Power battery thermal runaway online prediction method and system

Abstract

The invention discloses a power battery thermal runaway online prediction method and system. The method comprises the steps that a voltage deviation matrix at each moment is calculated according to avoltage value of each single battery in power batteries, wherein the voltage value comprises voltage data of the single battery in a moment range from a moment T-M to a current moment T; according tothe voltage deviation matrix, a rated voltage of the single battery and a voltage offset increment matrix at the last moment corresponding to each moment, a voltage offset increment matrix at each moment is calculated; a voltage offset increment rate matrix at the current moment T is calculated according to the voltage offset increment matrix at each moment; and a running mileage of a current automobile, a temperature average value of a current temperature probe and a voltage offset increment rate of each single battery corresponding to the voltage offset increment rate matrix at the current moment T are input into a single battery thermal runaway prediction model to obtain a power battery thermal runaway prediction result. According to the method, online prediction of thermal runaway of apower battery is realized in a real vehicle environment, so that the prediction precision is improved.

Description

technical field [0001] The invention relates to the technical field of battery thermal runaway prediction, in particular to an online prediction method and system for power battery thermal runaway. Background technique [0002] Lithium-ion batteries are widely used in electric vehicles due to their high specific energy, high specific power and long service life. However, with the improvement of power battery specific energy and the wide application of ternary lithium-ion batteries, the safety problems of lithium-ion batteries have become increasingly prominent. In 2018, there were 50 new energy vehicle safety accidents, among which battery thermal runaway was the main cause of the accidents. Battery thermal runaway accidents involve a large number of casualties and property losses, so battery thermal runaway is the core problem that needs to be solved in the development of electric vehicles. [0003] At present, the research on battery thermal runaway is mainly to explore t...

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Problems solved by technology

Existing methods can accurately diagnose the abnormal state of the battery through laboratory-measured battery voltage, temperature and other characterization parameters. Therefore, the existing methods are difficult to apply to real electric vehicles

[0004] In order to ensure driving safety and avoid potential failures of electric vehicles, some scholars have proposed methods for battery failure prediction and health status evaluation in recent years. These methods are mostly based on one-dimensional evaluation of SOH. Calculated by the ratio of the maximum available usage to the rated capacity, using SOH for prediction can well reflect the health status, aging degree and remaining life of the battery, but it cannot diagnose and predict short-term battery thermal runaway, overcharge, overdischarge, battery short circuit, etc. failure

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