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IEEE Energy Conversion Congress and Exposition

作者： Dawei Li Ronghai Qu Thomas Lipo State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical & Electronic Engineering Huazhong University of Science and Technology Wuhan China Department of Electrical and Computer Engineering University of Wisconsin Madison Madison USA

ISBN: (纸本)9781479903375

Vernier permanent magnet (VPM) machines are well known for high torque density but low power factor. This paper deals with the low power factor of VPM machines. The goal is not obtained by reducing the electrical loading or adjusting current advance angle but proposing a novel vernier topology- dual-stator, spoke-array (DSSA) VPM topology. In this paper, the characteristics, such as active part, auxiliary mechanical structure and rotor anisotropy, of the DSSA VPM topology are analyzed in detail. Performances, including power factor, torque density, and cogging torque etc., are evaluated based on finite element analysis (FEA). The analysis results show that the DSSA VPM topology exhibits high power factor viz.,～0.9 and significantly high torque capability. Finally, the prototype machine has been designed, built, and is under testing. The verification of the mechanical structure scheme is done in this paper, and the experimental results will be presented in the near future.

关键词： High power factor dual-stator spoke-array vernier permanent magnet machine Reactive power Domain-Specific Software Architecture high torque Permanent magnet synchronous machines cogging torque MECHANICAL STRUCTURES machine topology

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Research on the micro-void discharge in power frequency and high frequency

Research on the micro-void discharge in power frequency and ...

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Conference on Electrical Insulation and Dielectric Phenomena, (CEIDP)

作者： Qifu Lu Qizheng Ye Hong Lv Xingwang Li Chu Yang Siyang Wu Electric Power Research Institute of Guangdong Power Grid Corporation Guangdong China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (纸本)9781479925988

In this paper, a type of typical PD source, micro-void discharge, is designed and fabricated to imitate the defects in GIS online. The void in solid insulation is carved by the laser inside-carving machine and the machining operation, respectively. Comparing these two kinds of void discharge, a single void discharge form can be obtained using the void carved by the laser inside-carving machine. The void discharge characteristics in power frequency and high frequency are also compared and analyzed. The singleness of discharge forms in high frequency is better. The experimental results will be applied in PD monitoring and materials testing.

关键词： Discharges (electric) Partial discharges Fault location Lasers Gas insulation Machining

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Transform of lightning electromagnetic pulses based on laplace wavelet

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Telkomnika - Indonesian Journal of Electrical engineering 2013年第9期11卷 4911-4917页

作者： Li, Qin Li, Kaicheng Zhang, Changhua Chen, Xiaojing Department of Electrical Engineering Hubei University for Nationalities 39 Xueyuan Road Enshi Hubei China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei 430074 China

In this study, the fine structures of lightning electromagnetic pulse associated with 19 preliminary breakdown pulses, 37 stepped leaders, 8 dart leaders, 73 first and 52 subsequent return strokes were analyzed by using Laplace wavelet. The main characteristics of field waveforms such as, the correlation coefficient, the time of arrival and the dominant frequency of the initial peak field, the energy and the frequency of the power spectrum peak are presented. The instantaneous initial peak field pulse can be precisely located by the value of the correlation coefficient. The dominant frequencies of the initial peak field of PB pulses and leaders range from 100kHz to 1MHz, and that of the first and subsequent return strokes below 100 and 50kHz, respectively. The statistical results show that the Laplace wavelet is an effective tool and can be used to determine time and frequency of the lightning events with greater accuracy. © 2013 Universitas Ahmad Dahlan.

关键词： Wavelet transforms

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Stress and Thermal Analysis of the In-Vessel Resonant Magnetic Perturbation Coils on the J-TEXT Tokamak

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Plasma Science and technology 2012年第1期14卷 83-88页

作者： HAO Changduan ZHANG Ming DING Yonghua RAO Bo CEN Yishun ZHUANG Ge College of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan 430074China

A set of four in-vessel saddle coils was designed to generate a helical field on the J- TEXT tokamak to study the influences of the external perturbation field on plasma. The coils are fed with alternating current up to 10 kA at frequency up to 10 kHz. Due to the special structure, complex thermal environment and limited space in the vacuum chamber, Jt is very important to make sure that the coils will not be damaged when undergoing the huge electromagnetic forces in the strong toroidal field, and that their temperatures don＇t rise too much and destroy the in- sulation. A 3D finite element model is developed in this paper using the ANSYS code, stresses are analyzed to find the worst condition, and a mounting method is then established. The results of the stress and modal analyses show that the mounting method meets the strength requirements. Finally, a thermal analysis is performed to study the cooling process and the temperature distribution of the coils.

