Briefly describe the BMS system of electric vehicles

Introduction to the BMS system of electric vehicles: the staff and general electric vehicle technology of battery cells: batteries, motors, and electronic control technology are the core technologies of electric vehicles. Due to the use of these three technologies, every electric vehicle is necessary, which directly affects the vehicle's cruising range, acceleration time and other parameters. These three technologies are all wooden barrels that make up electric vehicles, and the existence of defects directly affects the expression of vehicle functions. In the three-power technology, the impact of batteries and motors on the performance of electric vehicles is very important. For example, the power of the motor directly affects the performance of the car, the battery energy storage of a pure electric car and the life of the car. And with the electrical control technology in the three-power system, what is the specific technical application in electric vehicles? How can it compete with batteries and electric motors and occupy a place in the three-power system? The core function of electronic control is the battery management system (BMS). Without this system, the charging and discharging of the power lithium-ion battery will greatly reduce the use of life. If the battery is compared to a group of soldiers, then the BMS system is the soldier's consultant and general, so the electric vehicle is achieved in practice and half the result of the effort. Twice. Why is there a BMS system? Suppose you want to know the generals on electric vehicles. The most important thing is to start with the soldiers below. The BMS system is mainly used for secondary batteries, especially the current mainstream lithium batteries are particularly important for electric new energy vehicles. No matter what kind of lithium battery is used in the vehicle, the power lithium ion battery is composed of a small battery cell in series and parallel to form a battery pack, and the battery pack finally constitutes the vehicle power lithium ion battery unit. In the battery pack, each small battery unit is used for energy storage, such as the 18650 lithium battery used by Tesla. In fact, the numbers indicate that each battery cell has a diameter of 18mm and a length of 65mm. And an 85-kilowatt? Tesla model battery pack consists of nearly 7,000 18650 lithium batteries. There are many battery cells in a car, and each small battery cell is manufactured separately. Due to the electrochemical characteristics of the battery, the consistency of the energy storage of a single battery after leaving the factory has different problems. When charging, the car is charged from the charging port. How to ensure that each battery is fully charged without damaging the battery due to overcharging is one of the problems that the BMS system must solve. So how does the BMS system handle so many cells? Generally, the BMS system has two parts to determine how to handle the battery pack: the detection module and the source code control module. The end of Tesla's battery processing module detection module is relatively short. First collect the battery parameter information during the use of the sensor, such as temperature, elegance of each battery, current, elegance of the battery pack, current, etc. These data play a vital role in the subsequent processing of the battery pack. It can be said that without the support of these battery data, the processing of the battery system will be impossible. According to the collected data, the BMS system will allocate how to charge the battery according to the actual situation of each battery, which battery is sufficient for continuous charging, and so on. In the application process, the state budget method is used to identify the situation of each battery, and the reasonable use of the battery is ended by means of state of charge, power state, SOH health state, equalization, and heat treatment. This process is briefly mentioned, but these are the essence of the BMS system address, and are also the technical difficulties that BMS manufacturers hope to grasp the most. The detailed ending principle will be analyzed in the following article. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Design requirements for polymer lithium battery power supply system