Method for pre-judging fault battery in power battery pack

Abstract

The invention provides a method for pre-judging a fault battery in a power battery pack. The method includes the steps of: dividing fault pre-judging intervals, recording abnormal data, pre-judging the abnormal battery, restarting abnormal data recording, and circularly performing detection. The method for pre-judging the fault battery in the power battery pack can effectively pre-judge the single battery which may break down by performing real-time monitoring and statistic analysis on the charging and discharging states of the single battery in the power battery pack, timely finds out the single battery with the fault hidden trouble, and improves the usage security of the battery pack in the whole service life period of the battery pack. The method for pre-judging the fault battery in the power battery pack can be directly implemented by a BMS system connected to the battery pack without extra hardware cost.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a method for predicting faulty batteries of a power battery pack. Background technique [0002] With the widespread promotion of electric vehicles, more and more attention has been paid to the safety of batteries. In the actual use of battery packs, in most cases, the poor performance of one battery affects the entire battery pack. When a battery with poor performance in the group reports a fault, it may happen that the high-voltage power is accidentally cut off during driving or the charging end is reached quickly during the charging process. For example, when an electric vehicle is driving at high speed, a single battery with poor performance may Continuous current discharge, the voltage drop is very fast, the vehicle or BMS system may carry out corresponding fault protection actions, cut off the high voltage relay, make the electric vehicle lose power, and cause serious safety hazards...

AI Technical Summary

Problems solved by technology

[0002] With the widespread promotion of electric vehicles, more and more attention has been paid to the safety of batteries. In the actual use of battery packs, in most cases, the poor performance of one battery affects the entire battery pack. When a battery with poor performance in the group reports a fault, it may happen that the high-voltage power is accidentally cut off during driving or the charging end is reached quickly during the charging process. For example, when an electric vehicle is driving at high speed, a single battery with poor performance may Continuous current discharge, the voltage drop is very fast, the vehicle or BMS system may perform corresponding fault protection actions, cut off the high voltage relay, make the electric vehicle lose power, and cause serious safety hazards to the safety of personnel on the vehicle

At the same time, when the battery pack is charging, the voltage of a single battery with poor performance may rise very fast, so that the charging cut-off condition is reached in advance and the charging ends. At this time, other batteries are not fully charged, which will affect the entire battery pack and reduce the battery life performance

At present, the maintenance of electric vehicle power battery packs at home and abroad is basically repaired and replaced after the fault is found. There is no effective method for predicting faults or poor performance batteries in advance.