关键词： J-TEXT tokamak resonant magnetic perturbation （RMP） coils finite ele- ment analysis （FEA）

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Networked Predictive Control Based Wide-Area Supplementary Damping Controller of SVC with Communication Delays Compensation

Networked Predictive Control Based Wide-Area Supplementary D...

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IEEE Power and Energy Society General Meeting

作者： Wei Yao L. Jiang J. Y. Wen S. J. Cheng Q. H. Wu State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science & Technology Wuhan 430074 China Department of Electrical Engineering & Electronics The University of Liverpool Liverpool L69 3GJ UK

ISBN: (纸本)9781479913022

This paper presents the design of a networked predictive control (NPC) based wide-area supplementary damping controller (WSDC) of SVC in order to damp the inter-area low frequency oscillations in large-scale interconnected power system. The major advantage of the proposed WSDC is that it can compensate constant and random communication delays existing in wide-area signals in an active way. Moreover, a recursive leastsquares algorithm (RLSA) with a variable forgetting factor is applied to identify the predictive model of the power system to overcome the model inaccuracies and uncertainties. Case studies undertaken on a two-area four-machine power system with a SVC device installed show that the proposed WSDC can provide better damping performances than the conventional WSDC especially when the wide-area signals exist communications delays.

关键词： Wide-area supplementary damping controller static var compensator (SVC) networked predictive control wide-area measurement system communication delays. Wide area measurement systems Static VAr compensators Neural network predictive control Communication Research absorption of shock power systems compensated Predictive control Controllers

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THz Spectrum Deconvolution with Total Variation Regularization

THz Spectrum Deconvolution with Total Variation Regularizati...

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International Congress on Image and Signal Processing

作者： Lizhen Deng Hu Zhu Guanming Lu State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China Jiangsu Province Key Lab on Image Processing & Image Communication Nanjing University of Posts and Telecommunications Nanjing 210003 China

ISBN: (纸本)9781479927654

Deconvolution has become one of the most used methods for improving spectral resolution, and blind deconvolution as a typical method has been researched widely. However, the predefined point spread function (PSF) used in blind deconvolution method is not known exactly in practice. In general, the PSF is estimated simultaneously from the observed spectrum, but it becomes difficult when the spectroscopic data are polluted by strong noise. In this paper, we present a deconvolution method used to improve the resolution of THz spectrum. In the method, the energy function is constructed, which includes the likelihood term, Total variation of spectrum term and L2 norm of the PSF term. The PSF is modeled as a parametric function combination with the a priori knowledge about the characteristics of the instrumental response. The spectrum and the parameter of PSF are obtained by minimizing the energy functional using alternate minimization approach. Experimental results are shown to demonstrate the efficiency of the proposed method used for THz spectrum.

关键词： THz spectrum Total variation deconvolution alternate minimization approach

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Character Diagnosis for Surface-Wave Plasmas Excited by Surface Plasmon Polaritons

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Plasma Science and technology 2012年第8期14卷 754-758页

作者：陈兆权夏广庆刘明海胡业林郑晓亮李平周启燕胡希伟 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

The plasma parameters of planar-type surface-wave plasmas （SWPs） are diagnosed based on the resonant excitation of surface plasmon polaritons （SPPs）. The plasma parameter distributions are obtained by changing the discharge conditions of gas pressure and incident power. The measured experimental results show that the plasma near the heating layer is excited by surface waves of SPPs while the plasma located downstream originates from diffusion Moreover, the influence of high-frequency oscillations plays a significant role in producing the proposed SWPs with bi-Maxwellian electron energy distributions.

