• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Electric Car Market Poised to Accelerate

    2021-07-08 02:55:38ChrisPalmer
    Engineering 2021年2期

    Chris Palmer

    Senior Technology Writer

    In October 2020,China announced plans to stop manufacturing and selling non-hybrid gas-pow ered vehicles by 2035[1].Proposed bans on sales of all new gas-pow ered cars w ere also recently announced by California in the United States(by 2035)[2],India(by 2030)[3],and many countries in the European Union(various dates)[3].

    Enacted to curb climate change,such restrictions seem likely to boost the prospects for electric vehicles(EVs),w hich are increasingly seen as the most viable alternative to gas-pow ered vehicles.One major obstacle of more w idespread adoption of electric cars,how ever,is so-called range anxiety,the concern that the car’s battery w ill drain before the driver can make it to the next charging station,despite 90%of daily driving—an average of 40 mi(~64 km)—being w ithin the range of most current electric cars.Now,bigger batteries,more eff icient drive trains,and other advances in some new models are bringing electric car ranges more in line w ith those of their gas-pow ered competition.In addition,w ireless charging technology now starting to be piloted could also make it easier for consumers to consider purchasing an EV.

    The three primary low-emission car options now available to consumers are battery-pow ered EV,hydrogen-fuel-cell vehicles,and plug-in hybrids.Several large manufacturers have recently abandoned the slow-to-evolve market for hydrogen fuel-cell cars[4],w hich has lagged due to diff iculties in bringing costs dow n and building a broad netw ork of fueling stations.Sales of plug-in hybrids,w hich operate primarily as battery-pow ered EV but have gas engine backups to either take over w hen the battery drains or charge the battery,have also failed to take off,possibly due to misunderstanding among consumers of their benef its[5].These challenges point to EV dominating an accelerating market for low-emission cars,at least in the near-term[4].

    ‘‘Alot of car companies in the last couple of years have been trying to decide if they need to make this huge investment to change to electric cars,or if they can delay it and w ait for some miracle to save them from making the shift,”said Gil Tal,director of the Plug-in Hybrid and Electric Vehicle Center at the University of California,Davis.‘‘What the European Union,and now California and China,are telling them is,‘It is not going to disappear,it is happening,and it is not going to be a 10%or 15%shift but a major change in your industry.’”

    As governments help to convince manufacturers to make this shift,consumers w ill also need to be convinced.EV have been around for decades now,but still make up only a fraction of vehicles on the road—just 3%of the market as of 2019[6].This proportion could quickly increase,how ever,w ith several large auto manufacturers currently planning to signif icantly boost their EV portfolios,including General Motors,w hich recently announced plans to introduce 30 new EV models by 2025[7].

    Although price and concerns about charging and range remain obstacles for many potential buyers,charging has become less of an issue as collaborations betw een manufacturers and electricity providers have expanded the number of charging stations and made them interoperable,able to charge any electric car[8].But even w ith improvements in charging,concerns about range remain a signif icant deterrent to buyers.The w orld’s three best-selling EV models have considerably less range,on average,than the three highest-selling gas-pow ered models,394 km versus 850 km[9,10].‘‘The market remains limited by the challenges of recharging and anxiety about range,”said Scott Samuelsen,professor emeritus of mechanical and aerospace engineering and founding director of the Advanced Pow er and Energy Program at the University of California,Irvine.

    Potentially removing range anxiety from the equation,a small handful of manufacturers are developing electric cars w ith ranges of 800 km and longer.Lucid Motors(New ark,CA,USA)recently announced it w ill begin production in spring 2021 of its Air model that w ill drive 800 km on a single charge(Fig.1)[11].The increased range comes not only from improvements to the car’s battery pack—w hich operates at more than 900 V and fast charges at 350 k W,compared to 350 V and 80 k W for the Tesla Model 3[12]—but also from design changes to the car that reduce air resistance and mechanical friction as w ell as eff iciency upgrades in nearly every facet of its electric drive chain.Meanw hile,Mercedes is w orking on a new model called the Vision EQXX w ith a 1200 km range,also largely resulting from eff iciency improvements[13].Cost of these long-range electric cars w ill probably remain a deterrent for many potential buyers,how ever,w ith the base price of the Lucid Air running about 70 000 USD,including government incentives.

    How much such improved range w ill move the market remains to be seen,Tal said,especially given studies of US driving habits suggesting that 98%of gas-pow ered cars could be replaced w ith current EV and still get people w here they need to go on a daily basis[14].‘‘Range anxiety is only important for the consumer w ho has not yet really considered an EV—it is kind of a boogeyman,”said Tal.You w ould need to sit in your car for 10 h nonstop to drive 1200 km,he added.‘‘To be honest,it is w ay overkill.”Nonetheless,having long-range electric cars in the market could prove helpful,he said.‘‘It could drive consumers in the same w ay that 1000-horsepow er cars once drove consumers.”

