Detailed explanation of the working principle of electric vehicle charging system

With the restrictions on traditional fuel vehicles and the introduction of the national double-point policy, people will have to consider accepting new energy vehicles in the future. At present, the mainstream domestic new energy vehicles include pure electric vehicles and hydrogen fuel cells. Among them, pure electric vehicles account for the main proportion. Many people worry about the long charging time, fewer charging piles, and inconvenient charging when buying electric vehicles. There are also some electric vehicle customers who often encounter some problems when using charging piles.

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1. AC slow charging pile

There are mainly standing and wall-mounted AC slow charging piles. There are also other installation methods. Generally speaking, there are indoor and outdoor AC slow charging piles, and the outdoor protection level is higher. But the principle is the same, that is, to provide AC 220V voltage to the on-board charger. An AC charging pile can also be called an AC power supply device. In addition to the power supply device, it also has a cable assembly, that is, a connecting device composed of a cable and a power supply plug. The cable device has the CC resistance value required by the national standard, and the power supply device also has a control guide module, which can output the CP signal according to the connection status.

2. Car charger

The on-board charger converts the 220V AC power of the grid into a high-voltage DC power suitable for the vehicle voltage platform. The power of common car chargers is mostly 6.4KW, and the peak current can reach 20A. Among them, the maximum allowable single-phase input of AC is 32A AC current. Because the car charger is also efficient, the power that can charge the whole car is about It is about 6.4KW. Generally, the voltage of the national grid cannot reach 220VAC during the peak period of electricity consumption, so the output power of the charger cannot reach the rated power. At this time, the charging time will be longer, but slow AC charging is beneficial to prolong the life of the power battery. If you are not particularly anxious, it is a wise choice to use slow communication.

3. Power battery

According to different materials, power batteries can be divided into lead-acid batteries, ternary lithium batteries, nickel-hydrogen fuel cells, etc. In comparison, lead-acid batteries are heavier and have low capacity density; ternary lithium batteries have mature technology and relatively high energy density. The current technical route is common in the market; nickel-hydrogen batteries are difficult to promote due to their high cost. Lithium battery charging is divided into three stages, trickle stage, constant current stage, constant voltage stage, and the terminal charging current is very low, about 5A, so the whole vehicle charging is generally from 30% to 80%. Because the time is ideal, the process from 80% to 100% is still very long.

4. Endurance mileage

The currently claimed cruising range is probably more than 200, but this cruising range is related to personal driving habits and the use of other power consumption of the vehicle. For example, your cruising range in high-speed driving conditions will definitely be better than NEDC operating conditions. The cruising range of driving down is short. This shows that electric vehicles are more suitable for low-speed driving and can better serve the city.

Post time: Mar-24-2021