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Design of Q-band FMCW reflectometry for electron density profile measurement on the Joint TEXT tokamak

Plasma Science and technology 2017年第2期19卷 101-107页

作者：万凌寒杨州军周若冰潘晓明张弛谢先立阮博文 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074People's Republic of China

The Q-band （33-50 GHz） fast sweep frequency modulated continuous wave （FMCW） reflectometry has been recently developed for electron density profile measurement on the Joint TEXT tokamak. It operates in ordinary mode （O-mode） with a 20 μs sweeping period, covering the density range from 1 × 10^19m 3 to 3 × 10^19m-3. On the bench test, a Yttrium Iron Garnet （YIG） filter is used for the dynamic calibration of the voltage controlled oscillator （VCO） to obtain a linear frequency sweep. Besides, the use of a power combiner helps to improve the sideband suppression level of the single side-band modulator （SSBM）. The reconstructed density profiles are presented, which demonstrate the capability of the reflectometry.

关键词： reflectometry density plasma diagnostics

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Study on characteristics of acoustic signals generated by different DC discharge modes

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Plasma Science and technology 2023年第5期25卷 85-92页

作者：熊紫兰王渝淇李孟琦 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430000People’s Republic of China

Acoustic signals contain rich discharge *** this study,the acoustic signal characteristics of transient glow,spark,and glow discharges generated through DC pin–pin discharge were *** signals were analyzed in the time,frequency,and time–frequency domains,and the correlation between the electric and the acoustic signal was studied *** results show that glow discharge does not produce measurable sound *** the other modes,with a decrease in the discharge gap,the amplitude of the acoustic signal increases sharply with mode transformation,the short-time average energy becomes higher,and the frequency components are more ***,the current pulse and sound pressure pulse have a one-to-one relationship in the transient glow and spark regimes,and they are positively correlated in amplitude.A brief theoretical analysis of the mechanism of plasma sound and the trends of signals in different modes is ***,the change in the discharge energy is closely related to the sound generation of the plasma.

关键词： low-temperature plasma DC discharge discharging modes acoustic signal sound generation

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Progress of the RF negative hydrogen ion source for fusion at HUST

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Plasma Science and technology 2022年第12期24卷 149-156页

作者： Chen ZUO Peng CHEN Zengshan LI Jinghan YANG Fei SONG Dezhi CHEN State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074People's Republic of China

Huazhong University of Science and technology has developed an experimental setup of a radio frequency(RF) driven negative hydrogen ion source,to investigate the physics of production and extraction of the H^(-)ions for neutral beam injection in nuclear fusion *** main design parameters of the ion source are:RF power ≤40 kW;extraction voltage ≤10kV;accelerator voltage ≤20 *** paper gives an overview of the progress of the ion source with particular emphasis on some *** RF driver and source plasma are analyzed and optimized in terms of impedance matching,plasma characteristics and power *** regard to the simulation analysis,a plasma model based on the particle-in-cell method and a beam trajectory model considering beam stripping loss are developed to investigate the plasma and negative ions transport inside the ion ***,a collisional radiative model of H and H2is built for plasma optical diagnosis.

关键词： negative ion sources radio frequency(RF) particle-in-cell(PIC) beam simulation

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Sterilization mechanism of helium/helium-oxygen atmospheric-pressure pulsed dielectric barrier discharge on membrane surface

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Plasma Science and technology 2022年第12期24卷 173-181页

作者： Xingyu CHEN Yuhan Li Mengqi LI Zilan XIONG State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074People's Republic of China

