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IEEE Power and Energy Society General Meeting

作者： Weixing Lin Dragan Jovcic Lu Miao Jinyu Wen School of Engineering University of Aberdeen State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology

ISBN: (纸本)9781467380416

A common modularized analytical modelling method is proposed to obtain the linearized state-space model of two different multiport DC hubs (the multiport LCL dc hub and multiport back-to-back dc-dc converting system). Linearization of the electrical circuit and modularized form of the controllers are firstly presented. The sub-systems in modularized linear forms are then linked to form an overall linearized system. Correctness of the linearized model is firstly compared with the linearized model obtained using linmod in Matlab/Simulink. Time domain simulations are then used to compare the linearized model with the nonlinear model in Matlab/Simulink and detailed switching model in PSCAD/EMTDC, for a 4-port test system. Results show that the proposed modularized analytical modelling method is able to obtain highly accurate linearized model and in the meantime significantly reduce the complexity of calculation.

关键词： DC power systems DC power transmission DC-DC power conversion HVDC converters HVDC transmission Wind Eenergy DC power transmission HVDC power transmission DC-DC power convertors multiport Modularity HUB

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Analysis and Control of Doubly Fed Induction Generator for Zero Voltage Ride Through

Analysis and Control of Doubly Fed Induction Generator for Z...

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International Conference on Electrical Machines and Systems

作者： Haiyan Tang Yuanzhu Chang Yongning Chi Bo Wang Yan Li Jiabing Hu State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems China Electric Power Research Institute. Beijing 100192 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China

ISBN: (纸本)9781467388634

The stator transient DC flux component emerges in the Double Fed Induction Generator (DFIG) following grid voltage dip, which results in an important influence on the controllability of rotor converter. In this paper, the research focuses on the responding time of the dynamic reactive current injection referring to DFIG with the crowbar protection under Zero Voltage Ride-Through (ZVRT). Firstly, theoretical analysis about the shortest quitting time of crowbar is carried out. Then, combined with crowbar protection and demagnetization control, ZVRT of DFIG is achieved as well as the fast injection of dynamic reactive current. Finally, the simulation results are presented to verify the theoretical analysis and the proposed control strategy. It is helpful to enhance fault ride through capability of DFIG.

关键词： Crowbar DFIG Dynamic reactive current injection ZVRT

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Exotic plasma bullets induced by residual electron control

Exotic plasma bullets induced by residual electron control

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IEEE International Conference on Plasma Science (ICOPS)

作者： Y. Xian X. Lu State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei China

Summary form only given. Atmospheric-pressure non-equilibrium plasma jets have recently received a major attention due to their widespread applications in surface and materials processing, biomedical engineering, and medicine. The discovery of fast-propagating plasma bullets opens an exciting possibility to control small bits of plasma solver sub-microsecond and possibly even nanosecond time scales. However, this fascinating phenomenon is still challenging to control and is far from being understood despite of a few mechanisms *** control the dynamics of the residual electrons and the plasma channel structure and the plasma bullet propagation, we customized the DC voltage to vary it over the timescales comparable with the expected lifetime of the residual electrons. Consequently plasma plumes with exotically segmented channel structure and plasma bullet propagation are produced in atmospheric plasma jets, as shown in Fig. 1. These phenomena are explained by studying the plasma dynamics using nanosecond-precision imaging. One of the plumes is produced using 2 - 10 μs interruptions in the 8 kV DC voltage and features a still bright channel from which a propagating bullet detaches. A shorter interruption of 900 ns produces a sophisticated plume with the additional long conducting dark channel between the jet nozzle and the bright area. In this way, the bullet size, formation dynamics, and propagation speed and distance can be controlled. This may lead to the as yet elusive micrometer- and nanosecond-precision delivery of quantized plasma bits, warranted for next-generation health, materials, and device technologies.

关键词： Plasmas electromagnetics Surface treatment Materials processing Biomedical engineering Biomedical imaging Voltage control

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Amplitude-Phase-Locked Loop: Estimator of Three-Phase Grid Voltage Vector

Amplitude-Phase-Locked Loop: Estimator of Three-Phase Grid V...

