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Dynamic performance of linear electromagnetic actuators in a stray magnetic field:theoretical analysis and experimental verification

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Plasma Science and technology 2022年第12期24卷 213-222页

作者： Rumeng WANG Yong YANG Shaoyu WANG Ming ZHANG 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

Linear electromagnetic actuators(LEAs) are widely used in tokamaks,but they are extremely sensitive to and are prone to fail in a high-strength stray magnetic field(SMF),which is usually a concomitant with *** this paper,a multi-physics coupling analysis model of LEA,including magnetic field,electric circuit and mechanical motion,is proposed,and the dynamic characteristics of LEAs in SMFs are studied in detail based on the proposed *** failure mechanism of LEAs in SMFs is revealed,and the influence of SMFs on the dynamic performance of LEAs is studied and *** is shown that the failure threshold of the LEA selected in this work under the rated condition is 27 mT and 14 mT in the positive and negative direction,*** a typical SMF of 10 mT in the negative direction,the closing time of the LEA will be extended by 40%,while its opening time will be shortened by about 10%.Experimental tests are also conducted,which verify the validity of the proposed model and the analysis *** paper provides a basis for the diamagnetic optimization design of LEA,and it is of great significance to ensure the reliable operation of the tokamak.

关键词： linear electromagnetic actuator stray magnetic field dynamic performance collision velocity

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The impact of toroidal mode coupling on high-density discharges in J-TEXT

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Plasma Science and technology 2024年第12期26卷 1-8页

作者： Peng DENG Wenzhe MAO Zhipeng CHEN Yinan ZHOU Peng SHI Zhoujun YANG Li GAO Tao LAN Jinlin XIE Hong LI Zian WEI Adi LIU Chu ZHOU Weixing DING Wandong LIU Ge ZHUANG School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026People’s Republic of China 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 Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People’s Republic of China

Density limit has long been a widely studied issue influencing the operating range of *** rapid growth of the m/n=2/1(where m and n are poloidal and toroidal mode numbers,respectively)tearing mode is generally regarded as a primary precursor to the density limit *** this experiment,the coupling of the m/n=1/1 mode and the m/n=2/1 mode in highdensity plasma was *** a sawtooth cycle,the frequencies of the two modes gradually converge until they become *** that,toroidal coupling occurs between the 1/1 and 2/1 modes,resulting in a mutually fixed phase *** the occurrence of toroidal coupling,the 2/1 mode is *** to the disruption,the cessation of the 1/1 and 2/1 mode coupling,along with the rapid growth in the amplitude of the 2/1 mode,can be ***,under the same parameters,comparing discharges with or without the 1/1 mode,it is found that the presence of the 1/1 mode leads to higher plasma density and temperature parameters.

关键词： toroidal coupling tearing mode density limit sawtooth

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Characterization of Lorentz Force Distribution in electromagnetic Repulsion Mechanism of Multiple Parallel Circuit Breakers 7

Characterization of Lorentz Force Distribution in Electromag...

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7th IEEE Conference on Energy Internet and Energy System Integration, EI2 2023

作者： He, Yinghui Chen, Lixue Yuan, Zhao Xu, Shengqin Sun, Likang Zou, Xinyang School of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology Key Laboratory of Pulsed Power Technology Ministry of Education Wuhan China

ISBN: (纸本)9798350345094

In order to meet the requirements of parallel circuit breaker opening rapidity and synchronization, a new structure of electromagnetic repulsion mechanism (EMRM) is proposed in this paper. A three-dimensional transient flexible body model of the mechanism was built in COMSOL. Simulation results show that the EMRM can reach the rated opening distance of 20mm in 4.86ms, and the maximum stress during the motion is 246MPa. There is vibration in the motion process due to the uneven distribution of Lorentz force, and the vibration is periodic. The maximum stress is related to the vibration characteristics. Through theoretical derivation and simulation analysis, an analytical formula describing the relationship between the Lorentz force distribution and structural parameters is proposed in this paper. Error between the formula results and the simulation results is less than 4.5%. The analytical formula can be applied to parameter design. © 2023 IEEE.

