Power Electronics and Electric Vehicle Performance-Tesla

实用资料：电气工程专业课(电力类)翻译参考专业外语：Professional English电路（上） electrical circuit (I)电路（下） electrical circuit (II)金工实习 machinery practice电机（上） electrical machinery (I)电工实验与测试 electrical experiment & test电子综合实践 integrated electronic practice信号与系统 signal & system电子技术基础（模拟） fundamentals of electronic (analog)电磁场electromagnetic field电子技术实验 electronic experiment(I)电子辅助设计EDA Electronic Design Automatic(I)发电厂动力工程基础 Heat power engineering in generating plant企业管理 enterprise management电气主系统electrical system principle电力系统稳态/暂态分析 Steady-State/ Transient-State Analysis of Power System 电力系统继电保护 Power System Relaying Protection电力系统潮流计算机分析：Computer Analysis of Power Flow数字电子技术 Digital Electrical Technique微机原理 microcomputer principle电子技术基础（数字） fundamentals of electronic (digital)自动控制 automatic control theory电力系统分析 electric power system analysis电子技术基础实验electronic experiment(II)电气主系统课程设计 electrical system principle-course design电子辅助设计EDA Electronic Design Automatic(II)通信与计算机网络 communication & computer networks电力系统继电保护 electric power system relaying电力系统继电保护 Power System Protective Relaying电力系统远动技术electric power system remote protocol生产实习productive practice Technology继电保护课程设计 electric power system relaying-course design电力电子技术 power electronics电力电子技术基础：Fundamentals of Electronics Power Technology电力电子课程设计 Power electronics course design电力系统自动控制 electric power system control & automation高电压技术 High voltage engineering Technology变电站自动化 substation automation电力经济 electric power system economics电能质量控制 electric power quality control配电网自动化 distribution system automation电力系统新技术 new techniques on electric power system控制电机 electrical machine control调度自动化与能量管理 energy management & automation灵活交流输电系统 flexible AC transmission system计算机保护 computer protection电力系统电磁兼容 EMC in electric power system毕业实习graduation practice毕业设计graduation dissertation数字信号处理：Digital Signal Processing自动控制理论：Automatic Control Theory电气工程基础：Fundamentals of Electrical Engineering电磁场概论：Introduction to Electro-Magnetic Field计算机继电保护：Microcomputer-Based Relaying Protection电气设备的绝缘检测与故障诊断：Insulation Diagnostics and Troubl-Shooting for Electrical Installations电网规划：Power System Planning可编程控制器原理及应用：Principles of PLC (Programmable logic Controller) And Application电磁场数值计算：Numerical Computation of Electro-Magnetic Field电力系统继电保护：Relay Protection of Power System电力系统自动装置原理 The Principle of Electric Power System Automatic Equipment 电力通信系统及调度自动化：Power System Communication and Dispatching Automatic专业方向电气工程 Electrical Engineering电机与电器 Electric Machines and Electric Apparatus电力系统及其自动化 Power System and its Automation高电压与绝缘技术 High Voltage and Insulation Technology电力电子与电力传动 Power Electronics and Power Drives电工理论与新技术 Theory and New Technology of Electrical Engineering电子科学与技术 Electronics Science and Technology。

ieee power electronics 引文格式IEEE Power Electronics 引文格式引言：在科学研究中，引用文献是非常重要的，它不仅可以支持和证明我们的观点，还能够表明我们对该领域的了解和研究进展。

IEEE Power Electronics 引文格式是一个被广泛采用的引文格式，适用于在电力电子领域发表的学术论文和期刊文章。

本文将一步一步回答有关IEEE Power Electronics引文格式的问题，以帮助读者更好地掌握和应用此引文格式。

1. 什么是IEEE Power Electronics引文格式？IEEE Power Electronics引文格式是一个遵循IEEE（Institute of Electrical and Electronics Engineers，电气和电子工程师学会）标准的引文格式。

它主要用于在电力电子领域发表的学术论文和期刊文章中引用其他相关文献。

该引文格式的目的是提供一个统一的标准，使读者能够轻松地找到和查阅引用文献。

2. 如何编写IEEE Power Electronics引文格式的书面引用？在书面引用中，IEEE Power Electronics引文格式要求提供几个核心信息：- 作者姓名- 引用标题- 学术期刊或会议名称- 出版年份- 卷号（如果适用）- 页码（如果适用）一般来说，IEEE Power Electronics引文格式遵循以下格式：[1] A. Author, "Title of the Paper," Name of Journal, vol. x, no. x, pp. xxx-xxx, Year.其中，作者姓名应按照“姓, 名”的格式书写，并用逗号分隔。

标题应以引号括起来，而期刊或会议名称应以斜体字书写。

对于卷号和页码，如果适用，应提供相应的信息。

例如，对于一篇名为“Power Electronics in Renewable Energy Systems”的论文，由作者John Smith和David Johnson在2020年发表在IEEE Transactions on Power Electronics期刊上的情况，引文可以写为：[1] J. Smith and D. Johnson, "Power Electronics in Renewable Energy Systems," IEEE Trans. Power Electron., vol. 35, no. 2, pp. 543-550, 2020.3. 如何编写IEEE Power Electronics引文格式的在线引用？对于在线引用，IEEE Power Electronics引文格式同样需要提供必要的核心信息。