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IEEE Power and Energy Society General Meeting

作者： Lei Shang Jiabing Hu Xiaoming Yuan Wenming Tang Xinwen Hou State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China

ISBN: (纸本)9781467380416

This paper presents a novel amplitude-phase locked loop (APLL) to simultaneously estimate the phase angle, frequency and amplitude of grid voltage, as well as the change rate of amplitude accurately. The proposed APLL can extract pure fundamental component when grid voltage contains noise and harmonic components. Furthermore, positive-sequence voltage component can be decoupled by APLL when grid voltage is asymmetric. Moreover the effect of APLL's controller parameters on its dynamic response is analyzed. Finally, simulation and experimental results are presented to verify the feasibility and effectiveness of APLL.

关键词： Amplitude-phase-locked loop (APLL) amplitude estimation change rate of amplitude (CRA) frequency estimation

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A battery-operated atmospheric-pressure plasma wand for biomedical applications

A battery-operated atmospheric-pressure plasma wand for biom...

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IEEE International Conference on Plasma Science (ICOPS)

作者： Xuekai Pei Xinpei Lu State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei China

Summary form only given. A handheld, battery-operated atmospheric-pressure plasma rod (named plasma wand, Fig. 1) which does not rely on external power source (e.g., wall power or power generator) and gas supply is reported 1 . The plasma wand can be used for killing bacteria, fungi, or viruses that are hidden in narrow channels such as nasal cavity and ear canal, which are difficult to access using most of currently available devices. Besides, the electrical characterization, plasma wand temperature, emission spectra of the plasma, ozone and OH radical concentration generated by the device, are investigated by different diagnostic methods. The temperature on the plasma wand stays at about 38°C after operating for about 5 minute and the outside electrode is grounded. So there is no feeling of hot or electrical shock at all when we hold the plasma wand. From the Lissajous-figure of the discharge, the power consumption is estimated to be about 12 W. The ozone concentration reaches 120 ppm at 1 mm away from the device and the OH concentration reaches 3.5×10 14 cm -3 in the plasma. The preliminary bacteria inactivation experiment results show that all bacteria samples on the microfiltration membrane are killed by this device within 30 s.

关键词： Atmospheric-pressure plasmas Microorganisms Plasma temperature Gases Physics electromagnetics

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Modeling and Analysis of the Inverter Type High Voltage Power Supply with Duty Cycle Modulation

Modeling and Analysis of the Inverter Type High Voltage Powe...

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IEEE Symposium on Fusion engineering

作者： M. Zhang X. L. Zhang L. L. Xia S. X. Ma Y. Pan State Key laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei China

The acceleration grid power supply (AGPS) is an important part of neutral beam injector (NBI) system. With the increasing of the NBI power, the requirement for output voltage of the AGPS is becoming higher and higher, even reaching to 1000 kV. As the Inverter type high voltage power supply uses the inverters located at lower voltage side to regulate and cut off the output voltage, it's very suitable for high voltage applications. The advised scheme for the AGPS of ITER NBI system is composed of five stages, each stage is an inverter type power supply with an output voltage of 200 kV. This paper investigates the inverter type power supply based on neutral point clamped (NPC) three phase three level (TPTL) inverter and three phase step-up transformer, which is equivalent to an insulated TPTL dc-dc converter connected with a dual dc link. In order to design a preferable controller for the inverter type power supply, the topology and principles of the TPTL dc-dc converter with duty cycle modulation has been analyzed. Our results indicate that only when the converter operates at a large duty cycle, the output voltage ripple can be limited to ± 5%. So the small signal model of the converter at a duty cycle larger than 2/3 is established. Following the mathematical model, a single loop PID controller has been designed. Simulation results verify the correctness of the theoretical analysis. The system achieves lower output voltage ripple and fast dynamic response.

关键词： AGPS inverter small signal model duty cycle modulation

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Analyze and Reduce the Impact of Sampling Delay on LCL Converter with Capacitor Current Feedback Active Damping

Analyze and Reduce the Impact of Sampling Delay on LCL Conve...