    Fig.1.The battery of Lucid Motor’s Air model w ill pow er a range of more than 800 km on a single charge,thanks to design features that reduce air resistance and mechanical friction and upgrades in the eff iciency of nearly every aspect of the electric drive chain.Credit:Lucid Motors(public domain).

    The ability to charge cars w irelessly through electromagnetic induction could also reduce the range anxiety of EV drivers.Electromagnetic induction involves tw o electromagnetic coils,usually made out of copper,that have oscillating electric currents running through them.To charge a vehicle w irelessly,one coil acts as a transmitter,embedded in a charging pad that sits under the car.The second coil is mounted to the car’s undercarriage and serves as a receiver.As electricity passes through the transmitter coil,it generates a magnetic f ield that transfers energy to the receiver coil,w hich then charges the car’s battery(Fig.2).Invented more than 100 years ago[15],induction technology is currently used for w irelessly recharging a w ide range of consumer devices,such as smartphones,electric toothbrushes,and other electronic products.

    Signif icant innovations over the past 15 years are now making w ireless charging practical for EV,said Morris Kesler,chief technology off icer of WiTricity(Watertow n,MA,USA),one of a handful of companies developing the technology.‘‘Now that the market is grow ing,in terms of numbers of EV on the road,there is more of a pull for this technology to be deployed,”Kesler said.WiTricity currently offers a w ireless system that charges at 11 k W—enough to deliver 30 mi·h-1(~48.28 km·h-1),equivalent to a typical plug-in charger—and has deals w ith Chinese automakers to include its system in select models[16].‘‘Wireless charging is another w ay to increase adoption w here users do not have to w orry about changing their behavior w ith their vehicles,”Kesler said.‘‘They do not have to think about plugging the car in every time they get out of it at home—the charging happens automatically.”

    Fig.2.In w ireless charging,electricity passes through a transmitter pad placed under the car to a receiving pad mounted to the car’s undercarriage through electromagnetic induction.Credit:WiTricity(public domain).

    In October 2020,the Society of Automotive Engineers(SAE)International,a US-based organization(w ith w orld headquarters in Warrendale,near Pittsburgh,PA,USA)that develops standards for engineering professionals around the globe,helped to move the technology closer to market.Its new SAEJ2954 w ireless charging standard is designed to achieve up to 94%grid-to-vehicle eff iciency under optimal conditions,enabling charging up to 11 k W over an air gap of 250 mm and interoperability among different vehicles[17].

    In addition to homes,WiTricity and other w ireless charger manufacturers are developing systems for places where vehicles often remain still for intermediate amounts of time,including parking lots,on-street parking spaces,taxi stands,and bus yards.In Oslo,Norw ay,for example,Momentum Dynamics(Malvern,PA,USA)w ill equip Jaguar I-Pace taxis w ith inductive charging pads so the vehicles can recharge w irelessly as they queue up for passengers;the technology adds 80 km of range for every 15 min the vehicles spend idling over inductive coils embedded in the pavement[18].

    Autonomous vehicles w ill also benef it from w ireless charging,Kesler said.‘‘You really need w ireless charging for autonomous vehicles because there is nobody around to plug those in.”In the future,having transmitter coils embedded in roads to charge cars on the move—a concept called dynamic charging—could revolutionize the experience of driving an EV,allow ing drivers to never again w orry about charging up.It could also allow manufacturers to build cars w ith smaller batteries,reducing both vehicle cost and w eight.Anticipating this future,in early 2019 WiTricity acquired San Diego-based Qualcomm’s‘‘Halo”w ireless charging technology that had demonstrated dynamic charging at 20 k W w ith a vehicle driving 96 km·h-1on a test track in France[19].

    Despite its potential promise,Tal and Samuelsen agreed that economic factors,including the cost to build the necessary infrastructure and the falling price of batteries,may prevent w idespread use of dynamic charging for personal vehicles.How ever,the technology may prove more viable for public transit,Tal said,w here around-the-clock operation is often desired and routes are f ixed,limiting the need for installing new infrastructure.Eyeing such public transit markets,the Israeli company ElectReon(Neurim,Israel)is building a dynamic charging system along a section of a bus route in Tel Aviv,as w ell as an 18 km shuttle route connecting the city of Eilat and Ramon International Airport[19].And in May 2020,Sw eden enlisted the company to establish a w ireless system for an airport shuttle route on the Baltic Sea island of Gotland,w hich w ill act as an initial foray for the country’s plan to outf it more than 1600 km of highw ays w ith dynamic charging[20].

    阜南县| 凤翔县| 安陆市| 建德市| 扎兰屯市| 察雅县| 祁东县| 甘南县| 进贤县| 东乌| 柳河县| 灌阳县| 马关县| 廉江市| 华容县| 鹤山市| 紫云| 乐山市| 峡江县| 集安市| 宁蒗| 沧州市| 黄梅县| 永济市| 西吉县| 巴中市| 霍林郭勒市| 涟源市| 中方县| 连平县| 福建省| 宁陕县| 祁连县| 襄城县| 高雄市| 南阳市| 栖霞市| 泸定县| 嵊州市| 宁远县| 铅山县|