关键词： Electric circuit breakers

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Contact Pressure Calculation Based on Vacuum Contact Materials and Operating Conditions 7

Contact Pressure Calculation Based on Vacuum Contact Materia...

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7th IEEE Conference on Energy Internet and Energy System Integration, EI2 2023

作者： Xu, Shengqin Chen, Lixue Yuan, Zhao He, Yinghui Zou, Xinyang Sun, Likang School of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology Key Laboratory of Pulsed Power Technology Ministry of Education Wuhan China

ISBN: (纸本)9798350345094

Pressure of vacuum circuit breaker contacts should meet the requirements of contact resistance, and inhibit contact bounce when short-circuit current is flowing. However, the value of contact pressure is often obtained empirically. This paper analyzes the worst electrical contact conditions based on the contact resistance of the electrical contact surfaces, and propose a method to calculate the contact pressure based on contact material, radius and short-time current withstand, which is based on the melting of the conductive spots. Finally, hrough the comparison of several sets of working conditions, it is verified that the calculation method is effective. © 2023 IEEE.

关键词： Contact resistance

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Heterostructural NiFeW disulfide and hydroxide dual‐trimetallic core‐shell nanosheets for synergistically effective water oxidatio

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Carbon Energy 2024年第8期6卷 192-204页

作者： Peng‐Fei Guo Yang Yang Bing Zhu Qian‐Nan Yang Yan Jia Wei‐Tao Wang Zhao‐Tie Liu Shi‐Qiang Zhao Xun Cui Key Laboratory of Chemical Additives for China National Light Industry College of Chemistry and Chemical EngineeringShaanxi University of Science and TechnologyXi'anChina School of Chemistry and Chemical Engineering Shaanxi Normal UniversityXi'anChina Key Laboratory of Carbon Materials of Zhejiang Province Wenzhou Key Lab of Advanced Energy Storage and ConversionZhejiang Province Key Lab of Leather EngineeringCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhouChina State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhanChina

A stable and highly active core‐shell heterostructure electrocatalyst is essential for catalyzing oxygen evolution reaction(OER).Here,a dual‐trimetallic core‐shell heterostructure OER electrocatalyst that consists of a NiFeWS_(2) inner core and an amorphous NiFeW(OH)_(z)outer shell is designed and synthesized using in situ electrochemical *** electrochemical measurements of different as‐synthesized catalysts with a similar mass loading suggest that the core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) nanosheets exhibit the highest overall performance compared with that of other bimetallic reference catalysts for the ***,the nanosheet arrays were in situ grown on hydrophilic‐treated carbon paper to fabricate an integrated three‐dimensional electrode that affords a current density of 10 mA cm^(−2) at a small overpotential of 182 mV and a low Tafel slope of 35 mV decade^(−1) in basic *** Faradaic efficiency of core‐shell Ni_(0.66)Fe_(0.17)W_(0.17)S_(2)@amorphous NiFeW(OH)_(z) is as high as 99.5% for *** scanning electron microscope,transmission electron microscope,and X‐ray photoelectron spectroscopy analyses confirm that this electrode has excellent stability in morphology and elementary composition after long‐term electrochemical ***,density functional theory calculations further indicate that the core‐shell heterojunction increased the conductivity of the catalyst,optimized the adsorption energy of the OER intermediates,and improved the OER *** study provides a universal strategy for designing more active core‐shell structure electrocatalysts based on the rule of coordinated regulation between electronic transport and active sites.

关键词： amorphous NiFeW hydroxide core‐shell heterojunction in situ electrochemical tuning NiFeW disulfide oxygen evolution reaction

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Prediction of Contact Terminal Temperature of Vacuum Circuit Breaker under Complex and Unknown Boundary Conditions 7

Prediction of Contact Terminal Temperature of Vacuum Circuit...