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IEEE International Conference on Power Electronics and Drive Systems

作者： Zhiqiang Wan Jian Xiong Ji Lei Chen Chen State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei China

The capacitor current feedback active damping is widely used in LCL converter. However, digital processor needs some time to calculate the output in digital control system which will result in sampling delay. The sampling delay will leads to system instability and unacceptable damping performance, especially in low switching frequency. This paper overcomes this issue by shifting the sampling instant close to the PWM updating instant. This approach can strengthen system stability and achieve sufficient active damping. Moreover, smaller sampling delay corresponds to larger damping ratio. The theoretical conclusions presented in this paper are verified by simulation and experiment.

关键词： Delays Damping Switching frequency Capacitors Mathematical model Integrated circuits Pulse width modulation

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Experimental investigation of arc formation and bubble expansion initiated by pulse discharge in water

Experimental investigation of arc formation and bubble expan...

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International Conference on Pulsed Power

作者： Yibo Han Yi Liu Fuchang Lin Zhiyuan Li Qiping Luo State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei China

Dynamic pressure wave generated by underwater pulse discharge are widely used in many industry applications including rock fragmentation, oil stimulation and acoustic source. A test stand was developed to measure the amplitude and waveform of dynamic pressure wave produced by underwater pulse discharge. Besides, the pulsations of underwater arc and the gaseous bubble generated by pulse discharges in several tens of microseconds were observed by a high speed camera with a frame speed at 525 kfps. Two distinct phases characterizing different arc shapes are observed and distinguished. The energy of shock wave and that of arc are calculated and compared in detail. Based on results of observation and energy analysis, it can be concluded that the water-atmosphere arc phase (more precisely, 0-15 μs after breakdown in this paper) exacts a decisive impact on the generation of shockwave. Which probably leads to necessary reconsiderations of several fundamental assumptions in modeling of.

关键词： Decision support systems Partial discharges Electronic mail Delay effects Discharges (electric)

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Design of the Transmission Lines for 140 GHz ECRH System on HL-2A

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Plasma Science and technology 2014年第3期16卷 267-272页

作者：夏冬辉周俊饶军黄梅陆志鸿王贺陈罡宇王超卢波庄革 State Key Laboratory of Advanced Electromagnetic Engineering and TechnologyHuazhong University of Science and Technology Southwestern Institute of Physics

A new 140 GHz/2 MW/3 s electron cyclotron resonance heating （ECRH） system composed of two units is now being constructed on HL-2A. As a part of the system, two trans- mission lines marked No.7 ＆ 8 play the role of carrying microwave power from two gyrotrons to the tokamak port. Based on the oversized circular corrugated waveguide technology, an evacu~ ated transmission system with high power capability and high transmission efficiency is designed. Details are presented for the design of the corrugated waveguide, the layout of the proposed lines and the vacuum pumping system. Then mode conversion losses due to coupling, misalignment, bends and gaps are discussed to serve as a reference for analyzing the transmission efficiency and alignment. Finally, a dual-modes propagation case consisting of the HEll and LPn even modes is discussed.

关键词： HL-2A tokamak electron cyclotron resonance heating transmission line

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Dense sampling of bird diversity increases power of comparative genomics (vol 587, pg 252, 2020)

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NATURE 2021年第7856期592卷 E24-E24页

