Charging pile refers to a charging device that provides energy supplement for electric vehicles. Its function is similar to that of a fuel dispenser in a gas station. It can be fixed on the ground or wall and installed in public buildings (public buildings, shopping malls, public parking lots, etc.) and residential areas In the parking lot or charging station, various types of electric vehicles can be charged according to different voltage levels. The input end of the charging pile is directly connected to the AC grid, and the output end is equipped with a charging plug for charging the electric vehicle.
At present, there are two common charging piles on the market, one is DC charging pile and the other is AC charging pile. DC charging piles: DC charging piles are fixedly installed in some public places outside electric vehicles, such as residential quarters, 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 for off-board electric vehicle batteries by connecting to the public grid.
Charging Pile Classification
According to the installation method, it can be divided into floor-mounted charging piles and wall-mounted charging piles. Floor-mounted charging piles are suitable for installation in parking spaces that are not close to walls.
According to the installation location, it can be divided into public charging piles and special charging piles. Public charging piles are charging piles built in public parking lots (garages) combined with parking spaces to provide public charging services for social vehicles.
According to the number of charging ports, it can be divided into one pile for one charge and one pile for multiple charges.
DC charging pile: DC electric vehicle charging station, commonly known as “fast charging”, is fixedly installed outside the electric vehicle and connected to the AC power grid. A power supply device that provides DC power from the power battery of an off-vehicle electric vehicle. The input voltage of the DC charging pile adopts three-phase four-wire AC380V±15%, the frequency is 50Hz, and the output is adjustable DC, which can directly charge the power battery of the electric vehicle. Since the DC charging pile is powered by a three-phase four-wire system, it can provide sufficient power, and the output voltage and current can be adjusted in a large range, which can meet the requirements of fast charging.
AC charging pile: AC electric vehicle charging pile, commonly known as “slow charging”, is fixedly installed outside the electric vehicle and connected to the AC grid. ) A power supply unit that provides AC power. The AC charging pile only provides power output and has no charging function. It needs to be connected to the car charger to charge the electric car. It is equivalent to just playing the role of controlling the power supply.
The difference between the two: Simply put, the AC charging pile needs to be charged with the help of a car charger, while the DC fast charging pile does not need this device. There is a huge difference in charging speed between the two. It takes 8 hours for a pure electric vehicle (ordinary battery capacity) to be fully charged through an AC charging pile, but only 2-3 hours through a DC fast charging pile. The AC charging pile provides electric energy input for the charger of the electric vehicle. Due to the low power of the car charger, fast charging cannot be achieved.
Advantages of charging piles:
1. It can provide convenient fast charging service for electric vehicles. The use of charging piles can help all electric vehicles to complete fast charging services, and no matter how far the speed of driving is, there will be no embarrassment of running out of power. There will be charging piles in many places. Build fixed-point services.
2. Can promote the continuous development of new energy
3. It can better protect electric vehicles from overcharging
Disadvantages of charging piles:
First of all, the cost of AC charging piles is low, the construction is relatively simple, and the load requirements on the transformer are not large, and the power distribution cabinets in the community can be installed directly. Simple structure, small size, can be hung on the wall, portable and can be carried in the car. The maximum charging power of the AC charging pile is 7KW. As long as it is an electric vehicle, it generally supports AC charging. Electric vehicles have two charging ports, one is a fast charging interface and the other is a slow charging interface. The charging interface of some non-national standard electric vehicles may only use AC, and DC charging piles cannot be used.
The input voltage of the DC charging pile is 380V, the power is usually above 60kw, and it only takes 20-150 minutes to fully charge. DC charging piles are suitable for scenarios that require high charging time, such as charging stations for operating vehicles such as taxis, buses, and logistics vehicles, and public charging piles for passenger cars. But its cost far exceeds the exchange pile. DC piles require large-volume transformers and AC-DC conversion modules. The manufacturing and installation cost of charging piles is about 0.8 yuan/w, and the total price of 60kw DC piles is about 50,000 yuan (excluding civil engineering and capacity expansion). In addition, large-scale DC charging stations have a certain impact on the power grid, and the high-current protection technology and methods are more complicated, and the cost of transformation, installation and operation is higher. And the installation and construction are more troublesome. Due to the relatively large charging power of DC charging piles, the requirements for power supply are relatively high, and the transformer must have sufficient load capacity to support such a large power. Many old communities do not have wiring and transformers laid out in advance. with installation conditions. There is also damage to the power battery. The output current of the DC pile is large, and more heat will be released during charging. High temperature will lead to a sudden decrease in the capacity of the power battery and long-term damage to the battery cell.
To sum up, DC charging piles and AC charging piles each have their own advantages and disadvantages, and each has its own application scenarios. If it is a newly built community, it is safer to directly plan DC charging piles, but if there are old communities, then use the charging method of AC charging piles, which can meet the charging needs of users and will not cause great damage to the transformer in the community load.
