Analysis of Principles and Characteristics of Electric Vehicle Car Charger

Analysis of Principles and Characteristics of Electric Vehicle Car Charger

The car charger is also called an AC charger. It is installed on an electric car. It is connected to an AC outlet through a socket and a cable, and provides charging power to the electric car with a three-phase or single-phase AC power supply. The advantage of the car charger is that the car battery can be charged at any time and anywhere, as long as there is an AC outlet with the rated voltage of the charger. The disadvantage of the car charger is that it is limited by the space of the electric car, the power is small, the output charging current is small, and the battery is charged for a long time. Figure 6-1 shows the connection between the car charger and the charging power supply.

Principle and characteristics of electric vehicle car charger

The car charger mainly supplements the electric energy of the small electric vehicle, and the charging power is small. The electric charging car built on the roadside, the community, etc. can be used to charge the electric vehicle, and the charging in the low valley period is fully utilized.

1, the principle structure

The input of the vehicle charger is based on the active power factor correction circuit. The electrical principle is shown in Figure 6-16, and the appearance is shown in Figure 6-17.

2, functional characteristics

(1) It has the ability to safely and automatically charge the electric vehicle battery. The charger can dynamically adjust the charging current or voltage parameters according to the data provided by the battery management system (BMS), and perform corresponding actions to complete the charging process.

(2) It has the function of high-speed CAN network and BMS communication, judging whether the battery connection status is correct, obtaining the battery system parameters and real-time data of the whole group and single battery before charging and during charging.

(3) It can communicate with the vehicle monitoring system through the high-speed CAN network, upload the working status, working parameters and fault alarm information of the charger, and accept the start charging or stop charging control commands.

(4) Complete safety protection measures.

1) AC input overvoltage protection function.

2) AC input under voltage alarm function.

3) AC input over current protection function.

4) DC output over current protection function.

5) DC output short circuit protection.

6) Output soft start function to prevent current surge.

7) During the charging process, the charger can ensure that the temperature, charging voltage and current of the power battery do not exceed the allowable value.

8) With single cell voltage limit function, the charging current is automatically adjusted according to the BMS battery information.

9) Automatically judge whether the charging connector and charging cable are properly connected. When the charger is properly connected to the charging post and the battery, the charger can start the charging process; when the charger detects that the charging pile or the battery is not connected properly, the charging is stopped immediately.

10) The charging interlock function ensures that the vehicle cannot be started before the charger is separated from the electric vehicle power battery.

11) High-voltage interlock function, when there is a high voltage that is harmful to personal safety, the module locks no output.

12) Has a flame retardant function.