检索结果-内蒙古大学图书馆

Dielectric Mechanism and Spectrum Prediction Model for Insulating Paper Based on Three-Dimensional Frequency-Domain Spectroscopy

引用

IEEE Transactions on Dielectrics and Electrical Insulation 2025年

作者： Liu, Ruiqi Wang, Shengkang Lin, Fuchang Li, Hua Ministry of Education State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Wuhan430074 China

Moisture is a serious concern for transformers, as it will degrade insulation properties and accelerate aging. The dielectric mechanisms of oil-immersed paper (OIP) and the influence of moisture still remains contentious in existing studies, which prevents the application of Frequency-Domain Spectroscopy (FDS) technology in moisture assessment of transformers. OIP is a biphasic composite material composed of oil and paper, and the existence of oil would complicate the understanding of the dielectric mechanisms in solid insulation. Therefore, this study focuses on investigating the dielectric properties of non-immersed insulating paper using FDS. Firstly, the spectra of paper with different moisture content were analyzed, and the relationship between dielectric parameters and moisture was quantified through the proposed dielectric model of insulating paper. Then, a three-dimensional dielectric model for spectrum prediction was established, and the feasibility and universality of model was verified. Results show three distinct dielectric response processes in insulating papers: the hopping conduction (RI), the low-frequency relaxation polarization (RII), and the high-frequency relaxation polarization (RIII). With increasing moisture content, RI and RII processes shift synchronously and exponentially towards higher frequencies with the dielectric curve shape maintained, while RIII process is unaffected. Moreover, the proposed spectrum prediction model can accurately predict the spectrum of insulating paper with varying moisture content. The dielectric response mechanism and three-dimensional dielectric model of insulating paper identified in this study provide the theoretical basis and data support for subsequent studies of the dielectric mechanism and moisture assessment of oil-immersed paper. © 1994-2012 IEEE.

关键词： Frequency domain analysis

来源：评论

学校读者我要写书评

暂无评论

Minimum Current Optimization of DBSRC Considering Dead-time Effect

Minimum Current Optimization of DBSRC Considering Dead-time ...

引用

2022 IEEE Transportation Electrification Conference and Expo, Asia-Pacific, ITEC Asia-Pacific 2022

作者： Yang, Jiawen Zhang, Yu Wu, Xinmi Huazhong University of Science and Technology State Key of Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Wuhan China

ISBN: (数字)9781665492065

ISBN: (纸本)9781665492065

In the dual-bridge series resonant converter (DBSRC) working at a high switching frequency, the dead-time effect becomes a serious issue. When the minimum current trajectory (MCT) method is applied, the inductor current cannot be minimized due to the dead-time effect, and the range of the soft switching is reduced. Considering the dead-time, this paper firstly performs a theoretical analysis of the transmission power and soft-switching characteristics based on the fundamental harmonic approximation (FHA) approach. Then, a minimum current trajectory method considering dead-time (MCT-d) is proposed to achieve minimum inductor current by compensating the dead-time. Meanwhile, the method can extend the soft-switching range as well. Finally, the experimental results validate the theoretical analysis and the improvement of the converter efficiency. © 2022 IEEE.

关键词： Zero voltage switching

来源：评论

学校读者我要写书评

暂无评论

In Situ Utilization of Martian Resources: Advances and Prospects in Plasma technology

引用

ACS Sustainable Chemistry & engineering 2025年第22期13卷 8406-8423页

作者： Haiwei Zhu Shihao Tan Cuntao Lan Dawei Liu Xinpei Lu State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan Hubei 430074 China

