Low voltage charging technology of 800V battery for V2G electric vehicle

With the gradual popularization and development of electric vehicle (EV), people's requirements for battery lifespan of EV are gradually increasing. Therefore, some researchers propose to increase the battery voltage of the vehicle to 800V. However, the increase of voltage also means the increase of voltage stress and loss in the circuit, in order to charge 800V batteries at a low voltage, a method is proposed by this study. On the basis of using the optimized 400V DC/DC converter, the charging circuit is divided into two 400V modules by adding the Battery Selection Circuit (BSC), and only one battery is charged at a time, which greatly reduces the voltage stress of the devices in the BSC. In addition, turning off the DC/DC converter will allow it to be separated from the BSC, so that the switching frequency of the BSC is designed independently of the previous converter. Finally, the effectiveness of the low-voltage charging technology is verified by simulation experiments.