Accenture study finds PEV rollouts challenged by cost of charging infrastructure and grid management 作者： Mike Millikin The large scale rollout of plug-in electric vehicles (PEVs) will be hindered unless investors stimulate demand, lower the cost of public charging infrastructure and manage the impact on the grid, according to a report published by Accenture. The report, “Changing the game: Plug-in electric vehicle pilots”, analyzed a range of electric vehicle trials around the world, focusing on pure electric vehicles (EVs) that depend entirely on charging from the electric grid. The report identified three key challenges: Cost : The business case for investing in public charging infrastructure is weak due to high costs and initial consumer preferences for home charging. Pilots reveal a risk that consumers may not use public charging spots at rates required to recover costs, which range from approximately $5,000 per charging station to $50,000 for units capable of fast charging a car in approximately 30 minutes. Control : Infrequent charging by consumers will limit the ability to control the impact of charging on power flows. Pilots show that PEVs meet the driving requirements of typical city users who may therefore not plug in their cars daily. This increases the unpredictability of charging and reduces control. Plugging in vehicles whenever parked will help grid management, easing the strain on the grid. Scale : While most electrification technologies work in isolation, there are too few electric vehicles in pilot areas to robustly test the technologies and their integration with each other. Grid impact will thus need to continue to be closely monitored as the market develops. Plug-in EVs have extensive implications for business models because they require changes in consumer behavior and can increase strain on the grid. It will be critical to improve understanding of consumer preferences and to change consumer behavior through creative incentives if utilities and service providers are to manage the impact on the grid. — Melissa Stark of Accenture “Changing the game” reviews a range of business models that have varying impacts on adoption and implications for service providers: Charging Business Models : Today’s public charging infrastructure model is needed to drive initial large scale roll outs but carries high risks due to upfront costs, unpredictable charging patterns and possibly limited demand. More profitable commercial models are needed for a sustainable PEV market. These include: private charging infrastructure which will include mechanisms, such as premium charging to manage demand and battery swapping services that reduce the strain on the grid; and the end-to-end model, where a single service provider will offer long term service contracts that remove the cost of the battery from the purchase price of the vehicle and include battery swapping as an option. Automotive Business Models : Direct vehicle sales to consumers are being tried by some manufacturers, but the high cost of the batteries makes this option unaffordable for most consumers unless large government subsidies are offered. Leasing of cars is more attractive, spreading the high purchase price over a long period of time. Automotive manufacturers will have to invest in capabilities to manage a new service-based relationship with consumers if they are to adopt this model. Battery Leasing Models : Some service providers own and maintain the battery, leasing it through a subscription service whereby consumers pay for ‘miles’ driven instead of electricity. The consumer is the most important factor in determining which business models will succeed. The capabilities needed to deliver these models will be the same across the world, but the players that choose to develop them will vary. This means that standardization of technologies is urgently needed to support the varied involvement of service providers. And greater efforts will be required to improve understanding of consumer preferences. —Melissa Stark “Changing the game: Plug-in electric vehicle pilots” features the following case studies of EV pilots: Showa Shell’s fast charging pilot in Tokyo; Alliander’s E-Laad pilot in The Netherlands; One North East’s Plugged in Places pilot in Newcastle Upon Tyne, UK; and Better Place’s Tokyo taxi battery switching demonstration. The study also examines the competitive battle between the Chevrolet Volt (plug-in hybrid electric vehicle) and the Nissan Leaf (plug-in hybrid electric vehicle).
Journal of Power Sources Article in Press, Accepted Manuscript - Note to users doi:10.1016/j.jpowsour.2011.02.025 | How to Cite or Link Using DOI Copyright 2011 Published by Elsevier B.V. Permissions Reprints Investigation of Battery End-of-Life Conditions for Plug-in Hybrid Electric Vehicles Eric Wood a , Marcus Alexander b and Thomas H. Bradley a , , a Colorado State University, Department of Mechanical Engineering, Fort Collins, Colorado, 80523-1374 b Electric Power Research Institute, 3420 Hillview Avenue, Palo Alto, California 94304 Received 6 January 2011; revised 1 February 2011; accepted 3 February 2011. Available online 12 February 2011. Abstract Plug-in hybrid electric vehicles (PHEVs)capable of drawing tractive energy from the electric grid represent an energy efficient alternative to conventional vehicles.After several thousand charge depleting cycles, PHEV traction batteriescan be subject to energy and power degradationwhich has the potential to affect vehicle performance and efficiency. This study seeks to understand the effect of battery degradation and the need for battery replacement in PHEVs through the experimental measurement of lithium ion battery lifetime under PHEV-type driving and charging conditions. The dynamic characteristics of the battery performance over its lifetime are then input into a vehicle performance and fuel consumption simulation to understand these effects as a function of battery degradation state, and as a function of vehicle control strategy. The results of this study show that active management of PHEV battery degradation by the vehicle control system can improve PHEV performance and fuel consumption relative to a more passive baseline. Simulation of the performance of the PHEV throughout its battery lifetime shows that battery replacement will be neither economically incentivized nor necessary to maintain performance in PHEVs. These results have important implications for techno-economic evaluations of PHEVs which have treated battery replacement and its costs with inconsistency.
