1、Hybrid-Powered Vehicles | Chapter | i Hybrid-Powered Vehicles Second Editionii | Hybrid-Powered Vehicles | Chapter Other SAE titles of interest: Electric and Hybrid-Electric Vehicles By Ronald K. Jurgen (Product Code: PT-143.SET) Advanced Hybrid Powertrains for Commercial Vehicles By Haoran Hu, Rudy
2、 Smaling, and Simon J. Baseley (Product Code: R-396) History of the Electric Automobile: Hybrid Electric Vehicles By Ernest H. Wakefield (Product Code: R-187) For more information or to order a book, contact SAE International at 400 Commonwealth Drive, Warrendale, PA 15096-0001, USA; phone 877-606-7
3、323 (U.S. and Canada only) or 724-776-4970 (outside U.S. and Canada); fax 724-776-0790; e-mail CustomerServicesae.org; website http:/books.sae.org.Hybrid-Powered Vehicles | Chapter | iii Warrendale, PA, USA Hybrid-Powered Vehicles Second Edition John M. German eISBN: 978-0-7680-4852-0 Copyright 2011
4、 SAE International iv | Hybrid-Powered Vehicles | Chapter 400 Commonwealth Drive Warrendale, PA 15096-0001 USA E-mail: CustomerServicesae.org Phone: 877-606-7323 (inside USA and Canada)724-776-4970 (outside USA) Fax: 724-776-1615 Copyright 2011 SAE International. All rights reserved. No part of this
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6、sae.org; phone: 724-772-4028; fax: 724-772-9765. ISBN 978-0-7680-3497-4 Library of Congress Catalog Number 978-0-7680-3497-4 SAE Order No. T-125 Information contained in this work has been obtained by SAE International from sources believed to be reliable. However, neither SAE International nor its
7、authors guarantee the accuracy or completeness of any information published herein and neither SAE International nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SAE International and
8、 its authors are supplying information, but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. To purchase bulk quantities, please contact: SAE Customer Service E-mail: CustomerServic
9、esae.org Phone: 877-606-7323 (inside USA and Canada)724-776-4970 (outside USA) Fax: 724-776-1615 Visit the SAE Bookstore at http:/store.sae.orgHybrid-Powered Vehicles | v Table of Contents Preface _ vii Executive Summary _ xi Chapter One Hybrid Vehicles Transitional Technology or Ultimate Solution?
10、_ 1 Chapter Two Hybrid System Design _ 7 Chapter Three Hybrid Components _ 21 Chapter Four Hybrid Design Constraints _ 33 Chapter Five Plug-In Hybrid Design and Challenges _ 37 Chapter Six Real-World Examples _ 43 Chapter Seven Hybrid System Optimization: Challenges and Opportunities _ 55 Chapter Ei
11、ght Customer Acceptance _ 63vi | Hybrid-Powered Vehicles | Contents Chapter Nine Future Hybrid Technology Development _ 77 Chapter Ten Future Conventional Hybrid Markets _ 87 Chapter Eleven Future PHEV Markets _ 101 References _ 113 About the Author _ 117Hybrid-Powered Vehicles | vii Preface In the
12、early days of the automobile, there was spirited competition between vehi- cles powered by electricity and those powered by internal-combustion engines. From around 1890 through 1905, electric vehicles, internal-combustion powered vehicles, and steam cars all were competitively marketed and sold in
13、the United States. Electric vehicles had an early development lead in the United States due to the work of electricity pioneers such as Edison, Tesla, and Westinghouse. Also, the limited range of electric vehicles was sufficient for the small U.S. cities of that period, and roads between cities were
14、 largely inadequate for vehicle travel. 1 It was obvious from the beginning that batteries imposed severe limitations on the range and utility of electric vehicles. Ten gallons of gasoline weighs only about 28 kg (62 lb) but contains about 330 kWh (kilowatt-hours) of energy (1.1 million BTU). By com
15、parison, even a modern lead-acid battery weighing the same 28 kg (62 lb) provides only about 1.1 kWh. This overwhelming energy advantage of liq- uid fuel ensured the dominance of the internal-combustion engine for the last 100 years, despite its relatively low efficiency. While most developers went
16、straight to internal-combustion powered vehicles, some tried to marry the advantages of the electric vehicle and the internal- combustion engine into a hybrid vehicle. The first hybrid vehicle was built in 1898, and several manufacturers sold hybrid vehicles in the early 1900s. How- ever, hybrid veh
17、icles also have significant problems. They require two propulsion systems, which take up space, add weight, and greatly increase the cost. Another problem is that careful coordination of the operation of the engine and the motor is necessary to achieve much of the efficiency benefits and to avoid dr
