Method and device for detecting micro short circuit of battery

Abstract

An embodiment of the invention discloses a method and a device for detecting micro short circuit of a battery. The method comprises the steps of: acquiring a target initial battery parameter value ofa target battery at an initial moment, and determining a reference initial battery parameter value of a virtual reference battery at the initial moment, wherein a response of the virtual reference battery is the same as a response of the target battery under the same excitation condition; acquiring a target battery parameter value of the target battery at a specified moment; determining a reference battery parameter value of the virtual reference battery at the specified moment according to the target battery parameter value and the reference initial battery parameters value; and calculating adifference value between the target battery parameter value and the reference battery parameter value, and determining whether short circuit occurs in the target battery according to the difference value. The method and the device disclosed by the invention have the advantages of improving precision of battery micro short circuit detection, enhancing the applicability of battery micro short circuit detection, and reducing the misjudgment rate of battery failures.

Description

technical field [0001] The invention relates to the field of battery management, in particular to a method and device for detecting a battery micro-short circuit. Background technique [0002] Secondary batteries are also called rechargeable batteries or storage batteries. During the use of secondary batteries, they are affected by factors such as battery raw materials or battery usage methods, which may cause safety problems such as thermal runaway, overcharge or overdischarge. Among them, thermal runaway is the ultimate manifestation of battery safety problems, and one of the main causes of thermal runaway is the micro-short circuit of the battery. The micro-short circuit of the battery mainly includes the micro-short circuit caused by external factors and the micro-short circuit caused by the internal structure change of the battery. Among them, the micro-short circuit caused by the internal structure change of the battery has a long evolution process. The initial phenom...

AI Technical Summary

Problems solved by technology

If there are many single cells connected in series in the battery pack, the real-time calculation of the equivalent internal resistance of each single cell by the micro-short circuit detection method in the prior art requires a large amount of calculation, which is very difficult for the battery management system (English: Battery Management System, BMS) has high hardware requirements and is difficult to implement

In addition, as the battery pack ages, the inconsistency of individual cells in the battery pack will increase, with ΔZ i When judging the battery micro-short circuit, it is easy to judge the inconsistency of the battery as a micro-short circuit, and it is easy to misreport the internal resistance change caused by contact resistance and other faults as a micro-short circuit. The probability of misjudgment is high and the applicability is poor.

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