Details of the Audi Q5 Hybrid Quattro Li-ion battery pack 作者： Mike Millikin by Jack Rosebro Components of the Q5 hybrid system. Click to enlarge. In a presentation at the 2011 Advanced Automotive Battery Conference (AABC) in Pasadena, California last week, Daniel Andree, a battery development engineer at Audi AG, outlined the implementation of a Sanyo lithium-ion battery pack in the upcoming 2012 Audi Q5 compact crossover hybrid. ( Earlier post .) The Q5 has an all-electric range of about 3 km (a little less than two miles) with a maximum all-electric speed of 100km/h (62 mph). The vehicle’s electric drive is mated to a 2.0L, turbocharged, direct injected four-cylinder gasoline engine. Combined weight of all hybrid components is less than 130 kg (286 pounds). SoC window for the Q5 Hybrid battery pack. Click to enlarge. Battery pack performance . The 266V, 1.3 kWh battery pack weighs about 35 kg, yielding a power density ratio of 1143 W/kg and an energy density ratio of 37 Wh/kg. The cells themselves account for slightly more than half of the pack’s total weight (ratio of cell weight/system weight of 0.52). The battery pack, which supplies 40 kW of a 180 kW total powertrain output, utilizes a broad maximum state-of-charge (SOC) window ranging between 20% to 80% pack charge, with full pack performance available between 30% and 70% SOC. (This is a much wider SoC window than some other automakers, such as GM, are currently utilizing for hybrid applications. GM, for example, is looking at a pack SOC window for a full hybrid of less than 20 percentage points. Earlier post .) Engine cranking is possible at temperatures as low as -30C (-22F) as long as battery pack SOC is 30% or greater. Cooling the battery pack . The Q5’s battery pack is air-cooled, with cooling air volume and temperature controlled as needed. The pack is split into two symmetrical parts, each with its own inlet and outlet interfaces. Particular attention was given to preventing turbulence within the air passages, which could lead to uneven pressures and cooling. Audi also found that a battery pack air conditioning system could significantly shorten the time to reach a specific cooling target. For example, an active battery pack could be cooled from 50 C (122 F) down to 40 C (104 F) by an air conditioning system in approximately sixteen seconds, as compared to approximately six seconds via forced-air cooling alone. The battery management System (BMS) can switch between passive and active modes. If the battery pack temperature rises above 34.5 C (94.1 F), fan cooling is activated. If pack temperature rises above 37 C (98.6 F), the vehicle’s air conditioning system is activated, cooling interior air via the front evaporator. At 42 C (107.6 F), a dedicated rear evaporator provides additional cooling capacity. “The electrification of a conventional vehicle concept has a very big impact on nearly all parts of the vehicle. For example, to merge the conventional Q5 with the q5 hybrid, you will find differences in nearly all parts of the vehicle.” —Daniel Andree Performance monitoring . The Q5’s battery management system stores historical stress data-cell resistance and capacity, pack temperature and current distribution, and violations of parameter limits—which can be displayed as histograms for evaluation. Audi’s testing indicates that in a worst-case scenario, battery pack capacity will be reduced to about 60%, with cell resistance increasing by 30%, by the end of the battery pack’s usable life. Audi expects to see no impact on battery performance during the battery pack’s first ten years of service, and intends to offer at least seven years of battery warranty, depending on vehicle miles driven. Safety protection. The Q5’s battery pack protection is divided into three levels: Protection Level 1: The vehicle’s battery management system detects cell imbalance (reduced cell capacity, increased cell resistance) and uses an algorithm to modify battery management strategy without affecting perceived vehicle performance. Protection Level 2: The vehicle’s control system can isolate the battery pack from the rest of the hybrid system, shutting off current flow, if the pack exceeds given voltage, current, and/or temperature thresholds, or if a collision is detected. Battery function may be restored following a crash, depending on the intensity of the crash. Protection Level 3: Mechanical and functional countermeasures are in place to prevent a chain reaction of thermal runaway in the event of a severe defect within one cell. Pack tests have been conducted in which one cell was purposely subjected to thermal runaway, to see if the effect would propagate across the pack. In all tests, the thermal event was confined to the original cell. Q5 battery pack testing was conducted in accordance with UN lithium battery testing requirements, as well as those developed by Sandia Laboratories Test 2005-3123, which is used by Sandia itself in support of USABC FreedomCar testing contracts. Audi also added a "foreign particle" test to the abuse testing protocol for the pack. A nickel particle was built into to a cell to create a fault in which a cell’s separator would rupture under stress. No fire or explosion occurred during testing, according to Andree. The 2012 Audi Q5 Hybrid Quattro is scheduled to be released in Europe this spring, and in North America later this year.
