Dad: 800V fast charging principle is to transfer large current to the vehicle's power battery at a specific time, because the DC charging pile uses three-phase four-wire power supply, it can provide enough power, and the output voltage and current adjustment range is large, which can achieve the requirements of fast charging.
Fast charging, as a method and way of quickly supplementing the power of the vehicle, is the core part of the electric vehicle and the most important indispensable part.
According to the principle of fast charging, in fact, fast charging is to transfer the electricity through the grid through the charger, through negotiation with the power battery management system BMS on the electric vehicle, it is simple to say that the charging pile makes itself temporarily a part of the car battery management system. According to the current state of the battery, BMS adopts intelligent control algorithm to implement the subsection adjustment of the charging current pulse width, intermittent time and discharge current pulse, and modulates the appropriate current and voltage to complete the charging.
And in the charging process, the charging current will be reduced with the charging process, the initial large current can be charged faster, that is, the concentrated high voltage (10kV) is introduced, converted into direct current, access to large battery packs. If we compare the lithium-ion battery to a bridge, the two ends of the bridge are the poles of the battery, and lithium ions are like crossing the bridge, and they need to run back and forth on the two ends of the bridge.
800v fast charge principle: power P= current I* voltage u, in order to achieve fast charging, improve the charging power of the mobile phone, it is necessary to increase the charging current or voltage, or both. There are two fast charging schemes: high voltage fast charging and high current fast charging, of which the former is Qualcomm's QC fast charging technology. High voltage fast charge will have a secondary decompression treatment, so it will cause high energy loss during the decompression process. High current requires the strengthening of charging lines and circuits, and the selection range of wires is not as good as that of high-voltage schemes.
In fact, fast charging is not directly related to 800V, mainly because the charging rate of the battery is higher, allowing greater power charging, which itself has nothing to do with 800V, just like Tesla's 400V platform, but it can also achieve super fast charging in the form of high current.
But 800V is to achieve high-power charging provides a good foundation, because the same to achieve 360kW charging power, 800V theory only needs 450A current, if it is 400V, it needs 900A current, 900A in the current technical conditions for passenger cars is almost impossible. Therefore, it is more reasonable to link 800V and super fast charge together, called 800V super fast charge technology platform.