Li-ion battery is widely used in electric vehicles,battery inconsistency faults and internal short-circuit faults are serious safety hazards for electric vehicles.The absolute mean difference method is used to amplify the voltage characteristics of faulty cells in a battery pack.Then,a nonlocal mean filtering algorithm is used to filter it to obtain a smooth fault voltage characteristic.Finally,the similarity distance between the eigenvalue curves is calculated by the dynamic time warping(DTW)algorithm to realize automatic localization of faulty batteries.Validation is carried out by using operating vehicle voltage data.The diagnostic method has a good detection effect on two types of faulty vehicles:one is the inconsistent faulty vehicle where the DTW distance of the faulty battery deviates from other batteries for a long period of time,the other is the faulty vehicle where the DTW distance of the faulty battery deviates from other batteries for a short period of time with an internal short-circuit.A comparison with the cosine similarity verifies that the proposed method is more accurate.
关键词
锂离子电池/不一致性故障/内短路故障/故障诊断/实车数据/动态时间归整(DTW)算法
Key words
Li-ion battery/inconsistency fault/internal short-circuit fault/fault diagnosis/real vehicle data/dynamic time warping(DTW)algorithm
维普
万方数据