Coupled electrothermal model and thermal fault diagnosis method for lithium-ion battery

The dynamic behaviour of lithium-ion battery system is analysed. The nonlinear parameters, residual errors and thermal faults of battery model are studied. In our study, a coupled electrothermal model is established based on the cell electrical dynamic characteristics. The parameter identification algorithm is presented based on Lyapunov observer. The core temperature and surface temperature of battery cell are calculated based on extended Kalman filter (EKF). We propose new thermal fault diagnosis method and the residual generation scheme. The urban dynamometer driving schedule (UDDS) dynamic working condition is used to verify our electrothermal model and fault diagnosis method. The experimental results indicate that the thermal characteristics can be described and the thermal fault can be diagnosed more accurately.