In situ resource utilization (ISRU) is essential for sustainable Mars exploration due to the high cost and complexity of Earth-based supply chains. Mars’ harsh environment─marked by a thin CO2-rich atmosphere, extreme temperature swings, dust storms, and high radiation─poses significant challenges for conventional processing. Plasma technologies, known for their high energy density, chemical reactivity, and operational flexibility, offer promising solutions. This review examines recent advances in nonthermal plasma systems for key ISRU tasks, including CO2decomposition for oxygen and fuel production, water extraction from hydrated minerals, and regolith sintering for habitat construction. Special attention is given to microwave and dielectric barrier discharge plasmas, which have shown enhanced oxygen yield and energy efficiency compared to traditional systems like NASA’s MOXIE. Spark plasma sintering is also highlighted for its potential in producing high-strength ceramics from Martian soil. Despite technical promise, deployment challenges remain, including thermal stress resistance, dust mitigation, and energy optimization. Strategies such as advanced material selection, self-cleaning surfaces, and integration with renewable energy are proposed to improve system resilience. Beyond Mars, these plasma technologies have strong potential for Earth-based applications including CO2valorization, decentralized water treatment, and low-energy waste recycling. By bridging extraterrestrial and terrestrial needs, plasma-driven ISRU represents a dual-use innovation platform for advancing sustainable engineering under extreme constraints.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Characteristics of divertor heat flux distribution with an island divertor configuration on the J-TEXT tokamak

引用

Plasma Science and technology 2024年第12期26卷 9-17页

作者： Yutong YANG Yunfeng LIANG Wei YAN Shuangbao SHU Jiankun HUA Song ZHOU Qinghu YANG Jinlong GUO Ziyang JIN Wei XIE the J-TEXT Team State Key Laboratory of Advanced Electromagnetic Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma PhysicsSchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China Forschungszentrum Jülich GmbH Institut für Energie-und Klimaforschung-PlasmaphysikPartner of the Trilateral Euregio Cluster(TEC)Jülich 52425Germany School of Instrument Science and Opto-electronics Engineering Hefei University of TechnologyHefei 230009People’s Republic of China 不详

On J-TEXT,the temporal evolution of heat flux distribution on the high-field side(HFS)divertor plate has been measured by an infrared(IR)camera during the plasma operation with an island divertor *** experiments,the island divertor configuration is an edge magnetic island chain structure surrounded by stochastic layers,which can be induced by resonant magnetic perturbations(RMPs).The experimental results show that the heat flux distribution on the HFS target plate depends significantly on the edge magnetic ***,the impact of hydrogen fueling using supersonic molecular beam injection(SMBI)on the divertor heat flux distributions is studied on J-TEXT with an island divertor *** has been observed that power detachment can be achieved when the radiation front approaches the last closed flux surface(LCFS)after each SMBI *** result may provide a method of access for divertor detachment on a fusion device with a three-dimensional(3D)boundary magnetic structure.

关键词： infrared camera island divertor heat flux SMBI power detachment

来源：评论

学校读者我要写书评

暂无评论

Mechanism Analysis of Subsequent Commutation Failure Considering PLL Dynamics in LCC-HVDC Systems 5

Mechanism Analysis of Subsequent Commutation Failure Conside...

引用

5th IEEE International Electrical and Energy Conference, CIEEC 2022

作者： Ban, Minghui Zhan, Meng Huazhong University of Science and Technology School of Electrical and Electronic Engineering State Key Laboratory of Advanced Electromagnetic Engineering and Technology Hubei China

ISBN: (数字)9781665411042

ISBN: (纸本)9781665411042

This paper analyzes the reasons of subsequent commutation failure (SCF) of line commutated converter based high voltage direct current (LCC-HVDC). Firstly, according to the mechanism of commutation failure (CF), it can be found that the actual firing angle, DC current and AC voltage of inverter all have influence on CF. Secondly, based on the generation mechanism of firing pulse in LCC-HVDC, it is pointed out that the phase locked loop (PLL) dynamics can cause the deviation between the actual firing angle and the firing angle order from control system. Then, the transient characteristics of PLL after the first commutation failure (FCF) are analyzed. Compared with other factors that affect SCF, the PLL dynamics in fault recovery period is considered as the main reason leading to SCF. Finally, a method to suppress SCF is proposed, and the effectiveness of the proposed conclusion and method is verified through the simulation of CIGRE benchmark model in PSCAD/EMTDC. © 2022 IEEE.

