Range anxiety is the biggest bottleneck restricting the prosperity of the electric vehicle market, and the meaning behind the careful analysis of range anxiety is "short endurance" and "slow charging". At present, in addition to battery life, it is difficult to make breakthrough progress, so "fast charge" and "supercharge" are the focus of the current layout of various car companies. So the 800V high voltage platform came into being.
For ordinary consumers, the 800V high-voltage platform promoted by car companies is only a technical term, but as an important technology in the future, it is also related to the consumer's car experience, and we should have a general understanding of this new technology. Therefore, this paper will conduct an in-depth analysis of the 800V high-pressure platform from different aspects such as principle, demand, development and landing.
Why do you need an 800V platform?
In the past two years, with the gradual increase in the number of electric vehicles, the number of charging piles has risen simultaneously, but the pile ratio has not decreased. By the end of 2020, the "car-pile ratio" of domestic new energy vehicles is 2.9:1 (the number of vehicles is 4.92 million and the number of charging piles is 1.681 million). In 2021, the ratio of car to pile will be 3:1, which will not decrease but increase. The result is that the queue time is longer than the charging time.
Then in the case of the number of charging piles can not keep up, in order to reduce the occupation time of charging piles, fast charging technology is very necessary.
The increase in charging speed can be simply understood as the increase in charging power, that is, P = U·I in P (P: charging power, U: charging voltage, I: charging current). Therefore, if you want to increase the charging power, keep one of the voltage or current unchanged, increasing the voltage or current can improve the charging power. The introduction of the high voltage platform is to improve the charging efficiency of the vehicle end and realize the rapid recharge of the vehicle end.
The 800V platform for electric vehicles is the mainstream choice for fast charging. For power batteries, fast charging is essentially to increase the charging current of the cell, also known as the charging ratio; At present, many car companies are in the layout of 1000 kilometers of driving range, but the current battery technology, even if it is developed to solid-state batteries, it also needs the power battery pack with more than 100kWh, which will lead to an increase in the number of cells, if the mainstream 400V platform continues to be used, the number of parallel cells increases, resulting in an increase in bus current. It brings great challenge to copper wire specification and heat pipe tube.
Therefore, it is necessary to change the series parallel structure of the battery cells in the battery pack, reduce the parallel and increase the series, in order to increase the charging current while maintaining the platform current in a reasonable level range. However, as the number of series increases, the battery pack end voltage will be increased. The voltage required for the 100kWh battery pack to achieve 4C fast charge is about 800V. In order to be compatible with the fast charging function of all levels of models, 800V electrical architecture is the best choice.
Post time: Sep-18-2023