Introduction to High Voltage Battery Module and High Voltage Battery Management System of New Energy Vehicles

The high-voltage battery module is placed in a sealed and shielded high-voltage battery box, and the high-voltage battery system is connected to the whole vehicle with reliable high-voltage and low-voltage connectors. Installation position of high-voltage battery module BMS in high-voltage battery system collects data such as the voltage value of each battery cell, the temperature value of each temperature sensor, the total voltage and current value of the battery system, and the insulation resistance value of the battery system in real time, and judges whether the battery system works normally according to the threshold set in BMS, and monitors the fault in real time. The high-voltage battery system communicates with VCU or charger through BMS using CAN, and carries out comprehensive management such as charging and discharging of the high-voltage battery system. The high-voltage battery system also receives and stores the high-voltage direct current provided by on-board charger, generator, braking energy recovery device and external charging device, and provides high-voltage direct current for driving motor controller, DC/DC, electric air conditioner, PTC and other high-voltage components. The high-voltage battery system is mainly composed of four parts: high-voltage battery module, battery management system, high-voltage battery box and auxiliary components. High-voltage battery system battery cell is the smallest unit of high-voltage battery module, which is generally composed of positive electrode, negative electrode, electrolyte and casing, etc., and can realize the direct conversion between electrical energy and chemical energy; A battery module is a combination of a group of parallel battery cells, the rated voltage of which is equal to the rated voltage of the battery cells. It is the smallest grouping of battery cells connected in physical structure and circuit, and can be replaced as a unit. The module is a combination of multiple battery modules or battery cells connected in series. High-voltage battery module structure High-voltage battery box is a component that supports, fixes and surrounds the battery system. It mainly includes an upper cover and a lower tray, as well as auxiliary components, such as transition pieces, guard plates and bolts. High-voltage battery box has the function of bearing and protecting high-voltage battery packs and electrical components. The battery box is connected under the underbody by bolts, and its protection grade is IP67. The tightening torque of the bolts is 80 ~ 100nm. During the maintenance of the whole vehicle, it is necessary to observe whether the bolts of the battery box are loose, whether the battery box is damaged or severely deformed, and whether the sealing flange is complete to ensure that the high-voltage battery can work normally; In appearance, the color of the outer surface of the battery case should be silver gray or black, and matt; There shall be no scratches, sharp corners, burrs, residual oil stains and other appearance defects on the surface of the battery case, and the welded joints shall be polished and smooth. Auxiliary components of high-voltage battery box battery module mainly include the internal electrical components of high-voltage battery system, such as fuses, relays, shunts, connectors, maintenance switches, smoke sensors, etc., in addition to sealing strips and insulating materials. Auxiliary components in high-voltage battery module

Battery Management System is abbreviated as BMS. ① BMS function: the core component of battery protection and management. In high-voltage battery system, its function is equivalent to human brain. It not only ensures the safe and reliable use of the battery, but also gives full play to the battery capacity and prolongs its service life. As a bridge between the battery and the vehicle controller (VCU) and drivers, it controls the charging and discharging of the high-voltage battery pack by controlling the contactor, and reports the basic parameters and fault information of the high-voltage battery system to VCU. ② BMS function: It can protect the high-voltage battery system from over-voltage, under-voltage, over-current, over-temperature and over-low-temperature, relay control, SOC estimation, charge and discharge management, balance control, fault alarm and treatment, and communicate with other controllers. In addition, the battery management system also has the insulation detection function of the high-voltage circuit and the heating function for the high-voltage battery system. ③ BMS composition: it can be divided into hardware and software by nature, and data acquisition unit and control unit by function. ④ BMS hardware: main board, slave board and high-voltage box, including electronic devices for collecting data such as voltage, current and temperature. ⑤ BMS software: Monitor the voltage, current, SOC, insulation resistance and temperature of the battery, and control the charging and discharging of the high-voltage battery system through communication with VCU and charger.