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Analysis of an Axial-flux Slotted Limited-angle Torque Motor with Quasi-Halbach Array for Torque Performance Improvement

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CES Transactions on Electrical Machines and Systems 2023年第3期7卷 266-274页

作者： Mingjie Wang Dawei Li Ronghai Qu State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China IEEE

Better torque performance and higher reliability have long been the focus of research for slotted limited-angle torque motors(LATMs),which are primarily used to position first-stage valves in electrohydraulic *** paper presents a high reliability axial-flux slotted LATM with quasi-Halbach array for torque performance improvement including constant torque range(CTR)and output ***,the structure with two sets of windings and the operation principle of the proposed slotted LATM is ***,a brief design procedure is presented,the structure selections of open slot and double-stator single-rotor(DSSR)interior rotor with surface mounted quasi-Halbach permanent magnet(PM)array are illustrated,and the geometric parameters are optimized to obtain the optimal design of the proposed slotted ***,3-D finite-element method(FEM)is employed to compare the proposed slotted LATM with the conventional surface mounted PM slotted LATM in terms of cogging torque,no-load back EMF,and output torque,and the results show that the proposed LATM with quasi-Halbach array has a 10%improvement in output torque and a 25%improvement in ***,the flux linkages and torque performance of the two sets of windings under various conditions verify good magnetic ***,prototypes of two different rotor types are manufactured and a series of experiments are performed to validate the analysis.

关键词： Limited-angle torque motor(LATM) Axial-flux machine Quasi-Halbach array Finite-element method(FEM) Cogging torque Torque performance

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Minimum energy storage for power system with high wind power penetration using p-efficient point theory

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Science China(Information Sciences) 2014年第12期57卷 243-254页

作者： LI JingHua WEN JinYu CHENG ShiJie WEI Hua State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology School of Electrical Engineering Guangxi University

Minimum energy storage(ES)and spinning reserve(SR)for day-ahead power system scheduling with high wind power penetration is significant for system operations.A chance-constrained energy storage optimization model based on unit commitment and considering the stochastic nature of both the wind power and load demand is *** solve this proposed chance-constrained model,it is first converted into a deterministic-constrained model using p-efficient point theory.A single stochastic net load variable is developed to represent the stochastic characteristics of both the wind power and load demand for convenient use with the p-efficient point theory.A probability distribution function for netload forecast error is obtained via the Kernel estimation *** proposed model is applied to a wind-thermal-storage combined power system.A set of extreme scenarios is chosen to validate the effectiveness of the proposed model and *** results indicate that the scheduled energy storage can effectively compensate for the net load forecast error,and the increasing wind power penetration does not necessarily require a linear increase in energy storage.

关键词： energy storage spinning reserve wind power penetration chance constraints p-efficient theory kernel estimation

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Study of Star-Delta Soft Switch to Extend AC Motor High Speed Operation Region

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CES Transactions on Electrical Machines and Systems 2023年第3期7卷 248-255页

作者： Yixuan Shuai Dong Jiang Zhuo Chen Zicheng Liu Haijing Sun Peng Li IEEE State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China

In traction application,speed range of motor is an important index for motor *** AC motor control,the maximum speed of the motor is limited by the output voltage capability of the traditional three-phase inverter with star connenction of *** the star connection to delta connection in high-speed range can extend the speed *** order to extend the speed operation region,star-delta switch proposed by many literatures relies on mechanical relay,which needs a dead zone of tens of milliseconds and seriously affects torque ***,the traditional method will cause current overshoot during the switch transient process,decreasing the device security and *** at the defects existing in the star-delta hard switching,this paper proposes a star-delta soft switching *** adding extra power electronics devices,DC-bus capacitor is used to provide the path of zero axis current in the transient process,which helps to achieve the smooth torque output and zero current switch in the *** have been done to validate the performance of the proposed *** switching transient from star to delta connection in the motor drive can be much more stable than hard switching method.

