New energy vehicles are commonly referred to as the "Big Three" of batteries, motors, and electronic controls. Among them, electronic controls mainly refer to the battery management system (BMS).
The battery management system (BMS) is mainly used for real-time monitoring of the power battery parameters of electric vehicles, fault diagnosis, SOC estimation, driving mileage estimation, short circuit protection, leakage monitoring, display alarms, charging and discharging mode selection. Through the information exchange with the vehicle integrated controller or charger through the CAN bus, the efficient, reliable and safe operation of electric vehicles is ensured.
Real-time tracking of battery operation status and parameter detection of the battery management system
Real-time collection of battery charging and discharging status. Data collection includes total battery voltage, total battery current, temperature of each battery measuring point inside each battery box, and battery voltage of each cell module. Since the power batteries are all used in series, the real-time, rapid, and accurate measurement of these parameters is the basis for the normal operation of the battery management system.
Estimation of remaining battery capacity for the battery management system
The remaining battery energy is equivalent to the fuel of a traditional car. The estimation of state of charge (SOC) is for drivers to understand the system operation condition in a timely manner. Real-time collection of charging and discharging currents, voltages and other parameters, and the use of corresponding algorithms to estimate the remaining battery capacity.
Charging and discharging control in the battery management system
According to the SOC control of the battery's charging and discharging, when a parameter exceeds the standard, such as the cell voltage being too high or too low, in order to ensure the normal use of the battery pack and the performance's effectiveness, the system will cut off the relay, stop the supply and release of energy of the battery.
Thermal management of the battery management system
Real-time collection of temperature of each battery measuring point inside each battery box, and control of the cooling fan to prevent the battery temperature from becoming too high.
Balancing control of the battery management system
Due to the differences in individual batteries and different usage statuses, the inconsistency of the battery during use will become more and more severe, and the battery management system should be able to judge and automatically perform balancing operations.
Fault diagnosis of the battery management system
The working voltage of the electric vehicle battery is generally high (90V-700V), and the system should monitor situations that may pose a danger to personnel and equipment, such as power supply short circuits and leaks.
Battery condition prediction and alarm of the battery management system
Through the collection of battery parameters, the system has functions such as predicting the performance of individual batteries in the battery pack, fault diagnosis, and early warning, in order to maintain and replace the battery and ensure safety.
Information monitoring of the battery management system
The main information of the battery is displayed in real-time on the vehicle-mounted display terminal.
Parameter calibration of the battery management system
Since different vehicle models use different battery types and quantities, and each battery box has different capacities and quantities, the system should have functions such as calibration of vehicle model, vehicle number, battery type and battery mode information.