The difference between DC charging piles and AC charging piles

The difference between DC charging piles and AC charging piles

1.Charging principle of charging piles

The charging pile is fixed on the ground, using a special charging socket, and selecting a transmission method to give AC electromagnetic energy to new energy electric vehicles with on-board chargers, and obtain corresponding communication, charging and security guarantees. The masses only need to buy IC cards and recharge online, and they can use charging piles for car charging piles.

After the battery of the new energy electric vehicle is discharged, the battery is restored to the working level according to the battery in the opposite direction of the discharge current, which is called battery charging.

2. The charging method of the charging pile has constant current flow

The constant current charging method should be used to adjust the charging power supply voltage or adjust the series resistor with the battery to maintain the eternal charging current value of the battery. The control measures are simple, but because the current force that can be accepted by the battery is gradually reduced with the development of the battery charging process, in the middle and late stage of battery charging, the current is generally used for the electrolysis of water, causing vapor and excessive gas, so the link charging method is often used.

The working voltage of the charging power supply maintains a relatively stable standard value during all battery charging times, and the current flow decreases day by day with the gradual increase of the DC voltage of the battery. Compared with the constant current charging method, the whole process of battery charging is closer to a good charging curve. Fast charging with stable working voltage, because the battery induced EMF is relatively low in the early stage of battery charging, the current is very large, and the current will decrease day by day with the charging development, so only a simple automatic control system is required.

3. The difference between DC charging piles and AC charging piles

DC electric vehicle charging station, also known as "fast charging", is fixed installed outside the new energy electric vehicle, connected to the AC power grid, and can provide DC power supply system equipment for non-on-board electric vehicle power batteries. The input voltage of the DC charging pile is 380V±15% of the three-phase four-wire AC380V, and the working frequency is 50Hz, which is exported as adjustable DC power to immediately charge the driving power battery of the new energy vehicle. Because the DC charging pile uses a three-phase and four-wire power supply system, it can provide sufficient output power, and the output current and voltage adjustment range are wide, which can realize the demand for fast charging.

AC new energy electric vehicle charging piles, also known as "slow charging", are fixed and installed outside the new energy electric vehicles, connected to the AC power grid, and provide AC power supply system equipment for the on-board chargers of new energy electric vehicles (that is, battery chargers installed in new energy electric vehicles). AC charging piles will provide power engineering export, and there is no charging function, and they need to be connected to the on-board charger to charge the electric vehicle.