Hybrid Electric Vehicle Hybrid Electric Vehicle is to install an internal combustion engine on a pure electric vehicle in order to reduce vehicle pollution and improve the mileage of the pure electric vehicle. Hybrid electric vehicles have two structural forms: series and parallel. ? Hybrid electric vehicle (also known as hybrid electric vehicle) refers to a vehicle equipped with more than two power sources, including motor drive, which conforms to automobile road traffic and safety regulations. There are many kinds of vehicle-mounted power sources: batteries, fuel cells, solar cells and diesel locomotive generator sets. At present, hybrid electric vehicle generally refers to diesel locomotive generator plus battery. The advantages of hybrid electric vehicles are: 1. The maximum power of internal combustion engine can be determined according to the average required power after using hybrid electric vehicle, and it works under the best working conditions of low fuel consumption and less pollution. When the high power required by the internal combustion engine is insufficient, it is supplemented by the battery; When the load is small, the surplus power can generate electricity to charge the battery. Because the internal combustion engine can work continuously and the battery can be charged continuously, its journey is the same as that of an ordinary car. 2. Because of the battery, it is very convenient to recover energy when braking, downhill and idling. 3. In busy urban areas, the internal combustion engine can be turned off and driven only by batteries to achieve "zero" emissions. 4. With the internal combustion engine, it is convenient to solve the high energy consumption problems such as air conditioning, heating and defrosting encountered by pure electric vehicles. 5, you can use the existing gas station to refuel without investment. 6, can keep the battery in good working condition, without overcharge and overdischarge, prolong its service life and reduce the cost. Hybrid electric vehicles have two basic working modes, namely series, parallel and series-parallel (or series-parallel). The disadvantages of hybrid electric vehicle are: there are two sets of power, plus two sets of power management and control systems, which have complex structure, great technical difficulty and high price. With the "New Generation Automobile Partnership" (P NGV) program promoting the three major American automobile companies to screen and compare hundreds of schemes of various unit technologies and their different organizations, it is considered that hybrid power is a feasible scheme to realize the fuel consumption of 3 liters per 100 kilometers for mid-size cars, which has attracted more attention. After years of research, hybrid electric vehicles have developed some successful examples. Toyota Motor Corporation of Japan announced in February 1997 that P rius, a hybrid vehicle, would be put into commercial production in small batches. Vehicle weight 15 15kg, equipped with four-cylinder overhead camshaft, 1500cc displacement gasoline engine, maximum power of 42.6 kW/4600 r/min, and no permanent magnet. The rated power of the driving motor is also 30kW, and the series-parallel control mode is realized by using Ni-MH battery. The fuel consumption per 100 kilometers is 3.4L, which is reduced by half compared with the original gasoline vehicle, and the C O2 displacement is also reduced by half. However, C O, HC and NOX are only 65,438+00% of the allowable values in the current laws and regulations, and the price of each vehicle is 2,654,380+06,000 yen (about 65,438+05,000 US dollars). Chrysler Automobile Company of the United States exhibited the second generation Dodge Fearless E SX2 hybrid electric vehicle in Detroit in February 1998. The car is equipped with 1500cc direct injection diesel engine, with generator, lead-acid battery, AC induction motor drive, aluminum frame, composite body, dead weight 1022kg, and fuel consumption of 3.4L per 100 kilometers. In 2000, GM, Ford, DaimlerChrysler have developed 65,438+000 km prototypes, which consume 3 liters of gasoline or nearly 3 liters, but are expensive.

Talk about HEV

Hev (Hybrid Electric Vehicle)-A hybrid power device. Hybrid power refers to two driving modes: gasoline driving and electric driving. The advantage is that when the vehicle starts and stops, it is only driven by the generator. If a certain speed is not reached, the engine will not work. Therefore, the engine can always keep the best working condition, with good power and low emission. And the source of electric energy is the engine, just need to refuel.

The key of hybrid electric vehicle is hybrid power system, and its performance is directly related to the performance of hybrid electric vehicle. After more than ten years of development, the hybrid power system assembly has changed from the initial.

The discrete structure of engine and motor has developed into the integrated structure of engine, motor and gearbox, that is, integrated hybrid power system. Hybrid power system according to the power transmission route classification, can be divided into series,

Parallel and series.

Series power: Series power consists of three parts: engine, generator and motor, which are connected in series to form the SHEV power unit system, and the engine drives to generate electricity.

The machine generates electricity, and the electric energy is transmitted to the battery or motor through the controller, and the motor drives the car through the speed change mechanism. When the load is low, the battery-driven motor drives the wheels, and when the load is high, the motor drives the wheels.

The generator generates electricity to drive the motor. When the vehicle is in starting, accelerating and climbing conditions, the engine, the motor set and the battery pack provide electric energy to the motor in the same direction; When the electric vehicle is at a low speed,

When taxiing and idling, the battery pack drives the motor, and when the battery pack is insufficient, the engine generator set charges the battery pack. The series structure is suitable for frequent starting and low-speed driving in cities.