Journal of Power Sources Article in Press, Accepted Manuscript - Note to users doi:10.1016/j.jpowsour.2011.01.076 | How to Cite or Link Using DOI Copyright 2011 Published by Elsevier B.V. Permissions Reprints An evaluation of the hybrid car technology for the Mexico Mega City Aron D. Jazcilevich a , , , Agustin Garcia Reynoso a , Michel Grutter a , Javier Delgado b , Ulises Diego Ayala e , Manuel Suarez Lastra b , Miriam Zuk d , Rogelio Gonzalez Oropeza c , Jim Lents f and Nicole Davis f a Universidad Nacional Autónoma de México, Centro de Ciencias de la Atmósfera b Universidad Nacional Autónoma de México, Instituto de Geografía c Universidad Nacional Autónoma de México, Facultad de Ingeniería d University of California at Berkeley e Electronic Variable Technologies SL, Barcelona, Spain f International Sustainable System Research Received 6 December 2010; revised 19 January 2011; accepted 20 January 2011. Available online 28 January 2011. Abstract The introduction of Hybrid Electric Vehicle (HEV) technology in the private car fleet of Mexico City is evaluated in terms of private costs, energy, public health and CO2 emission benefits. In addition to constructing plausible scenarios for urban expansion, emission, car fleet, and fuel consumption for year 2026 and comparing them with a 2004 base case, a time series is built to obtain accumulated economic benefits. Experimental techniques were used to build a vehicle library for a car simulator that included a Prius 2002, chosen as the HEV technology representative for this work. The simulator is used to estimate the emissions and fuel consumption of the car fleet scenarios. In the context of an urban scenario for year 2026, a complex air quality model obtains the concentrations of criterion pollutants corresponding to these scenarios. Using a technology penetration model, the hybridized fleet starts unfolding in year 2009 reaching to 20% in 2026. In this year, the hybridized fleet resulted in reductions of about 10% of CO2 emissions, and yielded reductions in daytime mean concentrations of up to 7% in ozone and 3.4% in PM2.5 compared to the 2004 base case. These reductions are concentrated in the densely populated areas of Mexico City. By building a time series of costs and benefits it is shown that, depending on fuel prices and using a 5% return rate, positive accumulated benefits (CO2 benefits+energy benefits+ public health benefits - private costs) will start generating in year 2015 reaching between 2.8 and 4.5 billion US Dlls. in 2026. Another modernized private fleet consisting exclusively of Tier I and II cars did not yield appreciable results, signaling that a change in private car technology towards HEV's is needed to obtain significant accumulated benefits. Keywords: HEV technology; Accumulated Benefits; Air Pollution; Vehicular Emissions
正当国人开始 Fan 混合动力车（ Hybrid Car ）的时候，大洋彼岸的电动车（ Electric Car ）已经上市销售。 Tesla Motors 的 Roadster 正在北美大陆上奔驰，新款的 Model S 据说也很快会 touch the road 。 上世纪 90 年代，曾经出现过电动车热。当时主要使用镍电池。比较成功的车型，时速可以达到 60 英里（大约 100 公里），每次充电后可以走 100 英里左右（不到 2 小时）。主要的挑战是： 1 ）时速比较慢——美国人喜欢的理想时速，最快速度至少应该达到每小时 100 英里（美国西部的很多州没有 Speed Limit ，有的州只设了夜间的限速： Night 95 ——当然是 mph 不是 kmph ，可以想见人们对车速的期待值）； 2 ）充电问题——车用电池充电时间至少要 6 小时，远比加一缸油的几分钟来得长！ 对后一个问题，人们很快想出了解决办法：把加油站变成“加电站”——和存储很多汽油一样，存储大量汽车电池。你的电池用完就近找一个加油站换一个新的就是了。因为高速路上加油站的分布是大约 25-45 英里一个，可以行驶 100 英里的蓄电量足矣。 但是对前一个问题，当时人们觉得还没有技术去大幅度提高速度，加上底特律汽车商们的利益考虑，电动车这一零排放新技术就搁置起来。 但日本人却打了一个时间差——在电动汽车可以被市场接受之前，采用汽油—电池混合动力的办法，在车下坡和“怠速”的时候，给电池充电；在其它状态下以常规的汽油动力为主。丰田的 Hybrid Car 一上市，就受到全世界爱车一族的追捧，市场份额急剧增长。 而此时热衷于新技术的车迷们开始自己动手，利用锂电池技术的发展，在加州而不是底特律尝试生产电动车。他们用电力应用的先驱者（交流电机的发明者） Nikola Tesla 的名字命名自己的工厂。现在第一款 Roadster 已经出售，售价超过 10 万美元依然供不应求，据说 back order 要三年！下一款的 Model S 也即将在 2012 年面世。 笔者现在担心的倒是：有多少加油站可以给这些车换电池？ 不过，从中国一些城市推广汽车充气技术来看，只要有车，就会有这样的加油站。 只是开电动车到偏远地区兜风的时候，还是要多带几组备用电池的。
标签: 混合动力