18、ivability viii | Hybrid-Powered Vehicles | Preface problems, which was not possible with mechanical controls. Thus, production of hybrid vehicles did not survive the continued development of the internal-com- bustion engine in the early 1900s. The oil crises of 1973 and 1979 turned the auto industry
19、 on its head. Gaso- line shortages, fuel price spikes, and predictions of continued oil shortages and increasing fuel prices caused the public to suddenly demand higher-efficiency vehicles. The U.S. Congress also responded in 1975 by passing Corporate Average Fuel Economy (CAFE) standards, which man
20、dated that cars double their average fuel economy by 1985 and that the U.S. Department of Transportation set cost- effective standards for light trucks. As fuel prices went down in the early 1980s and stayed down, the buying public gradually forgot about fuel economy concerns and returned to demandi
21、ng other attributes it valued more highly than fuel savings, such as luxury, performance, and utility. The average fuel economy of new cars and light trucks combined peaked in 1987 and slowly declined through 2004. Gradually rising fuel prices through the 2000s reversed this trend. The U.S. National
22、 Highway and Transportation Safety Agency (NHTSA) also contributed by effectively raising light truck CAFE standards starting with 2005. The long war in Iraq and the 2008 fuel price spike to more than $4 per gallon reawakened con- cerns about energy security and vehicle efficiency. Although oil pric
23、es moderated somewhat in 2009 and 2010, concerns remain that the supply of cheap oil will come to an end soon. Average fuel economy of new vehicles has increased from 24.0 mpg in 2004 to 28.3 mpg in 2010. 2Global warming is another increasing concern. Every gallon of gasoline burned produces about 2
24、0 lb (9.07 kg) of carbon dioxidethe primary greenhouse gas accused of increasing global temperatures. Pressures are rising worldwide to decrease oil consumption and greenhouse gas emissions. Most countries have imposed high fuel taxes to raise revenue and reduce oil consumption and green- house gase
25、s. Standards to reduce vehicle fuel consumption and greenhouse gas emissions are being implemented and strengthened worldwide.Hybrid-Powered Vehicles | Preface | ix The increasing concerns with global warming and energy security have spurred increasing interest in hybrid vehicles. This interest was
26、facilitated by increasingly sophisticated computer controls and improved batteries. Sophisticated computer controls allow maximum efficiency benefits while providing smooth, seamless coordination of the two propulsion systems. Advanced batteries, such as nickel- metal hybrid (NiMH) and now Lithium-i
27、on (Li-ion), provide higher energy den- sity and much longer cycle life. Hybrid vehicles offer a way to significantly reduce fuel use, with corresponding reductions in global warming gases, fuel cost to con- sumers, and criteria air pollutants from fuel refining, distribution, and evaporative emissi
28、ons during refueling. An early recognition of the potential of hybrid vehicles was the “Supercar” pro- gram announced by U.S. President Bill Clinton, Vice President Al Gore, and the chief executive officers of Ford, General Motors, and Chrysler in the fall of 1993. Officially named the Partnership f
29、or a New Generation of Vehicles (PNGV), the goal was to work together to build a family car that got 80 mpg (34 km/L), or approximately three times the mileage of an average car. The program spurred advances in materials and hybrid design, but it did not produce a vehicle that the automakers felt co
30、uld be mass-produced at a price con- sumers would be willing to pay. While the objectives were laudable, the primary problem with the Supercar program was the arbitrary goal of 80 mpg (34 km/L). This goal was never questioned during the nine-year process, and it led the auto- makers to choose option
31、s that were not cost-effective or were not marketable. For example, gasoline engines were not considered because the 80-mpg (34-km/L) target could not be reached with a gasoline-electric hybrid system. Similarly, the 80-mpg (34-km/L) target forced expensive choices for lightweight materials and extr
32、eme aerodynamic improvements that were not cost-effective at the time. Arbi- trary adherence to an arbitrary target ensured that the Supercar program would not succeed in putting a high-mileage vehicle into production. The program was successful in spurring public interest in hybrid vehicles and adv
33、ancing material and component designs. The announcement of the PNGV program also helped spur Toyota into designing its own hybrid vehicle in secret. The goal of Toyota was a more realistic 55 mpg (23.4 km/L) or twice the mileage x | Hybrid-Powered Vehicles | Preface of an average car. Toyota unveile