Pulsed dielectric barrier discharge(PDBD) exhibits several applications in different fields;however,the interaction of its components with substances remains a key *** this study,we employed experimental and numerical modeling to investigate the interactions between different PDBD components and substances in pure helium and a helium-oxygen mixture.A membrane comprising a Staphylococcus aureus strain was utilized as the treatment object to demonstrate the trace actions of the evolutions and distributions of certain components on the surface of the *** results revealed that the shapes and sizes of the discharging area and inhibition zone differed between *** a pure helium condition,a discharge layer existed along the membrane surface,lying beside the main discharging channel within the electrode ***,an annulus inhibition zone was formed at the outer edge of the electrode in the pure helium group at 30 s and 1 min,and this zone extended to a solid circle at 2 min with a radius that was~50% larger than that of the electrode ***,the discharging channel and inhibition zone in the helium-oxygen mixture were constrained inside the electrode area without forming any annulus.A 2D symmetrical model was developed with COMSOL to simulate the spatiotemporal distributions of different particles over the membrane surface,and the result demonstrated that the main components,which formed the annulus inhibition zone under the pure helium condition,contributed to the high concentration of the He^(+)annulus that was formed at the outer edge of the ***,O^(+)and O_(2)^(+)were the main components that killed the bacteria under the helium-oxygen mixture *** results reveal that the homogenization treatment on a material surface via PDBD is closely related to the treatment time and working gas.

关键词： pulsed dielectric barrier discharge interaction mechanism numerical modeling spatiotemporal distribution of species treatment substance

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Distributed Stochastic Scheduling of Massive Backup Batteries in Cellular Networks for Operational Reserve and Frequency Support Ancillary Services

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 393-404页

作者： Kun Li Jiakun Fang Xiaomeng Ai Shichang Cui Rongkang Zhao Jinyu Wen State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China IEEE

Base station(BS)backup batteries(BSBBs),with their dispatchable capacity,are potential demand-side resources for future power *** enhance the power supply reliability and post-contingency frequency security of power systems,we propose a two-stage stochastic unit commitment(UC)model incorporating operational reserve and post-contingency frequency support provisions from massive BSBBs in cellular networks,in which the minimum backup energy demand is considered to ensure BS power supply *** energy,operational reserve,and frequency support ancillary services are co-optimized to handle the power balance and post-contingency frequency security in both forecasted and stochastic variable renewable energy(VRE)***,we propose a dedicated and scalable distributed optimization framework to enable autonomous optimizations for both dispatching center(DC)and *** BS model parameters are stored and processed locally,while only the values of BS decision variables are required to upload to DC under the proposed distributed optimization framework,which safeguards BS privacy *** studies on a modified IEEE 14-bus system demonstrate the effectiveness of the proposed method in promoting VRE accommodation,ensuring post-contingency frequency security,enhancing operational economics,and fully utilizing BSBBs'energy and power ***,the proposed distributed optimization framework has been validated to converge to a feasible solution with near-optimal performance within limited ***,numerical results on the Guangdong 500 kV provincial power system in China verify the scalability and practicality of the proposed distributed optimization framework.

关键词： Base station backup battery operational reserve frequency security distributed optimization privacy

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Design and development of the beamline for a proton therapy system

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Nuclear Science and Techniques 2021年第12期32卷 53-63页

作者： Bin Qin Xu Liu Qu-Shan Chen Dong Li Wen-Jie Han Ping Tan Zhong-Qi Zhang Chong Zhou Ao-Te Chen Yi-Cheng Liao Wei Wang State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina

A proton therapy(PT)facility with multiple treatment rooms based on the superconducting cyclotron scheme is under development at Huazhong University of Science and technology(HUST).This paper attempts to describe the design considerations and implementation of the PT beamline from a systematic *** considerations covering beam optics and the influence of high-order aberrations,beam energy/intensity modulation,and beam orbit correction are *** addition to the technical implementation of the main beamline components and subsystems,including the energy degrader,fast kicker,beamline magnets,beam diagnostic system,and beamline control system are introduced.

关键词： Proton therapy Beamline Beam optics Beam energy/intensity modulation

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Supplementary Control for Mitigation of Successive Commutation Failures Considering the Influence of PLL Dynamics in LCC-HVDC Systems

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CSEE Journal of Power and Energy Systems 2022年第3期8卷 872-879页

作者： Jun Lu Xiaoming Yuan Meiqing Zhang Jiabing Hu State Key Laboratory of Advanced Electromagnetic Engineering and Technology and the School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhan430074China

