What to do about the surge problem in OBC communication charging

Vehicle mounted charger (OBC) is an important electronic device that connects AC charging stations and converts AC electricity into DC electricity. AC charging, also known as "slow charging", refers to the charging station that supplies single-phase AC (220V) or three-phase AC (380V) current from the AC power grid to the on-board charger (OBC) installed in the vehicle. The OBC can convert AC power into DC power to charge new energy vehicles.

一、Some common problems encountered in OBC AC charging

During the charging process, there may be a charging interruption, abnormal alarm, or malfunction of the car audio, air conditioning system, etc.

二、 Brother Leiditech analyzes the reasons

Based on the phenomenon of warranty products returned by customers and EMC's participation in rectification analysis, it was found that these issues were caused by surge issues. For example:

1）If the input voltage surge exceeds the design range of the OBC, the OBC may detect abnormalities and interrupt the charging process.

2）OBC may issue abnormal alarms through the vehicle's control system, indicating input voltage surges or other issues.

3）Severe input voltage surges may cause damage or malfunction of the OBC circuit.

4）The issue of input voltage surge may have an impact on other electrical devices in the vehicle, such as the car audio system, air conditioning system, etc.

三、 Brother Leiditech recommends the following protection solutions to solve the problem

AC 220V 380V AC power surge protection scheme

Advantages of the solution: Used for surge protection of 220V and 380V AC power supply interfaces, different levels of protection devices are selected according to the environment of the power supply, and meet the testing requirements of different levels of 4KV~8KV in IEC61000-4-5.

The above parameters may be adjusted specifically based on the line parameters.

Shanghai Leiditech Electronics provides customers with electromagnetic compatibility EMC design services and laboratory testing for free