Oil resources are not inexhaustible. As the main fuel of the car, it will always have an alternative day. Although in the process of searching for new energy, the major automobile enterprises have once been independent and committed to different directions. But after a long period of exploration and collision, the global automobile industry is now stepping into the energy revolution. There is a basic consensus that clean energy, such as diesel, gas, and ethanol, is recognized as an effective way, and is in the promotion period, and hydrogen power is regarded as the ultimate perfect solution.
as the second stage technology, the hybrid electric power industry is developing vigorously.
Although hybrid power is still based on oil as fuel, it can not solve the problem of energy shortage completely, but in many solutions, only the hybrid power has been successfully industrialized, and even some European auto companies, which have not been optimistic about hybrid technology, have started to pursue and have launched their own. Mass production model.
What is a hybrid power?
The hybrid electric vehicle (HEV) uses the traditional internal combustion engine and motor as a power source. It can save fuel and reduce exhaust pollution by using two sets of heat and electric power systems. The internal combustion engine has both diesel engine and gasoline engine, but the common characteristics are small displacement, light weight, high speed and good exhaust. The key of hybrid electric vehicle is hybrid power system, whose performance is directly related to the performance of hybrid electric vehicle. After more than 10 years of development, the hybrid power system assembly has developed from the original engine and motor discrete structure to the integrated structure of engine, motor and transmission, that is, integrated hybrid power assembly system. The hybrid powertrain is classified by power transmission line. It can be divided into three parts: series, parallel and hybrid.
a power unit consisting of three parts of engine, generator and motor, and a power unit connected in series. The engine drives the generator to generate electricity, and the electric energy is conveyed to the battery or motor through the controller. The motor drives the car through the speed changing mechanism. When the vehicle is in the starting, accelerating, and climbing conditions, the engine, the generator set and the battery pack provide the electric energy to the motor. When the vehicle is in low speed, gliding, idle speed, the battery group drives the motor. When the battery is short, the battery is charged by the engine and the generator group. The series type is suitable for the frequent start and low speed conditions in the city. It can adjust the engine to stable operation near the best working condition point, and adjust the speed by adjusting the output of the battery and motor. The engine avoids idle speed and low speed operation, thereby improving engine efficiency and reducing exhaust emissions. Its disadvantage is that the energy is converted and the mechanical efficiency is low. It is difficult to reduce the fuel consumption obviously. At present, it is mainly used in the city bus, which is very rare in the car.
the engine and motor of the parallel device drive the car together, the engine and the motor belong to two sets of systems, which can separately provide torque to the automobile drive system, which can be driven and driven on different roads. When the car is speeding up the slope, the motor and the engine can provide power to the transmission mechanism at the same time. Once the speed of the car reaches the cruise speed, the car will only rely on the engine to maintain the speed. The motor can be used as an electric motor as well as a generator, so as to balance the load of the engine and make it work in high efficiency area. But because of the mechanical connection between the engine and the driving wheel, the engine can not always run at the best operating point in the condition of the city, and the fuel economy of the vehicle is worse than that in the series. Because there is no single generator, the engine can drive the wheel directly through the transmission mechanism. This device is closer to the traditional car driving system. The loss of mechanical efficiency is similar to that of the ordinary car, so it is widely used.
Parallel representative models — — Honda Civic Hybrid
The civic hybrids are based on the latest Honda 1.3 L three segment i-VTEC engine as the active force. Its characteristic is that the valve can be controlled through the three stages of low speed, high speed, and cylinder stop according to the variable valve timing and lift system (VTEC). The auxiliary power is to install the Honda miniaturized IMA integrated motor auxiliary system. This system can reduce fuel consumption by the way of the motor in the condition of starting, low speed cruising and acceleration, and the motor is stored in nickel metal storage battery when the vehicle decelerates. When the vehicle stops, the engine will shut down on its own. The combination of these two power components makes the HEV achieve the same driving power as the 1.8 L engine, and its fuel economy and driving comfort have been successfully improved because of the use of the combined regenerative braking system. According to the test of the Automotive Engineering Department of Tsinghua University, in the actual road of Beijing City, the 1.3 L hybrid power version is better than the ordinary 1.8 L is 36 to 41%, and the efficiency of the comprehensive oil saving is 38%.
Since its advent in December 2001, the civic hybrids have been sold in more than 40 countries and regions in the world, and up to now, the total volume of global sales has been nearly 200 thousand.
