From Time Series to Feature Matrix: A Novel PSO-SVM Framework for Self-discharge Diagnosis of Lithium-Ion Batteries
摘要
Lithium-ion power batteries are currently the most widely used energy storage devices in electric vehicles. Rapid and accurate diagnosis of battery faults is crucial for the safe operation of vehicles. This paper proposes a method for diagnosing self-discharge faults in power batteries based on individual adaptive voltage thresholds and Particle Swarm Optimization-Support Vector Machine (PSO-SVM). The research focuses on the voltage signals of power batteries, combines the boxplot method with expert review to label samples of self-discharge faults. Through the sliding window method, 16 features in the time domain and frequency domain are extracted. Principal component analysis is then used to further reduce the dimensionality of voltage features, obtaining the first five principal components with a cumulative variance contribution of 95% as inputs for the PSO-SVM model. The aim of this method is to improve the accuracy of self-discharge fault identification in batteries. The final results show that the proposed method has high recognition accuracy, strong reliability, and potential value in practical electric vehicle applications. It provides theoretical support for enhancing the safety performance of electric vehicles.