The State of the Art of Electric and Hybrid VehiclesC.C.CHAN,FELLOW,IEEEInvited PaperIn a world where environment protection and energy conser-vation are growing concerns,the development of electric vehicles (EV)and hybrid electric vehicles(HEV)has taken on an acceler-ated pace.The dream of having commercially viable EVs and HEVs is becoming a reality.EVs and HEVs are gradually available in the market.This paper will provide an overview of the present status of electric and hybrid vehicles worldwide and their state of the art, with emphasis on the engineering philosophy and key technologies. The importance of the integration of technologies of automobile, electric motor drive,electronics,energy storage,and controls and also the importance of the integration of society strength from gov-ernment,industry,research institutions,electric power utilities,and transportation authorities are addressed.The challenge of EV com-mercialization is discussed.Keywords—Electric and hybrid vehicles,electric drives,electric propulsion.I.I NTRODUCTIONElectric vehicle(EV)is a road vehicle which involves with electric propulsion.With this broad definition in mind,EVs may include battery electric vehicles(BEVs),hybrid elec-tric vehicles(HEVs),and fuel-cell electric vehicles(FCEVs). EV is a multidisciplinary subject which covers broad and complex aspects.However,it has core technologies,namely, chassis and body technology,propulsion technology,and en-ergy source technology.It is a tough task to write a survey paper on this multidisciplinary subject.Although this paper is written based on BEV,it also addresses the major issues of emerging HEV and FCEV.The paper begins with reviewing the status of BEV and HEV,then focusing on the engineering philosophy of EV development.Subsequent to the illustra-tion of the configurations of both BEV and HEV,it discusses Manuscript received April11,2001;revised August10,2001.This paper was supported by the Hong Kong Research Grant Council under Grant HKU 7035/97E.The author is with the Department of Electrical and Electronic Engi-neering,the University of Hong Kong,Hong Kong.Publisher Item Identifier S0018-9219(02)01129-5.in detail the major technologies,namely,the propulsion tech-nology,energy source technology,and infrastructure tech-nology.Finally,the commercialization aspects are discussed. The conclusion summarizes the state of the art and the chal-lenges of BEV,HEV,and FCEV.Today,BEV,HEV,and FCEV are in different stages of development,facing different challenges and requiring dif-ferent strategies.In order to assist the reader’s appreciation of the features and issues of these vehicles before reading the whole text,the major characteristics of these three types of vehicles are given in Table1.It can be seen that the crit-ical issue of BEV is the battery.Therefore,BEV is mainly suitable for small EV for short-range low-speed community transportation,which requires only smaller battery size.HEV can meet consumers’meet,but cost is the major issue.FCEV has long-term potential for future mainstream vehicles.How-ever,the technology is still in the early development stage be-cause its cost and refueling system are the major concerns. II.W HY E LECTRIC V EHICLES?Let us begin with the investigation of the growth of popu-lation and vehicles,as shown in Fig.1.In the next50years, the global population will increase from6billion to10bil-lion and the number of vehicles will increase from700mil-lion to2.5billion.If all these vehicles are propelled by in-ternal combustion engines(ICEs),where will the oil come from?Where should the emissions be disseminated?Would the sky be permanently grey?The gloomy answers to these questions compel people to strive for sustainable road trans-portation for the21st century[1],[2].In a world where environmental protection and energy conservation are growing concerns,the development of EV technology has taken on an accelerated pace to fulfill these needs.Concerning the environment,EVs can provide emission-free urban transportation.Even taking into account the emissions from the power plants needed to fuel the vehicles,the use of EVs can still significantly reduce global air pollution.From the energy aspect,EVs can offer a secure,0018-9219/02$17.00©2002IEEEPROCEEDINGS OF THE IEEE,VOL.90,NO.2,FEBRUARY2002247Table 1Characteristics of BEV ,HEV ,andFCEV(a)(b)Fig.1.Growth of population and vehicles.comprehensive,and balanced energy option that is efficient and environmental friendliness,such as the utilization of various kinds of the renewable energies.Therefore,EVswill have the potential to have a great impact on energy,environment and transportation as well as hi-tech promotion,new industry creation,and economic development.III.P AST ,P RESENT ,AND F UTURE OF EV S A.Past Years DevelopmentEV was invented in 1834.During the last decade of the 19th century,a number of companies produced EVs in America,Britain,and France.Fig.2shows the London Electric Cab Company’s taxi.Due to the limitations associ-ated with the batteries and the rapid advancement of internal combustion engine vehicles (ICEVs),EVs have almost vanished from the scene since 1930.In the early 1970s,some countries,compelled by the en-ergy crisis,started the rekindling of interests in EVs.In 1976,the USA launched the Electric and Hybrid Vehicle Research,Development,and Demonstration Act,Public Law 94–413.At that time,the main question to be answered was “Can EVs do the job in our modern society?”although EVs did work well in the late 1800s and early 1900s.The develop-ment of EVs over the years has answered the above ques-tion—yes.For example,an experimental EV in 1968racing from the California Institute of Technology (Caltech)to the Massachusetts Institute of Technology (MIT)suffered from failures in virtually every critical component,whereas a com-mercially built EV in 1998running from Los Angeles to De-troit exhibited a success with no component failures.Within the 1970s,EVs were still in research and development stage and most of them were conversion of ICEVs.Today,major automobile manufacturers are offering EVs for sale or lease.Most of them are the purpose-built EV ,not conversion EV [1],[16]B.Present Major IssuesAt present,the major driving force for EVs is the envi-ronment issue,such as mandate by California rule,rather248PROCEEDINGS OF THE IEEE,VOL.90,NO.2,FEBRUARY 2002Fig.2.London electric cab company’s taxi(courtesy of Scientific American supplement;photo courtesy of History of the Electric Automobile by Ernest H.Wakefied).than the previous energy issue.Thus,the main question to be answered becomes“Can EVs be made affordable?”The major factors that make EV affordable are the range and cost.To tackle the range,the development of advanced batteries such as nickel-metal hydride(Ni-MH),zinc/air (Zn/Air),and lithium-ion(Li-Ion)are in progress.However, since both specific energy and energy density of batteries are much lower than that of gasoline,the development of fuel cells(FCs)for EVs has taken on an accelerated pace in recent years.Meanwhile,the development of commercial HEVs is also going on rapidly.HEVs essentially improve the range and performance of EVs at higher complexity and cost because of the additional energy source,engine, and other accessories.To tackle the cost,efforts are being made to improve various EV subsystems,such as electric motors,power converters,electronic controllers,energy management units,battery chargers,batteries,and other EV auxiliaries,as well as EV system-level integration and optimization.C.Development TrendsIn order to see the development trends of various EV aspects,a survey has been made with respect to the number of papers published on various topics in leading EV related international conferences from1984to2001.With regard to propulsion system,it was observed that the research papers on induction motor(IM)drives and permanent magnet (PM)motor drives are highly dominant,whereas those on direct current(DC)motor drives are dropping while those on switched reluctance(SR)motor drives are still in a crawling stage.With regard to the development trend of various energy sources,including lead-acid(LA)batteries ,nickel-based(NB)batteries,lithium-based(LB)batteries, FCs,and capacitors/flywheels(CFs).The number of papers published in LB,FC,and CF are becoming more and more attractive,though LA and NB are still undergoing continual improvement.With regard to the configurations of EVs, it was observed that the conversion EV is becoming less attractive than the purpose-built EV,while the HEV is of growing interest for the coming EV markets.It was also observed that EVs are on the verge of commercialization, since more and more papers were published on the topics of demonstration as well as standardization and marketing of EVs.In the next few decades,it is anticipated that both EVs and HEVs will be commercialized and they will have their market shares.EVs will be well accepted by some niche markets,namely,the users for community transportation,the places where electricity is cheap,and ease of access and the places with zero-emission mandate.On the other hand, HEVs will have a niche market for those users desiring long driving ranges.The ultimate penetration of EVs and HEVs will mainly depend on their respective costs.The commer-cialization of FCEVs will be accelerated in later decades, since they have the greatest potential to deliver the same range and performance as our ICEVs,but now it is still in the development stage.In summary,electric propulsion and energy sources will still be the key technologies to be addressed and EVs and HEVs will still be coexistent,while energy,environment,and economy will still be the key issues for EV commercializa-tion.Fig.3illustrates the development trends of EVs and HEVs.It should be noted that some core technologies canCHAN:THE STATE OF THE ART OF