Battery management system (BATTERY MANAGEMENT SYSTEM), electric vehicle battery management system (BMS) is the link between the battery and the user, the main object is the secondary battery. Secondary batteries have the following shortcomings, such as low energy storage, short life, serial and parallel use problems, safety in use, and difficulty in estimating battery power. The performance of the battery is very complicated, and the characteristics of different types of batteries are also very different. The battery management system (BMS) is mainly to improve the utilization rate of the battery, prevent the battery from being overcharged and over-discharged, extend the service life of the battery, and monitor the status of the battery. With the development of the battery management system, other functions will be added.
Generally speaking, the electric vehicle battery management system must realize the following functions:
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.
Dynamically monitor the working status of the power battery pack:
In the process of battery charging and discharging, the terminal voltage and temperature, charging and discharging current and total voltage of the battery pack of each battery in the electric vehicle battery pack are collected in real time to prevent the battery from being overcharged or overdischarged. 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.
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.