On-board thermal fault diagnosis of lithium-ion batteries for hybrid electric vehicle application

Lithium-ion batteries with different applications in industries need to be safe, reliable and long-lasting energy storage systems. The internal temperature of the battery, which is higher and more critical compared to the surface temperature, can be affected by internal thermal failures. Hence, internal temperature estimation and fault diagnosis is necessary for Lithium-ion batteries to avoid the problem of overheating. In this paper, a Luenberger observer is designed to detect and isolate three main thermal failures in the battery, consisting of thermal runaway, convective cooling resistance fault, and internal thermal resistance fault. The primary residuals generated by the observer are fed into two designed filters to create secondary residuals. By using the secondary residuals, an estimation of effect of the faults on the system can be obtained.