关键词： Speed range Soft switch 0-axis current Zero current switch

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Sodium phytate stabilizing lattice oxygen in high-nickel oxide cathodes for thermal runaway inhibition and high voltage operation

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Science Bulletin 2025年

作者： Yuanke Wu Qiang Wu Ziqi Zeng Yixuan Dong Shijie Cheng Jia Xie State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of Materials Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

The reactive oxygen species (O*) released from the nickel-rich layered oxide cathodes (LiNi x Co y Mn 1− x − y O 2 , NCM) are responsible for triggering thermal runaway (TR) in lithium-ion batteries (LIBs). Specifically, the charge compensation from transition metal (TM) 3d to oxygen (O) 2p in NCM plays a pivotal role in O* release. Here, inspired by the strong chelating effect of sodium phytate (PN) on TM, we employ PN as a cathode additive to coordinate with nickel, thereby weakening the charge compensation of TM 3d to O 2p on the surface of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) and ultimately enhancing battery safety. It is shown that the chelation successfully stabilizes lattice oxygen and suppresses the release of O*, preventing detrimental phase transitions in NCM811 and reducing heat generation from O* related crosstalk reactions. Consequently, the TR trigger temperature ( T tr ) of NCM811 pouch cell with PN elevates from 125.9 to 184.8 °C, while the maximum temperature ( T max ) decreases from 543.7 to 319.7 °C. Moreover, the PN-derived modification layer allows NCM811 to maintain exceptional cycling stability for over 700 cycles at 4.6 V. This strategy provides a facile method for stabilizing lattice oxygen in NCM, inhibiting O*-triggered TR, and enhancing high-voltage performance.

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Preliminary Design and Analysis of the DC Reactor for the ITER Converter

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Plasma Science and technology 2014年第3期16卷 273-277页

作者：杨拧张明李传宋执权于克训庄革徐涛 College of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Institute of Plasma Physics Chinese Academy of Sciences

The DC reactor is an important piece of equipment for restraining loop and ripple currents in the international thermonuclear experimental reactor （ITER） converter power supply system. As the reactor is operated at a steady state of 27.5 kA and needs to withstand a peak current of 175 kA, so the design of the DC reactor used in the ITER converter power supply system is necessary. A new water-cooling dry-type air-core reactor is designed in this work. The detailed structural parameters are calculated by theoretical formulas, and then the structure is optimized by electromagnetic simulation with ANSYS. Finally, thermal and dynamic stability analyses are performed to verify the temperature and stress at a rated current of 27.5 kA and pulsed current of 175 kA. The analysis results show that the temperature and stress meet the requirements of the ITER converter power supply system.

关键词： ITER converter reactor electromagnetic simulation thermal stability dy-namic stability

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Characterization of a Raman-based distributed fiber optical temperature sensor in liquid nitrogen

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Superconductivity 2022年第4期4卷 22-28页

作者： Yi Yue Guilun Chen Jiajie Long Li Ren Kao Zhou Xianhao Li Ying Xu Yuejin Tang State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhanChina

Distributed Temperature Sensor(DTS)based on Raman scattering have a promising application in temperature monitoring and quench detection of high‐temperature superconducting(HTS)fiber optic *** this paper,a series of mechanical property tests were carried out on fiber optical cables with different encapsulation materials to select the best material for the engineering *** was followed by loss testing of fiber optic cables with different outer diameters under liquid nitrogen(LN_(2))and the optimal outer diameter to meet measurement accuracy and engineering practicability was ***,the temperature measurement of fiber optic cables laid on HTS fiber optic cables were calibrated using thermocouple as a *** results of this research results provide a suitable fiber optic cable for engineering *** the same time,it provides a reference for the selection of optical cable structure parameters in HTS optical cable projects.

