The fault tree ana lysis is presented in Figure 2. failure. When the battery cell undergoes mechanical stress. An external short circuit occurs when the motor is und er load. Environment al exposure also co ntributes to therm al runaway. cell to be under volta ge, leading to a shutdown. action due to thei r high severity. Additionally, the
The faults of the battery system cause significant damage to people's life and property safety. Meanwhile, it also increases people's safety anxiety about EVs [5, 6]. Although various fault analysis and diagnosis methods have been widely used in battery faults research [7, 8].
In addition to lithium-induced battery failure, the cycle life is another problem. For instance, the use of lithium as an anode causes dendrite growth and pulverization during cycling, thereby significantly reducing the life of the cell. The large volume change in a cell with a lithium anode is also an unsolved problem.
In battery system fault diagnosis, finding a suitable extraction method of fault feature parameters is the basis for battery system fault diagnosis in real-vehicle operation conditions. At present, model-based fault diagnosis methods are still the hot spot of research.
Table 1. Faults performance of the battery system and interrelationships. Mechanical deformation, Over-charge/Over-discharge fault, induction of active materials, thermal fault. It is often accompanied by discharge and exothermic, and the main fault activates BTR. Connection fault, mechanical deformation, aging fault, water immersion.
Fig. 14 shows the progression of battery faults, including the early development (fault precursor), fault occurrence (fault features), and further deterioration leading to disasters. Current research focuses on pre-warning by studying precursors and diagnosing faults through feature extraction.