Electric vehicles and hydrogen power
Electric vehicle — — MITSUBISHI i MiEV
MITSUBISHI i MiEV is developed by improving the minimum range of the mini car I. It is equipped with the maximum output power 47 the kW motor and the deceleration gear, instead of the engine and the transmission, and the lithium ion rechargeable battery. The joint research vehicle in 2006 is equipped with a voltage of 330 V, capacity 16 kWh battery, the target maximum speed of 130 km/h, the constant driving distance to 130 km. By 2007, the battery capacity will be increased to 20 , kWh, and the continuous travel distance will extend to 160 km. MITSUBISHI motor will also improve the battery and reduce the quality of each part in the future, and strive to keep the running distance to 200 , KM before and after 2010. At the same time, MITSUBISHI i  and MiEV are still making plans to strive for listing in 2010.
technical bottlenecks: battery capacity, efficiency and cost of electric system.
internal combustion engine hydrogenation power — — BMW Hydrogen 7 system.
The 7 system of BMW hydrogen energy is equipped with 6.0 , which can use liquid hydrogen fuel and gasoline; L V12 engine, the maximum output power is 191 kW, the maximum torque can reach 390 N• m, in 9.5 s can be accelerated from static to 100 km/h, maximum electricity subunit speed limit. In addition to a common tank with capacity 74  and L, the 7 hydrogen system is also equipped with an extra fuel tank, which can hold about 8  and kg of liquid hydrogen. The dual mode drive provides a total mileage of more than 700  and KM for BMW hydrogen energy 7 system, where hydrogen drives 200 , KM is above, gasoline drives 500 , km. The driver can manually complete the conversion from hydrogen power to gasoline power mode, and will not affect the running state and performance of the 7 hydrogen system at all. If a fuel is exhausted, the system will automatically switch to another fuel form, ensuring that fuel supply is continuous and reliable.
The technical bottleneck: hydrogen supply system and use cost
the parallel connection device has the characteristics of series connection and parallel connection. The power system includes engine, generator and motor. According to the auxiliary device, it is divided into two parts: engine and motor. Because the mixing mode is a combination of series and parallel, it also combines the series type to make the engine not affected by the driving condition of the car. It can always make the engine run steadily in the best working area, and can choose the less power engine, and the parallel type can be driven by the engine and the motor. The characteristics of the driving car can make the engine, motor and other components more optimal matching, so as to ensure the optimal state of the system in the more complex conditions, so it is easier to achieve the control target of emission and fuel consumption. The drawback of the mixed type is that the structure is more complex.
hybrid &mdash, &mdash, TOYOTA Prius.
the TOYOTA Prius belongs to a hybrid electric motor. The hybrid power system includes the engine and motor two power assemblies, including the generator, motor, hybrid power special transmission, Ni MH battery and power control assembly. The Prius's hybrid power system has one feature, which is the use of planetary gear transmission, the built-in dynamic separation device of the transmission, and the planetary gear mechanism that ingeniously coupled the dynamic components such as the reducer, generator and motor, and the planetary gear functions as a stepless speed converter, with a very compact structure. An integrated hybrid power assembly system.
start up and travel below medium speed. At this time, the efficiency of the engine is low, so the Prius's engine is closed, and only the high power motor drives the vehicle. In regular driving, the engine is the main power source, the power separation device divides power into two roads, one drives the generator to generate electricity, the electric drive motor runs, the other directly drives the wheel, and the system will automatically divide the power of the two paths to maximize the efficiency.
when accelerating, the battery pack will be added to supply the motor and enhance the output power of the motor. When decelerating or braking, the motor is driven by the inertia force of the wheel. At this time, the motor becomes a generator, and the braking energy of vehicle is converted into electric energy. The battery power is kept at a constant level. When the system finds that the battery power is down, it will start the engine driven generator to generate electricity and charge to the battery pack.
The idea of a more avant-garde hybrid
What is a fuel cell (Fuel Cells)?
A fuel cell is an energy conversion device that converts the chemical energy of the fuel to the electric energy. It is a power generation device that continuously supplies power by continuous supply of fuel. Because of its advantages of high power generation efficiency and adaptability to various fuels and environmental characteristics, it has been actively developing in recent years.
