Voltage monitoring method
There are two main methods for detecting the voltage of the power battery: distributed detection and centralized detection. The two detection methods have their own advantages and disadvantages. Generally, a comprehensive collection method of “concentrating first and then distributing” is adopted.
Taking 72 battery cells as an example, it is divided into 6 groups, each group has 12 battery cells, and a detection module is used for each group of batteries to carry out “centralized” detection. The whole system is connected by several detection modules through CAN bus. The essence is that the detection unit is partially modularized and localized.
The voltage acquisition wire is connected to the BMS voltage acquisition module through the CAN bus. After high-voltage isolation and digital-to-analog conversion inside the BMS, the voltage of the battery pack is converted into digital data, and the SOC calculation is made to judge whether the battery pack is normal. If the voltage is lower than the set value and the current is still being discharged, an alarm will be issued.