What is a battery management System BMS?
The three major parts of new energy vehicles are battery, motor and electronic control. Among them, electronic control mainly refers to battery management system, also known as BMS.
BMS is mainly used for real-time monitoring, fault diagnosis, SOC estimation, mileage estimation, short-circuit protection, leakage monitoring, display alarm, charge and discharge mode selection of power battery parameters of electric vehicles, and information exchange with vehicle integrated controller or charger through CAN bus to ensure efficient, reliable and safe operation of electric vehicles.
Real time tracking of battery operation status and parameter detection: real time collection of battery charge and discharge status. The collected data include total battery voltage, total battery current, battery measuring point temperature in each battery box and battery voltage of single module. Because the power batteries are used in series, the real-time, fast and accurate measurement of these parameters is the basis for the normal operation of the battery management system.
Estimation of remaining power: the remaining energy of the battery is equivalent to the fuel volume of traditional vehicles. The estimation of state of charge (SOC) is to let the driver know the operation status of the system in time. The parameters such as charge and discharge current and voltage are collected in real time, and the residual power is estimated by the corresponding algorithm.
Charge and discharge control: control the charge and discharge of the battery according to the charging state of the battery. When a parameter exceeds the standard, such as the voltage of the single battery is too high or too low, in order to ensure the normal use and performance of the battery pack, the system will cut off the relay and stop the energy supply and release of the battery.
Thermal management: collect the temperature of the battery measuring point in each battery box in real time, and prevent the battery temperature from being too high through the control of the cooling fan.
Balance control: due to individual differences of batteries and different use states, the inconsistency of batteries will become more and more serious in the use process. The system shall be able to judge and automatically balance.
Fault diagnosis: the working voltage of electric vehicle battery is generally high (90v-700v). The system shall monitor the power supply short circuit, leakage and other conditions that may cause harm to personnel and equipment.
Battery condition prediction and alarm: through the collection of battery parameters, the system has the functions of predicting the performance of single battery in the battery pack, fault diagnosis and early alarm, so as to maintain and replace the battery and ensure safety.
Information monitoring: the main information of the battery is displayed in real time on the on-board display terminal.
Parameter calibration: since the type and quantity of batteries used by different vehicle models and the capacity and quantity of each battery box are different, the system shall have the function of calibrating the vehicle model, vehicle number, battery type, battery mode and other information.