Line commutated converter based high voltage direct current(LCC-HVDC)links are widely employed for long distance bulk power transmission and asynchronous alternating current(AC)grid ***,LCC-HVDC systems often suffer from commutation failures when AC voltage is distorted,oscillating or reduced by AC faults,which leads to overheating of converter valves and interruptions in transmitted *** of which can have an adverse impact on the safety and stability of the entire power *** paper proposes a supplementary control for mitigation of successive commutation failures on the basis of analyzing the influence of phase-locked loop(PLL)dynamics on the commutation *** analyzing the impact of PLL dynamics on the actual leading angle,it is found that changes in the AC voltage phase remarkably influence ***,the error between the AC voltage phase and PLL’s output angle is added to the output of the extinction angle or DC voltage control to mitigate the successive commutation failures of LCC-HVDC *** conducted on the CIGRE benchmark model in PSCAD/EMTDC validate the performance of the supplementary control,which effectively mitigates successive commutation failures.

关键词： Commutation failure dynamics LCC-HVDC mitigation PLL supplementary control

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electromagnetic interaction between local surface plasmon polaritons and an atmospheric surface wave plasma jet

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Chinese Physics B 2014年第3期23卷 404-411页

作者：陈兆权胡东刘明海夏广庆郑晓亮胡业林叶秋波陈明功祝龙记胡希伟 College of Electrical & Information Engineering Anhui University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology State Key Laboratory of Structure Analysis for Industrial Equipment Dalian University of Technology

We analyze the electromagnetic interaction between local surface plasmon polaritons （SPPs） and an atmospheric surface wave plasma jet （ASWPJ） in combination with our designed discharge device. Before discharge, the excitation of the SPPs and the spatial distribution of the enhanced electric field are analyzed. During discharge, the critical breakdown electric field of the gases at atmospheric gas pressure and the surface wave of the SPPs converted into electron plasma waves at resonant points are studied. After discharge, the ionization development process of the ASWPJ is simulated using a two- dimensional fluid model. Our results suggest that the local enhanced electric field of SPPs is merely the precondition of gas breakdown, and the key mechanism in maintaining the discharge development of a low-power ASWPJ is the wave-mode conversion of the local enhanced electric field at the resonant point.

关键词： surface wave plasma surface plasmon polaritons numerical simulation electromagnetic interac-tion

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Centralized control of parallel connected power conditioning system in electric vehicle charge-discharge and storage integration station

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Journal of Modern Power Systems and Clean Energy 2015年第2期3卷 269-276页

作者： Jiuqing CAI Changsong CHEN Peng LIU Shanxu DUAN State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhanChina

This study presents a centralized control scheme that coordinates parallel operations of power conditioning system(PCS)for the grid interactions of electric vehicles(EVs)in EV charge-discharge and storage integration *** issues for the control and operation of PCS under various operation modes are discussed,including vehicle to grid(V2G)mode,stand-alone mode and seamless transfer *** intelligent multi-mode charge-discharge method is utilized for the V2G mode,and the parallel control method based on communication network is adopted for the standalone *** addition,a novel seamless transfer strategy is proposed,which is able to implement PCS transition between V2G mode and stand-alone *** detailed process of the seamless transfer between the two modes is *** results are presented to show the performance and feasibility of this strategy.

关键词： Centralized control Power conditioning system(PCS) Charge-discharge and storage integration station Vehicle to grid(V2G) Seamless transfer

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CHANNEL ACCESS PROTOCOLS FOR KU-BAND VSAT NETWORKS - A COMPARATIVE-EVALUATION

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IEEE COMMUNICATIONS MAGAZINE 1988年第5期26卷 34-44页

作者： RAYCHAUDHURI, D JOSEPH, K State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

The performance of candidate protocols for first-generation Ku-band very small aperture terminal (VSAT) satellite networks is compared. The goal is to assist the process of selecting a protocol. The performance comparison is carried out over a range of possible traffic, channel and satellite parameters, leading to an understanding of the appropriate regime for each of the protocols under consideration. The protocols considered are unslotted Aloha, slotted Aloha, selective-reject (SRE) Aloha, and demand-assigned time-division multiple-access (TDMA) or DAMA.< >

关键词： Access protocols Satellite broadcasting Costs Satellite ground stations Artificial satellites Time division multiplexing Local area networks Apertures Wide area networks Power generation economics

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