磷酸铁锂电池充电后静置的电压预测方法

混合动力电动汽车在行驶过程中的动态充电后静置开路电压不稳定。特别是再生制动充电时开路电压的变化,而导致常用的开路电压法存在SOC估计误差大和混合动力电动汽车动力控制策略难以实施。以磷酸铁锂电池为对象,依据电化学理论分析了其充电后静置过程中正负极表面锂离子扩散对开路电压的影响机理以及开路电压随时间的变化关系。再通过充电后静置实验和参数辨识方法,建立了充电后磷酸铁锂电池静置开路电压预测模型。以此对其充电后静置的开路电压进行了预测实验。结果表明,在实验工况下,该模型的最大预测误差为0.017V。

Voltage Forecasting Methods for Still Standing Lithium Iron Phosphate Battery After Charging

Contraposing the problem that the still standing open circuit voltage was unstable after the hybrid electric vehicle was charged in the running process, especially in regenerative braking process, which resulted in the great error in the SOC estimate for open circuit voltage method and difficulty in implementation of the power control strategy for hybrid electric vehicle, the lithium iron phosphate battery, as a research object, was analysed in the influence mechanism about the electrode surface lithium ion diffusion and open circuit voltage that was time-varying according to theory of electrochemistry. And the still standing voltage forecasting model for lithium iron phosphate battery was established by still standing experiment and parameter identification. The prediction by the model in the prediction experiment showed that the biggest prediction error was 0.017V in the experimental operating conditions.