Self-discharge Fault Diagnosis of Lithium-Ion Battery Packs Based on Remaining Charge Capacity Prediction Under Multi-stage Charging Conditions
摘要
The increasing adoption of lithium-ion batteries in energy storage systems is challenged by safety concerns, particularly self-discharge faults, which can lead to thermal runaway and pose significant risks. Monitoring the remaining charging capacity (RCC) is a typical approach for detecting self-discharge and mitigating potential hazards. However, RCC evaluation in battery systems faces challenges under short-cycle data and multi-stage charging with current switching. A deep learning-based method is proposed to estimate the RCC of individual battery cells under multi-stage charging conditions for self-discharge diagnosis, achieving advancements in three areas: (1) online RCC estimation based on short-cycle voltage/current sequences; (2) an adaptive mechanism for multi-stage charging with current switching; (3) early detection of self-discharge faults. Validation shows that the method achieves a mean absolute error (MAE) of 0.63 Ah in RCC prediction under current switching, successfully identifying self-discharge faults and quantifying its evolution, offering a high-precision, generalizable monitoring solution for dynamic energy storage systems.