关键词： Dynamics

来源：评论

学校读者我要写书评

暂无评论

Small Disturbance Relationship with Internal-Voltage Amplitude/Frequency Excitation and Active/reactive Current Response and Its Linearization Method of AC Network for AC Power System Dynamic Analysis 4

Small Disturbance Relationship with Internal-Voltage Amplitu...

引用

4th International Conference on Electrical engineering and Control Technologies, CEECT 2022

作者： Wang, Sicheng Yuan, Xiaoming School of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan China

ISBN: (纸本)9781665498999

With the high penetration of renewable generations, increasingly serious impact of dynamics of AC network as an important part of power systems on system dynamic behaviors urgently asks for constructing corresponding small disturbance linearization relationship of AC network to achieve dynamic analysis for today's new system by applying mature linear system mathematics. However, due to the existence of AC signals in the network, relevant DC state variables and operating points required for establishing and linearizing small disturbance relationship are not intuitive. But existing researches almost have not yet understood appropriate state variables and operating points from the perspective of AC power systems' basic operation principle and physical connotation of system dynamics, causing there is still a lack of a universal construction idea and a general linearization method of the small disturbance relationship of AC network suitable for system dynamic analysis. Thus, system operation principle and physical dynamics are first concerned by taking a simplified converter interfaced power system as an example in this paper, and internal-voltage amplitude/frequency (A/F) and active/reactive (A/R) current are revealed as state variables and operating points of AC power systems. A universal construction idea of small disturbance relationship with internal-voltage A/F excitation and A/R current response of AC network and relevant linearization method are then proposed. Finally, small disturbance linearization relationship of a typical inductive transmission line is established and is validated by simulation. © 2022 IEEE.

关键词： Linearization

来源：评论

学校读者我要写书评

暂无评论

Temperature Optimization for Efficient Power-to-Hydrogen Water Electrolysis

Temperature Optimization for Efficient Power-to-Hydrogen Wat...

引用

2023 IEEE Sustainable Power and Energy Conference, iSPEC 2023

作者： Chen, Ke Hu, Kewei Yang, Jie Chen, Feng Fang, Jiakun State Grid Hubei Electric Power Company Limited Economic Research Institute Wuhan China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9798350322699

This paper proposes an optimization model for temperature of water electrolyzers in pursuit of maximum power-to-hydrogen efficiency. Unlike the traditional operating strategy which controls constant temperature, the model aims at obtaining optimal temperature according to the variation of supplied current. In order to realize the maximum efficiency, the temperature-dependent electrochemical model of the electrolyzer, as well as the thermal model of the heater, is established. The optimal temperature occurs where the electrochemical loss and the thermal loss meet the balance. From the simulation results, the proposed model can acquire optimal temperature based on the supplied current, which can be applied to the scene of fluctuating power supply, e.g. wind and solar power. The test results show that up to 15% efficiency improvement can be achieved with the proposed temperature control method, compared with the traditional constant temperature control. © 2023 IEEE.

关键词： fluctuating power supply power-to-hydrogen efficiency temperature optimization water electrolyzers wind and solar power

来源：评论

学校读者我要写书评

暂无评论

An Improved Valve-Side Fault-Riding-Through Control Strategy for Hybrid MMC

An Improved Valve-Side Fault-Riding-Through Control Strategy...

