[Charge pile principle] electric vehicle charging pile principle Secret DC charging pile and AC charging pile difference
 1, charging pile charging principle
Charging pile fixed to the ground, the use of special charging interface, using conduction mode, for the car charger with electric vehicles to provide AC power, with the corresponding communication, billing and security features. The public only need to buy IC card and recharge, you can use the charging pile for the car charge.
Electric car battery discharge, with DC and discharge current in the opposite direction through the battery, so that it can restore the ability to work, this process is called battery charging. When the battery is charged, the positive pole of the battery is connected with the positive pole of the power supply. The negative pole of the battery is connected with the negative pole of the power supply. The charging power supply voltage must be higher than the total electromotive force of the battery.
2, charging pile charging method
Charging methods are constant current charging and constant voltage charging two.
Constant current charging method
Constant current charging method is to adjust the charging device output voltage or change with the battery series resistance method, to maintain the charging current intensity of the same charging method. The control method is simple, but because the battery's current capacity is gradually decreased with the charging process, to the end of the charge, the charging current is used for electrolysis of water, resulting in gas, so that the gas is too much, so often use stage charging method.
Constant voltage charging method
The voltage of the charging power supply is kept constant at all charging times. As the battery voltage gradually increases, the current gradually decreases. Compared with the constant current charging method, the charging process is closer to the best charging curve. Fast charge with a constant voltage, due to the initial charging battery electromotive force is low, the charging current is very large, with the charge, the current will gradually reduce, therefore, simply control the system.
3, DC charging pile and AC charging pile difference
DC charging pile: DC electric car charging station, commonly known as "fast charge", it is fixed in the electric car, and AC power grid connection, can be non-vehicle electric vehicle power battery to provide DC power supply device. DC charging pile input voltage using three-phase four-wire AC380V ± 15%, frequency 50Hz, the output is adjustable DC, directly for the electric vehicle power battery charge. As the DC charging pile with three-phase four-wire power supply, can provide sufficient power, the output voltage and current adjustment range, you can achieve fast charge requirements.
AC charging pile: AC electric car charging pile, commonly known as the "slow charge", fixedly installed in the electric car, and AC power grid connection for the electric car car charger (that is fixed on the electric car charger) to provide AC power Of the power supply device. AC charging pile only provides power output, no charging function, need to connect the car charger for the electric car charging. Equivalent to just play a role in controlling the power supply.
The difference between the two: In simple terms, AC charging pile need to use the car charger to charge, DC fast charge pile does not need this equipment. The two in the charging speed is quite different, a pure electric vehicle (ordinary battery capacity) after the full discharge through the AC charging pile filled with 8 hours, and through the DC fast charge pile only need 2 to 3 hours. AC charging pile to the electric vehicle charger to provide power input, because the car charger power is not large, it can not achieve fast charging. DC fast charging pile is fixed outside the electric vehicle, connected with the AC power grid, can be non-vehicle electric vehicle power battery to provide DC power supply device, DC charging pile can provide sufficient power, the output voltage and current adjustment range , Can achieve fast charge requirements.