Battery management system, electric vehicle battery management system (BMS) is an important link connecting vehicle power battery and electric vehicle, and its main functions include:

1. Real-time monitoring of battery physical parameters;

2. Battery status estimation;

3. Online diagnosis and early warning;

4. Charge, discharge and precharge control;

5. Balance management and thermal management, etc.

The development of the battery management system (BMS) industry may be similar to that of lithium batteries. In order to master key technologies, automakers will work closely with long-term cooperative suppliers to develop products, making it difficult for new entrants to enter. In the process of battery charging and discharging, real-time collection of the terminal voltage and temperature of each battery in the battery pack of the electric vehicle (should be a power battery pack), charging and discharging current and the total voltage of the battery pack, to prevent the battery from overcharging or overdischarging. .

Generally speaking, the electric vehicle battery management system must realize the following functions:

1. Accurately estimate the state of charge of the power battery pack

Accurately estimate the State of Charge (SOC) of the power battery pack, that is, the remaining battery capacity, to ensure that the SOC is maintained within a reasonable range, and prevent damage to the battery due to overcharge or overdischarge, so as to predict hybrid power at any time How much energy is left in the car's energy storage battery or the state of charge of the energy storage battery.

2. Dynamically monitor the working status of the power battery pack

In the process of battery charging and discharging, real-time collection of the terminal voltage and temperature of each battery in the battery pack of the electric vehicle (should be a power battery pack), charging and discharging current and the total voltage of the battery pack, to prevent the battery from overcharging or overdischarging. . At the same time, the battery status can be given in time, the problematic battery can be selected, and the reliability and efficiency of the entire battery group can be maintained, making the realization of the remaining power estimation model possible. In addition, it is necessary to establish a history file of each battery to provide information for further optimization and development of new types of electricity, chargers, motors, etc., and to provide a basis for offline analysis of system failures.

3. Balance between single cells

That is, the single battery is charged in a balanced manner, so that each battery in the battery pack reaches a balanced and consistent state. Equalization technology is the key technology of a battery energy management system that is currently being researched and developed in the world.