Battery fault detection method and device, controller and medium

Abstract

The invention provides a battery fault detection method. The battery fault detection method comprises the following steps: collecting monomer voltage and monomer current of each battery monomer in a charge-discharge cycle; calculating a first correlation coefficient of each battery monomer and a second correlation coefficient of the battery pack based on the monomer voltage and the monomer current of each battery monomer in the charge-discharge cycle, and calculating a first slope of each battery monomer and a second slope of the battery pack; when the first correlation coefficient and / or the second correlation coefficient meet a preset condition, determining whether each single battery has a fault in the charge-discharge cycle based on a first slope, and determining whether the battery pack has a fault in the charge-discharge cycle based on a second slope; wherein the first correlation coefficient and the first slope of each single battery are both related to the voltage and the current of the single battery; the second correlation coefficient and the second slope of the battery pack are both related to the total voltage and current of the battery pack.

Description

technical field [0001] The invention is applied to the local and remote data platform fault diagnosis system of electric vehicle power lithium battery or lithium battery energy storage system, and specifically relates to a battery fault detection method, device, controller and medium. Background technique [0002] Lithium-ion batteries have the advantages of long cycle life, high specific energy and low self-discharge rate. Electric vehicles using lithium-ion batteries as power batteries have gradually become the mainstream direction of future vehicle development. Power battery safety issues and driving range are market concerns. An important obstacle to the acceptance of new energy vehicles, the thermal runaway of the power battery will cause huge casualties and property losses, and it will also severely damage the market's confidence in accepting electric vehicles and hinder the popularization of new energy vehicles. Therefore, accurate and advanced fault diagnosis technol...

AI Technical Summary

Problems solved by technology

If there is a connection problem or abnormal internal resistance in the battery pack, the mileage will be shortened, and it may even cause local overheating, resulting in abnormal cell temperature, which will further cause thermal runaway accidents

[0003] At present, the method of internal resistance fault early warning is to calculate the internal resistance of each battery cell at a special operating point under the selected characteristic working conditions, and then compare whether there are outliers in the internal resistance of each cell to issue an alarm. ; This kind of early warning method requires independent calculation of the internal resistance of each battery cell, and requires data under specific working conditions, so it is impossible to provide simple and fast early warning

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