ELECTRIC AND HYBRID VEHICLES249Fig.3.Development trends of EVs and HEVs(courtesy of EV AA).be shared among ICEVs,EVs,and HEVs.Our ultimate goal is the use of clean,efficient,and intelligent energy to achieve sustainable transportation system for the21st century.IV.P RESENT S TATUSAfter many years of development,EV technologies are becoming mature.Many advanced technologies are em-ployed to extend the driving range and reduce the cost.For example,the use of advanced IM drives and PM brushless motor drives to improve the electric propulsion system, the employment of advanced valve-regulated lead-acid (VRLA)battery,Ni-MH battery,Li-Ion battery,FCs,and ultracapacitors to improve the EV energy source,application of light body technology with light,but rigid material, low-drag coefficient body to reduce the aerodynamic resis-tance and low rolling resistance tires to reducing running resistance at low and medium driving speed,as well as the adoption of advanced charging,power steering,or variable temperature seats to enhance the EV auxiliaries.In the following paragraphs,some of the recently developed EV, HEV,and FCEV are illustrated with the intention to show the achievable technology,despite particular vehicle model. For example,EV1has been discontinued and some models are for demonstration purpose only,i.e.,NECAR5and Ford P2000.These typical vehicles have been carefully chosen to represent the state of the art.GM EV1and Nissan Altra EV represent advanced BEV using different types of motor and battery.Ford2000P and NECAR5represent the development stage of FCEV,Toyota Prius and Honda Insight represent the commercialization of HEV,Luciole and HKU200represent showcase BEV,and Reva represents commercially produced low-cost BEV.Showcasing the most advanced propulsion system, the1997two-seater GM EV1is shown in Fig.4.It had a front-wheel drive that adopted a102-kW three-phase IM and a single-speed transaxle with dual-reduction of 10.946:1.It contained26-module312-V VRLA batteries that were inductively charged by a6.6-kW offboard charger or a1.2-kW onboard charger.This EV1could offer an axle torque of1640Nm from zero to7000rpm and a propulsion power of102kW from7000to14000rpm,leading to achieve a top speed of128km/h(electronically limited)and an acceleration from zero to96km/h in less than9s.For city driving,it could provide a range of112km per charge, whereas on highway operation,it offered144km per charge. In1999,the EV1adopted nickel-metal hybrid batteries as an optional equipment,hence,reaching220km per charge. Fig.5shows the1997four-seater Altra EV,which was the flagship of Nissan.It used a62-kW PM brushless motor, which weighed only39kg,the highest power-to-weight ratio (1.6kW/kg)for any EV motor available.Making use of max-imum efficiency control,the total efficiency of the propulsion system was more than89%.Power came from the cobalt-based Li-Ion batteries,which had a specific energy of90 Wh/kg,a specific power of300W/kg,and a long cycle life of about1200recharges.This battery pack could be charged up by an onboard inductive charging system within five hours. It could achieve a top speed of120km/h and a range of 192km for city driving.In1999,the Altra adopted the man-ganese-based Li-Ion batteries to further increase both spe-cific energy and specific power to91Wh/kg and350W/kg, respectively.The Ford P2000symbolized the dedication of Ford in the development of FCEVs.Fig.6shows this four-door sedan,250PROCEEDINGS OF THE IEEE,VOL.90,NO.2,FEBRUARY2002Fig.4.GM EV1(photo courtesy of GeneralMotors).Fig.5.Nissan Altra EV(photo courtesy ofNissan).Fig.6.Ford P2000(photo courtesy of Ford Motor Company).which was launched in the year2000.It was powered by the Ford’s Th!nk FC system,namely,the proton exchange membrane(PEM)FCs,which was fuelled by compressed hy-drogen gas(CHG)stored at25MPa and oxygen gas simply from the air.It adopted a three-phase IM,offering a peak power of67kW,a peak torque of190Nm,and a peak ef-ficiency of91%.With the curb weight of1514kg,the P2000 could achieve a top speed of128km/h and a driving range of 160km per charge.Daimler-Benz,now DaimlerChrysler,presented its first methanol-fuelled FCEV in1997—the NECAR3.It used PEM FCs to generate a power of50kW for propulsion. The hydrogen fuel was directly extracted from methanol via a mini reformer,thus bypassing the problem of having compressed gas canisters onboard the vehicle.The FCs were stored beneath the floor,while the reformer,methanol tank, and control systems were located in the boot.Based on this first generation methanol-fuelled FC propulsion system,CHAN:THE STATE OF THE ART OF ELECTRIC AND HYBRID VEHICLES251Fig.7.DaimlerChrysler NECAR5(photo courtesy ofDaimlerChrysler). Fig.8.Toyota Prius(photo courtesy of Toyota).the NECAR3could travel over400km on38L of liquid methanol.As shown in Fig.7,the NECAR5launched in 2000was the technological successor of the NECAR3, while reducing the size of the drive system by half and the weight of the vehicle by300kg.It also boosted up the power to75kW to reach speeds over150km/h.The world’s first mass-production HEV was the Toyota Prius,as shown in Fig.8.Its motive power was sourced from both a four-cylinder ICE(52kW at4500rpm)and a PM brushless motor(33kW at1040–5600rpm).Since it was an ICE-heavy HEV,a power split device,namely,the plane-tary gear,sent part of the ICE power to the wheels and part to a generator.The generated electrical energy could supply the electric motor to increase the motive power or could be stored in the38-module nickel-metal hybrid batteries.The Prius could offer a top speed of160km/h,an acceleration from zero to96km/h in12.7s,and a fuel economy of20 km/l for combined city and highway operation.Both of its fuel economy and exhaust emissions were much better than that of any conventional ICEVs.The Honda Insight,shown in Fig.9,went on sale in December2000.It employed an ICE-heavy hybrid system, combining a three-cylinder ICE(50kW at5700rpm)and a PM synchronous motor(10kW at3000rpm).The electric motor was powered by a144-V Ni-MH battery pack, which was recharged by regenerative braking during normal cruising and downhill driving.The Insight was claimed to be the most fuel-efficient HEV with the fuel economy of26–30 km/l.Also,it satisfied the stringent ultra low-emission vehicle(ULEV)standard in California.To simultaneously address the problems of air pollution, wasteful energy consumption,and traffic safety,the Na-252PROCEEDINGS OF THE IEEE,VOL.90,NO.2,FEBRUARY2002Fig.9.Honda Insight(photo courtesy ofHonda). Fig.10.NIES Luciole(photo courtesy of NIES,Japan).tional Institute for Environmental Studies(NIES)in Japan presented a high-performance lightweight EV,namely,the Luciole(formerly called Eco-Vehicle)in1996for conve-nient city commuting.As shown in Fig.10,it adopted a tandem two-seater layout so that the seats could be kept comfortable and the safety in side crushes could be im-proved by thickening the doors.It was rear-wheel drive, which was powered by two inwheel PM brushless motors with the total output of72kW and154Nm.The battery pack contained224-V VRLA batteries,mounted inside the square holes of the purpose-built chassis.The battery pack could be charged up by normal charging within five hours, by fast charging within fifteen minutes or even partially charged by solar charging.The Luciole could achieve a top speed of130km/h,a range on the Japan10.15Mode driving cycle of130km,and an acceleration from zero to 40km/h in3.9s.Fig.11shows an EV,the U2001,which was developed by the University of Hong Kong(HKU)in1993.It was a four-seater EV,which adopted a45-kW PM hybrid motor and a264-V nickel-cadmium(Ni-Cd)battery pack.This specially designed EV motor could offer high efficiencies over a wide operating range.It also incorporated a number of advanced EV technologies,such as the adoption of thermoelectric variable temperature seats to minimize the energy used for air-conditioning,the use of an audio nav-igation system to facilitate safe and user-friendly driving, and the use of an intelligent energy management system (EMS)to optimize the energy flow within the vehicle.The U2001could offer a top speed of110km/h,an acceleration from zero to48km/h in6.3s,and a range of176km at 88-km/h operation.Apart from the USA,Europe,and Japan,India also plays an active role to commercialize EVs.Fig.12shows aCHAN:THE STATE OF THE ART OF ELECTRIC AND HYBRID VEHICLES253Fig.11.HKUU2001.Fig.12.Reva EV(photo courtesy of Reva Electric Car Company).two-door hatchback EV,the Reva EV,which was launched in the year2001and would be India’s first mass-produced EV.It adopted a separately excited DC motor(70Nm,13 kW peak)and a48-V tubular LA battery pack.Its onboard charger(220V,2.2kW)could provide80%charge within3 h and100%within6h.With the curb weight of650kg,the Reva EV could achieve a top speed of65km/h and a range of80km per charge.The most attractive feature was its incredibly low initial and running costs—the exfactory cost is about5000U.S.dollars and the running cost is less than one U.S.cent per kilometer.The major means of reducing the cost of this EV includes the system optimization and integration,low-cost local components,low-cost tooling, and simple automation.It can be seen from Table2that the sale and lease of EVs in USA from1996to2000were not successful;the major reason was that their cost was too expensive and their driving range did not fully satisfy the users’need(Table3).254PROCEEDINGS OF THE IEEE,VOL.90,NO.2,FEBRUARY2002Table 2EVs Sold/Leased in the USA1996–2000Table 3Key Data of ModernEVsV .E NGINEERING P HILOSOPHY OF EV D EVELOPMENT A.EV ConceptAlthough the EV was around before the turn of the 20th century,the modern EV is a completely new machine that is totally different from the classical EV .It is not only a trans-portation vehicle,but also a new type of electric equipment.The modern EV