Research On Inconsistency And Connection Fault Diagnosis Methods Of Lithium-ion Power Battery Packs For Vehicles

In the context of the energy and environmental crisis facing the world today,new energy vehicles have been internationally recognized as the direction of automobile development,among which electric vehicles are one of the most promising directions.As a key power supply component in electric vehicles,the reliability of lithium ion power batteries will directly affect the working performance and safety of the entire battery system,and may even affect the safety performance of electric vehicles and cause vehicle scrap.Research on fault diagnosis methods of lithium battery pack inconsistency and connection failure can improve the working performance and reliability of the battery pack,thereby ensuring the safety of electric vehicles.This article first through the fault tree analysis method in the qualitative analysis,the failure causes and possible consequences of common hidden faults in automotive lithium battery systems are analyzed,and the lithium batteries that are more frequent and may have serious consequences are selected inconsistently.Research on diagnostic algorithms for connectivity and connection failures;Based on the analysis of the causes,possible hazards and manifestations of lithium battery pack in consistency,a lithium battery pack inconsistency analysis algorithm with information entropy as the characteristic parameter is adopted,and the feasibility of the algorithm is verified using big data of electric vehicle operation and based on the big data monitoring platform of electric vehicles and vehicle terminal design and build a big data-based power battery pack inconsistency analysis platform,to provide safety guarantee for the actual running vehicles;Perform normal connection charge and discharge tests and connection failure tests on lithium battery packs.Analysis of the data obtained from the test found that the normal connection charge-discharge test and connection failures of the lithium battery packs are in voltage distribution.There are differences in temperature and other aspects.You can choose the voltage relationship and temperature rise.Rate is used as two characteristic parameters for fault analysis to diagnose connected faulty batteries;a voltage abnormality analysis method based on the class correlation coefficient(ICC)is selected,and tests verify that the ICC value less than 0.75 can be regarded as the threshold value of the voltage abnormality,and combined with the single cell A temperature rise rate greater than0.1℃/s is used as the basis for judging the connection failure of the lithium battery pack,and the faulty battery can be located based on this method.The research in this paper clarifies the causes and some manifestations of the implicit failure of the lithium battery pack,and explores the diagnosis method of inconsistency and connection failure of the lithium battery pack based on big data and experimental data,the research results can provide a method and idea for the real-time diagnosis of implicit failures of lithium battery packs.