关键词： surface-wave plasmas plasma diagnosing surface plasmon polaritons

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XPower system transient stability analysis and critical cutset detection based on branch ridge

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Diangong Jishu Xuebao/Transactions of China Electrotechnical Society 2013年第11期28卷 X262-269页

作者： Wang, Ke You, Dahai Yin, Xianggen Ye, Lei Huang, Ruoyin Wu, Junchun State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China

Effective online power system transient stability analysis and critical cutset detection method has important significance for the safe and stable operation of interconnected power system. Aiming at the disadvantages of the PEBS(potential energy boundary) method based on branch potential energy, a high reliable method named Branch RIDGE method is proposed in this paper for power system transient stability analysis and critical cutset detection. Also, a simple stability index of branch and system and a method to detect the stability status and critical cutsets of power system based on BPR and branch stability index are proposed. This method is established on the dynamic response trajectories of power system network information. In the case of known parameters of network structure, the method only needs real-time data of bus voltage magnitude and phase angle to do online power transient stability analysis and critical cutset detection. Because the method doesn't make assumption of two group instability mode, this method can be used in multi-swing instability and multi-group instability mode. The simulation on New England 10 machines show the validation of the proposed method.

关键词： Potential energy

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Effects of cooling rates on glass formation and magnetic behavior for the Fe73.0C7.0Si3.3B5.0P 8.7Mo3.0 bulk metallic glass

Effects of cooling rates on glass formation and magnetic beh...

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作者： Gao, J.E. Li, H.X. Jiang, F. Winiarski, B. Withers, P.J. Liaw, P.K. Lu, Z.P. State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China Department of Materials Science and Engineering University of Tennessee Knoxville TN 37996 United States School of Materials University of Manchester Manchester M1 7HS United Kingdom

In this paper, effects of cooling rates on glass formation and magnetic behavior of the Fe73.0C7.0Si3.3B 5.0P8.7Mo3.0 (at. pct) alloy were investigated via different purging gases (i.e., helium and argon) during suction casting. X-ray diffraction patterns and transmission electron microscopy characterization confirmed that the maximum attainable diameter for glass formation is increased from 5 to 7 mm with the helium as the purging gas, relative to the argon. Meanwhile, the coercivity value (H c) of the sample cast in helium is almost 5 times larger than that fabricated in argon, although the magnetization saturation in these two alloys is similar. Our pair distribution function analysis, density, and positron annihilation lifetime spectroscopy measurements indicated that the sample cast in helium possesses more free volume;however, the difference between them is insubstantial. Further, experimental results revealed that the residual stress in the samples cast under helium is much larger than that in those prepared in Argon, which could be responsible for the abrupt change in the coercivity. © 2012 The Minerals, Metals & Materials Society and ASM International.

关键词： Helium

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Experimental Studies of Electrostatic Fluctuations and Turbulent Transport in the Boundary of J-TEXT Tokamak Using Reciprocating Probe

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Plasma Science and technology 2012年第12期14卷 1041-1047页

作者： CHEN Zhipeng SUN Yue WANG Zhijiang YANG Zhoujun DING Yonghua ZHUANG Ge J-TEXT team State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan 430074 China Key Laboratory of Geospace Environment Chinese Academy of Sciences University of Science & Technology of China Hefei 230026 China

As the basic of a deeper investigation on the turbulent transport, the fluctuation property in the boundary of the newly-reconstructed Joint Texas Experimental Tokamak （J- TEXT） is studied experimentally using the reciprocating Langmuir four-tip probe, which has been built and operated as the primary diagnostic tool in the boundary of J-TEXT tokamak. In this paper, spatial profiles of the plasma-edge parameters are obtained, such as electron temperature, plasma density, plasma potential, poloidal electric field and their fluctuations. The results indicate the existence of a Er ×BT shear layer at the vicinity of last closed flux surface （LCFS）, with the fluctuations suppressed in varying degrees. The turbulence-induced particle and energy fluxes can be calculated by the local plasma parameters above. Convection dominates the cross-field turbulent transport in boundary plasma. Electrostatic fluctuations properties are also studied in detail with the help of numerical analysis. Statistical analysis on density fluctuation shows that, the intermittency can affect the turbulence in the scrape-off layer （SOL）.

关键词： electrostatic fluctuations anomalous transport J-TEXT reciprocating Lang- muir probe

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