Ford Edge plug in hybrid electric vehicle
Ford Edge is the world's first concept vehicle that can charge batteries by household power supply and use hydrogen fuel cell hybrid power. It uses a power system that combines a vehicle with a hydrogen fuel cell, a generator and a lithium ion battery, which reduces the size, quality, cost and complexity of the traditional fuel cell by more than 50%, and hopes to double the life of the fuel cell group.
the.Edge hybrid powered by a 336 V lithium ion battery pack provides full time power and can be charged with a standard home power supply, which makes Edge a real plug in hybrid. When the power is filled, the car will automatically give priority to the stored power to drive 40 km, when the battery's power is consumed to 40%, the hydrogen fuel cell starts to automatically charge the battery. The hydrogen fuel cell is supplied by a 35 , MPa hydrogen tank, and the available hydrogen of kg is converted into electrical energy to charge the battery pack. Now, if a battery is full of electricity and filled with 4.5  and kg of hydrogen, Edge hybrid electric vehicle can continuously drive 362.25 , km, and achieve real zero emissions at the same time. In addition, Edge has been able to reach the maximum speed of 136.85  and km/h at present.
The inadequacies of the hybrid power
the most notable drawback of hybrid power is the high cost of carrying two power systems. To overcome this obstacle, it is not enough for users and manufacturers. At present, many developed countries have implemented preferential policies for hybrid vehicles and other environmentally friendly and low fuel consumption vehicles from tax aspects. For example, Japan, under the premise of tax neutrality, has good emission performance and energy saving performance, and reduces the tax rate for cars with small environmental load. After a certain year of new car registration, it is necessary to increase the tax rate for a car with large environmental load as a special case. The European and American countries have also helped to promote the popularization and development of low fuel consumption vehicles such as hybrid vehicles by reducing the preferential policies of automobile purchase tax, consumption tax and personal income tax to varying degrees.
Second, battery technology. At present, in hybrid electric vehicles, the mature nickel metal battery has almost become the standard, but this also means that the nickel metal battery will not have a big leap in energy density and power density. The battery life and battery capacity have some constraints on the efficiency of the hybrid electric vehicle. A more efficient lithium battery is the best alternative to nickel metal batteries, but the high cost of lithium batteries is also a difficult problem in addition to a number of technological breakthroughs, but many industry experts believe that the improvement in the battery determines the future direction of the hybrid.
Other brand hybrids dynamics
Mercedes Benz S400 HYBRID
Mercedes Benz exhibited a S400  at the 2007 Frankfurt auto show; HYBRID, the hybrid S class carrying a maximum power 205 kW 3.5 L V6 gasoline engine, and combined with a 15 kW power and 160 N• torque motor. The maximum power of the combination of the two is 220 kW, the maximum torque is 375 N• m, 0 to 100 km/h acceleration time only needs 7.3 s, the maximum speed can reach 250 km/h. The hybrid version of S will be launched in Europe in the first half of 2009.
Audi Q7 3.6FSI HYBRID
Q7 HYBRID uses a parallel hybrid power system, using 3.6 L FSI gasoline engine and an electric motor driving the vehicle together. The power passes through Quattro® the full wheel drive system is passed to four wheels, the overall performance index is over 3.6& nbsp; L FSI engine Standard Version Q7. The motor is powered by a 288 , V nickel hydrogen battery, which can increase the power by 37 , kW. The fuel consumption of this hybrid vehicle is greatly reduced, while the CO2 emission is also reduced by 23%, 0~100 , and the acceleration time of km/h is only 8.5 , s. This Q7 HYBRID will be listed by the end of 08.
Ford Escape Hybrid
Ford signed the hybrid technology patent license agreement with TOYOTA in 2004, and then launched the first hybrid SUV Escape in the market. The 08 Escape Hybrid carried the 2.3 the L gasoline engine, as well as the motor, the generator, and the 330  under the bottom of the luggage compartment; the V nickel hydrogen battery. In 6 000 r/min, the engine can give full play to 98 the maximum power of kW, while 4 250 r/min can output 174 N• m maximum torque; the motor is maintained between 3000 and 5000 The V6 engine is the same.
Cadillac Hybrid Escalade.
The Hybrid should be the first model to use the energy saving hybrid on the large luxury SUV so far. It is based on two small motors and the original 6.2 L V8 engine is the power base, can produce 244 kW power and 497 N• m torque, and it also has a 300 V. Hybrid power system. It is said that the economy of the hybrid version of Escalade equipped with electric motor is 25% higher than that of the original. Escalade Hybrid is expected to go on sale in the summer of 2008.