battery management system (BMS) is a key part in electric car .Currently commercial batteries must have BMS. , the battery can be controlled and managed more efficiently through BMS, and each battery works within the range of runnable range to avoid the problem of over-charge and over-discharge of the battery and thermal runaway. The capacity of a single cell is relatively low, which requires many cells to be integrated into modules ,and one battery system contains multiple modules. A typical battery system contains hundreds, even thousands of cells. BMS plays an important role in keeping the cells operating within the proper range.
The function of BMS is to monitor the battery state, establish the battery state, protect the battery, report data, balance, etc. The main tasks of BMS in the whole vehicle are:
1.Protect the cell and Battery Pack from damage
2.Keep the battery operate within the proper range of voltage and temperature.
3.After keeping the battery running under the right conditions, the BMS meet the requirements of the whole vehicle
BMS basic hardware structure:
4.Battery parameter detection: including total voltage, total current, single voltage detection, temperature detection, insulation detection, collision detection, impedance detection, smoke detection, etc
5.Battery status established: including SOC, SOH, SOF
6.Online diagnosis: faults include sensor fault, network fault, battery fault, over-charge and over-discharge. Overcurrent, insulation failure, etc
7.Battery safety protection and alarm: including the temperature control system control and high pressure control, when diagnosed with fault, BMS reports to the vehicle controller and charger, at the same time to cut off the high pressure to protect cells from damage, including leakage protection, etc
8.Charging control: BMS slow charge and fast charge control
9.Battery consistency control: BMS collects individual voltage information, uses balance mode to achieve battery consistency, battery balance mode has dissipative type and non-dissipative type.
10.Heat management function: the temperature collection of each point of the battery pack. During charging and discharging, BMS decides whether to turn on heating and cooling
11.Network functions: including online calibration and health, online program download. CAN network is usually adopted
12.Information storage: BMS needs to store key data such as SOC, SOH, charge and discharge hours, fault codes, etc
