主被动均衡电池管理系统设计

为了克服新能源汽车电池组在使用过程中内部单体电池充放电速率不一致问题,提出了一种基于现场可编程门阵列(field-programmable gate array,FPGA)的主被动均衡相结合的电池管理系统。该设计通过LTC6811电池采集芯片,将电压、电流、温度等数据传到FPGA进行容量估算。主控微控制单元(microcontroller unit,MCU)通过设置单体间荷电状态(state of charge,SOC)差值阈值,控制均衡电路中的回路开关的通断,使单体电池在不同容量差值时,进行不同的均衡策略。同时运用MATLAB/Simulink仿真软件搭建出核心主被动均衡电路模型,对电路的均衡方案进行仿真分析。仿真结果表明:通过采用主被动相结合的均衡策略,电池在充放电过程中均衡速度较单一均衡方式有明显的提升。可见通过主被动均衡结合的方式,能有效地提升电池均衡速度,改善电池使用效率。

Design of active and passive balanced battery management system

To address the issue of inconsistent charging and discharging rates among individual cells within battery packs during the operation of new energy vehicle battery packs, this paper proposes a battery management system based on FPGA that combines active and passive balancing. This design transmits data such as voltage, current, and temperature to the FPGA for capacity estimation through the LTC6811 battery acquisition chip. The main control MCU controls the on-off state of the loop switch in the balancing circuit by setting the SOC difference threshold between the cells, allowing each individual battery to implement different balancing strategies based on varying capacity differences. Furthermore, MATLAB/Simulink simulation software is used to create the core model of the active and passive equalization circuit, enabling simulation and analysis of the circuit''s equalization scheme. The simulation results indicate that by adopting the balance strategy that combines active and passive methods, the battery''s balance speed during the charging and discharging process significantly improves compared to using a single balancing method. This underscores the effectiveness of combining active and passive balancing in enhancing battery balancing speed and overall efficiency.