34、d its design at the 1997 Tokyo Motor Show: the Prius, a highly efficient gasoline-electric hybrid vehicle. The initial design was tai- lored to the congested urban driving conditions in Japan and the performance was not adequate for the U.S. market. However, the Prius began selling in Japan while Su
35、percar was still establishing concepts. There is no question that the world must improve the efficiency of vehicles, but many uncertainties remain about how and when. There is no consensus on when or if liquid fuel production will peak and how much fuel prices will increase in the future. There are
36、many different ways to design a hybrid vehicle with differ - ent tradeoffs. The recent rise in oil prices and the development of higher energy density Li-ion batteries has also created interest in hybrids that can be recharged from the electric grid for further reductions in fuel consumption. There
37、are many competitors to hybrid technology, such as diesels, fuel cells, electric vehicles, alter- native fuels, and even advanced gasoline engine technology. Hybrid vehicles are challenged by the cost and complexity of having two different propulsion systems in the same vehicle. The goal for hybrids
38、 is to find ways to reduce costs and to use the on-board electric power to provide additional features desired by customers, thereby producing a vehicle that most consumers would be willing to purchase.Hybrid-Powered Vehicles | xi Executive Summary Gasoline and diesel internal-combustion engines hav
39、e two huge advantages over competitors. First, liquid fuels have extremely high-energy density, allowing long driving ranges with small storage tanks. Second, they enjoy an established infra- structure that would cost hundreds of billions of dollars to recreate for any new fuel. These have proven to
40、 be daunting barriers to alternative fuel and propulsion technologies. Even more important, the internal-combustion engine keeps raising the bar every time it is challenged. For example, 15 years ago, it was “common knowledge” that the internal-combustion engine was inherently dirty and must be repl
41、aced to achieve air-quality goals. Engineers responded by developing emissions control technology that reduced criteria-pollutant emissions so much that little additional improvement is available from any alternative. The remaining drivers to switch to a new propulsion technology or fuel are global
42、warming and energy security. Again, recent developments in computer simula- tion and computer-aided design are facilitating the design of a host of new tech- nologies to improve the efficiency of conventional vehicles and engines. These improvements make it harder to justify spending hundreds of bil
43、lions of dollars to create a new infrastructure because they reduce the incremental efficiency advan- tages of alternative technologies. Thus, internal-combustion engines running on liquid fuels will likely remain the dominant technology for light-duty vehicles until the supply of relatively cheap o
44、il starts to run out. The increasing concerns with global warming and energy security also are spur- ring interest in hybrid vehicles. Hybrid vehicles use the existing infrastructure xii | Hybrid-Powered Vehicles | Executive Summary and offer a way to significantly reduce fuel use, with correspondin
45、g reductions in global warming gases, fuel cost to consumers, and upstream air pollutants from fuel refining, distribution, and refueling evaporative emissions. A hybrid vehicle combines two different types of propulsion systems. Most hybrid vehicles combine an electric motor and an internal-combust
46、ion engine, although other types of hybrid systems are possible. In light-duty vehicles, parallel hybrid systems generally are used, where the internal-combustion engine, the electric motor, or both can drive the vehicle. This design offers improvements in efficiency by turning off the engine at idl
47、e, using the motor as a generator to recapture energy usually lost to the brakes, improving alternator efficiency, reducing accessory loads, and using the electric motor to improve the efficiency of the engine. For example, the engine can be downsized as a result of the motor assist on acceleration,
48、 the engine can be operated at higher efficiency speed and load points by carefully inte- grating engine operation with operation of the electric motor and transmission, and the electric motor and battery pack can be used to supply propulsion energy at low speeds and loads, allowing the engine to be shut off under inefficient conditions. Hondas hybrids bolt the electric motor to the engine, which is an example of a single-clutch parallel system. Either