concept is summarized as follows.1)The EV is a road vehicle based on modern electric propulsion that consists of the electric motor,power converter,and energy source and it has its own distinct characteristics.2)The EV is not just a car,but a new system for our so-ciety,realizing clean and efficient road transportation.3)EV users’expectations must be studied and,hence,appropriate education must be conducted.The system architecture of EVs has its own distinct features that may differ from that of ICEVs,similar to the fact that the system architecture of quartz-based electronic watches is very different from that of spring-based mechan-ical watches.In short,their appearances are very similar,whereas their principles are very different.The unique features of EVs must be fully appreciated.B.EV Engineering PhilosophyThe EV engineering philosophy essentially is the integra-tion of automobile engineering and electrical engineering.Thus,system integration and optimization are prime con-siderations to achieve good EV performance at affordable cost.Since the characteristics of electric propulsion arefundamentally different from those of engine propulsion,a novel design approach is essential for EV engineering.Moreover,advanced energy sources and intelligent energy management are key factors to enable EVs competing with ICEVs.Of course,the overall cost effectiveness is the fundamental factor for the marketability of EVs.The design approach of modern EVs should include state-of-the-art technologies from automobile engineering,electrical and electronic engineering,and chemical engi-neering,adopt unique designs particularly suitable for EVs,and develop special manufacturing techniques particularly suitable for EVs.Every effort should be made to optimize the energy utilization of EVs.The following points are those typical considerations for EV design.1)Identify the niche market and environment.2)Determine the technical specifications including the driving cycle.3)Determine the infrastructure required including the recycling of batteries.4)Determine the overall system configuration—BEV ,HEV ,or FCEV configurations.5)Determine the chassis and body.6)Determine the energy source—generation or storage,single or hybrid.7)Determine the propulsion system—motor,converter,and transmission types,single or multiple motors,gearless or geared,mounting methods,and ICE sys-tems in case of an HEV .8)Determine the specifications of electric propulsion (power,torque,speed)and energy source (capacity,CHAN:THE STATE OF THE ART OF ELECTRIC AND HYBRID VEHICLES255(a)(b)Fig.13.Torque-speed requirements of typical driving cycles.voltage,current)according to various driving cycles;for example,Fig.13shows that the torque-speed requirement of the Federal Urban Driving Schedule (FUDS)is very different from that of the Federal Highway Driving Schedule (FHDS).In Fig.13,the density of dots represents the frequency of operating condition.Hence,in FUDS,the powertrain often operates at low speed and high torque,while in FHDS,it operates at a high-speed low-torque profile.9)Adopt intelligent EMS.10)Analyze the interaction of EV subsystems by using the quality function matrix as shown in Fig.14,hence,understanding the degree of interaction that affects the cost,performance,and safety.11)Optimize the efficiency of the motor drive according to the selected driving pattern and operating condi-tions.12)Optimize the overall system using computer simula-tion.C.Key EV TechnologyThe key technologies of EVs include automotive technology,electrical technology,electronic technology,information technology,and chemical technology.Although the energy source is the most crucial area,body design,electric propulsion,energy management,and system opti-mization are equally important.In fact,the integration of all these areas is the key to success.For ease of reading,only body design,energy management,and system optimization technologies are discussed in this section,while the major technologies of electric propulsion and energy source will be discussed separately in the subsequent sections.1)Body Design:There are two basic approaches for pro-ducing EVs—either conversion or purpose-built.For the con-version EV ,the engine and associated equipment of an ex-isting ICEV are replaced by the electric motor,power con-verter,and battery.This offers some economy for a small volume production because the existing ICEV chassis can be utilized.However,in most conversions,the resulting EV suffers from a greater curb weight,a higher centre of gravity and an unbalanced weight distribution.Therefore,this ap-proach is gradually fading out.At present,the modern EVs are mostly purpose-built,sometimes called groundup design.This purpose-built EV takes the definite advantage over the conversion ones because they allow the engineers having the flexibility to coordinate and integrate various EV subsystems so that they can work together efficiently [17].256PROCEEDINGS OF THE IEEE,VOL.90,NO.2,FEBRUARY 2002Fig.14.Interactions among EV sybsystems.There are some design concepts for purpose-built EVs so that the overall performances such as range,gradeability,ac-celeration,and top speed can be improved.These concepts include the consistent weight-saving design,low drag co-efficient body design,and low rolling resistance concept. First,the vehicle weight directly affects the performance of EVs,especially the range and gradeability.To reduce the curb weight,the use of lightweight materials such as alu-minum and composite material for the body and chassis can be adopted.Second,low drag coefficient body design can ef-fectively reduce the vehicle aerodynamic resistance,which has a significant effect on extending the range of EVs in highway driving or cruising.In general,the aerodynamic resistance can be reduced by tapering front and rear ends, adopting undercover and flat underfloor design,optimizing airflow around the front and rear windows,using rear spats, providing airflow streaks along the front and rear tires,and employing slanted front nose design.Third,low rolling re-sistance tires are particularly effective in reducing running resistance at low and medium driving speeds and play an im-portant role in extending the range of EVs in city driving. This can be achieved through the use of a newly developed blended tire polymer,together with an increase in tire pres-sure.2)Energy Management:Compared with ICEVs,EVs offer a relatively short driving range.Thus,in order to maximize the utilization of onboard stored energy,an intelligent EMS needs to be adopted.Making use of sensory inputs from various EV subsystems,including sensors for temperatures of outside and inside air,current,and voltage of the energy source during charging and discharging, current and voltage of the electric motor,vehicle speed,and acceleration as well as external climate and environment, the EMS can realize the following functions.1)Optimize the system energy flow.2)Predict the remaining available energy and hence theresidual driving range.3)Suggest more efficient driving behavior.4)Direct regenerative energy from braking to receptiveenergy sources such as batteries.5)Modulate temperature control in response to externalclimate.6)Adjust lighting brightness in response to external en-vironment.7)Propose a suitable battery charging algorithm.8)Analyze the operation history of the energy source,especially the battery.9)Diagnose any incorrect operation or defective compo-nents of the energy source.When the EMS is coupled with a navigation system,it can plan energy efficient routes,locate charging facilities for extended trips,and modify range predictions on the basis of traffic conditions.In summary,the EMS has the distinct features of integrated multifunctions,flexibility,and adapt-ability(just like the brain of EVs)such that the limited on-board energy can be used wisely.3)System Optimization:As mentioned before,the EV system has a complex architecture that contains multidisci-plinary technologies.Since the EV performance can be af-fected by many multidisciplinary interrelated factors,com-puter simulation is the most important technology to carry out the optimization for performance improvement and cost reduction.Also,EV simulation can help those manufacturers to minimize prototyping cost and time and to provide rapid concept evaluation.Since the whole EV system consists of various subsystems clustered together by mechanical,elec-trical,control,and thermal links,the simulation should be based on the concept of mixed-signal simulation.Hence,the system optimization can be carried out in the system level in which there are many tradeoffs among various subsystem criteria.Generally,numerous iterative processes are involved for the preferred system criteria[1].In summary,the system-level simulation and optimization of EVs should consider the following key issues.1)As the interactions among various subsystems greatlyaffect the performance of EVs,the significance ofthose interactions should be analyzed and taken intoaccount.2)As the model accuracy is usually coherent withthe model complexity but may be contradictory tothe model usability,tradeoffs among the accuracy,complexity,and usability as well as simulation timeshould be considered.3)As the system voltage generally causes contradictoryissues for EV design,including the battery weight(higher voltage requires higher number of batterymodules in series,hence more weight for the batterycase),motor drive voltage and current ratings,ac-celeration performance,driving range and safety,itshould be optimized on the system level.4)In order to increase the driving range,multiple energysources may be adopted for modern EVs.The corre-sponding combination and hybridization ratio shouldbe optimized on the basis of the vehicle performanceand cost.CHAN:THE STATE OF THE ART OF ELECTRIC AND HYBRID VEHICLES257。

