At present, when the global automobile industry is facing the great challenge of energy and environmental problems, there has been a broad consensus in the world to develop electric vehicles, realize the electrification of automobile energy power system and promote the strategic transformation of traditional automobile industry. According to the product listing plans released by major automobile companies, it is expected that there will be a climax of international electric vehicle industrialization around 2012. Once the electric vehicle makes a market breakthrough, it will have a huge and far-reaching impact on the pattern of the international automobile industry.
- Development status of foreign new energy vehicles
In the 1970s, due to the geometric growth of car ownership, serious environmental pollution was caused. Especially in some big cities, with the occurrence of a series of environmental pollution events such as photochemical pollution, the governments of western developed countries began to pay attention to environmental protection, which made some famous automobile companies turn to the research and development of new energy vehicles. Since then, developed countries in the world have invested heavily in the commercial development and application of electric vehicles. By the 1990s, developed countries in Europe and the United States had formulated and strictly implemented automobile exhaust emission standards.
1.1. Development of pure electric vehicles
Pure electric vehicles came out in the 1990s, but they once withdrew from the historical stage because the battery performance could not meet the demand. With the development and application of high-performance lithium-ion battery and integrated electric drive system, pure electric vehicle has attracted the attention of governments and enterprises again. Pure electric vehicles have made gratifying progress in driving range, power performance and fast charging, and are about to enter the practical stage.
Pure electric vehicles have been commercialized and applied on a small scale in the United States, Japan, Europe and other countries and regions. At present, nearly 40000 pure electric vehicles are in operation in the world, mainly in the fields of municipal vehicles, buses, official vehicles and private vehicles. Before the breakthrough of battery technology is clear, the development priorities of foreign pure electric vehicles are as follows: first, the development of small passenger vehicles; Second, develop large buses, municipal, postal and other special-purpose vehicles. In order to meet the needs of users, the program increase scheme is usually adopted, and the conventional energy system is added to the pure electric vehicle to supplement electric energy for the vehicle.
The research focus of pure electric vehicles is on improving battery performance and reducing cost. Compared with the performance and cost of traditional vehicles, in order to meet the requirements of industrialization, the mass and energy density of pure electric vehicle power battery needs to be greatly improved, and the cost also needs to be greatly reduced. Therefore, it is too early for pure electric vehicles to enter the market on a large scale.
1.2. Development of hybrid electric vehicle
Japan first started the development of hybrid electric vehicles and first realized industrialization. At present, the total sales volume has reached more than 2 million and began to make profits. The Prius, which came out at the end of October 1997, is the first hybrid vehicle to realize mass production in the world. The first generation product has a self weight of 1515kg, a gasoline engine displacement of 1500cc, a maximum power of 42.6kw/4600 (R / min), a permanent magnet brushless generator with a rated power of 30kW, a series parallel control mode of hydrogen nickel battery, and a fuel consumption of 3.4L per hundred kilometers.
At present, Prius has launched the third generation of products, the power battery has been changed to lithium battery, and other performances have been greatly improved. Toyota Prius has sold more than 2 million vehicles worldwide.
Since Toyota first launched Prius hybrid vehicles in Japan in 1997, major automobile enterprises have launched hybrid vehicle products, such as Honda Insight, GM Saturn Vue, Ford Escape, etc. With the maturity of technology and the expansion of production scale, the cost has decreased significantly. European hybrid vehicle technology started relatively late and shared hybrid powertrain technology in cooperation with the United States, which is mainly used in vehicles with high fuel consumption using traditional technology.
Internationally, hybrid commercial vehicles have also achieved rapid development, and hybrid buses, municipal vehicles and military vehicles have been developed. In particular, the United States has made some achievements in the development and application of hybrid bus. At present, many models are in operation. European bus and truck manufacturers have focused on hybrid technology. Germany Benz, Sweden Volvo and Poland Solaris have successively developed hybrid commercial vehicles.
Hybrid technology is a necessary link for the transfer from single engine drive to pure electric drive. Reasonable use of hybrid technology can significantly save fuel and carbon, and control the cost within a certain range. Therefore, hybrid vehicles have become the focus of automobile companies all over the world. With the gradual maturity of battery technology, gradually improving the degree of mixing to realize the transformation from traditional energy to electrification is the development direction of hybrid technology. In the early stage, there are mainly schemes such as single motor parallel, double motor parallel and double motor hybrid connection. In the later stage, it will develop to plug-in scheme to realize the transition to pure electric scheme. In terms of power system structure, hybrid electric vehicles will develop to a higher degree of integration. According to the development of vehicle energy, there are two trends: integration of engine and motor and integration of transmission train and motor, so as to realize the transformation to electrification.
1.3. Development of fuel cell vehicles
Fuel cell vehicle is to make hydrogen as fuel react with oxygen in the atmosphere in the fuel cell carried by the vehicle, so as to produce electric energy to start the motor and drive the vehicle. Due to the great strategic significance of fuel cell vehicle technology, developed countries and regions such as the United States, Japan and Europe are devoted to the research of fuel cell vehicles. In addition to China’s fuel cell development plan, American General Motors and Japanese Toyota, American international fuel cell company and Japanese Toshiba, German Mercedes Benz and Siemens, French Renault and Italian de Nora have formed strong multinational alliances with complementary advantages, Jointly developed and launched a series of fuel cell vehicles.
