部绝缘电容状态之间的关系。设计绕组内部绝缘在线监测方案,包括开关振荡频率提取以及内部绝缘状态评估等。最后,通过热疲劳与老化模拟等实验对该方法的可行性与有效性进行验证。结果表明,该方法能有效监测变频电机内部绕组绝缘状态的微弱变化,具有信噪比高、工况鲁棒等优点。

关键词：变频电机绕组内部绝缘开关振荡中性点对地电压绝缘状态监测

Asynchronous gain-scheduled control of deepwater drilling riser system with hybrid event-triggered sampling and unreliable communication

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 272-285页

作者： Na PANG dawei ZHANG Shuqian ZHU School of Mathematics Shandong UniversityJinan250100China

This paper investigates the recoil control of the deepwater drilling riser system with nonlinear tension force and energy-bounded friction force under the circumstances of limited network resources and unreliable *** from the existing linearization modeling method,a triangle-based polytope modeling method is applied to the nonlinear riser *** on the polytope model,to improve resource utilization and accommodate random data loss and communication delay,an asynchronous gain-scheduled control strategy under a hybrid event-triggered scheme is *** asynchronous linear parameter-varying system that blends input delay and impulsive update equation is presented to model the nonlinear networked recoil control system,where the asynchronous deviation bounds of scheduling parameters are *** to the Lyapunov-Krasovskii functional method,some solvable conditions of disturbance attenuation analysis and recoil control design are derived such that the resulting networked system is exponentially mean-square stable with prescribed H∞*** obtained numerical results verified that the proposed nonlinear networked control method can achieve a better recoil response of the riser system with less transmission data compared with the linear control method.

关键词： Riser system Recoil control Asynchronous gain-scheduled control Data loss Event-triggered scheme

Dynamic Response of Foundations during Startup of High-Frequency Tunnel Equipment

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 821-844页

作者： dawei Ruan Mingwei Hu College of Civil and Transportation Engineering Shenzhen UniversityShenzhen518060China State Key Laboratory of Intelligent Geotechnics and Tunnelling Shenzhen UniversityShenzhen518060China Key Laboratory of Coastal Urban Resilient Infrastructures of Ministry of Education Shenzhen UniversityShenzhen518060China Underground Polis Academy Shenzhen UniversityShenzhen518060China Shenzhen Key Laboratory of Green Efficient and Intelligent Construction of Underground Metro StationShenzhen UniversityShenzhen518060China

The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex *** vibration caused by the high-frequency units during regular operation is supported by the foundation of the units,and the magnitude of vibration and the operating frequency fluctuate in different engineering contexts,leading to variations in the dynamic response of the *** high-frequency units yield significantly diverse outcomes under different startup conditions and times,resulting in failure to meet operational requirements,influencing the normal function of the tunnel,and causing harm to the foundation structure,personnel,and property in severe *** article formulates a finite element numerical computation model for solid elements using three-dimensional elastic body theory and integrates field measurements to substantiate and ascertain the crucial parameter configurations of the finite element *** proposing a comprehensive startup timing function for high-frequency dynamic machines under different startup conditions,simulating the frequency andmagnitude variations during the startup process,and suggesting functions for changes in frequency and magnitude,a simulated startup schedule function for high-frequency machines is created through *** into account the selection of the transient dynamic analysis step length,the dynamic response results for the lower dynamic foundation during its fundamental frequency crossing process are *** validation checks if the structural magnitude surpasses the safety threshold during the critical phase of unit startup traversing the structural resonance *** design recommendations for high-frequency units’dynamic foundations are provided,taking into account the startup process of the machine and ensuring the safe operation of the tunnel.

关键词： Tunnel equipment high-frequency units startup conditions transient dynamics dynamic response foundation design

Eventually homological isomorphisms and Gorenstein projective modules

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Science China Mathematics 2024年第8期67卷 1719-1734页

作者： Yongyun Qin dawei Shen School of Mathematics Yunnan Normal UniversityKunming 650500China School of Mathematics and Statistics Henan UniversityKaifeng 475004China

We prove that a certain eventually homological isomorphism between module categories induces triangle equivalences between their singularity categories,Gorenstein defect categories and stable categories of Gorenstein projective ***,we show that the Auslander-Reiten conjecture and the Gorenstein symmetry conjecture can be reduced by eventually homological *** these results to arrow removal and vertex removal,we describe the Gorenstein projective modules over some non-monomial algebras and verify the Auslander-Reiten conjecture for certain algebras.

关键词： singularity categories Gorenstein defect categories Gorenstein projective modules AuslanderReiten conjecture Gorenstein symmetry conjecture eventually homological isomorphisms

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