作者： Feng, Shaohong Stiller, Josefin Deng, Yuan Armstrong, Joel Fang, Qi Reeve, Andrew Hart Xie, Duo Chen, Guangji Guo, Chunxue Faircloth, Brant C. Petersen, Bent Wang, Zongji Zhou, Qi Diekhans, Mark Chen, Wanjun Andreu-Sanchez, Sergio Margaryan, Ashot Howard, Jason Travis Parent, Carole Pacheco, George Sinding, Mikkel-Holger S. Puetz, Lara Cavill, Emily Ribeiro, Angela M. Eckhart, Leopold Fjeldsa, Jon Hosner, Peter A. Brumfield, Robb T. Christidis, Les Bertelsen, Mads F. Sicheritz-Ponten, Thomas Tietze, Dieter Thomas Robertson, Bruce C. Song, Gang Borgia, Gerald Claramunt, Santiago Lovette, Irby J. Cowen, Saul J. Njoroge, Peter Dumbacher, John Philip Ryder, Oliver A. Fuchs, Jerome Bunce, Michael Burt, David W. Cracraft, Joel Meng, Guanliang Hackett, Shannon J. Ryan, Peter G. Jonsson, Knud Andreas Jamieson, Ian G. da Fonseca, Rute R. Braun, Edward L. Houde, Peter Mirarab, Siavash Suh, Alexander Hansson, Bengt Ponnikas, Suvi Sigeman, Hanna Stervander, Martin Frandsen, Paul B. van der Zwan, Henriette van der Sluis, Rencia Visser, Carina Balakrishnan, Christopher N. Clark, Andrew G. Fitzpatrick, John W. Bowman, Reed Chen, Nancy Cloutier, Alison Sackton, Timothy B. Edwards, Scott V. Foote, Dustin J. Shakya, Subir B. Sheldon, Frederick H. Vignal, Alain Soares, Andre E. R. Shapiro, Beth Gonzalez-Solis, Jacob Ferrer-Obiol, Joan Rozas, Julio Riutort, Marta Tigano, Anna Friesen, Vicki Dalen, Love Urrutia, Araxi O. Szekely, Tamas Liu, Yang Campana, Michael G. Corvelo, Andre Fleischer, Robert C. Rutherford, Kim M. Gemmell, Neil J. Dussex, Nicolas Mouritsen, Henrik Thiele, Nadine Delmore, Kira Liedvogel, Miriam Franke, Andre Hoeppner, Marc P. Krone, Oliver Fudickar, Adam M. Mila, Borja Ketterson, Ellen D. Fidler, Andrew Eric Friis, Guillermo Parody-Merino, Angela M. Battley, Phil F. Cox, Murray P. Lima, Nicholas Costa Barroso Prosdocimi, Francisco Parchman, Thomas Lee Schlinger, Barney A. Loiselle, Bette A. Blake, John G. Lim, Haw Chuan Day, Lainy B. Fuxjager, Matthew J. Baldwin, Maude W. Braun, Michael J. Wirthlin, Morgan Dikow, China National GeneBank BGI-Shenzhen Shenzhen China State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Kunming China BGI-Shenzhen Shenzhen China Villum Centre for Biodiversity Genomics Section for Ecology and Evolution Department of Biology University of Copenhagen Copenhagen Denmark BGI Education Center University of Chinese Academy of Sciences Shenzhen China MOE Laboratory of Biosystems Homeostasis and Protection Life Sciences Institute Zhejiang University Hangzhou China Department of Neuroscience and Developmental Biology University of Vienna Vienna Austria Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences Kunming China James D. Watson Institute of Genome Sciences Hangzhou China UC Santa Cruz Genomics Institute UC Santa Cruz Santa Cruz CA USA Natural History Museum of Denmark University of Copenhagen Copenhagen Denmark Center for Macroecology Evolution and Climate GLOBE Institute University of Copenhagen Copenhagen Denmark Department of Biological Sciences Louisiana State University Baton Rouge LA USA Museum of Natural Science Louisiana State University Baton Rouge LA USA Centre of Excellence for Omics-Driven Computational Biodiscovery (COMBio) Faculty of Applied Sciences AIMST University Kedah Malaysia Section for Evolutionary Genomics The GLOBE Institute Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark Institute of Molecular Biology National Academy of Sciences Yerevan Armenia University Museum Norwegian University of Science and Technology Trondheim Norway Center for Reproductive Medicine The 2nd Affiliated Hospital School of Medicine Zhejiang University Hangzhou China Novogene Durham NC USA Duke University Medical Center Durham NC USA The Rockefeller University New York NY USA Howard Hughes Medical Institute Chevy Chase MD USA Department of Dermatology Medical University of Vienna Vienna Austria

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