Design On Management Unit Of Power Lithium-ion Battery Based On BQ76PL536A

With the global energy crisis and environmental pollution, governments have introduced a policy to encourage the development of new and clean energy. The innovation and development of lithium-ion battery technology are of great interest. Compared with other commonly used batteries, lithium-ion batteries are featured by high energy density, high power density, long life and environmental friendliness and thus have found wide application in the area of consumer electronics. However, power lithium-ion batteries have high capacity and large serial-parallel numbers, which, coupled with such problems as safety, durability, uniformity and cost, imposes limitations on the wide application of lithium-ion batteries. The narrow area in which lithium-ion batteries operate with safety and reliability necessitates the effective control and management of battery management system.In this paper, the basic working principle of lithium-ion battery and the charging and discharging characteristics of lithium-ion battery are analyzed. Through the analysis of literature and in combination with our practical experience, gives a brief introduction to the composition of the battery management system(BMS) and its key issues such battery cell voltage measurement, battery states estimation, battery uniformity and equalization. In the end, the hardware circuit of the battery management unit (BMU) which is a very important part for the BMS is designed, and the chip BQ76PL536A is used as the Active-Front-End (AFE) of the BMU. The chip STM32F103 is used as the master chip of BMS. The main innovation points are:the BMU is designed with isolated power supply and isolated communication signal to ensure the safety of system operation and the accuracy of signal measurement; the unit can be stacked on a large scale, which could improve the system configuration, with using CAN (Controller Area Network) bus communication.Finally, with the construction of test environment, the function of the lithium-ion battery management unit is tested. Experiments suggest that the designs of the basic functions achieve the desired.uoals.