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Comparison of Flux-Switching Machines With and Without Permanent Magnets

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Chinese Journal of Electrical Engineering 2015年第1期1卷 78-84页

作者： Christopher H.t.Lee k.t.chau C.C.Chan Department of Electrical and Electronic Engineering The University of Hong KongHong KongChina

In this paper,three advanced flux-switching(FS)machines,namely the radial-field flux-switching permanent-magnet(RF-FSPM)machine,the radial-field flux-switching DC-field(RF-FSDC)machine,and the axial-field FSDC(AF-FSDC)machine are quantitatively *** the installation of the high-energy-density PM materials,the RF-FSPM machine can definitely provide the superior torque performances as compared to its magnetless ***,the PM machines suffer from two major fundamental problems,namely the high material costs,and the uncontrollable flux *** utilizing the concept of axial-field structure,the AF-FSDC machine can offer comparable torque performance as the RF-FSPM ***,with the consideration of the cost-effectiveness and the control flexibility,the magnetless AF-FSDC machine has exhibited promising potential in various applications.

关键词： Flux-switching magnetless radial-field axial-field cost-effectiveness

Design and Analysis of Double-Stator Permanent Magnet Brushless Motor for Hybrid Electric Vehicles

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Design and Analysis of Double-Stator Permanent Magnet Brushl...

震源特性、传播路径及场地条件对建筑物震害影响的研究

11th International Conference on Electrical Machines and Systems

作者： k.t.chau School of Electrical Engineering Southeast University Department of Electrical and Electronic Engineering the University of Hong Kong

＜正＞this paper presents the design and analysis of a new double-stator permanent brushless（DSPMBL） *** corresponding output power equation is analytically *** initial calculation of motor dimensions and parameters,including, the core diameter,stack length,permanent magnet size,and winding turns,are also discussed.A DSPMBL motor is designed. By using finite element analysis,the field distributions of the DSPMBL motor at different loads and rotor positions are *** static characteristics of the proposed motor are also *** on these characteristics,the system mathematics model can be ***,the evaluation of system performance is conducted by computer simulation.

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震源特性、传播路径及场地条件对建筑物震害影响的研究

3种谐波电流注入模式下的磁通切换永磁电机缺相容错控制

中国地震学会第九次学术大会

作者：温增平 k.t.chau 胡聿贤中国地震局地球物理研究所香港理工大学土木与结构工程系中国地震局地球物理研究所

＜正＞大量宏观震害资料表明:震源特性、地震波的传播路径及局部场地条件对建筑物震害分布影响很大。许多地震的震害现象也反复说明:不同地震对结构影响的选择性,即大震级、远距离及软厚场地上高柔结构震害较重,中小地震、近距离、坚...

＜正＞大量宏观震害资料表明:震源特性、地震波的传播路径及局部场地条件对建筑物震害分布影响很大。许多地震的震害现象也反复说明:不同地震对结构影响的选择性,即大震级、远距离及软厚场地上高柔结构震害较重,中小地震、近距离、坚硬场地上刚性结构震害较重。针对震害的这些特点,本文将震源特性—传播路径—局部场地—结构特性有机地结合起来,系统研究了震级、传播距离及其场地条件对建筑物地震破坏的影响,构筑了与之相适应的理论计算多高层钢筋混凝土结构的可能震害分布的方法。直接以震级、传播距离及场地条件为输入参数,建立与此相适宜的分析模型,在地震反应计算的

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中国电机工程学报 2016年第3期36卷 836-844页

作者：於锋程明夏子朋邹国棠东南大学电气工程学院江苏省南京市210096 香港大学电机电子工程学系中国香港特别行政区

对矢量控制九相定子36槽/转子34极磁通切换永磁(flux-switching permanent magnet,FSPM)电机驱动系统中一相断路故障工况进行研究。单相故障时,根据转矩电流分量不变及定子铜耗方程,提出了3种谐波电流注入模式下无扰运行的容错控制策略... 详细信息

对矢量控制九相定子36槽/转子34极磁通切换永磁(flux-switching permanent magnet,FSPM)电机驱动系统中一相断路故障工况进行研究。单相故障时,根据转矩电流分量不变及定子铜耗方程,提出了3种谐波电流注入模式下无扰运行的容错控制策略,即在容错运行时分别注入3次,3、5次以及3、5、7次谐波电流,进而获得铜耗最小优化目标的容错电流通用在线生成方法。仿真分析和原理样机容错实验结果,证明了所提方案可以减小定子绕组断路故障引起的转矩脉动,使九相FSPM电机在故障状态下的运行性能得到明显改善,有效提高调速系统的可靠性。

关键词：磁通切换永磁(FSPM) 永磁电机容错断路谐波电流铜耗

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车用电机及其控制器设计、分析及应用

国外科技新书评介 2016年第9期 15-16页

作者： k.t.chau 宁圃奇不详中国科学院电工研究所

发展电动汽车被世界各国确立为保障能源安全和转型低碳经济的重要途径，据法国著名咨询公司Yole推测，到2020年全世界电动汽车产销量将达到2000万辆，我国也制定了到2020年实现累计产销量500万辆的目标。

关键词：控制器设计电机车用应用电动汽车能源安全咨询公司产销量

Riding towards a sustainable future:an evaluation of bike sharing’s environmental benefits in Xiamen Island,China

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Geography and Sustainability 2024年第2期5卷 276-288页

作者： Jianxiao Liu Meilian Wang Pengfei Chen Chaoxiang Wen Yue Yu kW chau Department of Real Estate and Construction Faculty of ArchitectureThe University of Hong KongPokfulamHong Kong 999077China Department of Land Surveying and Geo-informatics The Hong Kong Polytechnic UniversityHung HomHong Kong 999077China School of Geospatial Engineering and Science Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Department of Urban Planning School of Architecture and Civil EngineeringXiamen UniversityXiamen 550002China Ronald Coase Centre for Property Rights Research HKUrbanLabThe University of Hong KongPokfulamHong Kong 999077China

