The Research Of Lithium Battery Fault Diagnosis Based On Observer

The identification of degradation of a battery in terms of fault and/or failurein a real-life operation has been a challenging issue, so to diagnosis the abruptdamage of a degraded Li-ion battery is of great significance. This paper proposesa lithium battery fault diagnosis program, which is based on the observer theory,the Luenberger and learning observer is synthesized design, the fault in thebattery pack can be isolated and estimated accurately.For studying the battery fault diagnosis, the battery model provides atheoretical basis, after analyzing and comparing the commonly used types Li-ionbattery models, Thevenin equivalent circuit model is selected as the Li-ionbattery model which is study in this paper. The model parameters are obtained byexperimental identification, while the model simulation accuracy is verificationby simulation.For the fault system of battery cells in series, the fault diagnosis strategy isproposed based on the synthesized design of the Luenberger and learningobserver. In this strategy, Luenberger observer for fault detection and isolation isdesigned, a learning observer for fault estimation is designed, each Luenbergerobserver for fault detection and isolation corresponds to a special battery failure,but also corresponds to a preset threshold, when the Luenberger isolationobserver is sensitive to the fault information, the residual signal is smaller thanthe preset threshold; if the both is no sensitive,the residual signal is more thanthe preset threshold, thereby the battery failure is isolated, while the battery faultis estimated online by the learning observer. Based on experimental identificationof parameters, the effectiveness of the proposed fault diagnosis method is verify.