功率半导体开关行业市场现状分析及未来三到五年发展趋势报告As of now, the power semiconductor switch industry is experiencing robust growth due to the increasing demand for energy-efficient devices in various applications such as industrial, automotive, consumer electronics, and renewable energy systems. The market is driven by the need for higher power density, improved performance, and reliability in power electronic systems.The power semiconductor switch market is witnessing a shift towards wide bandgap (WBG) materials such as silicon carbide (SiC) and gallium nitride (GaN) due to their superior properties compared to traditional silicon-based devices. This transition is expected to continue over the next few years, driving the market growth.In addition, the increasing adoption of electric vehicles (EVs) and the growing emphasis on renewable energy sources are contributing to the expansion of the power semiconductor switch market. EVs require efficient power electronic systems, andrenewable energy systems rely on power semiconductor devices for power conversion and conditioning.Furthermore, advancements in technology such as the development of advanced packaging techniques, integration of power modules, and the rise of Industry 4.0 are expected to shape the future of the power semiconductor switch industry. These technological advancements will lead to enhanced efficiency, miniaturization, and improved thermal performance of power semiconductor devices.In the next three to five years, the power semiconductor switch market is anticipated to witness significant growth in the Asia Pacific region, particularly in countries like China, Japan, and South Korea. The rapid industrialization, urbanization, and infrastructure development in these regions will drive the demand for power electronic devices across various sectors.Moreover, the increasing focus on energy efficiency, coupled with government initiatives to promote clean energy, will fuel the demand for power semiconductor switches in thecoming years. This trend is expected to accelerate the deployment of smart grid systems, energy storage solutions, and electric vehicle infrastructure, thereby creating opportunities for the power semiconductor switch market.With the ongoing technological innovations and the shift towards WBG materials, the power semiconductor switch industry is poised for substantial growth in the near future. The market players are investing in research and development activities to introduce innovative products and gain a competitive edge. Overall, the industry is set to witness dynamic changes and emerge as a key enabler for the advancement of power electronic systems across various applications.中文：截至目前，功率半导体开关行业正经历着强劲增长，原因在于各种应用领域对节能设备的需求不断增加，如工业、汽车、消费电子和可再生能源系统。