In the pursuit of sustainable urbanization,Bike-Sharing Services(BSS)emerge as a pivotal instrument for promoting green,low-carbon *** BSS is often commended for its environmental benefits,we offer a more nuanced analysis that elucidates previously neglected *** the Dominant travel Distance Model(DtDM),we evaluate the potential of BSS to replace other transportation modes for specific journey based on travel *** multiscale geographically weighted regression(MGWR),we illuminate the relationship between BSS’s environmental benefits and built-environment *** life cycle analysis(LCA)quantifies greenhouse gas(GHG)emissions from production to operation,providing a deeper understanding of BSS’s environmental ***,our study focuses on Xiamen Island,a Chinese“type II large-sized city”(1–3 million population),contrasting with the predominantly studied“super large-sized cities”(over 10 million population).Our findings highlight:(1)A single BSS trip in Xiamen Island reduces GHG emissions by an average of 19.97 g CO_(2)-eq,accumulating monthly savings of 144.477 t CO_(2)-eq.(2)Areas in the southwest,northeast,and southeast of Xiamen Island,characterized by high population densities,register significant BSS environmental benefits.(3)At a global level,the stepwise regression model identifies five key built environment factors influencing BSS’s GHG mitigation.(4)Regionally,MGWR enhances model precision,indicating that these five factors function at diverse spatial scales,affecting BSS’s environmental benefits variably.

关键词： Greenhouse gases Shared mobility Carbon emission Multiscale geographically weighted regression travel behavior Urban mobility

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： N.D.NGUYEN t.N.NGUYEN Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and technology Kien Giang UniversityChau Thanh 92000Viet Nam

this study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(tD)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBt)

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A kinetic model for a single step biodiesel production from a high free fatty acid (FFA) biodiesel feedstock over a solid heteropolyacid catalyst

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Green Energy & Environment 2019年第3期4卷 328-341页

作者： Aashish Gaurav Stéphane Dumas chau t.Q.Mai Flora t.t.Ng Department of Chemical Engineering University of Waterloo

Production of biodiesel from yellow grease(waste cooking oil and waste animal fats) is fast emerging as a promising alternative to address the twin challenges before the biodiesel industry today-fluctuation in prices of vegetable oil and the food versus fuel debate. Yellow grease has a high percentage of free fatty acids(FFA) and proves to be an unsuitable feedstock for biodiesel production from commercially viable alkalicatalyzed production systems due to saponification problems.'Green' methodologies based on heterogeneous solid acid catalyzed reactions have the potential to simultaneously promote esterification and transesterification reactions of yellow grease to produce biodiesel without soap formation and offer easy catalyst separation without generation of toxic streams. this paper presents kinetic studies for the conversion of model yellow grease feeds to biodiesel using a heteropolyacid supported on alumina(HSiW/Al2O3) using a batch autoclave. three model yellow grease feeds were prepared using canola oil with added FFA such as palmitic, oleic and linoleic acid. A pseudo homogeneous kinetic model for the parallel esterification and transesterification was developed. the rate constants and activation parameters for esterification and transesterification reactions for the model yellow grease feeds were determined. the rate constants for esterification are higher than the transesterification rate constants. the kinetic model was validated using the experimental biodiesel data obtained from processing a commercial yellow grease feed. the kinetic model could be used to design novel processes to convert various low-value waste oils, fats and non-food grade oils to sustainable biodiesel.

关键词： Yellow grease Canola oil Free fatty acids Heteropolyacid kinetics for esterification and transesterification

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Reconfiguring wireless environments via intelligent surfaces for 6G: reflection, modulation, and security

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Science China(Information Sciences) 2023年第3期66卷 60-79页

作者： Jindan XU chau YUEN Chongwen HUANG Naveed UL HASSAN George C.ALEXANDROPOULOS Marco DI RENZO Mérouane DEBBAH Engineering Product Development Pillar Singapore University of Technology and Design College of Information Science and Electronic Engineering Zhejiang University Department of Electrical Engineering Lahore University of Management Sciences Department of Informatics and telecommunications National and Kapodistrian University of Athens technology Innovation Institute Université Paris-Saclay CNRS Centrale Supélec Laboratoire des Signaux et Systèmes

the reconfigurable intelligent surface(RIS) has been recognized as an essential enabling technology for sixth-generation(6G) mobile communication networks. An RIS comprises a large number of small and low-cost reflecting elements whose parameters can be dynamically adjusted with a programmable *** of these elements can effectively reflect a phase-shifted version of the incident electromagnetic wave. By configuring the wave phases in real time, the propagation environment of the information-bearing signals can be dynamically manipulated to enhance communication reliability, boost transmission rate, expand cellular coverage, and strengthen communication security. In this study, we provide an overview on RIS-assisted wireless communications. Specifically, we elaborate on the state-of-the-art enabling techniques for the RIS technology as well as their corresponding substantial benefits from the perspectives of RIS reflection and RIS modulation. With these benefits, we envision the integration of RISs into emerging applications for6G. In addition, communication security is of unprecedented importance in future 6G networks with ubiquitous wireless services in multifarious verticals and areas. We highlight potential contributions of RISs to physical-layer security, in terms of secrecy rate and secrecy outage probability, exemplified by a typical case study from both theoretical and numerical aspects. Finally, we discuss challenges and opportunities on the deployment of RISs in practice to motivate future research.

关键词： reconfigurable intelligent surface physical-layer security RIS-assisted wireless communications phase modulation 6G