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7th IEEE Conference on Energy Internet and Energy System Integration, EI2 2023

作者： Li, Yingzhuo Chen, Lixue Yuan, Zhao Xu, Shengqin Sun, Likang Zou, Xinyang School of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology Key Laboratory of Pulsed Power Technology Ministry of Education Wuhan China

ISBN: (纸本)9798350345094

The monitoring of contact terminal temperature of vacuum circuit breakers is of great significance for fault prediction, life assessment, and structural improvement of circuit breakers. This article proposes a prediction method for steady-state temperature of vacuum circuit breaker's contact based on RBF neural network. Firstly, a finite element simulation model based on the actual characteristics of ZKTD 2S00/36-31.5kV vacuum circuit breakers is built, according to which, 793 electromagnetic and thermal model samples of circuit breakers with different boundary conditions are generated. Then, Random Forest regression, LASSO regression and ReliefF regression are used to rank the importance of temperature measurement points at different locations, based on the ranking results from 3 regression models, 4 optimal temperature measuring points are obtained. While the actual boundary conditions of the vacuum circuit breaker are unknown, the contact terminal temperature is accurately predicted by only using the temperatures of four temperature measuring points and the contact resistance values. Finally, a control experiment was set up to further verify the predictive ability of multiple temperature measuring points for contact terminal temperature under complex and unknown boundary conditions. © 2023 IEEE.

关键词： Boundary conditions

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Development of a double-side ordered membrane electrode assembly based on titanium nitride nanoarrays

Industrial Chemistry & Materials

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Industrial Chemistry & Materials 2024年第4期2卷 622-633页

作者： Lingfeng Xuan Deqing Mei Caiying Zhou Wenze Mao Yancheng Wang State Key Lab of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Zhejiang Province Key Laboratory of Advanced Manufacturing Technology School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China

The membrane electrode assembly(MEA)plays a crucial role in the functionality of proton exchange membrane fuel cells(PEMFCs).The channels present within the catalyst layer of MEAs exhibit a disordered configuration,which consequently give rise to low efficiency in mass *** order to enhance the mass transfer performance and the corrosion resistance of the catalyst layer,this paper developed a double-side ordered MEA based on TiN nanorod *** synthesized TiN nanorod arrays on the ITO surface by a seed-assisted hydrothermal reaction and nitriding treatment,and coated the catalyst uniformly on the TiN support by ultrasonic *** the double-side ordered MEA was fabricated by transfer printing,and achieved a peak power of 678.30 mW cm^(-2) with a cathode platinum loading of 0.2 mg cm^(-2) at 80℃ and anode saturated *** 200 hours of accelerated stress test(AST)at 90℃ and 30/30%relative humidity,the peak performance only dropped by 4.8%.These results provide substantial evidence for the effectiveness of our developed double-side ordered MEA which can mitigate catalyst polarization ***,this study reveals the immense potential of the TiN nanorod array-based double-side ordered MEA in advancing the development of efficient and stable MEAs.

关键词： PEMFC Preparation of MEA Ordered MEA TiN nanorod array Catalyst carrier

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Metal-organic polyhedra as dynamic cross-linker for recyclable mixed matrix membranes with promising dimension stability

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Science China Chemistry 2025年第2期68卷 705-713页

作者： Linjie Lan Mingxin Zhang Haiyan Xiao Wei Liu-Fu Yuyan Lai Jiadong Chen Jia-Fu Yin Panchao Yin State Key Laboratory of Luminescent Materials and Devices&South China Advanced Institute for Soft Matter Science and Technology Guangdong Basic Research Center of Excellence for Energy and Information Polymer MaterialsSouth China University of TechnologyGuangzhou 510641China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Lab of Fine ChemistrySchool of Chemical Engineering and TechnologyHainan UniversityHaikou 570228China

