The Secret of Electric Vehicle Charging Pile

At present, there are two types of car charging piles on the market, AC charging piles and DC charging piles. DC charging pile, commonly known as "fast charging", the input voltage of the DC charging pile adopts three-phase four-wire AC 380 V ±15%, the frequency is 50Hz, and the output is adjustable DC, directly charging 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 (3.5KW, 7KW, 11KW, 21KW, 41KW, 60KW, 120KW, 200KW or even higher), and the output voltage and current can be adjusted in a large range. To meet the requirements of fast charging. It takes about 20 to 150 minutes to fully charge a car, so it is generally installed at a charging station next to a highway for the occasional needs of users on the way.

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. However, its cost is far higher than that of AC piles. DC piles require large-scale transformers and AC-DC conversion modules. In addition, large-scale DC charging stations have a certain impact on the power grid. High-current protection technologies and methods are more complicated, and the transformation, installation and operation costs are higher. . And the installation and construction are more troublesome. Due to the relatively large charging power of the DC charging pile, the requirements for power supply are relatively high, and the transformer must have sufficient load capacity to support such a large power, and many places do not have the 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.

For us, the DC charging pile is a relatively large project, the power is too large, it takes a long time, and requires more funds, and after it comes out, the DC charging pile is more prone to fire than the AC charging pile, so we don’t do too much research. We mainly look at AC charging piles.

AC charging piles are divided into household charging piles and shared charging piles. The main difference between the home charging pile and the shared charging pile is that there is an additional communication module in the shared charging pile. Whether it is 4G communication or WiFi communication, after scanning the code or swiping the card, the fee will be deducted to give the hardware signal, and then start charging the car. So here we only discuss other specifications of the AC charging pile.

At present, AC charging piles on the market have national standard, European standard, and American standard according to the charging interface, so how to distinguish them?

The first and second pictures are national standard, with a total of 7 holes; the third and fourth pictures are American standard (American standard is mainly 120V and 240V), with a total of 5 holes. The fifth and sixth pictures are the European standard, the European standard and the national standard, and the American standard are different. The charging gun is a male socket, and the charging interface is a female socket. The rated voltage of the European standard is generally 230V. European standard charging gun (single-phase and three-phase current divided into 16A and 32A) American javelin 16A 32A 40A (regardless of single-phase and three-phase) National javelin (single-phase and three-phase) current 16A and 32A.

At present, when we use the portable charging gun, we must pay attention to the thickness of the charging cable. The 10A socket may be connected to a 1.5 square pure copper cable, which cannot carry the charging power of the 16A charging gun (the 16A socket is connected to a 2.5 square pure copper electricity). Be careful, otherwise it may cause short circuit or fire.

General charging guns have: anti-leakage, lightning protection, anti-short circuit, anti-overcurrent, anti-overheating, grounding protection.

The charging current of the portable charging gun generally has 5 levels: 6A, 8A, 10A, 13A, 16A, and a few have 32A.