Abstract: To address the overcharge and over-discharge problems of power batteries in battery electric vehicles, this paper proposes a closed-loop control method for motor torque limits based on the calculation of real-time motor efficiency and current ratio. Combined with the vehicle energy management architecture, it analyzes the energy distribution and limiting logic under the two operating conditions of motor driving and motor braking. A model of the vehicle energy management and closed-loop control strategy for torque limits is established via Simulink, and the control logic is flashed into the vehicle control unit by means of code generation and flashing tools for real vehicle tests. The results show that when the charge-discharge capacity of the power battery is pre-treated to the designed minimum value and the full-throttle driving and full-brake braking performance tests are conducted, the motor torque can dynamically track the limit value, and no overcharge or over-discharge fault occurs in the power battery.

Key words: over-discharge fault occurs in the power battery.

摘要： 为解决纯电汽车动力电池过充和过放问题，文章提出基于电机实时效率和电流比值计 算的电机扭矩限值闭环控制方法。结合整车能量管理架构，分析电机驱动与制动两种工况下的 能量分配及限制逻辑，通过 Simulink 搭建整车能量管理与扭矩限值闭环控制策略模型，采用 代码生成刷写工具将控制逻辑刷入整车控制器开展实车测试。结果表明，将动力电池充放电 能力预处理至设计最小值，进行全油门驱动与全刹车制动性能测试时，电机扭矩可动态贴合 限制值，动力电池未出现过充过放故障。

关键词: 动力电池；过充和过放；能量管理；闭环控制；实车测试