引用

2022 International Power Electronics Conference, IPEC-Himeji 2022-ECCE Asia

作者： Zhang, Jiawei Peng, Li Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Wuhan China

ISBN: (纸本)9784886864253

The hybrid Modular Multilevel Converter (HMMC) with half half-bridge submodules (HBSMs) and half full-bridge submodules (FBSMs) has been widely studied in High-Voltage Direct Current (HVDC) transmission systems for its dc fault blocking capability. The valve-side single-phase-to-ground (SPG) fault cannot be handled well by the schemes proposed to handle the grid-side faults. There will be fundamental-frequency fluctuation of dc-bus pole-to-ground voltage and dc current, which may cause insulation breakdown and arm overcurrent. Therefore, an improved control strategy with adaptive arm voltage reference is proposed in this paper. A current controller is utilized to eliminate the fluctuation. In the meantime, dc voltage should reduce cooperatively to change the arm voltage reference so that the arm voltages will be shifted down to avoid arm overmodulation. Considering that HBSMs cannot generate negative level as FBSMs, the energy of HBSMs' capacitor is analyzed in detail to explore the range that the proposed scheme can handle. Simulation results confirm the effectiveness. © 2022 IEEJ-IAS.

关键词： Power converters

来源：评论

学校读者我要写书评

暂无评论

Divertor heat flux challenge and mitigation in the EHL-2 spherical torus

引用

Plasma Science and technology 2025年第2期27卷 97-109页

作者： Fuqiong WANG Xiang GU Jiankun HUA Yumin WANG Xiaokun BO Bo CHEN Yuejiang SHI Shuai XU Erhui WANG Yunfeng LIANG the EHL-2 Team College of Physics Donghua UniversityShanghai 201620People’s Republic of China Hebei Key Laboratory of Compact Fusion Langfang 065001People’s Republic of China ENN Science and Technology Development Co. Ltd.Langfang 065001People’s Republic of China International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China Forschungszentrum Jülich GmbH Institute of Fusion Energy and Nuclear Waste Management-Plasma PhysicsJülich 52425Germany

The divertor design is critical to heat load handling and thus to achievements of highperformance plasma operations in the EHL-2(ENN He-Long 2)*** paper presents the design of an X-point target(XPT)divertor,featuring a conventional inner divertor and an XPT outer divertor,aimed at the effective control of heat loads,which may be extremely high during high ion temperature *** divertor target plates are made from carbon-based materials,which can handle heat loads of up to 5 MW/m².Divertor performances,including the heat load controllability,the onset of detachment and the in-out/up-down asymmetry,etc.,are evaluated using both the simple particle-tracking strategy and the complicated SOLPS-ITER *** attention is paid to the drift effects on particle/heat transport in the divertor/scrape-off layer region and on the divertor heat loads,focusing on the semi-detached/detached operation *** from SOLPS-ITER simulations demonstrated that the currently designed magnetic equilibrium and divertor configuration can effectively handle the power heat load in EHL-2.

关键词： heat flux divertor EHL-2

来源：评论

学校读者我要写书评

暂无评论

Transient Stability Assessment and Dynamic Security Region in Power Electronics Dominated Power Systems 13

Transient Stability Assessment and Dynamic Security Region i...

引用

2022 IEEE International Conference on Power Systems technology, POWERCON 2022

作者： Ma, Rui Zhan, Meng School of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan China

ISBN: (数字)9781665417754

ISBN: (纸本)9781665417754

Transient stability accidents induced by converter-based resources have been emerging frequently around the world. In this paper, the transient stability of the grid-tied voltage source converter (VSC) system is studied through estimating the basin of attraction (BOA) based on the hyperplane or hypersurface method. Meanwhile, fault critical clearing times are estimated, based on the approximated BOA and numerical fault trajectory. Further, the dynamic security region (DSR), an important index in traditional power systems, is extended to power-electronics-dominated power systems in this paper. The DSR of VSC is defined in the space composed of active current references. Based on the estimated BOA, the single-VSC-infinite-bus system is taken as an example and its DSR is evaluated. Finally, all these analytical results are well verified by several numerical simulations in MATLAB/Simulink. © 2022 IEEE.

关键词： Power electronics

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：