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Introduction
Improving mechanical efficiency and reducing energy consumption are the cornerstones for electric vehicles to go further.
Author 丨 Deng Yongtuo
Responsible editor 丨 Luo Chao
Editor 丨Zhu Jinbin
"We were able to produce a Model S with a range of almost 1,000 kilometers as early as 12 months ago, but I think that would make the product worse because most of the time you would carry an extra weight battery and it would be less accelerated, handled and efficient."
Whether it is the big guys in the car circle or the consumer group, there has been a debate about whether electric vehicles need to have a cruising range of more than 1,000 kilometers. Tesla CEO Musk once said on social platforms that it does not make sense for electric vehicles to have too high range. From the perspective of existing technical ideas, long-lasting electric vehicles must be based on larger capacity batteries, and larger batteries will increase the weight of the body structure, which will have an impact on endurance.
This seems to have entered a dead loop of thinking. However, Mercedes-Benz offers a different line of thinking.
Recently, a mercedes-Benz test has become a hot topic. A brief review, Mercedes-Benz's new pure electric concept car VISION EQXX completed an endurance test of more than 1,000 kilometers with "one box of electricity", which was completely completed in the real traffic environment, through multiple road conditions such as high-speed and mountain roads, and through a variety of complex climates. The total distance is 1008 km/ h, with an average speed of 87.4 km/h and an average energy consumption of only 8.7 kWh/100 km/ h.
By the time we reach the established finish line in Cassis, France, there is about 15% of the remaining electricity, or about 140 kilometers of cruising range. This long-distance test of 11 hours and 32 minutes not only allows Mercedes-Benz to show the king posture of "uncle is still uncle" in the electric field, but also leads the energy consumption level of electric vehicles to a new height, giving people who sing about the decline of electric vehicles a beautiful counterattack. Specifically, what efforts Mercedes-Benz has made to improve endurance.
Energy efficiency is the latest weapon
The VISION EQXX isn't the first electric car to hit the 1,000km, and before that, both the AION LX Plus and NIO ET7 had launched "Maxima" versions, but they both needed larger batteries. Mercedes-Benz did not refresh the battery capacity to a new height, but emphasized that energy efficiency is the "hard currency".
First of all, it is to reduce the resistance. Unless it is possible to fly in the sky, air resistance and rolling resistance are always the biggest obstacles to the speed of ground vehicles. Vision EQXX has a wind resistance coefficient of Only 0.17 cd and a windward area of only 2.12 square meters. In contrast, the EQS has a wind resistance coefficient of 0.2, a windward area of 2.51 square meters for the front face, and an effective air resistance area of only 0.5 square meters. As a result, the air resistance of the VISION EQXX will be further reduced.
In addition, vision EQXX uses energy-efficient oriented tires with lower rolling resistance. Mercedes-Benz and Bridgestone have tailored a set of low roll-drag tires from the Turanza Eco series. And the size design of the narrow tire width and large diameter commonly used in electric models, 20 inches tire diameter, but the tire width is only 185 mm. Combined with the fully enclosed wheel shape and the air breather wind curtain composed of ventilation holes on the front wrapping sides and fenders, the EQXX tire roll resistance coefficient is only 4.7.
Secondly, weight loss is also very critical. On the body of vision EQXX, Mercedes-Benz uses lightweight composite materials and one-piece bionic casting structure to reduce weight on the body. For example, the doors are made of a mixture of carbon fiber, fiberglass and aluminium, and the battery top cover is made of sustainable carbon fiber-sugarcane composites derived from the Formula 1 racing process. Lightweight monomer castings replace heavy parts made up of splicing multiple parts, reducing weight by 20 percent compared to traditional processes.
Weight reduction measures in batteries cannot be ignored either. The VISION EQXX is equipped with a dedicated battery pack with nearly 100 kWh of energy, which is almost the same as the battery power of the overseas version of the EQS, while the battery pack is reduced by 50%, the size is only 200 x 126 x 11 cm, the mass is reduced by 30%, and it weighs only 495 kg, which makes it enough to be placed in a compact model. With such a combination punch, the total weight of the VISION EQXX is only 1755 kg, which is only slightly heavier than a medium-sized fuel vehicle.
Finally, it has to be mentioned that the VISION EQXX has amazing transmission efficiency. As a Mercedes-Benz who has competed in FE and F1 for many years and achieved excellent results, he understands the importance of mechanical efficiency. To this end, Mercedes-Benz in the development of each system, from the system design, material selection, lubrication and thermal management and other aspects of the system loss as much as possible, so as to achieve VISION EQXX up to 95% of the system transmission efficiency, the extremely high transmission efficiency has become a guarantee of low energy consumption.
