Electric vehicle charging principle:

The power battery of the electric vehicle can only receive direct current (DC) voltage, while the power grid/household outlets provide alternating current, which can't directly charge the battery of the vehicle. It needs AC-DC conversion, and the converted DC can charge the battery. All alternating current (AC) charging piles are only the power supply lines of charging equipment (OBC), although they may be very intelligent power supply lines; The power module is integrated in the direct current (DC) pile, AC-DC conversion is carried out in the pile, and the direct current is output to charge the battery.

The alternating current (AC) pile supplies power for OnBoard Charger: OBC), and the on-board charger carries out AC-DC rectification conversion to charge the power battery; While the direct current (DC) pile directly charges the battery.

Standard classification:

Different charging guns and vehicle charging interfaces can't be used universally. The current standards are formulated by automobile industry countries and important market countries: Europe/America/Japan/China. There are three standards for AC charging interface: American/Japanese Type 1, European Type 2 and China GB/T. There are four standards for DC charging interface, namely: CCS 1 in the United States (North America), CHAdeMO in Japan, CCS 2 in Europe and GB/T in China. Other countries in the world basically follow American/European standards.

Power classification:

The power of the charging pile ranges from 1kW to 500kW. Common charging piles have 3kW portable pile (AC) power level; 7/11kW Wallbox(AC), 22/43kW AC column pile, 20-350 or even 500kW DC pile.

The (maximum) power of the charging pile is the maximum possible power it can provide for the battery. The algorithm is voltage (V)x current (A), and three phases are multiplied by 3. 1.7/3.7kW refers to the charging pile with the maximum current of 16A in single-phase power supply (110-120V or 230-240V), and 7kW/11kW/22kW refers to the charging pile of single-phase power supply 32A and three-phase power supply 16/32A respectively. Voltage is easy to understand. Household voltage standards and current are generally the standards of existing electrical infrastructure (sockets, cables, insurance, power distribution equipment, etc.). North America, especially the United States, is a special market. There are many types of American household sockets (NEMA sockets in shape, voltage and current), so the power level of AC charging piles in American households is more and more abundant.

The power of DC piles mainly depends on the internal power module (internal parallel connection). At present, there are 20/25/30kW modules in the mainstream, so the power of DC piles is a multiple of the above modules. However, it is also considered to match the charging power of electric vehicle batteries, so 50/100/120kW DC charging piles are very common in the market.