Battery thermal runaway early warning method and device

Abstract

The invention discloses a battery thermal runaway early warning method and device. The battery thermal runaway early warning method comprises the steps of: S1, calculating the leakage current of eachsingle battery according to the statistical data in a preset time range; S2, collecting battery thermal runaway characteristic data in real time through a battery management system BMS, and acquiringa real-time diagnosis result indicating whether thermal runaway occurs or not according to the battery thermal runaway characteristic data; and S3, judging whether thermal runaway occurs or not according to the size relationship between the leakage current of each single battery and a diagnosis threshold or according to the real-time diagnosis result, and carrying out early warning when it is judged that thermal runaway occurs. The battery thermal runaway early warning method is close to the actual demand for the thermal runaway early warning function at present, reduces the false alarm and missing alarm probability of thermal runaway early warning, reserves as much time as possible for user escape and after-sales rescue, and greatly improves the reliability of battery thermal runaway early warning.

Description

technical field [0001] The invention belongs to the technical field of new energy vehicles, and in particular relates to a battery thermal runaway early warning method and device. Background technique [0002] The sudden combustion and explosion of the power battery is the result of the thermal runaway of the battery. Battery thermal runaway refers to the overheating phenomenon in which the exothermic chain reaction inside the battery causes a sharp change in the temperature rise rate of the battery. Thermal runaway is the result of battery safety problems, not the cause of battery safety problems. After an internal short circuit occurs in the battery, the Joule heat generated by the short circuit current in the battery will cause the temperature of the battery to rise, and the heat cannot be dissipated in time. Continued temperature rise will trigger an uncontrolled chain reaction of the battery, which will lead to thermal runaway of the battery. [0003] At present, the ...

AI Technical Summary

Problems solved by technology

This method has the following defects: 1) It relies on the reliability of BMS for battery temperature and voltage data collection, and in some cases it is impossible to distinguish between battery thermal runaway faults and sensor electrical faults (such as sampling line disconnection fault, and the sampling line will also be blown when thermal runaway occurs); 2) The voltage and temperature data will only change drastically in a short period of time before the thermal runaway occurs, and only by identifying these severe Changing data characteristics, the time reserved for an early warning signal to inform vehicle users to evacuate or rescue personnel to deal with dangerous battery packs is very short, only a few minutes

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