Method for identifying abnormal self-discharge of battery cell of power battery based on operation data

Abstract

The invention relates to the technical field of fault diagnosis, and discloses a power battery cell abnormal self-discharge identification method based on operation data, and the method comprises the following steps: 1, carrying out the analysis to obtain basic battery signal data; 2, cleaning the basic battery signal data to obtain standard battery signal data; step 3, selecting charging state data from the standard battery signal data; 4, performing feature extraction on the voltage data of each battery cell in the charging state data according to an extraction strategy to obtain a battery cell feature value; step 5, performing anomaly detection; 6, according to the real-time anomaly detection result, whether sudden self-discharge anomaly exists in the battery cell or not is judged; and according to a long-period anomaly detection result, judging whether continuous self-discharge anomaly exists in the battery cell or not. According to the method, the abnormal self-discharge condition of the battery cell can be identified in time, the identification accuracy and the high efficiency of fault identification and judgment are ensured, the self-discharge abnormal fault is positioned to the battery cell level, and the identification precision is high.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis, in particular to a method for identifying abnormal self-discharge of power battery cells based on operating data. Background technique [0002] With the rapid development of technologies such as battery motor electronic control, changes in consumer demand, and the promotion and application of new energy technologies, the production and sales of new energy vehicles have also continued to grow. However, as more and more new energy vehicles are put into use, correspondingly, battery safety accidents in new energy vehicles begin to increase. Among them, one of the more common battery failure phenomena is abnormal self-discharge failure phenomenon. [0003] The self-discharge phenomenon itself is a battery characteristic. All batteries will be affected by self-discharge. When the battery is in an open circuit state, due to its own internal chemical reaction, the stored power will gradually dec...

AI Technical Summary

Problems solved by technology

Ideally, the self-discharge of the battery should be kept at an extremely low level. However, during the use of the battery, a physical micro-short circuit will occur to form an abnormal self-discharge. Dust, burrs, metal impurities, etc. may cause a micro-short circuit. When the self-discharge develops for a certain period of time, the difference in power between the cells in the battery system will increase. In severe cases, it will cause insufficient power of the vehicle, frequent fault reports, and severe reduction in cruising range. Abnormal self-discharge is extreme. In this case, it may lead to a short circuit between the positive and negative poles of the battery and cause thermal runaway

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