国外讲解新能源汽车技术的书籍
另外一本值得一提的书是《Electric and Hybrid Vehicles: Power Sources, Models, Sustainability, Infrastructure and the Market》。

这本书由Gijs Mom和Auke Hoekstra合著，涵盖了电动和混合动力汽车的动力来源、模型、可持续性、基础设施和市场等方面。

它不仅介绍了新能源汽车的技术原理，还分析了相关的市场趋势和可持续发展的问题，对于想要了解新能源汽车在整个社会和市场环境中的角色的读者来说是一本很有价值的书籍。

此外，还有一本名为《Plug-in Electric Vehicles: What Role for Washington?》的书，由National Research Council编写。

这本书主要讨论了插电式电动汽车在美国华盛顿州的发展前景以及相关的政策建议。

它从政策和地区发展的角度探讨了新能源汽车技术，对于关注政策与法规对新能源汽车发展影响的读者来说是一本很有参考价值的书籍。

总的来说，以上这些书籍都涵盖了新能源汽车技术在不同方面的内容，包括技术原理、市场趋势、可持续发展以及政策建议等，对于想要全面了解新能源汽车技术的读者来说都是很好的选择。

希望这些推荐对你有所帮助。

电力英语词汇汇总一、电力系统基本词汇1. 电站（Power Station）2. 发电机（Generator）3. 变压器（Transformer）4. 断路器（Circuit Breaker）5. 线路（Transmission Line）6. 电容器（Capacitor）7. 电抗器（Reactor）8. 继电器（Relay）9. 保护装置（Protection Device）10. 控制系统（Control System）二、电力设备与部件1. 母线（Busbar）2. 避雷器（Surge Arrester）3. 电缆（Cable）4. 绝缘子（Insulator）5. 钢筋（Rebar）6. 混凝土（Concrete）7. 齿轮（Gear）8. 轴承（Bearing）9. 油箱（Tank）10. 油冷却器（Oil Cooler）三、电力工程术语1. 电力工程（Electric Power Engineering）2. 设计规范（Design Specification）3. 施工图纸（Construction Drawing）4. 工程预算（Project Budget）5. 施工方案（Construction Scheme）6. 质量验收（Quality Acceptance）7. 安全生产（Safety Production）8. 环境保护（Environmental Protection）9. 节能减排（Energy Saving and Emission Reduction）10. 智能电网（Smart Grid）四、电力行业组织与机构1. 国家能源局（National Energy Administration）2. 电力公司（Electric Power Corporation）3. 电力设计院（Electric Power Design Institute）4. 电力科学研究院（Electric Power Research Institute）5. 电力行业协会（Electric Power Industry Association）6. 电力工会（Electric Power Trade Union）7. 电力市场（Electricity Market）8. 电力监管机构（Electric Power Regulatory Authority）9. 电力消费者协会（Electric Power Consumer Association）10. 国际电力组织（International Electric Power Organization）五、电力技术与发展1. 火力发电（Thermal Power Generation）2. 水力发电（Hydroelectric Power Generation）3. 核能发电（Nuclear Power Generation）4. 风能发电（Wind Power Generation）5. 太阳能发电（Solar Power Generation）6. 新能源（New Energy）7. 分布式发电（Distributed Generation）8. 电动汽车（Electric Vehicle）9. 能源互联网（Energy Internet）10. 电力系统自动化（Electric Power System Automation）六、电力运行与维护1. 电网调度（Power Grid Dispatching）2. 运行监控（Operation Monitoring）3. 设备巡检（Equipment Patrol Inspection）4. 预防性维修（Preventive Maintenance）5. 故障处理（Fault Handling）6. 状态检修（ConditionBased Maintenance）7. 安全操作（Safe Operation）8. 电力可靠性（Electric Power Reliability）9. 负荷预测（Load Forecasting）10. 电力质量（Power Quality）七、电力法律法规与政策1. 电力法（Electricity Law）2. 电力市场监管条例（Electricity Market Regulation）3. 电力设施保护条例（Regulations for the Protection of Electric Power Facilities）4. 电力供应与使用条例（Regulations on Electric Power Supply and Use）5. 电力价格政策（Electricity Pricing Policy）6. 电力体制改革（Electricity System Reform）7. 能源发展战略行动计划（Energy Development Strategy Action Plan）8. 环境保护法律法规（Environmental Protection Laws and Regulations）9. 节能减排政策（Energy Saving and Emission Reduction Policy）10. 电力行业发展规划（Electric Power Industry Development Plan）八、电力市场与交易1. 电力市场交易规则（Electricity Market Trading Rules）2. 电力中长期合同（Longterm Electricity Contract）3. 电力现货市场（Electricity Spot Market）4. 电价形成机制（Electricity Price Formation Mechanism）5. 售电公司（Electricity Sales Company）6. 用户侧响应（Customer Side Response）7. 跨区电力交易（Crossregional Electricity Trade）8. 电力市场分析（Electricity Market Analysis）9. 电力市场竞争（Electricity Market Competition）10. 电力市场风险管理与控制（Electricity Market Risk Management and Control）九、电力行业发展趋势1. 电力行业数字化转型（Digital Transformation of Electric Power Industry）2. 电力系统灵活性（Flexibility of Electric Power System）3. 电力储能技术（Electricity Storage Technology）4. 电力需求侧管理（Electricity Demand Side Management）5. 电力行业智能化（Intelligence of Electric Power Industry）6. 电力行业绿色低碳发展（Green and Lowcarbon Development of Electric Power Industry）7. 电力行业国际合作（International Cooperation inElectric Power Industry）8. 电力行业人才培养（Talent Training in Electric Power Industry）9. 电力行业科技创新（Technological Innovation in Electric Power Industry）10. 电力行业可持续发展（Sustainable Development of Electric Power Industry）十、电力行业热点问题1. 电力供需平衡（Electricity Supply and Demand Balance）2. 电力系统安全稳定（Safety and Stability of Electric Power System）3. 电力扶贫（Electricity Poverty Alleviation）4. 电动汽车充电基础设施建设（Electric Vehicle Charging Infrastructure Construction）5. 电力行业去产能（Capacity Reduction in Electric Power Industry）6. 电力行业环境保护（Environmental Protection in Electric Power Industry）7. 电力行业信用体系建设（Credit System Construction in Electric Power Industry）8. 电力行业反垄断（Antitrust in Electric Power Industry）9. 电力行业对外开放（Openingup of Electric Power Industry）10. 电力行业社会责任（Social Responsibility of Electric Power Industry）十一、电力技术创新与应用1. 智能电网技术（Smart Grid Technology）2. 分布式能源系统（Distributed Energy Systems）3. 微电网技术（Microgrid Technology）4. 能量管理系统（Energy Management System）5. 高压直流输电（High Voltage Direct Current Transmission）6. 超导技术（Superconductivity Technology）7. 电力电子技术（Power Electronics Technology）8. 量子计算在电力领域的应用（Application of Quantum Computing in Electric Power Field）9. 大数据与电力系统分析（Big Data and Electric Power System Analysis）10. 云计算在电力行业的应用（Application of Cloud Computing in Electric Power Industry）十二、电力工程项目管理1. 项目可行性研究（Project Feasibility Study）2. 项目立项（Project Approval）3. 项目招投标（Project Bidding）4. 项目合同管理（Project Contract Management）5. 项目进度控制（Project Schedule Control）6. 项目成本管理（Project Cost Management）7. 项目质量管理（Project Quality Management）8. 项目风险管理（Project Risk Management）9. 项目验收与移交（Project Acceptance and Handover）10. 项目后评价（Project Postevaluation）十三、电力行业职业素养与技能1. 电力工程师职业道德（Professional Ethics for Electrical Engineers）2. 电力行业职业技能培训（Vocational Skills Training in Electric Power Industry）3. 电力行业职称评定（Professional Title Evaluation in Electric Power Industry）4. 电力行业从业资格证书（Qualification Certificates in Electric Power Industry）5. 电力行业创新能力培养（Innovation Ability Training in Electric Power Industry）6. 电力行业团队协作（Team Collaboration in Electric Power Industry）7. 电力行业沟通与协调能力（Communication and Coordination Skills in Electric Power Industry）8. 电力行业应急处理能力（Emergency Handling Ability in Electric Power Industry）9. 电力行业法律法规知识（Legal Knowledge in Electric Power Industry）10. 电力行业国际视野（International Perspective in Electric Power Industry）十四、电力行业国际合作与交流1. 国际电力组织（International Electric Power Organizations）2. 国际电力展览会（International Electric Power Exhibitions）3. 国际电力技术交流（International Electric Power Technology Exchange）4. 国际电力项目合作（International Electric Power Project Cooperation）5. 国际电力市场分析（International Electric Power Market Analysis）6. 国际电力标准制定（International Electric Power Standards Development）7. 国际电力人才培养与合作（International Electric Power Talent Training and Cooperation）8. 国际电力政策研究（International Electric Power Policy Research）9. 国际电力环境保护合作（International Electric Power Environmental Protection Cooperation）10. 国际电力行业发展趋势探讨（Discussion on International Electric Power Industry Development Trends）。