关键词： DTS HTS cable Mechanical property Optical loss

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The anode power supply for the ECRH system on the J-TEXT tokamak

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Plasma Science and technology 2018年第1期20卷 120-126页

作者：夏冬辉崔芳泰刘昌海余振雄金易坤王之江 J-TEXT team State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Zibo Power Supply Company State Grid Shandong Electric Power Company

The electron cyclotron resonance heating （ECRH） system with a 60 GHz/200 kW/0.5 s gyrotron donated by the Culham Science Center is being developed on the J-TEXT tokamak for plasma heating, current drive and MHD studies. Simultaneously, an anode power supply （APS） has been rebuilt and tested for the output power control of the gyrotron, of which the input voltage is derived from an 80 kV negative cathode power supply. The control strategy by controlling the grid voltage of the tetrode TH5186 is applied to obtain an accurate anode climbing voltage, of which the output voltage can be obtained from 0-30 kV with respect to the cathode power supply. The characteristics of the APS, including control, protection, modulation, and output waveform, were tested with a 100 kV/60 A negative cathode power supply, a dummy load and the ECRH control system. results indicate that the APS can meet the requirements of the ECRH system on J-TEXT.

关键词： J-TEXT ECRH APS Fiber isolation

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A permanent magnet electron beam spread system used for a low energy electron irradiation accelerator

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Chinese Physics C 2014年第10期38卷 111-116页

作者：黄江熊永前陈德智刘开峰杨军李冬余调琴樊明武杨波 College of Electrical and Electronics Engineering State Key Laboratory of Advanced Electromagnetic Engineering and TechnologyHuazhong University of Science and Technology China Electric Power Research Institute

The development of irradiation processing industry brings about various types of irradiation objects and expands the irradiation requirements for better uniformity and larger areas. This paper proposes an innovative design of a permanent magnet electron beam spread system. By clarifying its operation principles, the author verifies the feasibility of its application in irradiation accelerators for industrial use with the examples of its application in electron accelerators with energy ranging from 300 keV to 1 MeV. Based on the finite element analyses of electromagnetic fields and the charged particle dynamics, the author also conducts a simulation of electron dynamics in magnetic field on a computer. The results indicate that compared with the traditional electron beam scanning system, this system boosts the advantages of a larger spread area, non-power supply, simple structure and low cost, etc., which means it is not only suitable for the irradiation of objects with the shape of tubes, strips and panels, but can also achieve a desirable irradiation performance on irregular constructed objects of large size.

关键词： permanent magnet spread system irradiation accelerator finite element analysis beam dynamic,uniformity

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A Novel Method for Rigorously Analyzing Beam Loading Effect Based on the Macro-Particle Model

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Chinese Physics Letters 2014年第1期31卷 65-68页

作者：陈曲珊裴元吉胡桐宁秦斌 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230026

The beam loading effect is a considerable issue for a high average current beam. We apply a novel method without utilizing the specious beam current value to rigorously analyze the beam loading effect in S-band linacs. By tracking every macro-particle＇s state and using the energy conservation law, power dissipated from the beam is calculated in each cell. In the new particle-based algorithm, the concept of equivalent beam current is proposed. Its value is not constant and it has a small variation through the accelerating structure. Also, we introduce the iteration algorithm as comparison and we find that the two algorithms coincide with each other very well.

关键词： ENERGY conservation BEAM dynamics PARTICLE beams PARTICLE methods (Numerical analysis) NUMERICAL analysis MATERIAL point method

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Radial magnetic field in magnetic confinement device

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Chinese Physics B 2015年第9期24卷 337-342页

作者：熊昊刘明海陈明饶波陈杰陈兆权肖金水胡希伟 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology School of Electrical and Electric Engineering Huazhong University of Science and Technology College of Electrical and Information Engineering Anhui University of Science and Technology

The intrinsic radial magnetic field（B r） in a tokamak is explored by the solution of the Grad–Shafranov equation in axisymmetric configurations through an expansion of the four terms of the magnetic surfaces. It can be inferred from the simulation results that at the core of the device, the tokamak should possess a three-dimensional magnetic field configuration, which could be reduced to a two-dimensional one when the radial position is greater than 0.6a. The radial magnetic field and the amzimuthal magnetic field have the same order of magnitude at the core of the device. These results can offer a reference for the analysis of the plasma instability, the property of the core plasma, and the magnetic field measurement.

关键词： radial magnetic field minor toroidal coordinate three-dimensional magnetic field configuration

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