In the working state, the engine can be adjusted to run stably near the optimal working point, and the vehicle speed can be adjusted by adjusting the output of the battery and the motor. So that the engine can avoid idling and low speed.

Operating conditions, thereby improving the efficiency of the engine and reducing exhaust emissions. But its disadvantage is that the energy is converted several times and the mechanical efficiency is low.

Parallel power: the engine and motor of the parallel device jointly drive the automobile, and the engine and motor belong to two systems, which can provide torque to the automobile transmission system independently.

On the same road, you can drive together or alone. When the car accelerates climbing, the motor and the engine can provide power for the transmission mechanism at the same time. Once the vehicle speed reaches the cruising speed,

The car will only rely on the engine to maintain this speed. The motor can be used as both a motor and a generator, also known as a motor-generator set. Since there is no separate generator, the engine

The wheels can be directly driven by the transmission mechanism. This device is closer to the traditional automobile drive system, and the mechanical efficiency loss is almost the same as that of ordinary cars, so it is widely used.

Series-parallel power supply: Series-parallel devices include series and parallel features. The power system includes engine, generator and motor. According to different supercharging devices, it can be divided into engines as follows

There are two main types: main type and motor type. In the form of engine, the engine is the main power source and the motor is the auxiliary power source; In the form of an electric motor, the engine is used as an auxiliary power source, and the electric motor

As the main energy source. The advantage of this structure is easy to control, but the disadvantage is that the structure is more complicated. Toyota Prius belongs to the motor-based form.

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At present, the commonly used fuel engine cars have various shortcomings. Statistics show that an ordinary car only plays 40% of its power potential under more than 80% of the road conditions, and it is still in the urban area.

It will drop to 25%, and more seriously, it will emit waste gas and pollute the environment. Since the 1990s, the voice of countries all over the world for improving environmental protection has been growing, and various electric vehicles have emerged. although

However, it is generally believed that the future will be dominated by electric vehicles, but the current battery technology problems hinder the application of electric vehicles. Because the energy density of the battery is hundreds of times worse than that of gasoline, which is far from it.

To the required value, experts estimate that electric vehicles will not replace fuel-engine vehicles in 10 years (unless there is a major breakthrough in fuel cell technology).

Reality forces engineers to think of a way to kill two birds with one stone and develop hybrid cars. So-called hybrid power equipment

Installation is to combine the motor and auxiliary power device on the car as the driving force. The auxiliary power unit is actually a small fuel engine or generator set. Figuratively speaking, yes

Make the traditional engine as small as possible and let the battery-motor system bear part of the power. This hybrid power device not only gives full play to the advantages of long continuous working time and good power performance of the engine, but also can

Give full play to the advantages of pollution-free and low noise of the motor, and the two will "fight side by side" to learn from each other's strengths. The automobile thermal efficiency can be increased by more than 65,438+00%, and the exhaust emission can be increased by more than 30%.

According to the forms of energy synthesis, hybrid electric vehicles are mainly divided into series (SHEV) and parallel (PHEV).

Series power consists of three parts: engine, generator and motor, which are connected in series to form the power unit system of SHEV. When the load is small, it is driven by battery.

The engine drives the wheels to rotate, and when the load is heavy, the engine drives the generator to generate electricity to drive the motor. When an electric vehicle starts, accelerates and climbs a hill, the engine-motor unit and the battery pack are the same.

Providing electric energy to the motor; When the electric vehicle is at low speed, coasting and idling, the battery pack drives the motor, and the engine generator set charges the battery pack. This series of electric vehicles does not

Under what working conditions, the motor will eventually drive the wheels. For example, Ford's "new energy level-2065438+00" SHEV uses fuel cells, which are used when driving in urban areas.

Drive the motor, which drives the wheels through the reducer (transmission) and the drive axle to achieve the requirement of "zero emission". When climbing a hill at high speed, an engine-motor unit and a fuel cell stack are used.

* * * Power is supplied to the motor in the same direction to drive the wheels.

The parallel engine and motor drive the car by mechanical energy superposition. Engine and motor belong to two systems, which can independently provide torque for automobile transmission system.

On different roads, you can drive at the same time or independently. The motor can be used as both a motor and a generator, also known as a motor-generator set. Because there is no separate generator

The engine can directly drive the wheels through the transmission mechanism, so the device is closer to the traditional automobile drive system and is widely used. For example, Volkswagen's golf PHEV,

The engine drives the motor-generator through clutch 1, and outputs torque to drive the vehicle through clutch 2 on the other side. During static start-up, the battery supplies power to the motor generator. At this time, the motor-

The generator is the starter of the engine. After the engine is started, on the one hand, it drives the wheels as an independent power source of the vehicle, on the other hand, it drives the motor generator to generate electricity and charge the battery.

