Classification of electric cars
Types of electric vehicles: Battery Electric Vehicles (BEV), Hybrid Electric Vehicles (HEV), Fuel Cell Vehicles (FCEV).
Battery electric vehicle
Battery Electric Vehicle (BEV): A vehicle powered by an electric motor. The driving power of the electric motor comes from the on-board rechargeable battery or other energy storage device. Such as Tesla. Most of the vehicles are directly driven by electric motors. Some vehicles have the electric motor installed in the engine compartment, and some vehicles directly use the wheels as the rotors of the four electric motors. The difficulty lies in the power storage technology. It does not emit harmful gases that pollute the atmosphere. Even if the power consumption is converted into the emission of power plants, other pollutants except sulfur and particulates are also significantly reduced. Since most of the power plants are built far from densely populated cities, the harm to human beings is relatively low. In addition, the power plant is stationary, and it is easy to remove all kinds of harmful emissions because of centralized emissions, and related technologies are also available. Since electricity can be obtained from a variety of primary energy sources, such as coal, nuclear energy, water power, wind power, light, heat, etc., people's worries about the depletion of oil resources are relieved. Electric vehicles can also make full use of the surplus 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. Relevant studies have shown that the same crude oil is crudely refined, sent to power plants to generate electricity, charged into batteries, and then driven by batteries, the energy utilization efficiency is higher than that after refining into gasoline, and then driving vehicles through gasoline engines, 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 automotive industry. Some experts believe that for electric vehicles, the biggest obstacle at present is that infrastructure construction and price affect the process of industrialization. Compared with hybrid electric vehicles, electric vehicles require more infrastructure support, which cannot be solved by one company. , it needs all enterprises to unite and build together with local government departments, and then there will be opportunities for large-scale promotion.
Advantages: The technology is relatively simple and mature, and it can be charged wherever there is power supply.
Disadvantages: At present, the energy stored per unit weight of the battery is too small, and because the battery of the electric vehicle is more expensive and has not formed an economic scale, the purchase price is more expensive. As for the cost of use, some are more expensive than the car, and some are only the price of the car. 1/3, which mainly depends on the life of the battery and the local oil and electricity prices.
A hybrid vehicle is a vehicle capable of obtaining power from at least the following two types of on-board stored energy:
— consumable fuel;
- Rechargeable energy/energy storage devices.
According to the structure of the power system, it can be divided into the following three categories:
Series Hybrid Electric Vehicle (SHEV): A hybrid (electric) vehicle in which the driving force of the vehicle is derived only from the electric motor. The structural feature is that the engine drives the generator to generate electricity, and the electric energy is transmitted to the motor through the motor controller, and the motor drives the car to run. In addition, the power battery can also provide electric power to the electric motor alone to drive the car.
Parallel Hybrid Electric Vehicle (PHEV): A hybrid (electric) vehicle in which the driving force of the vehicle is supplied by the electric motor and the engine at the same time or separately. The structural feature is that the parallel drive system can use the engine or the motor as the power source alone, and can also use the motor and the engine as the power source to drive the car.
Hybrid Hybrid Vehicle (CHEV): A hybrid (electric) vehicle with both series and parallel drive modes. The structural feature is that it can work in the series hybrid mode or in the parallel hybrid mode, taking into account the characteristics of the series and parallel modes. (Note: With the development of hybrid electric vehicle technology, its types are not limited to the above, and can also be divided into other types.)
Those currently typically run on conventional fuels, coupled with an electric motor/engine to improve low-speed power output and fuel consumption. At present, in the domestic market, the mainstream of hybrid vehicles is gasoline hybrid, and diesel hybrid vehicles in the international market are also developing rapidly.
1. After the hybrid power is adopted, the maximum power of the internal combustion engine can be determined according to the average required power. At this time, it works under the optimal working conditions of low fuel consumption and less pollution. When the power of the high-power 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. Since the internal combustion engine can work continuously, the battery can be continuously charged, so its journey is the same as that of an ordinary car.
2. Because of the battery, it is very convenient to recover the energy during braking, downhill, and idling.
3. In prosperous urban areas, the internal combustion engine can be turned off and driven by the battery alone to achieve "zero" emissions. 4. With the internal combustion engine, it is very convenient to solve the problems encountered by pure electric vehicles such as air conditioning, heating, and defrosting, which consume a lot of energy.
5. You can use existing gas stations to refuel without having to invest again.
6. It can keep the battery in a good working condition without overcharging and overdischarging, prolonging its service life and reducing costs.
Disadvantages: Long-distance high-speed driving basically does not save fuel.
Fuel cell vehicle
Fuel cell vehicle: a vehicle that uses fuel cells as its power source. The chemical reaction process of fuel cells does not produce harmful products, so fuel cell vehicles are pollution-free vehicles, and the energy conversion efficiency of fuel cells is 2 to 3 times higher than that of internal combustion engines. Therefore, from the perspective of energy utilization and environmental protection, fuel cell vehicles are An ideal vehicle. Individual fuel cells must be combined into fuel cell stacks in order to obtain the necessary power to meet the requirements of vehicle use. Significant progress has been made in fuel cell technology in recent years. World-renowned car manufacturers, such as Daimler-Chrysler, Ford, Toyota and General Motors, have announced plans to put fuel cell vehicles on the market by 2004. Currently, fuel cell car prototypes are being tested, and fuel cell-powered transport buses are being demonstrated in several North American cities. There are still technical challenges in developing fuel cell vehicles, such as the integration of fuel cell stacks, increasing commercialization of electric vehicle fuel processors, and ancillary divisions. Automakers are all working toward integrating components and reducing component costs, and have already Significant progress has been made.
Compared with traditional vehicles, fuel cell vehicles have the following advantages:
1. Zero or near zero emissions.
2. Reduced water pollution caused by oil leakage.
3. Reduced greenhouse gas emissions.
4. Improved fuel economy.
5. Improved engine combustion efficiency.
6. Smooth and noiseless operation.