Mixed matrix membranes(MMMs)are designed by incorporating microporous inorganic fillers into polymer matrix for the integration of inorganics’excellent gas separation performance with polymers’promising ***,due to the complex interphase interaction,the prevention of long-term aging is still challenging and the poor processability/recyclability of MMMs hinders their extensive ***,a coordination assembly protocol is developed for the fabrication of MMMs with both excellent processability/recyclability upon thermal annealing and promising dimension stability even under high gas *** bearing isophthalic acid(IPA)as side chains are applied to coordinate with Cu^(2+)and the assembled 2.5 nm microporous metal-organic polyhedra(MOP),{Cu_(24)IPA_(24)},serves as multi-functional cross-linkers for the polymer network *** MOPs’well-defined microporosity grants MMMs the capability for O_(2)/N_(2) separation while their activated dynamics at high temperatures(>120℃)endows polymer networks with excellent *** contrast to conventional supramolecular units,the MOPs possess unique logarithmic ligand-exchange kinetics and they show nearly frozen bonding dynamics at room temperature,ensuring promising dimensional stability to overcome the long-term aging and high gas pressure *** work not only provides fundamental understanding of the unique relaxation dynamics of complex systems with intertwined dynamics of supramolecular bonds and polymer chains,but also paves new avenues for the fabrication of robust and recyclable MMMs and elastomers.

关键词： dynamic bonding metal-organic polyhedra mixed matrix membrane polymer recycling gas separation

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An Improved Calculation Method for AC Losses of 30 MJ/5 MW SMES

An Improved Calculation Method for AC Losses of 30 MJ/5 MW S...

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2023 IEEE International Conference on Applied Superconductivity and electromagnetic Devices, ASEMD 2023

作者： Qiu, Yifeng Ren, Li Xu, Ying Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan China Huazhong University of Science and Technology School of Electrical and Electronic Engineering Wuhan China

ISBN: (纸本)9798350301571

The toroidal D-shaped high-temperature super-conducting (HTS) magnet structure offers several advantages, such as low leakage magnetic field and vertical magnetic field on the tapes, and excellent mechanical properties characterized by pure tensile electromagnetic stress. As a result, it finds wide application in large-scale magnetic, including superconducting magnetic energy storage (SMES) and magnetic confinement fusion (MCF) devices. However, the highly asymmetric three-dimensional structure impose challenges in numerical modeling and electromagnetic computations, leading to difficulties in modeling, low computational efficiency, and even computational infeasibility. The "dimension reduction inversion"method is an innovative approach for electromagnetic calculations in toroidal magnets. this paper improved upon this method and applied it to the toroidal D-shaped structure, specifically calculating the electromagnetic field and AC loss of 30MJ/5MW liquid hydrogen superconducting composite energy storage (LIQHYSMES) magnet. This research provides a feasible approach for electromagnetic computations in large-scale toroidal D-shaped HTS magnets. © 2023 IEEE.

关键词： AC loss electromagnetic calculation HTS magnets toroidal D-shaped magnets

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Electrostatic Interference Suppression Method for Magnetic Flux Measurement in the Formation Area of HFRC Device 11th

Electrostatic Interference Suppression Method for Magnetic F...

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11th Frontier Academic Forum of Electrical engineering, FAFEE 2024

作者： Zhang, Yujun Chen, Zhipeng Rao, Bo Yang, Yong Li, Zhuolong Zhao, Yanhao Wang, Liye State Key Laboratory of Advanced Electromagnetic Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China

ISBN: (纸本)9789819788231

This paper proposes a comprehensive solution to address the interference challenges encountered during magnetic flux loop measurement of flux in Field-Reversed Configuration fusion devices. The high-frequency magnetic field generated by the high voltage discharge coil induces a high voltage in the magnetic flux loop circuit. However, the accompanying electrostatic interference significantly affects the measurement accuracy of magnetic flux. Although traditional isolation, shielding, and grounding techniques can mitigate electrostatic interference to some extent, their implementation is challenging, and they have stringent requirements for the grounding system. In view of this, this study added an electrostatic shielding layer between the magnetic flux loop and the discharge coil. Experimental results show that this measure effectively suppresses electrostatic interference. Simultaneously, this study utilizes a differential measurement method to further reduce electrostatic interference. Experiments show that the flux loop can accurately reflect the flux value, and the correlation coefficient between the measured flux and the theoretical value is 0.935. These improvements not only significantly enhance the accuracy and reliability of magnetic flux measurements but also provide more precise data support for magnetic diagostics research and experiments in Field-Reversed Configuration fusion devices. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Magnetic shielding

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