2024年6月四级英语试卷Part I Writing (30 minutes)Directions: For this part, you are allowed 30 minutes to write an essay on the topic "The Importance of Cultural Heritage Protection". You should write at least 120 words but no more than 180 words.Part II Listening Comprehension (25 minutes)Section A.Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D).News Report 1.Questions 1 and 2 will be based on the following news item.A new study shows that urban green spaces can significantly reduce the risk of certain diseases. The research, which was conducted over a five - year period in several major cities, found that people living near large parks or gardens had a lower incidence of respiratory and heart diseases compared to those in areas with little or no greenery.1. What did the new study mainly find?A) Urban green spaces are getting smaller.B) People prefer to live near large parks.C) Green spaces can reduce disease risks.D) Respiratory diseases are on the rise.2. How long was the research period?A) Three years.B) Four years.C) Five years.D) Six years.News Report 2.Questions 3 and 4 will be based on the following news item.A well - known tech company has announced a major breakthrough in battery technology. The new battery is said to be more efficient, longer - lasting, and safer than current models. This could have a huge impact on the development of electric vehicles and portable electronics.3. What is the achievement of the tech company?A) A new type of electric vehicle.B) A major breakthrough in battery technology.C) A new marketing strategy for electronics.D) An improvement in portable electronics.4. Which fields could be influenced by this achievement?A) Only electric vehicles.B) Only portable electronics.C) Both electric vehicles and portable electronics.D) Neither electric vehicles nor portable electronics.News Report 3.Questions 5 to 7 will be based on the following news item.A group of international scientists has discovered a new species of deep - sea fish. The fish was found at a depth of over 2,000 meters in the Pacific Ocean. It has unique physical characteristics that distinguish it from other known species.5. Where was the new species of fish discovered?A) In the Atlantic Ocean.B) In the Indian Ocean.C) In the Arctic Ocean.D) In the Pacific Ocean.6. At what depth was the fish found?A) Over 1,000 meters.B) Over 2,000 meters.C) Over 3,000 meters.D) Over 4,000 meters.7. What makes the new fish different from others?A) Its color.B) Its size.C) Its unique physical characteristics.D) Its living habits.Section B.Directions: In this section, you will hear two long conversations. At the end of each conversation, you will hear four questions. Both the conversation and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D).Conversation 1.Questions 8 to 11 will be based on the following conversation.M: Hi, Lisa. How was your weekend?W: It was great. I went to a concert with some friends.M: That sounds fun. Who did you see?W: A local rock band. They were really good.M: I like rock music too. Do you often go to concerts?W: Not really. This was my first time in a while.8. What did Lisa do on the weekend?A) She went to a movie.B) She went to a concert.C) She went to a party.D) She stayed at home.9. What kind of band did Lisa see?A) A pop band.B) A jazz band.C) A rock band.D) A classical band.10. Does Lisa often go to concerts?A) Yes, she does.B) No, she doesn't.C) She used to.D) She never goes.11. What does the man like?A) Pop music.B) Jazz music.C) Rock music.D) Classical music.Conversation 2.Questions 12 to 15 will be based on the following conversation. W: John, I'm thinking about taking a Spanish course.M: That's a great idea. Why do you want to learn Spanish?W: Well, I'm planning a trip to Spain next year, and I think it will be useful.M: You're right. Spanish is also very useful in business these days.W: Do you know any good language schools?M: There's one near my office. I heard it has very good teachers.12. What is the woman thinking about?A) Taking a French course.B) Taking a Spanish course.C) Taking a German course.D) Taking an Italian course.13. Why does the woman want to learn Spanish?A) She is interested in Spanish culture.B) She has Spanish friends.C) She is planning a trip to Spain.D) She wants to work in Spain.14. What else is Spanish useful for according to the man?A) Only for travel.B) Only for culture.C) For business.D) For nothing else.15. What does the man know about a language school?A) It has cheap courses.B) It has good teachers.C) It has a convenient location.D) It has a lot of students.Section C.Directions: In this section, you will hear three passages. At the end of each passage, you will hear three or four questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D).Passage 1.Questions 16 to 18 will be based on the following passage.The Internet has changed the way we communicate and access information. However, it also brings some problems, such as information overload and the spread of false information. To deal with these problems, we need to develop good information - literacy skills. This includes being able to evaluate the reliability of sources, distinguish between fact and opinion, and manage the amount of information we consume.16. What has the Internet changed?A) Only the way we communicate.B) Only the way we access information.C) Both the way we communicate and access information.D) Neither the way we communicate nor access information.17. What problems does the Internet bring?A) Only information overload.B) Only the spread of false information.C) Both information overload and the spread of false information.D) Neither information overload nor the spread of false information.18. What skills do we need to develop?A) Technical skills.B) Social skills.C) Information - literacy skills.D) Management skills.Passage 2.Questions 19 to 22 will be based on the following passage.In recent years, more and more people are choosing to live in small towns instead of big cities. There are several reasons for this. First, small towns usually have a lower cost of living. Second, they offer acloser - knit community where people can get to know their neighbors better. Third, the environment in small towns is often cleaner and more peaceful.19. What trend is mentioned in the passage?A) More people are moving to big cities.B) More people are living in small towns.C) People are moving from small towns to big cities.D) People are moving abroad.20. What is one advantage of small towns?A) High - paying jobs.B) A lot of entertainment options.C) A lower cost of living.D) Easy access to big cities.21. What can people do in small towns?A) They can only work.B) They can get to know their neighbors better.C) They can enjoy big - city life.D) They can avoid all problems.22. How is the environment in small towns?A) Dirty and noisy.B) Clean and peaceful.C) Polluted.D) Dangerous.Passage 3.Questions 23 to 25 will be based on the following passage.A new study has found that reading books can have a positive impact on our mental health. People who read regularly are less likely to suffer from depression and anxiety. Reading can also improve our cognitive abilities, such as memory and concentration.23. What has the new study found?A) Reading books is a waste of time.B) Reading books can harm our mental health.C) Reading books can improve our physical health.D) Reading books can have a positive impact on our mental health.24. Who are less likely to suffer from depression and anxiety?A) People who watch a lot of TV.B) People who play video games.C) People who read regularly.D) People who do no hobbies.25. What can reading also improve?A) Our physical strength.B) Our social skills.C) Our cognitive abilities.D) Our appearance.Part III Reading Comprehension (40 minutes)Section A.Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the word bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2. You may not use any of the words in the word bank more than once.The concept of time is something that humans have been trying to understand for centuries. Time is a fundamental part of our lives, yet itis also one of the most difficult things to define _(26)_. We use time to organize our days, plan our activities, and measure the passage of our lives. But what exactly is time?Some scientists believe that time is a physical property of the universe, like space or matter. Others think that time is a human _(27)_, created by our minds to make sense of the world around us. There are also those who argue that time is an illusion, and that there is no such thing as a past, present, or future.Despite these different views, one thing is certain: time is a precious _(28)_. We all have a limited amount of time in our lives, and we need to make the most of it. This means using our time _(29)_ to achieve our goals, whether they are personal, professional, or academic.One way to make better use of our time is to learn how to manage it effectively. This involves setting _(30)_, prioritizing tasks, and avoiding distractions. Another important aspect of time management is learning to say no to things that are not important or that will take up too much of our time.In addition to managing our time, we can also try to _(31)_ our perception of time. This can be done by engaging in activities that weenjoy, which can make time seem to pass more quickly. On the other hand, when we are bored or waiting for something, time can seem to drag on _(32)_.Finally, it is important to remember that time is not just aboutgetting things done. We also need to take time to relax, enjoy life, and spend time with the people we love. After all, life is not just about work and achievement, but also about _(33)_ and relationships.Word Bank:A) accurately.B) construct.C) efficiently.D) endlessly.E) goals.F) illusion.G) limited.H) manage.I) precious.J) property.K) relaxation.L) resource.M) sense.26. A) accurately.27. M) sense.28. L) resource.29. C) efficiently.30. E) goals.31. B) construct.32. D) endlessly.33. K) relaxation.Section B.Directions: In this section, you are going to read a passage with ten statements attached to it. Each statement contains information given in one of the paragraphs. Identify the paragraph from which the information is derived. You may choose a paragraph more than once. Each paragraph is marked with a letter. Answer the questions by marking the corresponding letter on Answer Sheet 2.The Benefits of Bilingualism.A) Bilingualism, or the ability to speak two languages fluently, has been shown to have numerous benefits. For one thing, it can improve cognitive abilities such as problem - solving, memory, and concentration. Studies have found that bilingual individuals tend to perform better on tasks that require these skills than monolingual individuals.B) Another benefit of bilingualism is that it can enhance cultural understanding. People who are bilingual are often more exposed to different cultures, which can lead to a greater appreciation and understanding of cultural differences. This can be especially important in today'sglobalized world, where cross - cultural communication is becoming increasingly common.C) Bilingualism can also have a positive impact on career opportunities. In many industries, being bilingual is seen as an asset. For example, in international business, bilingual employees can communicate moreeffectively with clients and partners from different countries. In thefield of education, bilingual teachers are in high demand, especially in areas with large immigrant populations.D) In addition to these practical benefits, bilingualism can also havea positive effect on mental health. Research has shown that bilingual individuals are less likely to develop age - related cognitive decline,such as dementia. This may be because using two languages keeps the brain active and stimulated.E) However, learning a second language is not without its challenges. One of the main difficulties is grammar. Different languages have different grammar rules, and it can be difficult to master them all. For example, in some languages, the verb comes at the end of the sentence, while in others, it comes in the middle.F) Another challenge is vocabulary. Building a large vocabulary in a second language can take a long time. There are often many words that have no direct equivalent in one's native language, which can make it difficultto understand and use them correctly.G) Despite these challenges, the benefits of bilingualism far outweigh the difficulties. There are many ways to learn a second language, such as taking classes, using language - learning apps, or immersing oneself in a language - speaking environment.H) One effective way to learn a second language is through immersion. This involves living in a country where the language is spoken or spendinga significant amount of time in such an environment. Immersion can help learners pick up the language more quickly and develop a more natural accent.I) Another way to learn a second language is through language exchange. This involves finding a partner who speaks the language you want to learn and who wants to learn your native language. You can then practice speaking with each other, which can be a fun and effective way to improve yourskills.J) In conclusion, bilingualism is a valuable skill that can bring many benefits. Whether it is for cognitive, cultural, career, or mental health reasons, learning a second language is well worth the effort.34. Bilingual individuals may perform better on tasks requiring problem - solving skills. (A)35. Bilingualism can help people understand cultural differences better.(B)36. In international business, bilingual employees have an advantage.(C)37. Bilingualism can reduce the risk of age - related cognitive decline.(D)38. Grammar is one of the main difficulties in learning a second language. (E)39. Building vocabulary in a second language can be time - consuming.(F)40. Immersion is an effective way to learn a second language. (H)41. Language exchange can be a fun way to improve language skills. (I)42. The benefits of bilingualism are greater than the difficulties. (G)43. Bilingualism has many benefits for various reasons. (J)Section C.Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on Answer Sheet 2.Passage 1.The sharing economy has emerged as a significant economic trend in recent years. Platforms like Airbnb and Uber have revolutionized the way people travel and get around. These platforms allow individuals to share their resources, such as spare rooms or cars, with others in exchange for money.One of the main advantages of the sharing economy is that it can make better use of underutilized resources. For example, many people have spare rooms in their homes that are empty most of the time. By listing these rooms on Airbnb, they can earn extra income while also providing accommodation for travelers. Similarly, cars are often parked and unusedfor long periods. Through Uber or other ride - sharing services, car owners can use their vehicles to earn money when they are not using them.Another advantage is that the sharing economy can provide more affordable options for consumers. Airbnb often offers cheaper accommodationthan hotels, especially in popular tourist destinations. Ride - sharing services can also be less expensive than traditional taxis in some cases.However, the sharing economy also faces some challenges. One issue is regulation. Since these platforms are relatively new, there are often no clear regulations governing their operations. This can lead to problems such as safety concerns and unfair.。

