With the continuous improvement of domestic air pollution control intensity in recent years, heavy-duty diesel vehicles have gradually become the focus of environmental protection departments. In particular, the coverage of new energy in the field of passenger vehicles is becoming wider and wider. Almost every brand has been involved in the research and development of new energy models, and heavy-duty diesel vehicles have also begun to develop in the direction of electric drive. Therefore, the electric semi-trailer came into the sight of car owners.

Electric semi-trailer means that the tractor of semi-trailer adopts the form of electric drive, which uses electric drive instead of fuel drive.

After the adoption of electric drive, the operating cost of vehicles will certainly decrease. Especially on the premise of the continuous rise of fuel price, the cost of power consumption is far lower than that of fuel consumption, and the economic benefit is very obvious; In addition, in terms of emissions, because the fuel drive is replaced, the vehicle can basically achieve zero emissions, and the benefits in environmental protection are also very considerable; In addition, the electric drive of semi-trailer can also reduce noise, facilitate gear shifting, reduce vibration, greatly improve the driving environment of car owners, and protect goods and reduce cargo damage to a certain extent.

Compared with the fuel semi-trailer, the electric semi-trailer also has an advantage, that is, the vehicle data is easier to collect and upload, which can further improve the technical service, optimize the energy supply in the transportation field, and realize the application of unmanned technology in closed scenes such as mines and ports.

No matter from which of the above levels, electric semi-trailer seems to have incomparable advantages of fuel vehicles, which is in line with the development trend of the industry. However, the electric semi-trailer has appeared on the market around 2017. Why did it not realize large-scale application? Mainly because of the following five aspects:

1. Vehicle self weight.

Generally, the electric semi-trailer is heavier than the same type of fuel semi-trailer, mainly because the electric semi-trailer needs to load more batteries. Because semi trailers are different from passenger cars, their main function is transportation, and they have high requirements for endurance. Taking an electrically driven 6x4 tractor as an example, its battery weight can reach about 3T, which increases the dead weight of the vehicle to a certain extent.

2. Slow charging speed and low charging efficiency.

The charging speed of electrically driven semi-trailer has always been an industry disadvantage. Generally speaking, an electric semi-trailer adopts the method of slow charging, which takes about several hours to fill; If the fast charging method is adopted, it will take at least nearly an hour to fill up, and there will be some damage to the battery, which is indeed much slower than the efficiency of going to the gas station to refuel.

3. Charging is inconvenient.

As we all know, it is not particularly convenient to charge new energy passenger vehicles in many cities, especially on highways. There are few charging piles, let alone new energy commercial vehicles, which largely leads to the reluctance of transportation owners to buy electric semi-trailer vehicles, especially medium and long-distance owners.

4. Limited endurance.

Although more batteries are equipped in the vehicle design in order to extend the endurance capacity of electric semi-trailer, due to the low energy density of battery, its endurance mileage can not meet the medium and long-distance transportation needs of heavy semi-trailer to a great extent.

5. The cost of buying a car is on the high side.

As a new model, although electric semi-trailer has limitations in many aspects, its price is still much higher than that of ordinary fuel semi-trailer, which also makes many car owners stop buying.

The above five reasons affect the popularity of electric semi-trailer to a great extent.

Objectively speaking, if it is used for Intercity short-distance transportation or fixed logistics shuttle bus, electric semi-trailer is still more appropriate, but if it is medium and long-distance transportation or heavy cargo transportation, the electric drive is limited to a certain extent.

In this case, hybrid semi trailers appear one after another. Compared with purely electric driven semi-trailer models, hybrid semi-trailer combines new energy with fuel power, such as oil electric hybrid semi-trailer, plug-in hybrid semi-trailer and incremental electric semi-trailer. It uses electric drive when charging is convenient and sufficient, and uses fuel drive when charging is inconvenient in high-speed environment. Although such models can make up for some insufficient support of pure electric semi-trailer, they can not get rid of their dependence on fuel, energy conservation and emission reduction are not ideal, the technology is complex, and the price remains high. Whether they can meet the use needs of vehicle owners still needs to be verified by the market.

However, whether it is fuel semi-trailer, electric semi-trailer or hybrid semi-trailer, lightweight is a common trend. Choosing lightweight axles is one of the important ways to realize vehicle lightweight. According to the calculation data of Darong group, using Darong's new disc brake lightweight axles can reduce the weight of each axle by about 15% on average compared with ordinary axles, which can not only reduce the body weight, but also help to save fuel, reduce tire damage and reduce the cost of comprehensive vehicles. The average price of Darong standard disc brake axle is about 6500 yuan, which is ultra-high cost performance, Let car owners spend less money and use higher quality axles.