Short circuit fault self-detection method in single battery

Abstract

The invention discloses a short circuit fault self-detection method in a single battery. The method comprises the following steps of: S1, building a first-order equivalent circuit model of the battery, determining a function relation between a state of charge (SOC) and an open-circuit voltage (OCV), and recognizing model parameters, S2, measuring load current and terminal voltage of the battery inreal time, S3, calculating ampere-hour increments at adjacent moments, estimating the SOC of the battery online by adopting a closed-loop state observer, and calculating an internal short circuit current according to the obtained ampere-hour increments and an SOC change value, S4, filtering the estimated internal short circuit current, and identifying the internal short circuit resistance of thebattery online by adopting a recursive least square method with an adaptive forgetting factor according to the filtered internal short circuit current and load voltage. According to a preset internalshort circuit resistance threshold, the internal short circuit state of the battery is compare3d and judged. Online identification of the short circuit resistance in the single battery can be realizedonly by measuring the terminal voltage and the load current of the single battery, and other single battery information in the battery pack is not needed.

Description

technical field [0001] The invention relates to the detection of short-circuit faults in batteries, in particular to a self-detection method for short-circuit faults in single batteries. Background technique [0002] Lithium-ion battery is currently the most commonly used power source for electric vehicles. It has the advantages of high specific energy, specific power, and long cycle life. However, in recent years, thermal runaway accidents of lithium-ion batteries have gradually aroused consumers' attention to the safety of lithium-ion batteries. The short-circuit fault in the battery is one of the most important reasons for the thermal runaway accident of the battery, so the detection of the short-circuit fault in the battery is particularly important to improve the safety and reliability of the lithium-ion battery. [0003] The existing method of detecting the internal short circuit of lithium-ion batteries based on abnormal heat release of the battery is suitable for the...

AI Technical Summary

Problems solved by technology

The internal short circuit detection method based on the electrical model can identify the early slight internal short circuit, representatively, the average equivalent model of the battery pack is combined with the single difference model; but this type of method requires information collection and charging of many battery cells State (SOC) estimation, and requires high accuracy of single difference model

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