Inject a cardiotonic agent into the tram
In today's rapid development of electric vehicle technology, even though many people have discovered the better side of electric vehicles, such as intelligence, tranquility and riding space, it can be said that they can be said to be all-round better than the same level of fuel vehicles, but endurance and energy replenishment are still the biggest shortcomings.
The endurance of pure electric vehicles has become the last knot of consumers' hesitation, and the problem of endurance and energy replenishment has also become the focus of research on major automobile brands. Nowadays, more than one Mercedes-Benz company claims that the new car can exceed 1,000 kilometers, but GAC Aeon and Weilai have only reported the mileage under THEDC working conditions, and the mileage in the real open road environment may have to be discounted.
In general, this endurance test covers the conditions that a household electric vehicle will often face in terms of road environment and weather conditions. Many of them are cruising at high speeds of 140 km / h, which is quite unfavorable to the endurance of electric vehicles, so it can better reflect the user's real car situation. Therefore, in such a test, the mileage can be achieved to break through 1000 kilometers, which undoubtedly injects a shot of strength into users who are anxious about the range of electric vehicles.
Taking a step back, whether 1000 km is necessary or not, it gives a certain advantage in terms of user use. Just like the performance of the vehicle, it exudes an attitude about whether today's increasingly powerful power is necessary, that is, whether it is used or not is not the same thing. At least, under the condition of such endurance, the journey of walking is probably also achievable on electric vehicles.
In vision EQXX, Mercedes-Benz can be said to be more about the pursuit of low energy consumption of electric vehicles, just like if you want to jump far, you must take off and jump high, and long endurance is only an accessory. The energy consumption of 8.7 kWh/100 km is almost equivalent to the theoretical data of Wuling MINIEV, and Mercedes-Benz can be said to give a "textbook" answer to how to achieve long battery life. Improving energy efficiency and reducing energy consumption than larger capacity batteries are the essential basis for electric vehicles to travel farther.
Effective effort is strength
Referring to the current commercially available models, the 1000 km endurance versions of NIO ET7 and ET5 are equipped with 150 kWh batteries with an average energy consumption of 15 kWh/100 km under theoretical conditions; the NEDC range of the AION LX Plus is 1008 km, the battery capacity is 144.4 kWh, and the average energy consumption is 14.44 kWh/100 km. The energy consumption of the open road environment is often higher, and the measured energy consumption of the VISION EQXX is more than 30% less than the theoretical value of these models.
It is true that vision EQXX is still a concept car, although its design and functional design and other aspects are fully in line with the production of regulatory requirements and market requirements, but a concept car investment and research and development can not be measured, its pursuit of cost and the mass production car to the market is not comparable.
Secondly, VISION EQXX uses a lot of top materials to reduce weight, from the lightweight subframe of F1, and the UBQ innovative material sealing patch made by 3D printers. On the roof, 117 solar panels can supplement the equivalent of 25 kilometers of battery energy, and these materials can be imagined to increase the cost price sharply. In the future, further efforts may be needed to further compress the manufacturing costs of these innovative designs and reach a price level acceptable to the civilian market.
However, with this test by VISION EQXX, it can be verified that Mercedes-Benz's research on electric vehicles is successful. Efficient energy management systems for passive and active cooling, as well as recommendations for the most efficient driving style based on multiple information such as energy flow, power, terrain, etc., can be put into use directly on the relevant models. When effort becomes valuable, it is a strength in itself.
In addition, the 400 WWh/L high-density battery and the first application of the 900 volt high-voltage battery system are an improvement in the efficiency and time of energy replenishment. In fact, whether it is from the flagship electric sedan EQS that has been listed in China, to the new concept car VISION EQXX, to the just unveiled EQS SUV, Mercedes-Benz is trying to fill the gap between electric vehicles and fuel vehicles, and in the future, electric vehicles may be able to do better.
From the results of this test by VISION EQXX, it can be seen that Mercedes-Benz's understanding of how electric vehicles can extend the range is aimed at pursuing lower energy consumption. This is in line with Mercedes-Benz's sustainable development goals for the future energy transition and also allows the entire vehicle to have a lower carbon footprint over its life cycle. Whether it is from transmission efficiency or drag reduction and weight reduction, it is inseparable from the exploration and pursuit of the ideal of how to achieve lower energy consumption for electric vehicles.
Perhaps, this is the re-"invention" of electric vehicles by automobile inventors in the process of new energy transformation.
| Deng Yongtuo |
Not a big problem, there is no fear of cars.