电力电子英文作文英文：Electric power electronics is a crucial field in the modern world, as it plays a vital role in the conversion, control, and conditioning of electric power. This technology is used in a wide range of applications, from renewable energy systems and electric vehicles to industrial motor drives and consumer electronics.One of the most common examples of electric power electronics in everyday life is the power supply for electronic devices. For instance, the charger for a smartphone uses power electronics to convert the AC power from the wall outlet into DC power that can be used to charge the phone. Without power electronics, it would be impossible to charge our devices efficiently and safely.Another example is the use of power electronics in renewable energy systems. Solar panels and wind turbinesgenerate DC power, which needs to be converted to AC power for use in our homes and businesses. This conversion is made possible by power electronics, allowing us to harness renewable energy sources and reduce our reliance on fossil fuels.In addition to these examples, power electronics also play a crucial role in electric vehicles. The motor drive system in an electric car relies on power electronics to control the speed and torque of the motor, as well as to manage the energy flow between the battery and the motor. This technology is essential for the widespread adoption of electric vehicles and the reduction of greenhouse gas emissions from transportation.Overall, electric power electronics have revolutionized the way we generate, distribute, and consume electric power. Without this technology, many of the conveniences and advancements of the modern world would not be possible.中文：电力电子在现代世界中扮演着至关重要的角色，它在电力转换、控制和调节中起着至关重要的作用。

新能源汽车技术英语New Energy Vehicle TechnologyThe development of new energy vehicle technology has gained significant momentum in recent years as the world seeks alternatives to traditional fossil-fuel-powered vehicles. New energy vehicles, also known as electric vehicles (EVs), are powered by electricity stored in batteries, hydrogen fuel cells, or a combination of both.One of the key technologies in new energy vehicles is the electric powertrain, which includes the electric motor, battery pack, and power electronics. The electric motor converts electrical energy from the battery into mechanical motion to drive the vehicle. The battery pack stores the electrical energy and provides power to the motor. Power electronics control the flow of electricity between the battery and the motor, ensuring optimal performance and efficiency.Another important technology is the charging infrastructure. To support the widespread adoption of new energy vehicles, a network of charging stations needs to be established. These charging stations can be categorized into three main types: home charging, workplace charging, and public charging. Home charging stations are typically installed in a garage or driveway and allow vehicle owners to conveniently charge their vehicles overnight. Workplace charging stations are installed at offices and parking lots, providing employees with a convenient and reliable charging option during the day. Public charging stations are located in public spaces such as shopping centers, parking lots, and along highways, enablingEV owners to charge their vehicles while on the go.The development of new energy vehicle technology also requires advancements in battery technology. Lithium-ion batteries are currently the most common type of battery used in electric vehicles due to their high energy density and long cycle life. However, research is ongoing to develop new battery chemistries that offer even higher energy density, faster charging times, and lower costs. Solid-state batteries, for example, are a promising next-generation technology that could offer significant improvements in all these areas.Additionally, new energy vehicle technology involves the integration of various smart features. These features include regenerative braking, which allows the vehicle to recover energy during braking and store it in the battery; remote monitoring and control, which enables vehicle owners to check their vehicle's status and control certain functions from a smartphone app; and advanced driver-assistance systems (ADAS), which use sensors and algorithms to enhance safety and convenience.In conclusion, new energy vehicle technology encompasses a wide range of advancements in areas such as electric powertrains, charging infrastructure, battery technology, and smart features. Continued research and development in these areas are crucial to further improve the performance, range, and affordability of new energy vehicles, ultimately driving the transition to a more sustainable transportation system.。

Power Electronics and Drives Power electronics and drives play a crucial role in modern technology, impacting various aspects of our daily lives. From electric vehicles to renewable energy systems, power electronics and drives are essential for efficient energy conversion and control. In this article, we will explore the significance of power electronics and drives, their applications, challenges, and future prospects. First and foremost, it's important to understand the significance of power electronics and drives in today's world. These technologies are the backbone of electric vehicles, renewable energy systems, industrial automation, and consumer electronics. They enable the efficient conversion of electrical power, control the speed and torque of electric motors, and provide a reliable and stable power supply for various applications. Without power electronics and drives, the transition towards sustainable energy and the advancement of electric transportation would not be possible. One of the key applications of power electronics and drives is in electric vehicles (EVs). With the global push towards reducing carbon emissions and combating climate change, EVs have gainedsignificant attention as a cleaner and more sustainable mode of transportation. Power electronics and drives are essential components in EVs, controlling the power flow from the battery to the electric motor, managing the vehicle's energy efficiency, and providing a smooth and responsive driving experience. As the demand for EVs continues to rise, the role of power electronics and drives in enabling this transition becomes increasingly vital. In addition to EVs, power electronics and drives are also integral to renewable energy systems. With the growing adoption of solar, wind, and other forms of renewable energy, the need for efficient power conversion and grid integration has become paramount. Power electronics enable the conversion of DC power generated by solar panels or wind turbines into AC power suitable for the grid. Moreover, they facilitate grid stabilization, voltage control, and seamless integration of renewable energy sources, thereby contributing to a more sustainable and resilient power infrastructure. Despite their numerous benefits and applications, power electronics and drives also face several challenges. One of the primary challenges is the need for higher efficiency and reliability. As the demand for energy-efficient technologies continues to grow, there is a constant pressure to improve the efficiency of power electronic converters and motor drives. This requires advancements in semiconductor materials, converter topologies, and control algorithms to minimize power losses and enhance overall system performance.Another challenge is the integration of power electronics and drives with smartgrid technologies. With the increasing digitalization and decentralization ofpower systems, there is a need for power electronic devices and drives to communicate and coordinate with grid management systems. This integration presents technical and regulatory challenges, as it requires standardization, cybersecurity measures, and interoperability among different grid components. Looking ahead,the future of power electronics and drives holds great promise. Advancements inwide-bandgap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) are poised to revolutionize power electronics by enabling higher efficiency,higher temperature operation, and greater power density. These materials have the potential to drive the next generation of power electronic devices and motor drives, paving the way for more compact, lightweight, and energy-efficient systems. Furthermore, the advent of digital control and advanced algorithms, such as model predictive control and artificial intelligence, is expected to enhance the performance and flexibility of power electronics and drives. These technologies enable predictive maintenance, adaptive control, and real-time optimization,thereby improving the reliability and responsiveness of power electronic systemsin diverse operating conditions. In conclusion, power electronics and drives are indispensable technologies that underpin the modern energy landscape and drive the transition towards sustainable and efficient power systems. From electric vehicles to renewable energy integration, these technologies continue to shape the way we generate, convert, and utilize electrical energy. While they face challenges in terms of efficiency, integration, and performance, ongoing research and innovation hold the key to unlocking their full potential and ushering in a new era of power electronics and drives.。