At present, great progress has been made in fuel cell technology. The service life of fuel cell membrane has exceeded 5000h, the laboratory service life of fuel cell stack has also been increased to more than 2000h, and the cost of fuel cell stack has been reduced to $94 / kW (calculated according to the output of 500000 sets). In recent years, the fuel cell has a modular trend, and the power range of a single fuel cell module is defined within a certain range. Modular assembly is realized by improving product performance to meet the requirements of different vehicles for fuel cell power level. By using hybrid technology, the energy distribution of battery and fuel cell is optimized to effectively improve the service life of fuel cell and reduce the system cost. The focus of fuel cell vehicle technology research is to improve reliability and durability, and it will be difficult to make a major breakthrough in the short term.
In recent years, governments of various countries have successively issued electric vehicle development strategies and national plans, increased policy support, increased R & D investment, and fully promoted the industrialization of electric vehicles. The expectation of breakthrough in electric vehicle technology has been greatly enhanced. The world electric vehicle industry has entered a new stage of rapid development.
- Development status of new energy vehicles in China
The guiding ideology of China’s new energy vehicles has been gradually clear and clear since the government’s “clean vehicle action” in 1995, until the formation of specific objectives, policies and new energy vehicle industry in recent years.
In 2001, the new energy vehicle research project was listed as the “863” major scientific and technological topic during the national “Tenth Five Year Plan”, and the major project of “energy saving and new energy vehicles” in the “863” plan of the eleventh five year plan passed the demonstration in June 2006.
Its key task is to promote the R & D and demonstration operation of fuel cell vehicles, realize the large-scale industrialization of hybrid electric vehicles, expand the application scope of pure electric vehicles, and further expand the promotion and application of alternative fuel vehicles; Promote the research and formulation of energy-saving and new energy vehicle industry policies, regulations and relevant standards, improve relevant testing and evaluation capabilities, form an intellectual property protection and investment and financing service system, build a public service platform for energy-saving and new energy vehicles, and establish China’s energy-saving and new energy vehicle industry alliance; Grasp the major opportunity of the transformation of transportation energy power system and establish an independent R & D and innovation system based on the combination of industry, University and research with enterprises as the main body.
In the demonstration operation of new energy vehicles for the Beijing Olympic Games in August 2008, there were 595 new energy vehicle models in total.
At present, China has mastered the key technology of vehicle development in electric vehicles, formed the development ability of various electric vehicles, independently developed a series of products, and comprehensively followed up the industrialization of key parts. In terms of the research and development of the core battery technology of hybrid electric vehicles, China has independently developed a series of nickel hydrogen and lithium-ion power battery products with a capacity of 6a · H ~ 100A · h. The energy density and power density are close to the international level. At the same time, it has broken through the bottleneck of safety technology and has been applied to urban bus for the first time in the world; The self-developed permanent magnet brushless motor, AC asynchronous motor and switched reluctance motor below 200kW have a weight specific power of more than 1300W / kg and the maximum efficiency of the motor system reaches 93%. In recent years, power battery enterprises such as Lishen, BYD, bick and Wanxiang have invested billions of funds to speed up the industrialization construction. Motor enterprises such as Shanghai electric drive, Dajun, Xiangtan Motor and CSR era have strengthened cooperation with upstream and downstream enterprises and actively improved the construction of industrial chain. In the next two to three years, it is expected to form a production capacity of more than 2 billion a · h power batteries and a full range of drive motors, which can meet the supporting requirements of 1 million hybrid and electric vehicles.
From the current situation, China has established a hybrid electric vehicle powertrain technology platform and an industry university research cooperation R & D system, and achieved a series of breakthrough achievements, laying a solid foundation for vehicle development. As of January 31, 2009, 1116 Chinese patent applications have been accepted and published by the China Intellectual Property Office in the field of hybrid vehicle technology. Of the 1116 patent applications, 782 were inventions (107 were authorized) and 334 were utility models. At the same time, hybrid electric vehicles have made remarkable progress in system integration, reliability and fuel saving performance. Different technical schemes can save fuel by 10% ~ 40%. The investment of automobile enterprises in the R & D and industrialization of hybrid electric vehicles has been significantly increased, the pace of industrialization has been accelerated, the industrialization of key parts has been fully followed up, and the production supporting capacity has been significantly enhanced.
At present, major automobile enterprises have established new energy vehicle R & D companies or departments to carry out research and development on energy conservation and new energy vehicle technology, research on key parts and components such as vehicle power battery, drive motor and fuel cell engine, as well as research on technical standards and test technology. At the same time, local governments have also increased their support for the new energy vehicle industry and planned the new energy vehicle industrial park. At the same time, the government has received high subsidies for the introduction of electric vehicles and ethanol fuel. Many Chinese automobile enterprises frequently display their self-developed fuel cell vehicles and hybrid vehicles at major international auto exhibitions, thus obtaining an immeasurable starting right in this new energy competition.