Introduction to the working principle, types, advantages and disadvantages of new energy vehicles
Electric vehicle refers to a vehicle driven by on-board power supply and driven by motor, which meets the requirements of road traffic and safety regulations. As the impact on the environment is relatively small compared with traditional cars, its prospects are widely optimistic, but the current technology is not yet mature.
Operating principle of electric vehicle
Working principle: battery – current – electric regulator – motor – power transmission system – driving the vehicle (Road).
Category of electric vehicles
According to the current technical state and vehicle driving principle, electric vehicles can be divided into three types: BEV, HEV and FCEV. Their working principles are slightly different.
Blade Electric Vehicles
A car driven by an electric motor. Compared with fuel vehicles, the main difference (difference) of pure electric vehicles lies in four parts: driving motor, speed regulation controller, power battery and on-board charger. Compared with the gas station, it consists of a public super fast charging station. The quality difference of pure electric vehicles depends on these four components, and their value also depends on the quality of these four components. The use of pure electric vehicles is also directly related to the selection and configuration of the four major components.
The speed per hour and starting speed of a pure electric vehicle depend on the power and performance of the driving motor. The length of its driving range depends on the capacity of the on-board power battery. The weight of the on-board power battery depends on which power battery is selected, such as lead-acid, zinc carbon, lithium battery, etc. Their size, proportion, specific power, specific energy, and cycle life are all different. This depends on the manufacturer's positioning and use of the vehicle grade, market definition and market segmentation.
The drive motors of pure electric vehicles include DC brush, brushless, permanent magnet, electromagnetic, and AC step motor. Their selection is also related to the vehicle configuration, purpose, and grade. In addition, the speed control of the drive motor can also be divided into step speed regulation and stepless speed regulation, and can be divided into electronic speed regulation controller and non speed regulation controller. The motors include hub motor, inner rotor motor, single motor drive, multi motor drive and combined motor drive.
Advantages and disadvantages of pure electric vehicles
Advantages: The technology is relatively simple and mature. It can be charged wherever there is power supply.
Disadvantages: The energy stored in the storage battery per unit weight is too small, and because the batteries of electric vehicles are expensive and there is no economic scale, the purchase price is relatively expensive. As for the use cost, some use prices are more expensive than cars, and some prices are only 1/3 of cars, which mainly depends on the battery life and local oil and electricity prices. The electric vehicle technology is still immature, and the charging technology, range, reliability and other aspects still need to be improved. The disposal of discarded batteries and the optimization of the power grid system are also key problems to be solved.
Hybrid electric vehicle
It refers to the vehicle that can obtain power from at least the following two types of on-board stored energy: consumable fuel or rechargeable energy, and energy storage device. According to the structural form of power system, it can be divided into the following three categories:
Series hybrid electric vehicle (SHEV): a hybrid electric vehicle whose driving force only comes from the electric motor. The structural feature is that the engine drives the generator to generate electricity, the electric energy is transmitted to the motor through the motor controller, and the motor drives the vehicle. In addition, the power battery can also provide electric energy to the motor independently to drive the vehicle.
Parallel hybrid electric vehicle (PHEV): a hybrid electric vehicle whose driving force is supplied by the motor and engine simultaneously or separately. The structural feature is that the parallel drive system can use the engine or motor alone as the power source, or simultaneously use the motor and engine as the power source to drive the vehicle.
Hybrid electric vehicle (CHEV): a hybrid electric vehicle with both series and parallel drive modes. The structure features that it can work in the series hybrid mode and also in the parallel hybrid mode, taking into account the characteristics of both series and parallel.
Note: With the development of hybrid electric vehicle technology, its types are not limited to the above, but can also be classified according to other types.
Those that usually use traditional fuels are equipped with motors and engines to improve low-speed power output and fuel consumption. In the domestic market, the mainstream of hybrid vehicles is gasoline hybrid vehicles, while diesel hybrid vehicles in the international market are also developing rapidly.
Advantages of hybrid vehicles
1. After using hybrid power, the maximum power of internal combustion engine can be determined according to the average required power. At this time, it works under the optimal working condition of low fuel consumption and less pollution. When the power of high-power internal combustion engine is insufficient, it shall be supplemented by batteries; 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 continuously charged, its journey is the same as that of ordinary cars.
2. With the battery, it is very convenient to recover the energy during braking, downhill and idling.
3. In the downtown area, the internal combustion engine can be shut down and driven by the battery independently 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, defrosting, etc., which consume a lot of energy.
5. The existing gas stations can be used for gas filling without further investment.
6. It can keep the battery in good working condition without overcharge and overdischarge, extend its service life and reduce costs.
Disadvantages of hybrid electric vehicles: they can hardly save fuel when driving at high speed for long distances.
Fuel cell vehicle
A vehicle powered by a fuel cell. The chemical reaction process of the fuel cell will not produce harmful products, so the fuel cell vehicle is a pollution-free vehicle, and the energy conversion efficiency of the fuel cell is 2-3 times higher than that of the internal combustion engine. Therefore, the fuel cell vehicle is an ideal vehicle in terms of energy utilization and environmental protection.
A single fuel cell must be combined into a fuel cell pack to obtain the necessary power and meet the requirements of vehicle use. Compared with traditional vehicles, fuel cell vehicles have the following advantages:
1. Zero or near zero emissions.
2. The water pollution caused by oil leakage is reduced.
3. Reduce greenhouse gas emissions.
4. Improved fuel economy.
5. The combustion efficiency of the engine is improved.
6. Stable operation without noise.
Among these new energy vehicles, the most energy-saving one is the fuel cell vehicle. Its fuel source is endless. The product after combustion is only water, and the range can reach 700 kilometers. Due to the imperfect technology, it is currently in the test and promotion stage. The second is pure electric vehicles, which use a wide range of electric energy sources and low use costs. At present, most of the market are electric vehicles. The third is plug-in hybrid and incremental hybrid, which can save energy in pure electric state, but consume a lot of fuel in pure oil state. For ordinary hybrid, it is essentially a gasoline vehicle, just allowing the gasoline engine to work more time in the efficient range.