When the development of automobiles to the era of electrification, some automated functions began to appear, such as automatic driving, automatic parking, automatic connection and so on. However, for the charging link that is crucial for electric vehicles every day, the automated charging function has not yet been realized.
So in the future car experience, can we experience "non-perceptual automatic charging", and how to achieve it? Is it the development route of charging equipment in the future? What kind of changes can it bring to the current charging equipment?
Wireless charging is difficult to popularize, why is it still pushing?
The charging methods we currently know include traditional fast charging, slow charging, and power exchange services that are accelerating popularization. But in the future we may face an insensible way of charging - automatic charging.
Then this charging method, there are currently several solutions given, the first is a continental solution, similar to a solution for wireless charging; the second is a charging robot that can move autonomously. After that, Volkswagen also had this similar conceptual product, but how to achieve it has not yet been announced.
So how are the solutions mentioned above implemented?
The solution given by Continental is an inductive charging solution, which requires the installation of charging components on the chassis and ground of the car, and the two components are automatically linked to achieve conductive charging. The identification function between the two charging components is to rely on ultra-wideband short-distance radio communication to detect each other, which has the characteristics of concentration, strong anti-interference, high transmission speed and good confidentiality, ensuring the fast and efficient link between the car end and the charging end.
It seems to be more similar to wireless connection charging in the traditional sense, but the hard wire connection between the charging end and the car end limits the charging loss and improves the overall charging efficiency. The two versions planned to be launched correspond to the two versions for home and commercial, and correspond to two versions of 22kW AC and DC charging above 50kW.
The charging power is not very high, what is the impact? 22kW and 50kW For the current electric vehicles, such charging power is not particularly fast, the current DC charging pile is generally 60, 80, 90kW or higher power. But then again, although the power of the charging pile increases, it is also limited by the voltage that the vehicle can accept and the thermal management limit of the BMS battery of the electric vehicle.
Therefore, the power of 22kW and 50kW is enough to charge most of the current electric vehicles, but it is not clear whether the charging power of this hard-link mode has the same charging efficiency as the fast charging pile; in addition, for example, high-energy density batteries and 800V architecture models may be far from enough.
Volvo gave a wireless charging solution in 2019, with a maximum charging power of 40kW, and the charging model is equipped with a battery with a capacity of 69kWh, which takes about 100 minutes to fill. In contrast, wired charging is more efficient.
Between wired charging and wireless charging, slow charging, regardless of the loss of power transmission, seems to be on par; while radio charging, often with wired charging, is more wasteful. From the perspective of fast charging, the level of output power, wired charging in the high power charging segment can hang wireless charging, which is also one of the reasons why wireless charging (including floor and chassis hard link mode) has not been rolled out in a large area.
We must admit that wireless charging is indeed more convenient than wired charging, and can be insensible charging, but the disadvantage is that the power is low, the charging efficiency is slow, and there is a certain gap with the current DC fast charging pile. The wireless charging technology of electric vehicles has had a prototype of mass production many years ago, but in the end there was no large-scale commercial application, because there was no high charging power, so it did not get a wide range of applications.
Charging robot, more reliable than wireless charging?
The second possibility is a robot that can move autonomously. The underlying logic is well understood, through its own perception device + automatic driving algorithm to achieve the link with the car end, in the existing example, it can carry a battery with a capacity of 70kWh, a power of 42kW, and an electric vehicle with a range of 600km for 2 hours.
First of all, the charging power of this product has been equated with the power of the fast charging pile, and the charging mode is no different from the fast charging pile through the charging interface of the car end, but it is a power supply that can be moved. Therefore, we can think of it as the "shared charging treasure" model used by mobile phones. Obviously, this is not a high-frequency application scenario, but can only solve the urgent needs of one need, is a transitional solution.
Then this charging mode will be easier to apply than the wireless charging mode above. For example, the basements of old residential areas and shopping malls did not reserve the location of independent charging piles in the early stage of construction, and the cost of transformation in the later stage was slightly higher. If there is a charging robot, it can be divided into a charging area, and the mobile charging robot can be managed and charged separately, which is a very practical application scenario.
In addition, for example, remote areas may not have a very popular infrastructure, or the power grid cannot support the construction of high-power charging piles. Then the charging robot can also be used to complete the charging of the vehicle, and it can reach the charging power of ordinary fast charging piles, and will not bring pressure to the power grid. There is no need for large-scale retrofitting of existing hardware, and it is also possible to charge pure electric vehicles at low cost. In addition to suppliers, the Volkswagen Group, a vehicle company, also has similar concept products, but it has not yet been mass-produced.
It can be seen as a transitional electric vehicle energy supply solution, and it is necessary to move the charging robot in the above use scenarios. The high cost of site renovation is eliminated, and the grid pressure caused by charging piles is solved, but what is the problem that this charging mode needs to face?
It is necessary to establish a stable, reliable and safe signal link between the car end and the power end, and it is necessary to match the different models of batteries of various battery suppliers, and later iterations of products may introduce versions corresponding to different power and density. Finally, the safety problem of this charging robot can be used traditional air-cooled or more advanced liquid cooling technology to solve the problem of overheating of charging equipment.
summary
The above two major types of charging modes, the first wireless charging (including hard link mode) is a bit chicken ribs, the reason is that its charging power is far less than the charging pile, and the charging process may also have power losses, which is also one of the reasons why there is no large-scale popularity so far.
The second charging mode has a charging power similar to that of the fast charging pile, and the charging mode is also the same as the charging pile, but the carrier is different; the application scenarios are diversified, flexible and other characteristics, which may be more widely used.