The battery management system (BMS) is a set of control systems that protects the safety of power battery usage. It monitors the battery usage status at all times, alleviates inconsistencies in the battery pack through necessary measures, and provides guarantee for the safety of new energy vehicle use.
As a domestic high-quality power system supplier, Hengrun Technology has strong strength and rich experience in the development of control systems, and can provide customers with high-quality engineering and supporting services in the development of battery management systems. BMS hardware topology
The BMS hardware topology is divided into two types: centralized and distributed.
Centralized is to concentrate all the functions of the battery management system in one controller. It is more suitable for the occasion where the battery pack capacity is small and the module and battery pack type are relatively fixed, which can significantly reduce the system cost.
Distributed is to separate the main control board and the slave control board of the BMS, and even separate the low-voltage and high-voltage parts to increase the flexibility of system configuration and adapt to modules and battery packs of different capacities and different specifications.
can provide various centralized or distributed BMS hardware solutions mentioned above.
State estimation and equilibrium control of BMS
Aiming at the inconsistencies in the manufacturing and use of the battery, and the changes in battery capacity and internal resistance with the battery life cycle, the Hengrun technology team creatively applied multi-state joint estimation, extended Kalman filtering algorithm, internal resistance / capacity online identification, etc. Method to achieve high-precision state estimation of the battery's entire life cycle. According to calculations, for ternary lithium batteries, the estimated deviation of the SOC of the single battery at room temperature can reach a maximum of 2%, and the average estimated deviation is 1%.
At the same time, aiming at the inconsistencies between battery cells, a balanced strategy based on the remaining charge capacity is used to maximize the maximum energy efficiency of the battery. Quick identification of shorts in the battery The short circuit in the battery is the most complicated and difficult to determine the cause of thermal runaway. It is an international problem in the field of battery safety and can lead to disastrous consequences. The short circuit in the battery cannot be completely eliminated. At present, it is generally observed through a long period of stay (more than 2 weeks) in order to detect the problem early. In terms of battery internal short circuit identification, Hengrun Technology has more than 10 leading patents and patent licenses worldwide. Using the symmetrical ring circuit topology (SLCT) and related algorithms, batch short-circuit detection can be performed on multiple battery cells in a short period of time (within 5 minutes), and internal short-circuits on the order of 0 to 100 kΩ can be identified and accurately estimated. Internal short resistance value. This method can significantly reduce the operating costs of cell manufacturers or module assembly manufacturers, and improve the safety of battery production and use.