What is a charging pile?
The charging pile, as the name suggests, is used to charge our electric vehicles, and it acts like a refueling machine in a gas station to refuel the fuel truck. Charging piles can be fixed on the ground or on the wall, installed in major public Spaces, residential areas and charging stations, and then charge various models of electric vehicles according to different voltage levels. People can use the specific charging card on the human-computer interactive interface provided by the charging pile to swipe the card and carry out the corresponding charging mode, charging time, cost data printing and other operations. The charging pile display screen can display the charging amount, cost, charging time and other data.
How to charge the charging pile?
Charging an electric vehicle with a charging pile is actually charging the battery in an electric vehicle. The charging principle is that after the battery is discharged, direct current is used to pass the battery in the opposite direction of the discharge current, so that it can restore its working ability, this process is called battery charging. When the battery is charged, the positive electrode of the battery is connected to the positive electrode of the power supply, the negative electrode of the battery is connected to the negative electrode of the power supply, and the charging power supply voltage must be higher than the total electromotive force of the battery. Generally speaking, the charging pile has two charging methods, namely constant current charging and constant voltage charging. In a new version of the terminology for electric vehicles implemented on May 1, the two charging methods are defined: constant-current charging, which charges the battery with a controlled constant current; Constant voltage charge, a way to charge a battery at a controlled constant voltage. So what is constant current charging and constant voltage charging?
Constant current charging method: Constant current charging method is the method of adjusting the output voltage of the charging device or changing the series resistance with the battery to keep the charging current strength unchanged. The control method is simple, but because the acceptable current capacity of the battery is gradually decreased with the charging process, to the late charging, the charging current is mostly used for electrolyzing water, producing gas, so that the gas is too much, therefore, the stage charging method is often used.
Constant voltage charging method: The voltage of the charging power supply maintains a constant value during the whole charging time, and the current gradually decreases with the gradual increase of the battery terminal voltage. Compared with the constant current charging method, the charging process is closer to the optimal charging curve. Fast charging with constant voltage. Due to the low electromotive force of the battery at the early stage of charging, the charging current is very large, and the current will gradually decrease with the charging process, so it only needs a simple control system.
What are the types of charging piles?
At present, there are two kinds of common charging piles on the market, one is DC charging pile and the other is AC charging pile.
Dc charging pile: DC charging pile is fixed in some public places outside electric vehicles, such as residential areas, residential parking lots, commercial areas, service areas, outdoor parking lots, electric vehicle charging stations and other places. It is a charging device that provides DC power to non-on-board electric vehicle batteries by connecting to the public grid. Because the DC charging pile can directly charge the battery of the electric vehicle, generally using the three-phase four-wire system or three-phase three-wire system power supply, the output voltage and current can be adjusted to a large range, so it can achieve fast charging of electric vehicles, DC charging pile is also called fast charging. Due to the large output power, the general specifications of DC charging pile are 30kW, 60kW, 80kW, 120kW, 150kW, 180kW, etc.
Ac charging pile: AC charging pile is also fixed in some public places outside the electric vehicle, providing a controllable one-way AC power supply or three-phase AC power supply device for the on-board charger of the electric vehicle. It should be noted that the AC charging pile itself does not have a charging function, it simply provides power output, and can charge the battery of the electric vehicle by connecting the on-board charger of the electric vehicle. Since the power of electric vehicle on-board chargers is generally relatively small, the AC charging pile cannot achieve fast charging, and the AC charging pile is therefore called slow charging. Ac charging pile output power will not be very large, generally 3.5kW, 7kW, 15kW and so on.
Difference: There are two differences between DC charging piles and AC charging piles. First, when charging, the DC charging pile can directly charge the battery of the electric vehicle, so there is no need for the car charger, and the AC charging pile can not directly charge the battery of the electric vehicle, so the car charger is needed. The second is the difference between the charging time, the charging speed of the DC charging pile is faster, generally for the electric vehicle battery full charge only takes dozens of minutes to two or three hours, and the AC charging pile for the electric vehicle battery full charge time will be much longer, generally takes about eight hours.
