Is BMS lithium battery pack management system also called lithium battery protection board?

2021-09-02 08:56:20 0

Is BMS lithium battery pack management system also called lithium battery protection board? The battery is the most frequently problematic component in electric vehicles, and it is a key factor hindering the promotion and industrialization of electric vehicles. If a single battery in the battery pack has a problem, the entire electric vehicle cannot work normally. BMS lithium battery pack management system And the lithium battery protection board is to protect the lithium battery, so is there a difference between the two? Is BMS lithium battery pack management system also called lithium battery protection board?

BMS Lithium Battery Pack Management System

The battery management system (BMS) is the link between the battery and the user, and the main target 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 battery power estimation. 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.

BMS hardware topology

The topological structure of BMS hardware is divided into two types: centralized and distributed. The centralized type is to concentrate all the functions of the battery management system in a controller, which is more suitable for the occasions where the capacity of the lithium battery pack is relatively small, and the module and battery pack types are relatively fixed, which can significantly reduce the system cost. Distributed is to separate the main control board and the slave control board of the BMS, and even separate the low-voltage and high-voltage parts, to increase the flexibility of system configuration and adapt to modules and battery packs of different capacities and different specifications.

BMS lithium battery pack management system function

The battery management system is a key component of electric vehicles and hybrid vehicles. In order to ensure the safe and reliable operation of the battery, the battery management system needs to have the following three functions:

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

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

3. Balance between single cells

Lithium battery protection board

Lithium battery protection board usually includes control IC, MOS switch, resistor, capacitor and auxiliary device NTC, ID memory and so on. It is the charge and discharge protection of the series lithium battery pack; when it is fully charged, the voltage difference between the single cells can be guaranteed to be less than the set value (generally ±20mV), and the single cells of the battery pack can be evenly charged and effectively improved The charging effect under the series charging mode is detected; at the same time, the overvoltage, undervoltage, overcurrent, short circuit, and overtemperature status of each single battery in the battery pack are detected to protect and extend the battery life; undervoltage protection enables each single cell Avoid battery damage due to over-discharge during use.

Among them, the control IC controls the MOS switch to turn on under all normal conditions to make the cell communicate with the external circuit. When the cell voltage or loop current exceeds the specified value, it immediately controls the MOS switch to turn off (tens of milliseconds). Protect the safety of batteries.

The main function of lithium battery protection board

Generally, it is required that Control (IC) detect and control the cell voltage and the working current and voltage of the charging and discharging circuit at -25℃~85℃. Under all normal conditions, the C-MOS switch tube is turned on to make the cell and the lithium battery protection circuit. The board is in a normal working state, and when the cell voltage or the working current in the loop exceeds the preset value of the comparison circuit in the control IC, within 15-30ms (different control ICs and C-MOS have different response times), the CMOS Turn off, that is, close the battery discharge or charging circuit to ensure the safety of the user and the battery.

The lithium battery BMS management system is a powerful guarantee for the safe use of the battery, so that the battery is always in a safe and controllable charge and discharge process, which greatly improves the cycle life of the battery during actual use. The lithium battery management system can ensure the safety of the power lithium battery pack and is the primary task of the lithium power battery management system.