The invention relates to a
lithium ion battery pack internal
short circuit fault diagnosis method based on relaxation time and an adaptive clustering
algorithm, and belongs to the technical field of batteries. The method comprises the following steps: firstly, establishing a battery operation
database, then screening out relaxation
voltage of each
monomer in a standing stage after charging of a
battery pack is finished, establishing a relaxation
time curve, and taking statistical characteristics of the relaxation
time curve as fault characteristics; taking the fault feature of each
monomer as the input of a self-adaptive
DBSCAN algorithm, obtaining a critical neighborhood
radius between an abnormal point and a normal point of each
monomer, and taking the critical neighborhood
radius as an
outlier index of each monomer; and calculating a fault
score of the corresponding monomer according to the
outlier index of each monomer, and realizing diagnosis and positioning of an internal
short circuit fault according to a set fault
score threshold. According to the method, the effective features of the short-circuit fault in the battery are extracted, and the adaptive clustering
algorithm is adopted for quantitative evaluation, so that the recognition accuracy is improved.