It's like a traditional car at this time. When driving in urban areas, the engine stops, the clutch 1 is disengaged, and the clutch 2 is engaged. As the only energy source, the battery supplies power to the motor, and the motor drives instead of the engine.

Move the steering wheel. When the electric vehicle needs high speed or high load, the engine starts the clutch 1 to close, and the engine and motor-generator system form a composite drive form to drive the vehicle with maximum power.

Hybrid electric vehicles have become increasingly mature in developed countries, and some have entered the practical stage. Due to the complex structure and high cost, before the advent of the era of electric vehicles, hybrid electric vehicles

It's just a transitional product.

In addition, electric vehicles

Electric vehicle (electric vehicle)

Electric vehicle refers to a vehicle that is powered by on-board power supply and driven by motor and meets the requirements of road traffic and safety regulations. Generally, high-efficiency rechargeable batteries or fuel cells are used as power sources. Electric vehicles do not need to use internal combustion engines. Therefore, the motor of an electric car is equivalent to the engine of a traditional car, and the battery is equivalent to the original fuel tank. Because electric energy is secondary energy, it can come from wind energy, water energy, heat energy, solar energy and other ways. The advantage of electric vehicles is that they do not emit harmful gases that pollute the atmosphere. Even if it is converted into power plant emissions according to electricity consumption, other pollutants except sulfur and particulate matter are obviously reduced. Because most power plants are built far away from densely populated cities, it is less harmful to human beings, and power plants are fixed and discharge centrally. It is easy to remove all kinds of harmful emissions, and related technologies have been developed. Because electricity can be obtained from various primary energy sources, such as coal, nuclear energy, water power and so on. People's worries about the exhaustion of oil resources have eased. Electric vehicles can also make full use of the remaining electricity when the electricity consumption is low at night, so that the power generation equipment can be fully utilized day and night, greatly improving its economic benefits. Studies have shown that the same crude oil, after rough refining, is sent to power plants to generate electricity, and then charged into batteries to drive cars. Its energy utilization efficiency is higher than that of refined gasoline and then driven by gasoline engine, so it is conducive to saving energy and reducing carbon dioxide emissions. It is these advantages that make the research and application of electric vehicles a "hot spot" in the automobile industry.

The difficulty of electric vehicles is that the energy stored in the battery per unit weight is too little at present, and the battery of electric vehicles is expensive, which does not form an economic scale, so it is expensive to buy. As for the use cost, some trial results are more expensive than cars, and some results are only 1/3 of cars, mainly depending on battery life and local oil and electricity prices.

Battery is the primary key to the development of electric vehicles, and it is difficult for automobile power batteries to meet the requirements of "low cost", "high capacity" and "high safety". In order to widely use electric vehicles, we must rely on advanced batteries, which have been screened by 10 for many years. At present, Ni-MH batteries, iron batteries, lithium-ion batteries and lithium polymer batteries are generally optimistic. Ni-MH battery has twice as much energy storage per unit weight as lead-acid battery, and other properties are also better than lead-acid battery. However, the current price is 4-5 times that of lead-acid batteries, and efforts are being made to reduce it. Iron battery is made of iron, which is rich in resources and low in price, greatly reducing the cost, and is also adopted by some manufacturers. Lithium is the lightest metal and has very active chemical characteristics. The energy storage per unit weight of lithium-ion battery is three times that of lead-acid battery and four times that of lithium polymer battery. Moreover, lithium is rich in resources and not very expensive, so it is a promising battery. China has made rapid progress in the industrial development of nickel-hydrogen batteries and lithium-ion batteries. Other related technologies of electric vehicles have also made great progress in recent years, such as AC induction motor and its control, rare earth permanent magnet brushless motor and its control, battery and vehicle energy management system, intelligent fast charging technology, low resistance tires, lightweight and low wind resistance body, braking energy recovery and so on. These technological advances make electric vehicles more and more perfect and practical. The air pollution in big cities of China can't be ignored, and automobile exhaust is one of the main pollution sources. There are 10 cities in China, which are listed as the 20 cities with the most serious air pollution in the world. At present, China's per capita car ownership is per 100 people 100 cars, but the oil resources are insufficient, and tens of millions of tons of oil are imported every year. With the development of economy, if the per capita car ownership in China reaches the current global level-1100 /65438 people, then the car ownership in China will become 65438. Therefore, the research and development of electric vehicles in China is not a temporary short-term measure, but a significant and long-term strategic consideration.

structure

Electric vehicle consists of six parts: chassis, body, battery pack, motor, controller and auxiliary facility battery. Because the motor has good traction characteristics, the transmission system of the battery car does not need clutches and transmissions. Speed control can be realized by the controller changing the speed of the motor through the speed regulation system.

I am now developing an air electric vehicle, which is equipped with an air compressor and solar energy to realize the combination of green energy and modern technology.