What Functions Should A Pure Electric Vehicle Battery Management System Have?
May 14, 2022
The main purpose of the battery management system is to improve the utilization rate of the battery, prevent the battery from overcharging and overdischarging, prolong the service life of the battery, and monitor the status of the battery. The electric vehicle battery management system is mainly used for real-time monitoring, fault diagnosis, SOC value estimation, driving range estimation, short circuit protection, leakage monitoring, display alarm, charging and discharging mode selection, etc. It can exchange information with the vehicle controller or charger in a way to ensure the efficient, reliable and safe operation of the electric vehicle, and ensure the safety of the vehicle during use.
A typical battery management system should have the following functions:
1. Real-time collection of battery system operating status parameters
Collect the terminal voltage and temperature of each battery in the electric vehicle battery pack, the charging and discharging current, and the total voltage of the battery pack in real time. Since the performance and status of each cell in the battery pack are inconsistent in use, the voltage, current and temperature data of each cell are monitored.
2. Determine the SOC value of the battery
Accurately estimate the SOC value of the power battery pack, so as to predict the remaining energy of the electric vehicle energy storage battery or the SOC value of the energy storage battery at any time, so that the SOC value of the battery is controlled within the working range of 30% to 70%.
3. Fault diagnosis and alarm
When the battery pack power or energy is too low and needs to be charged, it will alarm in time to prevent the battery from being over-discharged and damage the service life of the battery.
4. Thermal balance management of battery pack
The battery thermal management system is an integral part of the battery management system. Its function is to keep the battery temperature within the normal operating temperature range through cooling systems such as fans and thermal resistance heating devices.
5. Consistency compensation
When there is a difference between the batteries, there are certain measures to compensate to ensure that the battery pack has a stronger performance, and there are certain means to display the position of the batteries with poor performance for repair and replacement. The charging compensation function is generally used. A bypass shunt circuit is designed to ensure that each cell can be fully charged, which can slow down the progress of battery aging and prolong battery life.
6. Realize the communication between each detection module and the central processing unit through the bus
The difficulty and key to realizing battery management in electric vehicles lies in how to establish a more accurate mathematical model to determine the remaining energy of each battery according to the collected historical data of the voltage, temperature and charge and discharge current of each battery, that is, to accurately estimate the electric vehicle The SOC value of the battery.
