基于行驶工况的磷酸铁锂电池寿命模型研究

摘要

针对电动汽车在行驶过程中电池的放电电流不断变化，采用恒流充放电条件下建立的电池寿命模型来估计电池的寿命将带来较大误差的问题，本文中在对某一现有磷酸铁锂电池恒流充放电容量衰减模型进行实验验证的基础上，推导了电动汽车行驶工况条件下，磷酸铁锂电池的循环工况寿命预测模型，并采用NEDC循环工况对该模型进行了实验验证。结果表明，采用该模型能较准确地对电动汽车行驶过程中的寿命进行估计。%In view of that the discharge current of battery varies constantly in the driving process of electric vehicle, so adopting the battery life model established on a constant-current charge/discharge condition may lead to larger error, based on the experimental verification on an existing capacity decay model for LiFePO4 battery under a constant-current charge/discharge condition, a driving cycle life prediction model for LiFePO4 battery is derived and verified by experiments with NEDC driving cycle. The results show that using the model derived can relatively accu-rately predict the driving service life of electric vehicle.